tor-browser

implementation.js (329752B)

---

"use strict";

var htmlNamespace = "http://www.w3.org/1999/xhtml";

var cssStylingFlag = false;

var defaultSingleLineContainerName = "div";

// This is bad :(
var globalRange = null;

// Commands are stored in a dictionary where we call their actions and such
var commands = {};

///////////////////////////////////////////////////////////////////////////////
////////////////////////////// Utility functions //////////////////////////////
///////////////////////////////////////////////////////////////////////////////
//@{

function nextNode(node) {
   if (node.hasChildNodes()) {
       return node.firstChild;
   }
   return nextNodeDescendants(node);
}

function previousNode(node) {
   if (node.previousSibling) {
       node = node.previousSibling;
       while (node.hasChildNodes()) {
           node = node.lastChild;
       }
       return node;
   }
   if (node.parentNode
   && node.parentNode.nodeType == Node.ELEMENT_NODE) {
       return node.parentNode;
   }
   return null;
}

function nextNodeDescendants(node) {
   while (node && !node.nextSibling) {
       node = node.parentNode;
   }
   if (!node) {
       return null;
   }
   return node.nextSibling;
}

/**
* Returns true if ancestor is an ancestor of descendant, false otherwise.
*/
function isAncestor(ancestor, descendant) {
   return ancestor
       && descendant
       && Boolean(ancestor.compareDocumentPosition(descendant) & Node.DOCUMENT_POSITION_CONTAINED_BY);
}

/**
* Returns true if ancestor is an ancestor of or equal to descendant, false
* otherwise.
*/
function isAncestorContainer(ancestor, descendant) {
   return (ancestor || descendant)
       && (ancestor == descendant || isAncestor(ancestor, descendant));
}

/**
* Returns true if descendant is a descendant of ancestor, false otherwise.
*/
function isDescendant(descendant, ancestor) {
   return ancestor
       && descendant
       && Boolean(ancestor.compareDocumentPosition(descendant) & Node.DOCUMENT_POSITION_CONTAINED_BY);
}

/**
* Returns true if node1 is before node2 in tree order, false otherwise.
*/
function isBefore(node1, node2) {
   return Boolean(node1.compareDocumentPosition(node2) & Node.DOCUMENT_POSITION_FOLLOWING);
}

/**
* Returns true if node1 is after node2 in tree order, false otherwise.
*/
function isAfter(node1, node2) {
   return Boolean(node1.compareDocumentPosition(node2) & Node.DOCUMENT_POSITION_PRECEDING);
}

function getAncestors(node) {
   var ancestors = [];
   while (node.parentNode) {
       ancestors.unshift(node.parentNode);
       node = node.parentNode;
   }
   return ancestors;
}

function getInclusiveAncestors(node) {
   return getAncestors(node).concat(node);
}

function getDescendants(node) {
   var descendants = [];
   var stop = nextNodeDescendants(node);
   while ((node = nextNode(node))
   && node != stop) {
       descendants.push(node);
   }
   return descendants;
}

function getInclusiveDescendants(node) {
   return [node].concat(getDescendants(node));
}

function convertProperty(property) {
   // Special-case for now
   var map = {
       "fontFamily": "font-family",
       "fontSize": "font-size",
       "fontStyle": "font-style",
       "fontWeight": "font-weight",
       "textDecoration": "text-decoration",
   };
   if (typeof map[property] != "undefined") {
       return map[property];
   }

   return property;
}

// Return the <font size=X> value for the given CSS size, or undefined if there
// is none.
function cssSizeToLegacy(cssVal) {
   return {
       "x-small": 1,
       "small": 2,
       "medium": 3,
       "large": 4,
       "x-large": 5,
       "xx-large": 6,
       "xxx-large": 7
   }[cssVal];
}

// Return the CSS size given a legacy size.
function legacySizeToCss(legacyVal) {
   return {
       1: "x-small",
       2: "small",
       3: "medium",
       4: "large",
       5: "x-large",
       6: "xx-large",
       7: "xxx-large",
   }[legacyVal];
}

// Opera 11 puts HTML elements in the null namespace, it seems.
function isHtmlNamespace(ns) {
   return ns === null
       || ns === htmlNamespace;
}

// "the directionality" from HTML.  I don't bother caring about non-HTML
// elements.
//
// "The directionality of an element is either 'ltr' or 'rtl', and is
// determined as per the first appropriate set of steps from the following
// list:"
function getDirectionality(element) {
   // "If the element's dir attribute is in the ltr state
   //     The directionality of the element is 'ltr'."
   if (element.dir == "ltr") {
       return "ltr";
   }

   // "If the element's dir attribute is in the rtl state
   //     The directionality of the element is 'rtl'."
   if (element.dir == "rtl") {
       return "rtl";
   }

   // "If the element's dir attribute is in the auto state
   // "If the element is a bdi element and the dir attribute is not in a
   // defined state (i.e. it is not present or has an invalid value)
   //     [lots of complicated stuff]
   //
   // Skip this, since no browser implements it anyway.

   // "If the element is a root element and the dir attribute is not in a
   // defined state (i.e. it is not present or has an invalid value)
   //     The directionality of the element is 'ltr'."
   if (!isHtmlElement(element.parentNode)) {
       return "ltr";
   }

   // "If the element has a parent element and the dir attribute is not in a
   // defined state (i.e. it is not present or has an invalid value)
   //     The directionality of the element is the same as the element's
   //     parent element's directionality."
   return getDirectionality(element.parentNode);
}

//@}

///////////////////////////////////////////////////////////////////////////////
///////////////////////////// DOM Range functions /////////////////////////////
///////////////////////////////////////////////////////////////////////////////
//@{

function getNodeIndex(node) {
   var ret = 0;
   while (node.previousSibling) {
       ret++;
       node = node.previousSibling;
   }
   return ret;
}

// "The length of a Node node is the following, depending on node:
//
// ProcessingInstruction
// DocumentType
//   Always 0.
// Text
// Comment
//   node's length.
// Any other node
//   node's childNodes's length."
function getNodeLength(node) {
   switch (node.nodeType) {
       case Node.PROCESSING_INSTRUCTION_NODE:
       case Node.DOCUMENT_TYPE_NODE:
           return 0;

       case Node.TEXT_NODE:
       case Node.COMMENT_NODE:
           return node.length;

       default:
           return node.childNodes.length;
   }
}

/**
* The position of two boundary points relative to one another, as defined by
* DOM Range.
*/
function getPosition(nodeA, offsetA, nodeB, offsetB) {
   // "If node A is the same as node B, return equal if offset A equals offset
   // B, before if offset A is less than offset B, and after if offset A is
   // greater than offset B."
   if (nodeA == nodeB) {
       if (offsetA == offsetB) {
           return "equal";
       }
       if (offsetA < offsetB) {
           return "before";
       }
       if (offsetA > offsetB) {
           return "after";
       }
   }

   // "If node A is after node B in tree order, compute the position of (node
   // B, offset B) relative to (node A, offset A). If it is before, return
   // after. If it is after, return before."
   if (nodeB.compareDocumentPosition(nodeA) & Node.DOCUMENT_POSITION_FOLLOWING) {
       var pos = getPosition(nodeB, offsetB, nodeA, offsetA);
       if (pos == "before") {
           return "after";
       }
       if (pos == "after") {
           return "before";
       }
   }

   // "If node A is an ancestor of node B:"
   if (nodeB.compareDocumentPosition(nodeA) & Node.DOCUMENT_POSITION_CONTAINS) {
       // "Let child equal node B."
       var child = nodeB;

       // "While child is not a child of node A, set child to its parent."
       while (child.parentNode != nodeA) {
           child = child.parentNode;
       }

       // "If the index of child is less than offset A, return after."
       if (getNodeIndex(child) < offsetA) {
           return "after";
       }
   }

   // "Return before."
   return "before";
}

/**
* Returns the furthest ancestor of a Node as defined by DOM Range.
*/
function getFurthestAncestor(node) {
   var root = node;
   while (root.parentNode != null) {
       root = root.parentNode;
   }
   return root;
}

/**
* "contained" as defined by DOM Range: "A Node node is contained in a range
* range if node's furthest ancestor is the same as range's root, and (node, 0)
* is after range's start, and (node, length of node) is before range's end."
*/
function isContained(node, range) {
   var pos1 = getPosition(node, 0, range.startContainer, range.startOffset);
   var pos2 = getPosition(node, getNodeLength(node), range.endContainer, range.endOffset);

   return getFurthestAncestor(node) == getFurthestAncestor(range.startContainer)
       && pos1 == "after"
       && pos2 == "before";
}

/**
* Return all nodes contained in range that the provided function returns true
* for, omitting any with an ancestor already being returned.
*/
function getContainedNodes(range, condition) {
   if (typeof condition == "undefined") {
       condition = function() { return true };
   }
   var node = range.startContainer;
   if (node.hasChildNodes()
   && range.startOffset < node.childNodes.length) {
       // A child is contained
       node = node.childNodes[range.startOffset];
   } else if (range.startOffset == getNodeLength(node)) {
       // No descendant can be contained
       node = nextNodeDescendants(node);
   } else {
       // No children; this node at least can't be contained
       node = nextNode(node);
   }

   var stop = range.endContainer;
   if (stop.hasChildNodes()
   && range.endOffset < stop.childNodes.length) {
       // The node after the last contained node is a child
       stop = stop.childNodes[range.endOffset];
   } else {
       // This node and/or some of its children might be contained
       stop = nextNodeDescendants(stop);
   }

   var nodeList = [];
   while (isBefore(node, stop)) {
       if (isContained(node, range)
       && condition(node)) {
           nodeList.push(node);
           node = nextNodeDescendants(node);
           continue;
       }
       node = nextNode(node);
   }
   return nodeList;
}

/**
* As above, but includes nodes with an ancestor that's already been returned.
*/
function getAllContainedNodes(range, condition) {
   if (typeof condition == "undefined") {
       condition = function() { return true };
   }
   var node = range.startContainer;
   if (node.hasChildNodes()
   && range.startOffset < node.childNodes.length) {
       // A child is contained
       node = node.childNodes[range.startOffset];
   } else if (range.startOffset == getNodeLength(node)) {
       // No descendant can be contained
       node = nextNodeDescendants(node);
   } else {
       // No children; this node at least can't be contained
       node = nextNode(node);
   }

   var stop = range.endContainer;
   if (stop.hasChildNodes()
   && range.endOffset < stop.childNodes.length) {
       // The node after the last contained node is a child
       stop = stop.childNodes[range.endOffset];
   } else {
       // This node and/or some of its children might be contained
       stop = nextNodeDescendants(stop);
   }

   var nodeList = [];
   while (isBefore(node, stop)) {
       if (isContained(node, range)
       && condition(node)) {
           nodeList.push(node);
       }
       node = nextNode(node);
   }
   return nodeList;
}

// Returns either null, or something of the form rgb(x, y, z), or something of
// the form rgb(x, y, z, w) with w != 0.
function normalizeColor(color) {
   if (color.toLowerCase() == "currentcolor") {
       return null;
   }

   if (normalizeColor.resultCache === undefined) {
       normalizeColor.resultCache = {};
   }

   if (normalizeColor.resultCache[color] !== undefined) {
       return normalizeColor.resultCache[color];
   }

   var originalColor = color;

   var outerSpan = document.createElement("span");
   document.body.appendChild(outerSpan);
   outerSpan.style.color = "black";

   var innerSpan = document.createElement("span");
   outerSpan.appendChild(innerSpan);
   innerSpan.style.color = color;
   color = getComputedStyle(innerSpan).color;

   if (color == "rgb(0, 0, 0)") {
       // Maybe it's really black, maybe it's invalid.
       outerSpan.color = "white";
       color = getComputedStyle(innerSpan).color;
       if (color != "rgb(0, 0, 0)") {
           return normalizeColor.resultCache[originalColor] = null;
       }
   }

   document.body.removeChild(outerSpan);

   // I rely on the fact that browsers generally provide consistent syntax for
   // getComputedStyle(), although it's not standardized.  There are only
   // three exceptions I found:
   if (/^rgba\([0-9]+, [0-9]+, [0-9]+, 1\)$/.test(color)) {
       // IE10PP2 seems to do this sometimes.
       return normalizeColor.resultCache[originalColor] =
           color.replace("rgba", "rgb").replace(", 1)", ")");
   }
   if (color == "transparent") {
       // IE10PP2, Firefox 7.0a2, and Opera 11.50 all return "transparent" if
       // the specified value is "transparent".
       return normalizeColor.resultCache[originalColor] =
           "rgba(0, 0, 0, 0)";
   }
   // Chrome 15 dev adds way too many significant figures.  This isn't a full
   // fix, it just fixes one case that comes up in tests.
   color = color.replace(/, 0.496094\)$/, ", 0.5)");
   return normalizeColor.resultCache[originalColor] = color;
}

// Returns either null, or something of the form #xxxxxx.
function parseSimpleColor(color) {
   color = normalizeColor(color);
   var matches = /^rgb\(([0-9]+), ([0-9]+), ([0-9]+)\)$/.exec(color);
   if (matches) {
       return "#"
           + parseInt(matches[1]).toString(16).replace(/^.$/, "0$&")
           + parseInt(matches[2]).toString(16).replace(/^.$/, "0$&")
           + parseInt(matches[3]).toString(16).replace(/^.$/, "0$&");
   }
   return null;
}

//@}

//////////////////////////////////////////////////////////////////////////////
/////////////////////////// Edit command functions ///////////////////////////
//////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////////
///// Methods of the HTMLDocument interface /////
/////////////////////////////////////////////////
//@{

var executionStackDepth = 0;

// Helper function for common behavior.
function editCommandMethod(command, range, callback) {
   // Set up our global range magic, but only if we're the outermost function
   if (executionStackDepth == 0 && typeof range != "undefined") {
       globalRange = range;
   } else if (executionStackDepth == 0) {
       globalRange = null;
       globalRange = getActiveRange();
   }

   executionStackDepth++;
   try {
       var ret = callback();
   } catch(e) {
       executionStackDepth--;
       throw e;
   }
   executionStackDepth--;
   return ret;
}

function myExecCommand(command, showUi, value, range) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   // "If only one argument was provided, let show UI be false."
   //
   // If range was passed, I can't actually detect how many args were passed
   // . . .
   if (arguments.length == 1
   || (arguments.length >=4 && typeof showUi == "undefined")) {
       showUi = false;
   }

   // "If only one or two arguments were provided, let value be the empty
   // string."
   if (arguments.length <= 2
   || (arguments.length >=4 && typeof value == "undefined")) {
       value = "";
   }

   return editCommandMethod(command, range, (function(command, showUi, value) { return function() {
       // "If command is not supported or not enabled, return false."
       if (!(command in commands) || !myQueryCommandEnabled(command)) {
           return false;
       }

       // "Take the action for command, passing value to the instructions as an
       // argument."
       var ret = commands[command].action(value);

       // Check for bugs
       if (ret !== true && ret !== false) {
           throw "execCommand() didn't return true or false: " + ret;
       }

       // "If the previous step returned false, return false."
       if (ret === false) {
           return false;
       }

       // "Return true."
       return true;
   }})(command, showUi, value));
}

function myQueryCommandEnabled(command, range) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   return editCommandMethod(command, range, (function(command) { return function() {
       // "Return true if command is both supported and enabled, false
       // otherwise."
       if (!(command in commands)) {
           return false;
       }

       // "Among commands defined in this specification, those listed in
       // Miscellaneous commands are always enabled, except for the cut
       // command and the paste command. The other commands defined here are
       // enabled if the active range is not null, its start node is either
       // editable or an editing host, its end node is either editable or an
       // editing host, and there is some editing host that is an inclusive
       // ancestor of both its start node and its end node."
       return ["copy", "defaultparagraphseparator", "selectall", "stylewithcss",
       "usecss"].indexOf(command) != -1
           || (
               getActiveRange() !== null
               && (isEditable(getActiveRange().startContainer) || isEditingHost(getActiveRange().startContainer))
               && (isEditable(getActiveRange().endContainer) || isEditingHost(getActiveRange().endContainer))
               && (getInclusiveAncestors(getActiveRange().commonAncestorContainer).some(isEditingHost))
           );
   }})(command));
}

function myQueryCommandIndeterm(command, range) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   return editCommandMethod(command, range, (function(command) { return function() {
       // "If command is not supported or has no indeterminacy, return false."
       if (!(command in commands) || !("indeterm" in commands[command])) {
           return false;
       }

       // "Return true if command is indeterminate, otherwise false."
       return commands[command].indeterm();
   }})(command));
}

function myQueryCommandState(command, range) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   return editCommandMethod(command, range, (function(command) { return function() {
       // "If command is not supported or has no state, return false."
       if (!(command in commands) || !("state" in commands[command])) {
           return false;
       }

       // "If the state override for command is set, return it."
       if (typeof getStateOverride(command) != "undefined") {
           return getStateOverride(command);
       }

       // "Return true if command's state is true, otherwise false."
       return commands[command].state();
   }})(command));
}

// "When the queryCommandSupported(command) method on the HTMLDocument
// interface is invoked, the user agent must return true if command is
// supported, and false otherwise."
function myQueryCommandSupported(command) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   return command in commands;
}

function myQueryCommandValue(command, range) {
   // "All of these methods must treat their command argument ASCII
   // case-insensitively."
   command = command.toLowerCase();

   return editCommandMethod(command, range, function() {
       // "If command is not supported or has no value, return the empty string."
       if (!(command in commands) || !("value" in commands[command])) {
           return "";
       }

       // "If command is "fontSize" and its value override is set, convert the
       // value override to an integer number of pixels and return the legacy
       // font size for the result."
       if (command == "fontsize"
       && getValueOverride("fontsize") !== undefined) {
           return getLegacyFontSize(getValueOverride("fontsize"));
       }

       // "If the value override for command is set, return it."
       if (typeof getValueOverride(command) != "undefined") {
           return getValueOverride(command);
       }

       // "Return command's value."
       return commands[command].value();
   });
}
//@}

//////////////////////////////
///// Common definitions /////
//////////////////////////////
//@{

// "An HTML element is an Element whose namespace is the HTML namespace."
//
// I allow an extra argument to more easily check whether something is a
// particular HTML element, like isHtmlElement(node, "OL").  It accepts arrays
// too, like isHtmlElement(node, ["OL", "UL"]) to check if it's an ol or ul.
function isHtmlElement(node, tags) {
   if (typeof tags == "string") {
       tags = [tags];
   }
   if (typeof tags == "object") {
       tags = tags.map(function(tag) { return tag.toUpperCase() });
   }
   return node
       && node.nodeType == Node.ELEMENT_NODE
       && isHtmlNamespace(node.namespaceURI)
       && (typeof tags == "undefined" || tags.indexOf(node.tagName) != -1);
}

// "A prohibited paragraph child name is "address", "article", "aside",
// "blockquote", "caption", "center", "col", "colgroup", "dd", "details",
// "dir", "div", "dl", "dt", "fieldset", "figcaption", "figure", "footer",
// "form", "h1", "h2", "h3", "h4", "h5", "h6", "header", "hgroup", "hr", "li",
// "listing", "menu", "nav", "ol", "p", "plaintext", "pre", "section",
// "summary", "table", "tbody", "td", "tfoot", "th", "thead", "tr", "ul", or
// "xmp"."
var prohibitedParagraphChildNames = ["address", "article", "aside",
   "blockquote", "caption", "center", "col", "colgroup", "dd", "details",
   "dir", "div", "dl", "dt", "fieldset", "figcaption", "figure", "footer",
   "form", "h1", "h2", "h3", "h4", "h5", "h6", "header", "hgroup", "hr", "li",
   "listing", "menu", "nav", "ol", "p", "plaintext", "pre", "section",
   "summary", "table", "tbody", "td", "tfoot", "th", "thead", "tr", "ul",
   "xmp"];

// "A prohibited paragraph child is an HTML element whose local name is a
// prohibited paragraph child name."
function isProhibitedParagraphChild(node) {
   return isHtmlElement(node, prohibitedParagraphChildNames);
}

// "A block node is either an Element whose "display" property does not have
// resolved value "inline" or "inline-block" or "inline-table" or "none", or a
// Document, or a DocumentFragment."
function isBlockNode(node) {
   return node
       && ((node.nodeType == Node.ELEMENT_NODE && ["inline", "inline-block", "inline-table", "none"].indexOf(getComputedStyle(node).display) == -1)
       || node.nodeType == Node.DOCUMENT_NODE
       || node.nodeType == Node.DOCUMENT_FRAGMENT_NODE);
}

// "An inline node is a node that is not a block node."
function isInlineNode(node) {
   return node && !isBlockNode(node);
}

// "An editing host is a node that is either an HTML element with a
// contenteditable attribute set to the true state, or the HTML element child
// of a Document whose designMode is enabled."
function isEditingHost(node) {
   return node
       && isHtmlElement(node)
       && (node.contentEditable == "true"
       || (node.parentNode
       && node.parentNode.nodeType == Node.DOCUMENT_NODE
       && node.parentNode.designMode == "on"));
}

// "Something is editable if it is a node; it is not an editing host; it does
// not have a contenteditable attribute set to the false state; its parent is
// an editing host or editable; and either it is an HTML element, or it is an
// svg or math element, or it is not an Element and its parent is an HTML
// element."
function isEditable(node) {
   return node
       && !isEditingHost(node)
       && (node.nodeType != Node.ELEMENT_NODE || node.contentEditable != "false")
       && (isEditingHost(node.parentNode) || isEditable(node.parentNode))
       && (isHtmlElement(node)
       || (node.nodeType == Node.ELEMENT_NODE && node.namespaceURI == "http://www.w3.org/2000/svg" && node.localName == "svg")
       || (node.nodeType == Node.ELEMENT_NODE && node.namespaceURI == "http://www.w3.org/1998/Math/MathML" && node.localName == "math")
       || (node.nodeType != Node.ELEMENT_NODE && isHtmlElement(node.parentNode)));
}

// Helper function, not defined in the spec
function hasEditableDescendants(node) {
   for (var i = 0; i < node.childNodes.length; i++) {
       if (isEditable(node.childNodes[i])
       || hasEditableDescendants(node.childNodes[i])) {
           return true;
       }
   }
   return false;
}

// "The editing host of node is null if node is neither editable nor an editing
// host; node itself, if node is an editing host; or the nearest ancestor of
// node that is an editing host, if node is editable."
function getEditingHostOf(node) {
   if (isEditingHost(node)) {
       return node;
   } else if (isEditable(node)) {
       var ancestor = node.parentNode;
       while (!isEditingHost(ancestor)) {
           ancestor = ancestor.parentNode;
       }
       return ancestor;
   } else {
       return null;
   }
}

// "Two nodes are in the same editing host if the editing host of the first is
// non-null and the same as the editing host of the second."
function inSameEditingHost(node1, node2) {
   return getEditingHostOf(node1)
       && getEditingHostOf(node1) == getEditingHostOf(node2);
}

// "A collapsed line break is a br that begins a line box which has nothing
// else in it, and therefore has zero height."
function isCollapsedLineBreak(br) {
   if (!isHtmlElement(br, "br")) {
       return false;
   }

   // Add a zwsp after it and see if that changes the height of the nearest
   // non-inline parent.  Note: this is not actually reliable, because the
   // parent might have a fixed height or something.
   var ref = br.parentNode;
   while (getComputedStyle(ref).display == "inline") {
       ref = ref.parentNode;
   }
   var refStyle = ref.hasAttribute("style") ? ref.getAttribute("style") : null;
   ref.style.height = "auto";
   ref.style.maxHeight = "none";
   ref.style.minHeight = "0";
   var space = document.createTextNode("\u200b");
   var origHeight = ref.offsetHeight;
   if (origHeight == 0) {
       throw "isCollapsedLineBreak: original height is zero, bug?";
   }
   br.parentNode.insertBefore(space, br.nextSibling);
   var finalHeight = ref.offsetHeight;
   space.parentNode.removeChild(space);
   if (refStyle === null) {
       // Without the setAttribute() line, removeAttribute() doesn't work in
       // Chrome 14 dev.  I have no idea why.
       ref.setAttribute("style", "");
       ref.removeAttribute("style");
   } else {
       ref.setAttribute("style", refStyle);
   }

   // Allow some leeway in case the zwsp didn't create a whole new line, but
   // only made an existing line slightly higher.  Firefox 6.0a2 shows this
   // behavior when the first line is bold.
   return origHeight < finalHeight - 5;
}

// "An extraneous line break is a br that has no visual effect, in that
// removing it from the DOM would not change layout, except that a br that is
// the sole child of an li is not extraneous."
//
// FIXME: This doesn't work in IE, since IE ignores display: none in
// contenteditable.
function isExtraneousLineBreak(br) {
   if (!isHtmlElement(br, "br")) {
       return false;
   }

   if (isHtmlElement(br.parentNode, "li")
   && br.parentNode.childNodes.length == 1) {
       return false;
   }

   // Make the line break disappear and see if that changes the block's
   // height.  Yes, this is an absurd hack.  We have to reset height etc. on
   // the reference node because otherwise its height won't change if it's not
   // auto.
   var ref = br.parentNode;
   while (getComputedStyle(ref).display == "inline") {
       ref = ref.parentNode;
   }
   var refStyle = ref.hasAttribute("style") ? ref.getAttribute("style") : null;
   ref.style.height = "auto";
   ref.style.maxHeight = "none";
   ref.style.minHeight = "0";
   var brStyle = br.hasAttribute("style") ? br.getAttribute("style") : null;
   var origHeight = ref.offsetHeight;
   if (origHeight == 0) {
       throw "isExtraneousLineBreak: original height is zero, bug?";
   }
   br.setAttribute("style", "display:none");
   var finalHeight = ref.offsetHeight;
   if (refStyle === null) {
       // Without the setAttribute() line, removeAttribute() doesn't work in
       // Chrome 14 dev.  I have no idea why.
       ref.setAttribute("style", "");
       ref.removeAttribute("style");
   } else {
       ref.setAttribute("style", refStyle);
   }
   if (brStyle === null) {
       br.removeAttribute("style");
   } else {
       br.setAttribute("style", brStyle);
   }

   return origHeight == finalHeight;
}

// "A whitespace node is either a Text node whose data is the empty string; or
// a Text node whose data consists only of one or more tabs (0x0009), line
// feeds (0x000A), carriage returns (0x000D), and/or spaces (0x0020), and whose
// parent is an Element whose resolved value for "white-space" is "normal" or
// "nowrap"; or a Text node whose data consists only of one or more tabs
// (0x0009), carriage returns (0x000D), and/or spaces (0x0020), and whose
// parent is an Element whose resolved value for "white-space" is "pre-line"."
function isWhitespaceNode(node) {
   return node
       && node.nodeType == Node.TEXT_NODE
       && (node.data == ""
       || (
           /^[\t\n\r ]+$/.test(node.data)
           && node.parentNode
           && node.parentNode.nodeType == Node.ELEMENT_NODE
           && ["normal", "nowrap"].indexOf(getComputedStyle(node.parentNode).whiteSpace) != -1
       ) || (
           /^[\t\r ]+$/.test(node.data)
           && node.parentNode
           && node.parentNode.nodeType == Node.ELEMENT_NODE
           && getComputedStyle(node.parentNode).whiteSpace == "pre-line"
       ));
}

// "node is a collapsed whitespace node if the following algorithm returns
// true:"
function isCollapsedWhitespaceNode(node) {
   // "If node is not a whitespace node, return false."
   if (!isWhitespaceNode(node)) {
       return false;
   }

   // "If node's data is the empty string, return true."
   if (node.data == "") {
       return true;
   }

   // "Let ancestor be node's parent."
   var ancestor = node.parentNode;

   // "If ancestor is null, return true."
   if (!ancestor) {
       return true;
   }

   // "If the "display" property of some ancestor of node has resolved value
   // "none", return true."
   if (getAncestors(node).some(function(ancestor) {
       return ancestor.nodeType == Node.ELEMENT_NODE
           && getComputedStyle(ancestor).display == "none";
   })) {
       return true;
   }

   // "While ancestor is not a block node and its parent is not null, set
   // ancestor to its parent."
   while (!isBlockNode(ancestor)
   && ancestor.parentNode) {
       ancestor = ancestor.parentNode;
   }

   // "Let reference be node."
   var reference = node;

   // "While reference is a descendant of ancestor:"
   while (reference != ancestor) {
       // "Let reference be the node before it in tree order."
       reference = previousNode(reference);

       // "If reference is a block node or a br, return true."
       if (isBlockNode(reference)
       || isHtmlElement(reference, "br")) {
           return true;
       }

       // "If reference is a Text node that is not a whitespace node, or is an
       // img, break from this loop."
       if ((reference.nodeType == Node.TEXT_NODE && !isWhitespaceNode(reference))
       || isHtmlElement(reference, "img")) {
           break;
       }
   }

   // "Let reference be node."
   reference = node;

   // "While reference is a descendant of ancestor:"
   var stop = nextNodeDescendants(ancestor);
   while (reference != stop) {
       // "Let reference be the node after it in tree order, or null if there
       // is no such node."
       reference = nextNode(reference);

       // "If reference is a block node or a br, return true."
       if (isBlockNode(reference)
       || isHtmlElement(reference, "br")) {
           return true;
       }

       // "If reference is a Text node that is not a whitespace node, or is an
       // img, break from this loop."
       if ((reference && reference.nodeType == Node.TEXT_NODE && !isWhitespaceNode(reference))
       || isHtmlElement(reference, "img")) {
           break;
       }
   }

   // "Return false."
   return false;
}

// "Something is visible if it is a node that either is a block node, or a Text
// node that is not a collapsed whitespace node, or an img, or a br that is not
// an extraneous line break, or any node with a visible descendant; excluding
// any node with an ancestor container Element whose "display" property has
// resolved value "none"."
function isVisible(node) {
   if (!node) {
       return false;
   }

   if (getAncestors(node).concat(node)
   .filter(function(node) { return node.nodeType == Node.ELEMENT_NODE })
   .some(function(node) { return getComputedStyle(node).display == "none" })) {
       return false;
   }

   if (isBlockNode(node)
   || (node.nodeType == Node.TEXT_NODE && !isCollapsedWhitespaceNode(node))
   || isHtmlElement(node, "img")
   || (isHtmlElement(node, "br") && !isExtraneousLineBreak(node))) {
       return true;
   }

   for (var i = 0; i < node.childNodes.length; i++) {
       if (isVisible(node.childNodes[i])) {
           return true;
       }
   }

   return false;
}

// "Something is invisible if it is a node that is not visible."
function isInvisible(node) {
   return node && !isVisible(node);
}

// "A collapsed block prop is either a collapsed line break that is not an
// extraneous line break, or an Element that is an inline node and whose
// children are all either invisible or collapsed block props and that has at
// least one child that is a collapsed block prop."
function isCollapsedBlockProp(node) {
   if (isCollapsedLineBreak(node)
   && !isExtraneousLineBreak(node)) {
       return true;
   }

   if (!isInlineNode(node)
   || node.nodeType != Node.ELEMENT_NODE) {
       return false;
   }

   var hasCollapsedBlockPropChild = false;
   for (var i = 0; i < node.childNodes.length; i++) {
       if (!isInvisible(node.childNodes[i])
       && !isCollapsedBlockProp(node.childNodes[i])) {
           return false;
       }
       if (isCollapsedBlockProp(node.childNodes[i])) {
           hasCollapsedBlockPropChild = true;
       }
   }

   return hasCollapsedBlockPropChild;
}

// "The active range is the range of the selection given by calling
// getSelection() on the context object. (Thus the active range may be null.)"
//
// We cheat and return globalRange if that's defined.  We also ensure that the
// active range meets the requirements that selection boundary points are
// supposed to meet, i.e., that the nodes are both Text or Element nodes that
// descend from a Document.
function getActiveRange() {
   var ret;
   if (globalRange) {
       ret = globalRange;
   } else if (getSelection().rangeCount) {
       ret = getSelection().getRangeAt(0);
   } else {
       return null;
   }
   if ([Node.TEXT_NODE, Node.ELEMENT_NODE].indexOf(ret.startContainer.nodeType) == -1
   || [Node.TEXT_NODE, Node.ELEMENT_NODE].indexOf(ret.endContainer.nodeType) == -1
   || !ret.startContainer.ownerDocument
   || !ret.endContainer.ownerDocument
   || !isDescendant(ret.startContainer, ret.startContainer.ownerDocument)
   || !isDescendant(ret.endContainer, ret.endContainer.ownerDocument)) {
       throw "Invalid active range; test bug?";
   }
   return ret;
}

// "For some commands, each HTMLDocument must have a boolean state override
// and/or a string value override. These do not change the command's state or
// value, but change the way some algorithms behave, as specified in those
// algorithms' definitions. Initially, both must be unset for every command.
// Whenever the number of ranges in the Selection changes to something
// different, and whenever a boundary point of the range at a given index in
// the Selection changes to something different, the state override and value
// override must be unset for every command."
//
// We implement this crudely by using setters and getters.  To verify that the
// selection hasn't changed, we copy the active range and just check the
// endpoints match.  This isn't really correct, but it's good enough for us.
// Unset state/value overrides are undefined.  We put everything in a function
// so no one can access anything except via the provided functions, since
// otherwise callers might mistakenly use outdated overrides (if the selection
// has changed).
var getStateOverride, setStateOverride, unsetStateOverride,
   getValueOverride, setValueOverride, unsetValueOverride;
(function() {
   var stateOverrides = {};
   var valueOverrides = {};
   var storedRange = null;

   function resetOverrides() {
       if (!storedRange
       || storedRange.startContainer != getActiveRange().startContainer
       || storedRange.endContainer != getActiveRange().endContainer
       || storedRange.startOffset != getActiveRange().startOffset
       || storedRange.endOffset != getActiveRange().endOffset) {
           stateOverrides = {};
           valueOverrides = {};
           storedRange = getActiveRange().cloneRange();
       }
   }

   getStateOverride = function(command) {
       resetOverrides();
       return stateOverrides[command];
   };

   setStateOverride = function(command, newState) {
       resetOverrides();
       stateOverrides[command] = newState;
   };

   unsetStateOverride = function(command) {
       resetOverrides();
       delete stateOverrides[command];
   }

   getValueOverride = function(command) {
       resetOverrides();
       return valueOverrides[command];
   }

   // "The value override for the backColor command must be the same as the
   // value override for the hiliteColor command, such that setting one sets
   // the other to the same thing and unsetting one unsets the other."
   setValueOverride = function(command, newValue) {
       resetOverrides();
       valueOverrides[command] = newValue;
       if (command == "backcolor") {
           valueOverrides.hilitecolor = newValue;
       } else if (command == "hilitecolor") {
           valueOverrides.backcolor = newValue;
       }
   }

   unsetValueOverride = function(command) {
       resetOverrides();
       delete valueOverrides[command];
       if (command == "backcolor") {
           delete valueOverrides.hilitecolor;
       } else if (command == "hilitecolor") {
           delete valueOverrides.backcolor;
       }
   }
})();

//@}

/////////////////////////////
///// Common algorithms /////
/////////////////////////////

///// Assorted common algorithms /////
//@{

// Magic array of extra ranges whose endpoints we want to preserve.
var extraRanges = [];

function movePreservingRanges(node, newParent, newIndex) {
   // For convenience, I allow newIndex to be -1 to mean "insert at the end".
   if (newIndex == -1) {
       newIndex = newParent.childNodes.length;
   }

   // "When the user agent is to move a Node to a new location, preserving
   // ranges, it must remove the Node from its original parent (if any), then
   // insert it in the new location. In doing so, however, it must ignore the
   // regular range mutation rules, and instead follow these rules:"

   // "Let node be the moved Node, old parent and old index be the old parent
   // (which may be null) and index, and new parent and new index be the new
   // parent and index."
   var oldParent = node.parentNode;
   var oldIndex = getNodeIndex(node);

   // We preserve the global range object, the ranges in the selection, and
   // any range that's in the extraRanges array.  Any other ranges won't get
   // updated, because we have no references to them.
   var ranges = [globalRange].concat(extraRanges);
   for (var i = 0; i < getSelection().rangeCount; i++) {
       ranges.push(getSelection().getRangeAt(i));
   }
   var boundaryPoints = [];
   ranges.forEach(function(range) {
       boundaryPoints.push([range.startContainer, range.startOffset]);
       boundaryPoints.push([range.endContainer, range.endOffset]);
   });

   boundaryPoints.forEach(function(boundaryPoint) {
       // "If a boundary point's node is the same as or a descendant of node,
       // leave it unchanged, so it moves to the new location."
       //
       // No modifications necessary.

       // "If a boundary point's node is new parent and its offset is greater
       // than new index, add one to its offset."
       if (boundaryPoint[0] == newParent
       && boundaryPoint[1] > newIndex) {
           boundaryPoint[1]++;
       }

       // "If a boundary point's node is old parent and its offset is old index or
       // old index + 1, set its node to new parent and add new index − old index
       // to its offset."
       if (boundaryPoint[0] == oldParent
       && (boundaryPoint[1] == oldIndex
       || boundaryPoint[1] == oldIndex + 1)) {
           boundaryPoint[0] = newParent;
           boundaryPoint[1] += newIndex - oldIndex;
       }

       // "If a boundary point's node is old parent and its offset is greater than
       // old index + 1, subtract one from its offset."
       if (boundaryPoint[0] == oldParent
       && boundaryPoint[1] > oldIndex + 1) {
           boundaryPoint[1]--;
       }
   });

   // Now actually move it and preserve the ranges.
   if (newParent.childNodes.length == newIndex) {
       newParent.appendChild(node);
   } else {
       newParent.insertBefore(node, newParent.childNodes[newIndex]);
   }

   globalRange.setStart(boundaryPoints[0][0], boundaryPoints[0][1]);
   globalRange.setEnd(boundaryPoints[1][0], boundaryPoints[1][1]);

   for (var i = 0; i < extraRanges.length; i++) {
       extraRanges[i].setStart(boundaryPoints[2*i + 2][0], boundaryPoints[2*i + 2][1]);
       extraRanges[i].setEnd(boundaryPoints[2*i + 3][0], boundaryPoints[2*i + 3][1]);
   }

   getSelection().removeAllRanges();
   for (var i = 1 + extraRanges.length; i < ranges.length; i++) {
       var newRange = document.createRange();
       newRange.setStart(boundaryPoints[2*i][0], boundaryPoints[2*i][1]);
       newRange.setEnd(boundaryPoints[2*i + 1][0], boundaryPoints[2*i + 1][1]);
       getSelection().addRange(newRange);
   }
}

function setTagName(element, newName) {
   // "If element is an HTML element with local name equal to new name, return
   // element."
   if (isHtmlElement(element, newName.toUpperCase())) {
       return element;
   }

   // "If element's parent is null, return element."
   if (!element.parentNode) {
       return element;
   }

   // "Let replacement element be the result of calling createElement(new
   // name) on the ownerDocument of element."
   var replacementElement = element.ownerDocument.createElement(newName);

   // "Insert replacement element into element's parent immediately before
   // element."
   element.parentNode.insertBefore(replacementElement, element);

   // "Copy all attributes of element to replacement element, in order."
   for (var i = 0; i < element.attributes.length; i++) {
       replacementElement.setAttributeNS(element.attributes[i].namespaceURI, element.attributes[i].name, element.attributes[i].value);
   }

   // "While element has children, append the first child of element as the
   // last child of replacement element, preserving ranges."
   while (element.childNodes.length) {
       movePreservingRanges(element.firstChild, replacementElement, replacementElement.childNodes.length);
   }

   // "Remove element from its parent."
   element.parentNode.removeChild(element);

   // "Return replacement element."
   return replacementElement;
}

function removeExtraneousLineBreaksBefore(node) {
   // "Let ref be the previousSibling of node."
   var ref = node.previousSibling;

   // "If ref is null, abort these steps."
   if (!ref) {
       return;
   }

   // "While ref has children, set ref to its lastChild."
   while (ref.hasChildNodes()) {
       ref = ref.lastChild;
   }

   // "While ref is invisible but not an extraneous line break, and ref does
   // not equal node's parent, set ref to the node before it in tree order."
   while (isInvisible(ref)
   && !isExtraneousLineBreak(ref)
   && ref != node.parentNode) {
       ref = previousNode(ref);
   }

   // "If ref is an editable extraneous line break, remove it from its
   // parent."
   if (isEditable(ref)
   && isExtraneousLineBreak(ref)) {
       ref.parentNode.removeChild(ref);
   }
}

function removeExtraneousLineBreaksAtTheEndOf(node) {
   // "Let ref be node."
   var ref = node;

   // "While ref has children, set ref to its lastChild."
   while (ref.hasChildNodes()) {
       ref = ref.lastChild;
   }

   // "While ref is invisible but not an extraneous line break, and ref does
   // not equal node, set ref to the node before it in tree order."
   while (isInvisible(ref)
   && !isExtraneousLineBreak(ref)
   && ref != node) {
       ref = previousNode(ref);
   }

   // "If ref is an editable extraneous line break:"
   if (isEditable(ref)
   && isExtraneousLineBreak(ref)) {
       // "While ref's parent is editable and invisible, set ref to its
       // parent."
       while (isEditable(ref.parentNode)
       && isInvisible(ref.parentNode)) {
           ref = ref.parentNode;
       }

       // "Remove ref from its parent."
       ref.parentNode.removeChild(ref);
   }
}

// "To remove extraneous line breaks from a node, first remove extraneous line
// breaks before it, then remove extraneous line breaks at the end of it."
function removeExtraneousLineBreaksFrom(node) {
   removeExtraneousLineBreaksBefore(node);
   removeExtraneousLineBreaksAtTheEndOf(node);
}

//@}
///// Wrapping a list of nodes /////
//@{

function wrap(nodeList, siblingCriteria, newParentInstructions) {
   // "If not provided, sibling criteria returns false and new parent
   // instructions returns null."
   if (typeof siblingCriteria == "undefined") {
       siblingCriteria = function() { return false };
   }
   if (typeof newParentInstructions == "undefined") {
       newParentInstructions = function() { return null };
   }

   // "If every member of node list is invisible, and none is a br, return
   // null and abort these steps."
   if (nodeList.every(isInvisible)
   && !nodeList.some(function(node) { return isHtmlElement(node, "br") })) {
       return null;
   }

   // "If node list's first member's parent is null, return null and abort
   // these steps."
   if (!nodeList[0].parentNode) {
       return null;
   }

   // "If node list's last member is an inline node that's not a br, and node
   // list's last member's nextSibling is a br, append that br to node list."
   if (isInlineNode(nodeList[nodeList.length - 1])
   && !isHtmlElement(nodeList[nodeList.length - 1], "br")
   && isHtmlElement(nodeList[nodeList.length - 1].nextSibling, "br")) {
       nodeList.push(nodeList[nodeList.length - 1].nextSibling);
   }

   // "While node list's first member's previousSibling is invisible, prepend
   // it to node list."
   while (isInvisible(nodeList[0].previousSibling)) {
       nodeList.unshift(nodeList[0].previousSibling);
   }

   // "While node list's last member's nextSibling is invisible, append it to
   // node list."
   while (isInvisible(nodeList[nodeList.length - 1].nextSibling)) {
       nodeList.push(nodeList[nodeList.length - 1].nextSibling);
   }

   // "If the previousSibling of the first member of node list is editable and
   // running sibling criteria on it returns true, let new parent be the
   // previousSibling of the first member of node list."
   var newParent;
   if (isEditable(nodeList[0].previousSibling)
   && siblingCriteria(nodeList[0].previousSibling)) {
       newParent = nodeList[0].previousSibling;

   // "Otherwise, if the nextSibling of the last member of node list is
   // editable and running sibling criteria on it returns true, let new parent
   // be the nextSibling of the last member of node list."
   } else if (isEditable(nodeList[nodeList.length - 1].nextSibling)
   && siblingCriteria(nodeList[nodeList.length - 1].nextSibling)) {
       newParent = nodeList[nodeList.length - 1].nextSibling;

   // "Otherwise, run new parent instructions, and let new parent be the
   // result."
   } else {
       newParent = newParentInstructions();
   }

   // "If new parent is null, abort these steps and return null."
   if (!newParent) {
       return null;
   }

   // "If new parent's parent is null:"
   if (!newParent.parentNode) {
       // "Insert new parent into the parent of the first member of node list
       // immediately before the first member of node list."
       nodeList[0].parentNode.insertBefore(newParent, nodeList[0]);

       // "If any range has a boundary point with node equal to the parent of
       // new parent and offset equal to the index of new parent, add one to
       // that boundary point's offset."
       //
       // Only try to fix the global range.
       if (globalRange.startContainer == newParent.parentNode
       && globalRange.startOffset == getNodeIndex(newParent)) {
           globalRange.setStart(globalRange.startContainer, globalRange.startOffset + 1);
       }
       if (globalRange.endContainer == newParent.parentNode
       && globalRange.endOffset == getNodeIndex(newParent)) {
           globalRange.setEnd(globalRange.endContainer, globalRange.endOffset + 1);
       }
   }

   // "Let original parent be the parent of the first member of node list."
   var originalParent = nodeList[0].parentNode;

   // "If new parent is before the first member of node list in tree order:"
   if (isBefore(newParent, nodeList[0])) {
       // "If new parent is not an inline node, but the last visible child of
       // new parent and the first visible member of node list are both inline
       // nodes, and the last child of new parent is not a br, call
       // createElement("br") on the ownerDocument of new parent and append
       // the result as the last child of new parent."
       if (!isInlineNode(newParent)
       && isInlineNode([].filter.call(newParent.childNodes, isVisible).slice(-1)[0])
       && isInlineNode(nodeList.filter(isVisible)[0])
       && !isHtmlElement(newParent.lastChild, "BR")) {
           newParent.appendChild(newParent.ownerDocument.createElement("br"));
       }

       // "For each node in node list, append node as the last child of new
       // parent, preserving ranges."
       for (var i = 0; i < nodeList.length; i++) {
           movePreservingRanges(nodeList[i], newParent, -1);
       }

   // "Otherwise:"
   } else {
       // "If new parent is not an inline node, but the first visible child of
       // new parent and the last visible member of node list are both inline
       // nodes, and the last member of node list is not a br, call
       // createElement("br") on the ownerDocument of new parent and insert
       // the result as the first child of new parent."
       if (!isInlineNode(newParent)
       && isInlineNode([].filter.call(newParent.childNodes, isVisible)[0])
       && isInlineNode(nodeList.filter(isVisible).slice(-1)[0])
       && !isHtmlElement(nodeList[nodeList.length - 1], "BR")) {
           newParent.insertBefore(newParent.ownerDocument.createElement("br"), newParent.firstChild);
       }

       // "For each node in node list, in reverse order, insert node as the
       // first child of new parent, preserving ranges."
       for (var i = nodeList.length - 1; i >= 0; i--) {
           movePreservingRanges(nodeList[i], newParent, 0);
       }
   }

   // "If original parent is editable and has no children, remove it from its
   // parent."
   if (isEditable(originalParent) && !originalParent.hasChildNodes()) {
       originalParent.parentNode.removeChild(originalParent);
   }

   // "If new parent's nextSibling is editable and running sibling criteria on
   // it returns true:"
   if (isEditable(newParent.nextSibling)
   && siblingCriteria(newParent.nextSibling)) {
       // "If new parent is not an inline node, but new parent's last child
       // and new parent's nextSibling's first child are both inline nodes,
       // and new parent's last child is not a br, call createElement("br") on
       // the ownerDocument of new parent and append the result as the last
       // child of new parent."
       if (!isInlineNode(newParent)
       && isInlineNode(newParent.lastChild)
       && isInlineNode(newParent.nextSibling.firstChild)
       && !isHtmlElement(newParent.lastChild, "BR")) {
           newParent.appendChild(newParent.ownerDocument.createElement("br"));
       }

       // "While new parent's nextSibling has children, append its first child
       // as the last child of new parent, preserving ranges."
       while (newParent.nextSibling.hasChildNodes()) {
           movePreservingRanges(newParent.nextSibling.firstChild, newParent, -1);
       }

       // "Remove new parent's nextSibling from its parent."
       newParent.parentNode.removeChild(newParent.nextSibling);
   }

   // "Remove extraneous line breaks from new parent."
   removeExtraneousLineBreaksFrom(newParent);

   // "Return new parent."
   return newParent;
}


//@}
///// Allowed children /////
//@{

// "A name of an element with inline contents is "a", "abbr", "b", "bdi",
// "bdo", "cite", "code", "dfn", "em", "h1", "h2", "h3", "h4", "h5", "h6", "i",
// "kbd", "mark", "p", "pre", "q", "rp", "rt", "ruby", "s", "samp", "small",
// "span", "strong", "sub", "sup", "u", "var", "acronym", "listing", "strike",
// "xmp", "big", "blink", "font", "marquee", "nobr", or "tt"."
var namesOfElementsWithInlineContents = ["a", "abbr", "b", "bdi", "bdo",
   "cite", "code", "dfn", "em", "h1", "h2", "h3", "h4", "h5", "h6", "i",
   "kbd", "mark", "p", "pre", "q", "rp", "rt", "ruby", "s", "samp", "small",
   "span", "strong", "sub", "sup", "u", "var", "acronym", "listing", "strike",
   "xmp", "big", "blink", "font", "marquee", "nobr", "tt"];

// "An element with inline contents is an HTML element whose local name is a
// name of an element with inline contents."
function isElementWithInlineContents(node) {
   return isHtmlElement(node, namesOfElementsWithInlineContents);
}

function isAllowedChild(child, parent_) {
   // "If parent is "colgroup", "table", "tbody", "tfoot", "thead", "tr", or
   // an HTML element with local name equal to one of those, and child is a
   // Text node whose data does not consist solely of space characters, return
   // false."
   if ((["colgroup", "table", "tbody", "tfoot", "thead", "tr"].indexOf(parent_) != -1
   || isHtmlElement(parent_, ["colgroup", "table", "tbody", "tfoot", "thead", "tr"]))
   && typeof child == "object"
   && child.nodeType == Node.TEXT_NODE
   && !/^[ \t\n\f\r]*$/.test(child.data)) {
       return false;
   }

   // "If parent is "script", "style", "plaintext", or "xmp", or an HTML
   // element with local name equal to one of those, and child is not a Text
   // node, return false."
   if ((["script", "style", "plaintext", "xmp"].indexOf(parent_) != -1
   || isHtmlElement(parent_, ["script", "style", "plaintext", "xmp"]))
   && (typeof child != "object" || child.nodeType != Node.TEXT_NODE)) {
       return false;
   }

   // "If child is a Document, DocumentFragment, or DocumentType, return
   // false."
   if (typeof child == "object"
   && (child.nodeType == Node.DOCUMENT_NODE
   || child.nodeType == Node.DOCUMENT_FRAGMENT_NODE
   || child.nodeType == Node.DOCUMENT_TYPE_NODE)) {
       return false;
   }

   // "If child is an HTML element, set child to the local name of child."
   if (isHtmlElement(child)) {
       child = child.tagName.toLowerCase();
   }

   // "If child is not a string, return true."
   if (typeof child != "string") {
       return true;
   }

   // "If parent is an HTML element:"
   if (isHtmlElement(parent_)) {
       // "If child is "a", and parent or some ancestor of parent is an a,
       // return false."
       //
       // "If child is a prohibited paragraph child name and parent or some
       // ancestor of parent is an element with inline contents, return
       // false."
       //
       // "If child is "h1", "h2", "h3", "h4", "h5", or "h6", and parent or
       // some ancestor of parent is an HTML element with local name "h1",
       // "h2", "h3", "h4", "h5", or "h6", return false."
       var ancestor = parent_;
       while (ancestor) {
           if (child == "a" && isHtmlElement(ancestor, "a")) {
               return false;
           }
           if (prohibitedParagraphChildNames.indexOf(child) != -1
           && isElementWithInlineContents(ancestor)) {
               return false;
           }
           if (/^h[1-6]$/.test(child)
           && isHtmlElement(ancestor)
           && /^H[1-6]$/.test(ancestor.tagName)) {
               return false;
           }
           ancestor = ancestor.parentNode;
       }

       // "Let parent be the local name of parent."
       parent_ = parent_.tagName.toLowerCase();
   }

   // "If parent is an Element or DocumentFragment, return true."
   if (typeof parent_ == "object"
   && (parent_.nodeType == Node.ELEMENT_NODE
   || parent_.nodeType == Node.DOCUMENT_FRAGMENT_NODE)) {
       return true;
   }

   // "If parent is not a string, return false."
   if (typeof parent_ != "string") {
       return false;
   }

   // "If parent is on the left-hand side of an entry on the following list,
   // then return true if child is listed on the right-hand side of that
   // entry, and false otherwise."
   switch (parent_) {
       case "colgroup":
           return child == "col";
       case "table":
           return ["caption", "col", "colgroup", "tbody", "td", "tfoot", "th", "thead", "tr"].indexOf(child) != -1;
       case "tbody":
       case "thead":
       case "tfoot":
           return ["td", "th", "tr"].indexOf(child) != -1;
       case "tr":
           return ["td", "th"].indexOf(child) != -1;
       case "dl":
           return ["dt", "dd"].indexOf(child) != -1;
       case "dir":
       case "ol":
       case "ul":
           return ["dir", "li", "ol", "ul"].indexOf(child) != -1;
       case "hgroup":
           return /^h[1-6]$/.test(child);
   }

   // "If child is "body", "caption", "col", "colgroup", "frame", "frameset",
   // "head", "html", "tbody", "td", "tfoot", "th", "thead", or "tr", return
   // false."
   if (["body", "caption", "col", "colgroup", "frame", "frameset", "head",
   "html", "tbody", "td", "tfoot", "th", "thead", "tr"].indexOf(child) != -1) {
       return false;
   }

   // "If child is "dd" or "dt" and parent is not "dl", return false."
   if (["dd", "dt"].indexOf(child) != -1
   && parent_ != "dl") {
       return false;
   }

   // "If child is "li" and parent is not "ol" or "ul", return false."
   if (child == "li"
   && parent_ != "ol"
   && parent_ != "ul") {
       return false;
   }

   // "If parent is on the left-hand side of an entry on the following list
   // and child is listed on the right-hand side of that entry, return false."
   var table = [
       [["a"], ["a"]],
       [["dd", "dt"], ["dd", "dt"]],
       [["h1", "h2", "h3", "h4", "h5", "h6"], ["h1", "h2", "h3", "h4", "h5", "h6"]],
       [["li"], ["li"]],
       [["nobr"], ["nobr"]],
       [namesOfElementsWithInlineContents, prohibitedParagraphChildNames],
       [["td", "th"], ["caption", "col", "colgroup", "tbody", "td", "tfoot", "th", "thead", "tr"]],
   ];
   for (var i = 0; i < table.length; i++) {
       if (table[i][0].indexOf(parent_) != -1
       && table[i][1].indexOf(child) != -1) {
           return false;
       }
   }

   // "Return true."
   return true;
}


//@}

//////////////////////////////////////
///// Inline formatting commands /////
//////////////////////////////////////

///// Inline formatting command definitions /////
//@{

// "A node node is effectively contained in a range range if range is not
// collapsed, and at least one of the following holds:"
function isEffectivelyContained(node, range) {
   if (range.collapsed) {
       return false;
   }

   // "node is contained in range."
   if (isContained(node, range)) {
       return true;
   }

   // "node is range's start node, it is a Text node, and its length is
   // different from range's start offset."
   if (node == range.startContainer
   && node.nodeType == Node.TEXT_NODE
   && getNodeLength(node) != range.startOffset) {
       return true;
   }

   // "node is range's end node, it is a Text node, and range's end offset is
   // not 0."
   if (node == range.endContainer
   && node.nodeType == Node.TEXT_NODE
   && range.endOffset != 0) {
       return true;
   }

   // "node has at least one child; and all its children are effectively
   // contained in range; and either range's start node is not a descendant of
   // node or is not a Text node or range's start offset is zero; and either
   // range's end node is not a descendant of node or is not a Text node or
   // range's end offset is its end node's length."
   if (node.hasChildNodes()
   && [].every.call(node.childNodes, function(child) { return isEffectivelyContained(child, range) })
   && (!isDescendant(range.startContainer, node)
   || range.startContainer.nodeType != Node.TEXT_NODE
   || range.startOffset == 0)
   && (!isDescendant(range.endContainer, node)
   || range.endContainer.nodeType != Node.TEXT_NODE
   || range.endOffset == getNodeLength(range.endContainer))) {
       return true;
   }

   return false;
}

// Like get(All)ContainedNodes(), but for effectively contained nodes.
function getEffectivelyContainedNodes(range, condition) {
   if (typeof condition == "undefined") {
       condition = function() { return true };
   }
   var node = range.startContainer;
   while (isEffectivelyContained(node.parentNode, range)) {
       node = node.parentNode;
   }

   var stop = nextNodeDescendants(range.endContainer);

   var nodeList = [];
   while (isBefore(node, stop)) {
       if (isEffectivelyContained(node, range)
       && condition(node)) {
           nodeList.push(node);
           node = nextNodeDescendants(node);
           continue;
       }
       node = nextNode(node);
   }
   return nodeList;
}

function getAllEffectivelyContainedNodes(range, condition) {
   if (typeof condition == "undefined") {
       condition = function() { return true };
   }
   var node = range.startContainer;
   while (isEffectivelyContained(node.parentNode, range)) {
       node = node.parentNode;
   }

   var stop = nextNodeDescendants(range.endContainer);

   var nodeList = [];
   while (isBefore(node, stop)) {
       if (isEffectivelyContained(node, range)
       && condition(node)) {
           nodeList.push(node);
       }
       node = nextNode(node);
   }
   return nodeList;
}

// "A modifiable element is a b, em, i, s, span, strong, sub, sup, or u element
// with no attributes except possibly style; or a font element with no
// attributes except possibly style, color, face, and/or size; or an a element
// with no attributes except possibly style and/or href."
function isModifiableElement(node) {
   if (!isHtmlElement(node)) {
       return false;
   }

   if (["B", "EM", "I", "S", "SPAN", "STRIKE", "STRONG", "SUB", "SUP", "U"].indexOf(node.tagName) != -1) {
       if (node.attributes.length == 0) {
           return true;
       }

       if (node.attributes.length == 1
       && node.hasAttribute("style")) {
           return true;
       }
   }

   if (node.tagName == "FONT" || node.tagName == "A") {
       var numAttrs = node.attributes.length;

       if (node.hasAttribute("style")) {
           numAttrs--;
       }

       if (node.tagName == "FONT") {
           if (node.hasAttribute("color")) {
               numAttrs--;
           }

           if (node.hasAttribute("face")) {
               numAttrs--;
           }

           if (node.hasAttribute("size")) {
               numAttrs--;
           }
       }

       if (node.tagName == "A"
       && node.hasAttribute("href")) {
           numAttrs--;
       }

       if (numAttrs == 0) {
           return true;
       }
   }

   return false;
}

function isSimpleModifiableElement(node) {
   // "A simple modifiable element is an HTML element for which at least one
   // of the following holds:"
   if (!isHtmlElement(node)) {
       return false;
   }

   // Only these elements can possibly be a simple modifiable element.
   if (["A", "B", "EM", "FONT", "I", "S", "SPAN", "STRIKE", "STRONG", "SUB", "SUP", "U"].indexOf(node.tagName) == -1) {
       return false;
   }

   // "It is an a, b, em, font, i, s, span, strike, strong, sub, sup, or u
   // element with no attributes."
   if (node.attributes.length == 0) {
       return true;
   }

   // If it's got more than one attribute, everything after this fails.
   if (node.attributes.length > 1) {
       return false;
   }

   // "It is an a, b, em, font, i, s, span, strike, strong, sub, sup, or u
   // element with exactly one attribute, which is style, which sets no CSS
   // properties (including invalid or unrecognized properties)."
   //
   // Not gonna try for invalid or unrecognized.
   if (node.hasAttribute("style")
   && node.style.length == 0) {
       return true;
   }

   // "It is an a element with exactly one attribute, which is href."
   if (node.tagName == "A"
   && node.hasAttribute("href")) {
       return true;
   }

   // "It is a font element with exactly one attribute, which is either color,
   // face, or size."
   if (node.tagName == "FONT"
   && (node.hasAttribute("color")
   || node.hasAttribute("face")
   || node.hasAttribute("size")
   )) {
       return true;
   }

   // "It is a b or strong element with exactly one attribute, which is style,
   // and the style attribute sets exactly one CSS property (including invalid
   // or unrecognized properties), which is "font-weight"."
   if ((node.tagName == "B" || node.tagName == "STRONG")
   && node.hasAttribute("style")
   && node.style.length == 1
   && node.style.fontWeight != "") {
       return true;
   }

   // "It is an i or em element with exactly one attribute, which is style,
   // and the style attribute sets exactly one CSS property (including invalid
   // or unrecognized properties), which is "font-style"."
   if ((node.tagName == "I" || node.tagName == "EM")
   && node.hasAttribute("style")
   && node.style.length == 1
   && node.style.fontStyle != "") {
       return true;
   }

   // "It is an a, font, or span element with exactly one attribute, which is
   // style, and the style attribute sets exactly one CSS property (including
   // invalid or unrecognized properties), and that property is not
   // "text-decoration"."
   if ((node.tagName == "A" || node.tagName == "FONT" || node.tagName == "SPAN")
   && node.hasAttribute("style")
   && node.style.length == 1
   && node.style.textDecoration == "") {
       return true;
   }

   // "It is an a, font, s, span, strike, or u element with exactly one
   // attribute, which is style, and the style attribute sets exactly one CSS
   // property (including invalid or unrecognized properties), which is
   // "text-decoration", which is set to "line-through" or "underline" or
   // "overline" or "none"."
   //
   // The weird extra node.style.length check is for Firefox, which as of
   // 8.0a2 has annoying and weird behavior here.
   if (["A", "FONT", "S", "SPAN", "STRIKE", "U"].indexOf(node.tagName) != -1
   && node.hasAttribute("style")
   && (node.style.length == 1
       || (node.style.length == 4
           && "MozTextBlink" in node.style
           && "MozTextDecorationColor" in node.style
           && "MozTextDecorationLine" in node.style
           && "MozTextDecorationStyle" in node.style)
       || (node.style.length == 4
           && "MozTextBlink" in node.style
           && "textDecorationColor" in node.style
           && "textDecorationLine" in node.style
           && "textDecorationStyle" in node.style)
   )
   && (node.style.textDecoration == "line-through"
   || node.style.textDecoration == "underline"
   || node.style.textDecoration == "overline"
   || node.style.textDecoration == "none")) {
       return true;
   }

   return false;
}

// "A formattable node is an editable visible node that is either a Text node,
// an img, or a br."
function isFormattableNode(node) {
   return isEditable(node)
       && isVisible(node)
       && (node.nodeType == Node.TEXT_NODE
       || isHtmlElement(node, ["img", "br"]));
}

// "Two quantities are equivalent values for a command if either both are null,
// or both are strings and they're equal and the command does not define any
// equivalent values, or both are strings and the command defines equivalent
// values and they match the definition."
function areEquivalentValues(command, val1, val2) {
   if (val1 === null && val2 === null) {
       return true;
   }

   if (typeof val1 == "string"
   && typeof val2 == "string"
   && val1 == val2
   && !("equivalentValues" in commands[command])) {
       return true;
   }

   if (typeof val1 == "string"
   && typeof val2 == "string"
   && "equivalentValues" in commands[command]
   && commands[command].equivalentValues(val1, val2)) {
       return true;
   }

   return false;
}

// "Two quantities are loosely equivalent values for a command if either they
// are equivalent values for the command, or if the command is the fontSize
// command; one of the quantities is one of "x-small", "small", "medium",
// "large", "x-large", "xx-large", or "xxx-large"; and the other quantity is
// the resolved value of "font-size" on a font element whose size attribute has
// the corresponding value set ("1" through "7" respectively)."
function areLooselyEquivalentValues(command, val1, val2) {
   if (areEquivalentValues(command, val1, val2)) {
       return true;
   }

   if (command != "fontsize"
   || typeof val1 != "string"
   || typeof val2 != "string") {
       return false;
   }

   // Static variables in JavaScript?
   var callee = areLooselyEquivalentValues;
   if (callee.sizeMap === undefined) {
       callee.sizeMap = {};
       var font = document.createElement("font");
       document.body.appendChild(font);
       ["x-small", "small", "medium", "large", "x-large", "xx-large",
       "xxx-large"].forEach(function(keyword) {
           font.size = cssSizeToLegacy(keyword);
           callee.sizeMap[keyword] = getComputedStyle(font).fontSize;
       });
       document.body.removeChild(font);
   }

   return val1 === callee.sizeMap[val2]
       || val2 === callee.sizeMap[val1];
}

//@}
///// Assorted inline formatting command algorithms /////
//@{

function getEffectiveCommandValue(node, command) {
   // "If neither node nor its parent is an Element, return null."
   if (node.nodeType != Node.ELEMENT_NODE
   && (!node.parentNode || node.parentNode.nodeType != Node.ELEMENT_NODE)) {
       return null;
   }

   // "If node is not an Element, return the effective command value of its
   // parent for command."
   if (node.nodeType != Node.ELEMENT_NODE) {
       return getEffectiveCommandValue(node.parentNode, command);
   }

   // "If command is "createLink" or "unlink":"
   if (command == "createlink" || command == "unlink") {
       // "While node is not null, and is not an a element that has an href
       // attribute, set node to its parent."
       while (node
       && (!isHtmlElement(node)
       || node.tagName != "A"
       || !node.hasAttribute("href"))) {
           node = node.parentNode;
       }

       // "If node is null, return null."
       if (!node) {
           return null;
       }

       // "Return the value of node's href attribute."
       return node.getAttribute("href");
   }

   // "If command is "backColor" or "hiliteColor":"
   if (command == "backcolor"
   || command == "hilitecolor") {
       // "While the resolved value of "background-color" on node is any
       // fully transparent value, and node's parent is an Element, set
       // node to its parent."
       //
       // Another lame hack to avoid flawed APIs.
       while ((getComputedStyle(node).backgroundColor == "rgba(0, 0, 0, 0)"
       || getComputedStyle(node).backgroundColor === ""
       || getComputedStyle(node).backgroundColor == "transparent")
       && node.parentNode
       && node.parentNode.nodeType == Node.ELEMENT_NODE) {
           node = node.parentNode;
       }

       // "Return the resolved value of "background-color" for node."
       return getComputedStyle(node).backgroundColor;
   }

   // "If command is "subscript" or "superscript":"
   if (command == "subscript" || command == "superscript") {
       // "Let affected by subscript and affected by superscript be two
       // boolean variables, both initially false."
       var affectedBySubscript = false;
       var affectedBySuperscript = false;

       // "While node is an inline node:"
       while (isInlineNode(node)) {
           var verticalAlign = getComputedStyle(node).verticalAlign;

           // "If node is a sub, set affected by subscript to true."
           if (isHtmlElement(node, "sub")) {
               affectedBySubscript = true;
           // "Otherwise, if node is a sup, set affected by superscript to
           // true."
           } else if (isHtmlElement(node, "sup")) {
               affectedBySuperscript = true;
           }

           // "Set node to its parent."
           node = node.parentNode;
       }

       // "If affected by subscript and affected by superscript are both true,
       // return the string "mixed"."
       if (affectedBySubscript && affectedBySuperscript) {
           return "mixed";
       }

       // "If affected by subscript is true, return "subscript"."
       if (affectedBySubscript) {
           return "subscript";
       }

       // "If affected by superscript is true, return "superscript"."
       if (affectedBySuperscript) {
           return "superscript";
       }

       // "Return null."
       return null;
   }

   // "If command is "strikethrough", and the "text-decoration" property of
   // node or any of its ancestors has resolved value containing
   // "line-through", return "line-through". Otherwise, return null."
   if (command == "strikethrough") {
       do {
           if (getComputedStyle(node).textDecoration.indexOf("line-through") != -1) {
               return "line-through";
           }
           node = node.parentNode;
       } while (node && node.nodeType == Node.ELEMENT_NODE);
       return null;
   }

   // "If command is "underline", and the "text-decoration" property of node
   // or any of its ancestors has resolved value containing "underline",
   // return "underline". Otherwise, return null."
   if (command == "underline") {
       do {
           if (getComputedStyle(node).textDecoration.indexOf("underline") != -1) {
               return "underline";
           }
           node = node.parentNode;
       } while (node && node.nodeType == Node.ELEMENT_NODE);
       return null;
   }

   if (!("relevantCssProperty" in commands[command])) {
       throw "Bug: no relevantCssProperty for " + command + " in getEffectiveCommandValue";
   }

   // "Return the resolved value for node of the relevant CSS property for
   // command."
   return getComputedStyle(node)[commands[command].relevantCssProperty];
}

function getSpecifiedCommandValue(element, command) {
   // "If command is "backColor" or "hiliteColor" and element's display
   // property does not have resolved value "inline", return null."
   if ((command == "backcolor" || command == "hilitecolor")
   && getComputedStyle(element).display != "inline") {
       return null;
   }

   // "If command is "createLink" or "unlink":"
   if (command == "createlink" || command == "unlink") {
       // "If element is an a element and has an href attribute, return the
       // value of that attribute."
       if (isHtmlElement(element)
       && element.tagName == "A"
       && element.hasAttribute("href")) {
           return element.getAttribute("href");
       }

       // "Return null."
       return null;
   }

   // "If command is "subscript" or "superscript":"
   if (command == "subscript" || command == "superscript") {
       // "If element is a sup, return "superscript"."
       if (isHtmlElement(element, "sup")) {
           return "superscript";
       }

       // "If element is a sub, return "subscript"."
       if (isHtmlElement(element, "sub")) {
           return "subscript";
       }

       // "Return null."
       return null;
   }

   // "If command is "strikethrough", and element has a style attribute set,
   // and that attribute sets "text-decoration":"
   if (command == "strikethrough"
   && element.style.textDecoration != "") {
       // "If element's style attribute sets "text-decoration" to a value
       // containing "line-through", return "line-through"."
       if (element.style.textDecoration.indexOf("line-through") != -1) {
           return "line-through";
       }

       // "Return null."
       return null;
   }

   // "If command is "strikethrough" and element is a s or strike element,
   // return "line-through"."
   if (command == "strikethrough"
   && isHtmlElement(element, ["S", "STRIKE"])) {
       return "line-through";
   }

   // "If command is "underline", and element has a style attribute set, and
   // that attribute sets "text-decoration":"
   if (command == "underline"
   && element.style.textDecoration != "") {
       // "If element's style attribute sets "text-decoration" to a value
       // containing "underline", return "underline"."
       if (element.style.textDecoration.indexOf("underline") != -1) {
           return "underline";
       }

       // "Return null."
       return null;
   }

   // "If command is "underline" and element is a u element, return
   // "underline"."
   if (command == "underline"
   && isHtmlElement(element, "U")) {
       return "underline";
   }

   // "Let property be the relevant CSS property for command."
   var property = commands[command].relevantCssProperty;

   // "If property is null, return null."
   if (property === null) {
       return null;
   }

   // "If element has a style attribute set, and that attribute has the
   // effect of setting property, return the value that it sets property to."
   if (element.style[property] != "") {
       return element.style[property];
   }

   // "If element is a font element that has an attribute whose effect is
   // to create a presentational hint for property, return the value that the
   // hint sets property to.  (For a size of 7, this will be the non-CSS value
   // "xxx-large".)"
   if (isHtmlNamespace(element.namespaceURI)
   && element.tagName == "FONT") {
       if (property == "color" && element.hasAttribute("color")) {
           return element.color;
       }
       if (property == "fontFamily" && element.hasAttribute("face")) {
           return element.face;
       }
       if (property == "fontSize" && element.hasAttribute("size")) {
           // This is not even close to correct in general.
           var size = parseInt(element.size);
           if (size < 1) {
               size = 1;
           }
           if (size > 7) {
               size = 7;
           }
           return {
               1: "x-small",
               2: "small",
               3: "medium",
               4: "large",
               5: "x-large",
               6: "xx-large",
               7: "xxx-large"
           }[size];
       }
   }

   // "If element is in the following list, and property is equal to the
   // CSS property name listed for it, return the string listed for it."
   //
   // A list follows, whose meaning is copied here.
   if (property == "fontWeight"
   && (element.tagName == "B" || element.tagName == "STRONG")) {
       return "bold";
   }
   if (property == "fontStyle"
   && (element.tagName == "I" || element.tagName == "EM")) {
       return "italic";
   }

   // "Return null."
   return null;
}

function reorderModifiableDescendants(node, command, newValue) {
   // "Let candidate equal node."
   var candidate = node;

   // "While candidate is a modifiable element, and candidate has exactly one
   // child, and that child is also a modifiable element, and candidate is not
   // a simple modifiable element or candidate's specified command value for
   // command is not equivalent to new value, set candidate to its child."
   while (isModifiableElement(candidate)
   && candidate.childNodes.length == 1
   && isModifiableElement(candidate.firstChild)
   && (!isSimpleModifiableElement(candidate)
   || !areEquivalentValues(command, getSpecifiedCommandValue(candidate, command), newValue))) {
       candidate = candidate.firstChild;
   }

   // "If candidate is node, or is not a simple modifiable element, or its
   // specified command value is not equivalent to new value, or its effective
   // command value is not loosely equivalent to new value, abort these
   // steps."
   if (candidate == node
   || !isSimpleModifiableElement(candidate)
   || !areEquivalentValues(command, getSpecifiedCommandValue(candidate, command), newValue)
   || !areLooselyEquivalentValues(command, getEffectiveCommandValue(candidate, command), newValue)) {
       return;
   }

   // "While candidate has children, insert the first child of candidate into
   // candidate's parent immediately before candidate, preserving ranges."
   while (candidate.hasChildNodes()) {
       movePreservingRanges(candidate.firstChild, candidate.parentNode, getNodeIndex(candidate));
   }

   // "Insert candidate into node's parent immediately after node."
   node.parentNode.insertBefore(candidate, node.nextSibling);

   // "Append the node as the last child of candidate, preserving ranges."
   movePreservingRanges(node, candidate, -1);
}

function recordValues(nodeList) {
   // "Let values be a list of (node, command, specified command value)
   // triples, initially empty."
   var values = [];

   // "For each node in node list, for each command in the list "subscript",
   // "bold", "fontName", "fontSize", "foreColor", "hiliteColor", "italic",
   // "strikethrough", and "underline" in that order:"
   nodeList.forEach(function(node) {
       ["subscript", "bold", "fontname", "fontsize", "forecolor",
       "hilitecolor", "italic", "strikethrough", "underline"].forEach(function(command) {
           // "Let ancestor equal node."
           var ancestor = node;

           // "If ancestor is not an Element, set it to its parent."
           if (ancestor.nodeType != Node.ELEMENT_NODE) {
               ancestor = ancestor.parentNode;
           }

           // "While ancestor is an Element and its specified command value
           // for command is null, set it to its parent."
           while (ancestor
           && ancestor.nodeType == Node.ELEMENT_NODE
           && getSpecifiedCommandValue(ancestor, command) === null) {
               ancestor = ancestor.parentNode;
           }

           // "If ancestor is an Element, add (node, command, ancestor's
           // specified command value for command) to values. Otherwise add
           // (node, command, null) to values."
           if (ancestor && ancestor.nodeType == Node.ELEMENT_NODE) {
               values.push([node, command, getSpecifiedCommandValue(ancestor, command)]);
           } else {
               values.push([node, command, null]);
           }
       });
   });

   // "Return values."
   return values;
}

function restoreValues(values) {
   // "For each (node, command, value) triple in values:"
   values.forEach(function(triple) {
       var node = triple[0];
       var command = triple[1];
       var value = triple[2];

       // "Let ancestor equal node."
       var ancestor = node;

       // "If ancestor is not an Element, set it to its parent."
       if (!ancestor || ancestor.nodeType != Node.ELEMENT_NODE) {
           ancestor = ancestor.parentNode;
       }

       // "While ancestor is an Element and its specified command value for
       // command is null, set it to its parent."
       while (ancestor
       && ancestor.nodeType == Node.ELEMENT_NODE
       && getSpecifiedCommandValue(ancestor, command) === null) {
           ancestor = ancestor.parentNode;
       }

       // "If value is null and ancestor is an Element, push down values on
       // node for command, with new value null."
       if (value === null
       && ancestor
       && ancestor.nodeType == Node.ELEMENT_NODE) {
           pushDownValues(node, command, null);

       // "Otherwise, if ancestor is an Element and its specified command
       // value for command is not equivalent to value, or if ancestor is not
       // an Element and value is not null, force the value of command to
       // value on node."
       } else if ((ancestor
       && ancestor.nodeType == Node.ELEMENT_NODE
       && !areEquivalentValues(command, getSpecifiedCommandValue(ancestor, command), value))
       || ((!ancestor || ancestor.nodeType != Node.ELEMENT_NODE)
       && value !== null)) {
           forceValue(node, command, value);
       }
   });
}


//@}
///// Clearing an element's value /////
//@{

function clearValue(element, command) {
   // "If element is not editable, return the empty list."
   if (!isEditable(element)) {
       return [];
   }

   // "If element's specified command value for command is null, return the
   // empty list."
   if (getSpecifiedCommandValue(element, command) === null) {
       return [];
   }

   // "If element is a simple modifiable element:"
   if (isSimpleModifiableElement(element)) {
       // "Let children be the children of element."
       var children = Array.prototype.slice.call(element.childNodes);

       // "For each child in children, insert child into element's parent
       // immediately before element, preserving ranges."
       for (var i = 0; i < children.length; i++) {
           movePreservingRanges(children[i], element.parentNode, getNodeIndex(element));
       }

       // "Remove element from its parent."
       element.parentNode.removeChild(element);

       // "Return children."
       return children;
   }

   // "If command is "strikethrough", and element has a style attribute that
   // sets "text-decoration" to some value containing "line-through", delete
   // "line-through" from the value."
   if (command == "strikethrough"
   && element.style.textDecoration.indexOf("line-through") != -1) {
       if (element.style.textDecoration == "line-through") {
           element.style.textDecoration = "";
       } else {
           element.style.textDecoration = element.style.textDecoration.replace("line-through", "");
       }
       if (element.getAttribute("style") == "") {
           element.removeAttribute("style");
       }
   }

   // "If command is "underline", and element has a style attribute that sets
   // "text-decoration" to some value containing "underline", delete
   // "underline" from the value."
   if (command == "underline"
   && element.style.textDecoration.indexOf("underline") != -1) {
       if (element.style.textDecoration == "underline") {
           element.style.textDecoration = "";
       } else {
           element.style.textDecoration = element.style.textDecoration.replace("underline", "");
       }
       if (element.getAttribute("style") == "") {
           element.removeAttribute("style");
       }
   }

   // "If the relevant CSS property for command is not null, unset the CSS
   // property property of element."
   if (commands[command].relevantCssProperty !== null) {
       element.style[commands[command].relevantCssProperty] = '';
       if (element.getAttribute("style") == "") {
           element.removeAttribute("style");
       }
   }

   // "If element is a font element:"
   if (isHtmlNamespace(element.namespaceURI) && element.tagName == "FONT") {
       // "If command is "foreColor", unset element's color attribute, if set."
       if (command == "forecolor") {
           element.removeAttribute("color");
       }

       // "If command is "fontName", unset element's face attribute, if set."
       if (command == "fontname") {
           element.removeAttribute("face");
       }

       // "If command is "fontSize", unset element's size attribute, if set."
       if (command == "fontsize") {
           element.removeAttribute("size");
       }
   }

   // "If element is an a element and command is "createLink" or "unlink",
   // unset the href property of element."
   if (isHtmlElement(element, "A")
   && (command == "createlink" || command == "unlink")) {
       element.removeAttribute("href");
   }

   // "If element's specified command value for command is null, return the
   // empty list."
   if (getSpecifiedCommandValue(element, command) === null) {
       return [];
   }

   // "Set the tag name of element to "span", and return the one-node list
   // consisting of the result."
   return [setTagName(element, "span")];
}


//@}
///// Pushing down values /////
//@{

function pushDownValues(node, command, newValue) {
   // "If node's parent is not an Element, abort this algorithm."
   if (!node.parentNode
   || node.parentNode.nodeType != Node.ELEMENT_NODE) {
       return;
   }

   // "If the effective command value of command is loosely equivalent to new
   // value on node, abort this algorithm."
   if (areLooselyEquivalentValues(command, getEffectiveCommandValue(node, command), newValue)) {
       return;
   }

   // "Let current ancestor be node's parent."
   var currentAncestor = node.parentNode;

   // "Let ancestor list be a list of Nodes, initially empty."
   var ancestorList = [];

   // "While current ancestor is an editable Element and the effective command
   // value of command is not loosely equivalent to new value on it, append
   // current ancestor to ancestor list, then set current ancestor to its
   // parent."
   while (isEditable(currentAncestor)
   && currentAncestor.nodeType == Node.ELEMENT_NODE
   && !areLooselyEquivalentValues(command, getEffectiveCommandValue(currentAncestor, command), newValue)) {
       ancestorList.push(currentAncestor);
       currentAncestor = currentAncestor.parentNode;
   }

   // "If ancestor list is empty, abort this algorithm."
   if (!ancestorList.length) {
       return;
   }

   // "Let propagated value be the specified command value of command on the
   // last member of ancestor list."
   var propagatedValue = getSpecifiedCommandValue(ancestorList[ancestorList.length - 1], command);

   // "If propagated value is null and is not equal to new value, abort this
   // algorithm."
   if (propagatedValue === null && propagatedValue != newValue) {
       return;
   }

   // "If the effective command value for the parent of the last member of
   // ancestor list is not loosely equivalent to new value, and new value is
   // not null, abort this algorithm."
   if (newValue !== null
   && !areLooselyEquivalentValues(command, getEffectiveCommandValue(ancestorList[ancestorList.length - 1].parentNode, command), newValue)) {
       return;
   }

   // "While ancestor list is not empty:"
   while (ancestorList.length) {
       // "Let current ancestor be the last member of ancestor list."
       // "Remove the last member from ancestor list."
       var currentAncestor = ancestorList.pop();

       // "If the specified command value of current ancestor for command is
       // not null, set propagated value to that value."
       if (getSpecifiedCommandValue(currentAncestor, command) !== null) {
           propagatedValue = getSpecifiedCommandValue(currentAncestor, command);
       }

       // "Let children be the children of current ancestor."
       var children = Array.prototype.slice.call(currentAncestor.childNodes);

       // "If the specified command value of current ancestor for command is
       // not null, clear the value of current ancestor."
       if (getSpecifiedCommandValue(currentAncestor, command) !== null) {
           clearValue(currentAncestor, command);
       }

       // "For every child in children:"
       for (var i = 0; i < children.length; i++) {
           var child = children[i];

           // "If child is node, continue with the next child."
           if (child == node) {
               continue;
           }

           // "If child is an Element whose specified command value for
           // command is neither null nor equivalent to propagated value,
           // continue with the next child."
           if (child.nodeType == Node.ELEMENT_NODE
           && getSpecifiedCommandValue(child, command) !== null
           && !areEquivalentValues(command, propagatedValue, getSpecifiedCommandValue(child, command))) {
               continue;
           }

           // "If child is the last member of ancestor list, continue with the
           // next child."
           if (child == ancestorList[ancestorList.length - 1]) {
               continue;
           }

           // "Force the value of child, with command as in this algorithm
           // and new value equal to propagated value."
           forceValue(child, command, propagatedValue);
       }
   }
}


//@}
///// Forcing the value of a node /////
//@{

function forceValue(node, command, newValue) {
   // "If node's parent is null, abort this algorithm."
   if (!node.parentNode) {
       return;
   }

   // "If new value is null, abort this algorithm."
   if (newValue === null) {
       return;
   }

   // "If node is an allowed child of "span":"
   if (isAllowedChild(node, "span")) {
       // "Reorder modifiable descendants of node's previousSibling."
       reorderModifiableDescendants(node.previousSibling, command, newValue);

       // "Reorder modifiable descendants of node's nextSibling."
       reorderModifiableDescendants(node.nextSibling, command, newValue);

       // "Wrap the one-node list consisting of node, with sibling criteria
       // returning true for a simple modifiable element whose specified
       // command value is equivalent to new value and whose effective command
       // value is loosely equivalent to new value and false otherwise, and
       // with new parent instructions returning null."
       wrap([node],
           function(node) {
               return isSimpleModifiableElement(node)
                   && areEquivalentValues(command, getSpecifiedCommandValue(node, command), newValue)
                   && areLooselyEquivalentValues(command, getEffectiveCommandValue(node, command), newValue);
           },
           function() { return null }
       );
   }

   // "If node is invisible, abort this algorithm."
   if (isInvisible(node)) {
       return;
   }

   // "If the effective command value of command is loosely equivalent to new
   // value on node, abort this algorithm."
   if (areLooselyEquivalentValues(command, getEffectiveCommandValue(node, command), newValue)) {
       return;
   }

   // "If node is not an allowed child of "span":"
   if (!isAllowedChild(node, "span")) {
       // "Let children be all children of node, omitting any that are
       // Elements whose specified command value for command is neither null
       // nor equivalent to new value."
       var children = [];
       for (var i = 0; i < node.childNodes.length; i++) {
           if (node.childNodes[i].nodeType == Node.ELEMENT_NODE) {
               var specifiedValue = getSpecifiedCommandValue(node.childNodes[i], command);

               if (specifiedValue !== null
               && !areEquivalentValues(command, newValue, specifiedValue)) {
                   continue;
               }
           }
           children.push(node.childNodes[i]);
       }

       // "Force the value of each Node in children, with command and new
       // value as in this invocation of the algorithm."
       for (var i = 0; i < children.length; i++) {
           forceValue(children[i], command, newValue);
       }

       // "Abort this algorithm."
       return;
   }

   // "If the effective command value of command is loosely equivalent to new
   // value on node, abort this algorithm."
   if (areLooselyEquivalentValues(command, getEffectiveCommandValue(node, command), newValue)) {
       return;
   }

   // "Let new parent be null."
   var newParent = null;

   // "If the CSS styling flag is false:"
   if (!cssStylingFlag) {
       // "If command is "bold" and new value is "bold", let new parent be the
       // result of calling createElement("b") on the ownerDocument of node."
       if (command == "bold" && (newValue == "bold" || newValue == "700")) {
           newParent = node.ownerDocument.createElement("b");
       }

       // "If command is "italic" and new value is "italic", let new parent be
       // the result of calling createElement("i") on the ownerDocument of
       // node."
       if (command == "italic" && newValue == "italic") {
           newParent = node.ownerDocument.createElement("i");
       }

       // "If command is "strikethrough" and new value is "line-through", let
       // new parent be the result of calling createElement("s") on the
       // ownerDocument of node."
       if (command == "strikethrough" && newValue == "line-through") {
           newParent = node.ownerDocument.createElement("s");
       }

       // "If command is "underline" and new value is "underline", let new
       // parent be the result of calling createElement("u") on the
       // ownerDocument of node."
       if (command == "underline" && newValue == "underline") {
           newParent = node.ownerDocument.createElement("u");
       }

       // "If command is "foreColor", and new value is fully opaque with red,
       // green, and blue components in the range 0 to 255:"
       if (command == "forecolor" && parseSimpleColor(newValue)) {
           // "Let new parent be the result of calling createElement("font")
           // on the ownerDocument of node."
           newParent = node.ownerDocument.createElement("font");

           // "Set the color attribute of new parent to the result of applying
           // the rules for serializing simple color values to new value
           // (interpreted as a simple color)."
           newParent.setAttribute("color", parseSimpleColor(newValue));
       }

       // "If command is "fontName", let new parent be the result of calling
       // createElement("font") on the ownerDocument of node, then set the
       // face attribute of new parent to new value."
       if (command == "fontname") {
           newParent = node.ownerDocument.createElement("font");
           newParent.face = newValue;
       }
   }

   // "If command is "createLink" or "unlink":"
   if (command == "createlink" || command == "unlink") {
       // "Let new parent be the result of calling createElement("a") on the
       // ownerDocument of node."
       newParent = node.ownerDocument.createElement("a");

       // "Set the href attribute of new parent to new value."
       newParent.setAttribute("href", newValue);

       // "Let ancestor be node's parent."
       var ancestor = node.parentNode;

       // "While ancestor is not null:"
       while (ancestor) {
           // "If ancestor is an a, set the tag name of ancestor to "span",
           // and let ancestor be the result."
           if (isHtmlElement(ancestor, "A")) {
               ancestor = setTagName(ancestor, "span");
           }

           // "Set ancestor to its parent."
           ancestor = ancestor.parentNode;
       }
   }

   // "If command is "fontSize"; and new value is one of "x-small", "small",
   // "medium", "large", "x-large", "xx-large", or "xxx-large"; and either the
   // CSS styling flag is false, or new value is "xxx-large": let new parent
   // be the result of calling createElement("font") on the ownerDocument of
   // node, then set the size attribute of new parent to the number from the
   // following table based on new value: [table omitted]"
   if (command == "fontsize"
   && ["x-small", "small", "medium", "large", "x-large", "xx-large", "xxx-large"].indexOf(newValue) != -1
   && (!cssStylingFlag || newValue == "xxx-large")) {
       newParent = node.ownerDocument.createElement("font");
       newParent.size = cssSizeToLegacy(newValue);
   }

   // "If command is "subscript" or "superscript" and new value is
   // "subscript", let new parent be the result of calling
   // createElement("sub") on the ownerDocument of node."
   if ((command == "subscript" || command == "superscript")
   && newValue == "subscript") {
       newParent = node.ownerDocument.createElement("sub");
   }

   // "If command is "subscript" or "superscript" and new value is
   // "superscript", let new parent be the result of calling
   // createElement("sup") on the ownerDocument of node."
   if ((command == "subscript" || command == "superscript")
   && newValue == "superscript") {
       newParent = node.ownerDocument.createElement("sup");
   }

   // "If new parent is null, let new parent be the result of calling
   // createElement("span") on the ownerDocument of node."
   if (!newParent) {
       newParent = node.ownerDocument.createElement("span");
   }

   // "Insert new parent in node's parent before node."
   node.parentNode.insertBefore(newParent, node);

   // "If the effective command value of command for new parent is not loosely
   // equivalent to new value, and the relevant CSS property for command is
   // not null, set that CSS property of new parent to new value (if the new
   // value would be valid)."
   var property = commands[command].relevantCssProperty;
   if (property !== null
   && !areLooselyEquivalentValues(command, getEffectiveCommandValue(newParent, command), newValue)) {
       newParent.style[property] = newValue;
   }

   // "If command is "strikethrough", and new value is "line-through", and the
   // effective command value of "strikethrough" for new parent is not
   // "line-through", set the "text-decoration" property of new parent to
   // "line-through"."
   if (command == "strikethrough"
   && newValue == "line-through"
   && getEffectiveCommandValue(newParent, "strikethrough") != "line-through") {
       newParent.style.textDecoration = "line-through";
   }

   // "If command is "underline", and new value is "underline", and the
   // effective command value of "underline" for new parent is not
   // "underline", set the "text-decoration" property of new parent to
   // "underline"."
   if (command == "underline"
   && newValue == "underline"
   && getEffectiveCommandValue(newParent, "underline") != "underline") {
       newParent.style.textDecoration = "underline";
   }

   // "Append node to new parent as its last child, preserving ranges."
   movePreservingRanges(node, newParent, newParent.childNodes.length);

   // "If node is an Element and the effective command value of command for
   // node is not loosely equivalent to new value:"
   if (node.nodeType == Node.ELEMENT_NODE
   && !areEquivalentValues(command, getEffectiveCommandValue(node, command), newValue)) {
       // "Insert node into the parent of new parent before new parent,
       // preserving ranges."
       movePreservingRanges(node, newParent.parentNode, getNodeIndex(newParent));

       // "Remove new parent from its parent."
       newParent.parentNode.removeChild(newParent);

       // "Let children be all children of node, omitting any that are
       // Elements whose specified command value for command is neither null
       // nor equivalent to new value."
       var children = [];
       for (var i = 0; i < node.childNodes.length; i++) {
           if (node.childNodes[i].nodeType == Node.ELEMENT_NODE) {
               var specifiedValue = getSpecifiedCommandValue(node.childNodes[i], command);

               if (specifiedValue !== null
               && !areEquivalentValues(command, newValue, specifiedValue)) {
                   continue;
               }
           }
           children.push(node.childNodes[i]);
       }

       // "Force the value of each Node in children, with command and new
       // value as in this invocation of the algorithm."
       for (var i = 0; i < children.length; i++) {
           forceValue(children[i], command, newValue);
       }
   }
}


//@}
///// Setting the selection's value /////
//@{

function setSelectionValue(command, newValue) {
   // "If there is no formattable node effectively contained in the active
   // range:"
   if (!getAllEffectivelyContainedNodes(getActiveRange())
   .some(isFormattableNode)) {
       // "If command has inline command activated values, set the state
       // override to true if new value is among them and false if it's not."
       if ("inlineCommandActivatedValues" in commands[command]) {
           setStateOverride(command, commands[command].inlineCommandActivatedValues
               .indexOf(newValue) != -1);
       }

       // "If command is "subscript", unset the state override for
       // "superscript"."
       if (command == "subscript") {
           unsetStateOverride("superscript");
       }

       // "If command is "superscript", unset the state override for
       // "subscript"."
       if (command == "superscript") {
           unsetStateOverride("subscript");
       }

       // "If new value is null, unset the value override (if any)."
       if (newValue === null) {
           unsetValueOverride(command);

       // "Otherwise, if command is "createLink" or it has a value specified,
       // set the value override to new value."
       } else if (command == "createlink" || "value" in commands[command]) {
           setValueOverride(command, newValue);
       }

       // "Abort these steps."
       return;
   }

   // "If the active range's start node is an editable Text node, and its
   // start offset is neither zero nor its start node's length, call
   // splitText() on the active range's start node, with argument equal to the
   // active range's start offset. Then set the active range's start node to
   // the result, and its start offset to zero."
   if (isEditable(getActiveRange().startContainer)
   && getActiveRange().startContainer.nodeType == Node.TEXT_NODE
   && getActiveRange().startOffset != 0
   && getActiveRange().startOffset != getNodeLength(getActiveRange().startContainer)) {
       // Account for browsers not following range mutation rules
       var newActiveRange = document.createRange();
       var newNode;
       if (getActiveRange().startContainer == getActiveRange().endContainer) {
           var newEndOffset = getActiveRange().endOffset - getActiveRange().startOffset;
           newNode = getActiveRange().startContainer.splitText(getActiveRange().startOffset);
           newActiveRange.setEnd(newNode, newEndOffset);
           getActiveRange().setEnd(newNode, newEndOffset);
       } else {
           newNode = getActiveRange().startContainer.splitText(getActiveRange().startOffset);
       }
       newActiveRange.setStart(newNode, 0);
       getSelection().removeAllRanges();
       getSelection().addRange(newActiveRange);

       getActiveRange().setStart(newNode, 0);
   }

   // "If the active range's end node is an editable Text node, and its end
   // offset is neither zero nor its end node's length, call splitText() on
   // the active range's end node, with argument equal to the active range's
   // end offset."
   if (isEditable(getActiveRange().endContainer)
   && getActiveRange().endContainer.nodeType == Node.TEXT_NODE
   && getActiveRange().endOffset != 0
   && getActiveRange().endOffset != getNodeLength(getActiveRange().endContainer)) {
       // IE seems to mutate the range incorrectly here, so we need correction
       // here as well.  The active range will be temporarily in orphaned
       // nodes, so calling getActiveRange() after splitText() but before
       // fixing the range will throw an exception.
       var activeRange = getActiveRange();
       var newStart = [activeRange.startContainer, activeRange.startOffset];
       var newEnd = [activeRange.endContainer, activeRange.endOffset];
       activeRange.endContainer.splitText(activeRange.endOffset);
       activeRange.setStart(newStart[0], newStart[1]);
       activeRange.setEnd(newEnd[0], newEnd[1]);

       getSelection().removeAllRanges();
       getSelection().addRange(activeRange);
   }

   // "Let element list be all editable Elements effectively contained in the
   // active range.
   //
   // "For each element in element list, clear the value of element."
   getAllEffectivelyContainedNodes(getActiveRange(), function(node) {
       return isEditable(node) && node.nodeType == Node.ELEMENT_NODE;
   }).forEach(function(element) {
       clearValue(element, command);
   });

   // "Let node list be all editable nodes effectively contained in the active
   // range.
   //
   // "For each node in node list:"
   getAllEffectivelyContainedNodes(getActiveRange(), isEditable).forEach(function(node) {
       // "Push down values on node."
       pushDownValues(node, command, newValue);

       // "If node is an allowed child of span, force the value of node."
       if (isAllowedChild(node, "span")) {
           forceValue(node, command, newValue);
       }
   });
}


//@}
///// The backColor command /////
//@{
commands.backcolor = {
   // Copy-pasted, same as hiliteColor
   action: function(value) {
       // Action is further copy-pasted, same as foreColor

       // "If value is not a valid CSS color, prepend "#" to it."
       //
       // "If value is still not a valid CSS color, or if it is currentColor,
       // return false."
       //
       // Cheap hack for testing, no attempt to be comprehensive.
       if (/^([0-9a-fA-F]{3}){1,2}$/.test(value)) {
           value = "#" + value;
       }
       if (!/^(rgba?|hsla?)\(.*\)$/.test(value)
       && !parseSimpleColor(value)
       && value.toLowerCase() != "transparent") {
           return false;
       }

       // "Set the selection's value to value."
       setSelectionValue("backcolor", value);

       // "Return true."
       return true;
   }, standardInlineValueCommand: true, relevantCssProperty: "backgroundColor",
   equivalentValues: function(val1, val2) {
       // "Either both strings are valid CSS colors and have the same red,
       // green, blue, and alpha components, or neither string is a valid CSS
       // color."
       return normalizeColor(val1) === normalizeColor(val2);
   },
};

//@}
///// The bold command /////
//@{
commands.bold = {
   action: function() {
       // "If queryCommandState("bold") returns true, set the selection's
       // value to "normal". Otherwise set the selection's value to "bold".
       // Either way, return true."
       if (myQueryCommandState("bold")) {
           setSelectionValue("bold", "normal");
       } else {
           setSelectionValue("bold", "bold");
       }
       return true;
   }, inlineCommandActivatedValues: ["bold", "600", "700", "800", "900"],
   relevantCssProperty: "fontWeight",
   equivalentValues: function(val1, val2) {
       // "Either the two strings are equal, or one is "bold" and the other is
       // "700", or one is "normal" and the other is "400"."
       return val1 == val2
           || (val1 == "bold" && val2 == "700")
           || (val1 == "700" && val2 == "bold")
           || (val1 == "normal" && val2 == "400")
           || (val1 == "400" && val2 == "normal");
   },
};

//@}
///// The createLink command /////
//@{
commands.createlink = {
   action: function(value) {
       // "If value is the empty string, return false."
       if (value === "") {
           return false;
       }

       // "For each editable a element that has an href attribute and is an
       // ancestor of some node effectively contained in the active range, set
       // that a element's href attribute to value."
       //
       // TODO: We don't actually do this in tree order, not that it matters
       // unless you're spying with mutation events.
       getAllEffectivelyContainedNodes(getActiveRange()).forEach(function(node) {
           getAncestors(node).forEach(function(ancestor) {
               if (isEditable(ancestor)
               && isHtmlElement(ancestor, "a")
               && ancestor.hasAttribute("href")) {
                   ancestor.setAttribute("href", value);
               }
           });
       });

       // "Set the selection's value to value."
       setSelectionValue("createlink", value);

       // "Return true."
       return true;
   }
};

//@}
///// The fontName command /////
//@{
commands.fontname = {
   action: function(value) {
       // "Set the selection's value to value, then return true."
       setSelectionValue("fontname", value);
       return true;
   }, standardInlineValueCommand: true, relevantCssProperty: "fontFamily"
};

//@}
///// The fontSize command /////
//@{

// Helper function for fontSize's action plus queryOutputHelper.  It's just the
// middle of fontSize's action, ripped out into its own function.  Returns null
// if the size is invalid.
function normalizeFontSize(value) {
   // "Strip leading and trailing whitespace from value."
   //
   // Cheap hack, not following the actual algorithm.
   value = value.trim();

   // "If value is not a valid floating point number, and would not be a valid
   // floating point number if a single leading "+" character were stripped,
   // return false."
   if (!/^[-+]?[0-9]+(\.[0-9]+)?([eE][-+]?[0-9]+)?$/.test(value)) {
       return null;
   }

   var mode;

   // "If the first character of value is "+", delete the character and let
   // mode be "relative-plus"."
   if (value[0] == "+") {
       value = value.slice(1);
       mode = "relative-plus";
   // "Otherwise, if the first character of value is "-", delete the character
   // and let mode be "relative-minus"."
   } else if (value[0] == "-") {
       value = value.slice(1);
       mode = "relative-minus";
   // "Otherwise, let mode be "absolute"."
   } else {
       mode = "absolute";
   }

   // "Apply the rules for parsing non-negative integers to value, and let
   // number be the result."
   //
   // Another cheap hack.
   var num = parseInt(value);

   // "If mode is "relative-plus", add three to number."
   if (mode == "relative-plus") {
       num += 3;
   }

   // "If mode is "relative-minus", negate number, then add three to it."
   if (mode == "relative-minus") {
       num = 3 - num;
   }

   // "If number is less than one, let number equal 1."
   if (num < 1) {
       num = 1;
   }

   // "If number is greater than seven, let number equal 7."
   if (num > 7) {
       num = 7;
   }

   // "Set value to the string here corresponding to number:" [table omitted]
   value = {
       1: "x-small",
       2: "small",
       3: "medium",
       4: "large",
       5: "x-large",
       6: "xx-large",
       7: "xxx-large"
   }[num];

   return value;
}

commands.fontsize = {
   action: function(value) {
       value = normalizeFontSize(value);
       if (value === null) {
           return false;
       }

       // "Set the selection's value to value."
       setSelectionValue("fontsize", value);

       // "Return true."
       return true;
   }, indeterm: function() {
       // "True if among formattable nodes that are effectively contained in
       // the active range, there are two that have distinct effective command
       // values.  Otherwise false."
       return getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode)
       .map(function(node) {
           return getEffectiveCommandValue(node, "fontsize");
       }).filter(function(value, i, arr) {
           return arr.slice(0, i).indexOf(value) == -1;
       }).length >= 2;
   }, value: function() {
       // "If the active range is null, return the empty string."
       if (!getActiveRange()) {
           return "";
       }

       // "Let pixel size be the effective command value of the first
       // formattable node that is effectively contained in the active range,
       // or if there is no such node, the effective command value of the
       // active range's start node, in either case interpreted as a number of
       // pixels."
       var node = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode)[0];
       if (node === undefined) {
           node = getActiveRange().startContainer;
       }
       var pixelSize = getEffectiveCommandValue(node, "fontsize");

       // "Return the legacy font size for pixel size."
       return getLegacyFontSize(pixelSize);
   }, relevantCssProperty: "fontSize"
};

function getLegacyFontSize(size) {
   if (getLegacyFontSize.resultCache === undefined) {
       getLegacyFontSize.resultCache = {};
   }

   if (getLegacyFontSize.resultCache[size] !== undefined) {
       return getLegacyFontSize.resultCache[size];
   }

   // For convenience in other places in my code, I handle all sizes, not just
   // pixel sizes as the spec says.  This means pixel sizes have to be passed
   // in suffixed with "px", not as plain numbers.
   if (normalizeFontSize(size) !== null) {
       return getLegacyFontSize.resultCache[size] = cssSizeToLegacy(normalizeFontSize(size));
   }

   if (["x-small", "x-small", "small", "medium", "large", "x-large", "xx-large", "xxx-large"].indexOf(size) == -1
   && !/^[0-9]+(\.[0-9]+)?(cm|mm|in|pt|pc|px)$/.test(size)) {
       // There is no sensible legacy size for things like "2em".
       return getLegacyFontSize.resultCache[size] = null;
   }

   var font = document.createElement("font");
   document.body.appendChild(font);
   if (size == "xxx-large") {
       font.size = 7;
   } else {
       font.style.fontSize = size;
   }
   var pixelSize = parseInt(getComputedStyle(font).fontSize);
   document.body.removeChild(font);

   // "Let returned size be 1."
   var returnedSize = 1;

   // "While returned size is less than 7:"
   while (returnedSize < 7) {
       // "Let lower bound be the resolved value of "font-size" in pixels
       // of a font element whose size attribute is set to returned size."
       var font = document.createElement("font");
       font.size = returnedSize;
       document.body.appendChild(font);
       var lowerBound = parseInt(getComputedStyle(font).fontSize);

       // "Let upper bound be the resolved value of "font-size" in pixels
       // of a font element whose size attribute is set to one plus
       // returned size."
       font.size = 1 + returnedSize;
       var upperBound = parseInt(getComputedStyle(font).fontSize);
       document.body.removeChild(font);

       // "Let average be the average of upper bound and lower bound."
       var average = (upperBound + lowerBound)/2;

       // "If pixel size is less than average, return the one-element
       // string consisting of the digit returned size."
       if (pixelSize < average) {
           return getLegacyFontSize.resultCache[size] = String(returnedSize);
       }

       // "Add one to returned size."
       returnedSize++;
   }

   // "Return "7"."
   return getLegacyFontSize.resultCache[size] = "7";
}

//@}
///// The foreColor command /////
//@{
commands.forecolor = {
   action: function(value) {
       // Copy-pasted, same as backColor and hiliteColor

       // "If value is not a valid CSS color, prepend "#" to it."
       //
       // "If value is still not a valid CSS color, or if it is currentColor,
       // return false."
       //
       // Cheap hack for testing, no attempt to be comprehensive.
       if (/^([0-9a-fA-F]{3}){1,2}$/.test(value)) {
           value = "#" + value;
       }
       if (!/^(rgba?|hsla?)\(.*\)$/.test(value)
       && !parseSimpleColor(value)
       && value.toLowerCase() != "transparent") {
           return false;
       }

       // "Set the selection's value to value."
       setSelectionValue("forecolor", value);

       // "Return true."
       return true;
   }, standardInlineValueCommand: true, relevantCssProperty: "color",
   equivalentValues: function(val1, val2) {
       // "Either both strings are valid CSS colors and have the same red,
       // green, blue, and alpha components, or neither string is a valid CSS
       // color."
       return normalizeColor(val1) === normalizeColor(val2);
   },
};

//@}
///// The hiliteColor command /////
//@{
commands.hilitecolor = {
   // Copy-pasted, same as backColor
   action: function(value) {
       // Action is further copy-pasted, same as foreColor

       // "If value is not a valid CSS color, prepend "#" to it."
       //
       // "If value is still not a valid CSS color, or if it is currentColor,
       // return false."
       //
       // Cheap hack for testing, no attempt to be comprehensive.
       if (/^([0-9a-fA-F]{3}){1,2}$/.test(value)) {
           value = "#" + value;
       }
       if (!/^(rgba?|hsla?)\(.*\)$/.test(value)
       && !parseSimpleColor(value)
       && value.toLowerCase() != "transparent") {
           return false;
       }

       // "Set the selection's value to value."
       setSelectionValue("hilitecolor", value);

       // "Return true."
       return true;
   }, indeterm: function() {
       // "True if among editable Text nodes that are effectively contained in
       // the active range, there are two that have distinct effective command
       // values.  Otherwise false."
       return getAllEffectivelyContainedNodes(getActiveRange(), function(node) {
           return isEditable(node) && node.nodeType == Node.TEXT_NODE;
       }).map(function(node) {
           return getEffectiveCommandValue(node, "hilitecolor");
       }).filter(function(value, i, arr) {
           return arr.slice(0, i).indexOf(value) == -1;
       }).length >= 2;
   }, standardInlineValueCommand: true, relevantCssProperty: "backgroundColor",
   equivalentValues: function(val1, val2) {
       // "Either both strings are valid CSS colors and have the same red,
       // green, blue, and alpha components, or neither string is a valid CSS
       // color."
       return normalizeColor(val1) === normalizeColor(val2);
   },
};

//@}
///// The italic command /////
//@{
commands.italic = {
   action: function() {
       // "If queryCommandState("italic") returns true, set the selection's
       // value to "normal". Otherwise set the selection's value to "italic".
       // Either way, return true."
       if (myQueryCommandState("italic")) {
           setSelectionValue("italic", "normal");
       } else {
           setSelectionValue("italic", "italic");
       }
       return true;
   }, inlineCommandActivatedValues: ["italic", "oblique"],
   relevantCssProperty: "fontStyle"
};

//@}
///// The removeFormat command /////
//@{
commands.removeformat = {
   action: function() {
       // "A removeFormat candidate is an editable HTML element with local
       // name "abbr", "acronym", "b", "bdi", "bdo", "big", "blink", "cite",
       // "code", "dfn", "em", "font", "i", "ins", "kbd", "mark", "nobr", "q",
       // "s", "samp", "small", "span", "strike", "strong", "sub", "sup",
       // "tt", "u", or "var"."
       function isRemoveFormatCandidate(node) {
           return isEditable(node)
               && isHtmlElement(node, ["abbr", "acronym", "b", "bdi", "bdo",
               "big", "blink", "cite", "code", "dfn", "em", "font", "i",
               "ins", "kbd", "mark", "nobr", "q", "s", "samp", "small",
               "span", "strike", "strong", "sub", "sup", "tt", "u", "var"]);
       }

       // "Let elements to remove be a list of every removeFormat candidate
       // effectively contained in the active range."
       var elementsToRemove = getAllEffectivelyContainedNodes(getActiveRange(), isRemoveFormatCandidate);

       // "For each element in elements to remove:"
       elementsToRemove.forEach(function(element) {
           // "While element has children, insert the first child of element
           // into the parent of element immediately before element,
           // preserving ranges."
           while (element.hasChildNodes()) {
               movePreservingRanges(element.firstChild, element.parentNode, getNodeIndex(element));
           }

           // "Remove element from its parent."
           element.parentNode.removeChild(element);
       });

       // "If the active range's start node is an editable Text node, and its
       // start offset is neither zero nor its start node's length, call
       // splitText() on the active range's start node, with argument equal to
       // the active range's start offset. Then set the active range's start
       // node to the result, and its start offset to zero."
       if (isEditable(getActiveRange().startContainer)
       && getActiveRange().startContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().startOffset != 0
       && getActiveRange().startOffset != getNodeLength(getActiveRange().startContainer)) {
           // Account for browsers not following range mutation rules
           if (getActiveRange().startContainer == getActiveRange().endContainer) {
               var newEnd = getActiveRange().endOffset - getActiveRange().startOffset;
               var newNode = getActiveRange().startContainer.splitText(getActiveRange().startOffset);
               getActiveRange().setStart(newNode, 0);
               getActiveRange().setEnd(newNode, newEnd);
           } else {
               getActiveRange().setStart(getActiveRange().startContainer.splitText(getActiveRange().startOffset), 0);
           }
       }

       // "If the active range's end node is an editable Text node, and its
       // end offset is neither zero nor its end node's length, call
       // splitText() on the active range's end node, with argument equal to
       // the active range's end offset."
       if (isEditable(getActiveRange().endContainer)
       && getActiveRange().endContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().endOffset != 0
       && getActiveRange().endOffset != getNodeLength(getActiveRange().endContainer)) {
           // IE seems to mutate the range incorrectly here, so we need
           // correction here as well.  Have to be careful to set the range to
           // something not including the text node so that getActiveRange()
           // doesn't throw an exception due to a temporarily detached
           // endpoint.
           var newStart = [getActiveRange().startContainer, getActiveRange().startOffset];
           var newEnd = [getActiveRange().endContainer, getActiveRange().endOffset];
           getActiveRange().setEnd(document.documentElement, 0);
           newEnd[0].splitText(newEnd[1]);
           getActiveRange().setStart(newStart[0], newStart[1]);
           getActiveRange().setEnd(newEnd[0], newEnd[1]);
       }

       // "Let node list consist of all editable nodes effectively contained
       // in the active range."
       //
       // "For each node in node list, while node's parent is a removeFormat
       // candidate in the same editing host as node, split the parent of the
       // one-node list consisting of node."
       getAllEffectivelyContainedNodes(getActiveRange(), isEditable).forEach(function(node) {
           while (isRemoveFormatCandidate(node.parentNode)
           && inSameEditingHost(node.parentNode, node)) {
               splitParent([node]);
           }
       });

       // "For each of the entries in the following list, in the given order,
       // set the selection's value to null, with command as given."
       [
           "subscript",
           "bold",
           "fontname",
           "fontsize",
           "forecolor",
           "hilitecolor",
           "italic",
           "strikethrough",
           "underline",
       ].forEach(function(command) {
           setSelectionValue(command, null);
       });

       // "Return true."
       return true;
   }
};

//@}
///// The strikethrough command /////
//@{
commands.strikethrough = {
   action: function() {
       // "If queryCommandState("strikethrough") returns true, set the
       // selection's value to null. Otherwise set the selection's value to
       // "line-through".  Either way, return true."
       if (myQueryCommandState("strikethrough")) {
           setSelectionValue("strikethrough", null);
       } else {
           setSelectionValue("strikethrough", "line-through");
       }
       return true;
   }, inlineCommandActivatedValues: ["line-through"]
};

//@}
///// The subscript command /////
//@{
commands.subscript = {
   action: function() {
       // "Call queryCommandState("subscript"), and let state be the result."
       var state = myQueryCommandState("subscript");

       // "Set the selection's value to null."
       setSelectionValue("subscript", null);

       // "If state is false, set the selection's value to "subscript"."
       if (!state) {
           setSelectionValue("subscript", "subscript");
       }

       // "Return true."
       return true;
   }, indeterm: function() {
       // "True if either among formattable nodes that are effectively
       // contained in the active range, there is at least one with effective
       // command value "subscript" and at least one with some other effective
       // command value; or if there is some formattable node effectively
       // contained in the active range with effective command value "mixed".
       // Otherwise false."
       var nodes = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode);
       return (nodes.some(function(node) { return getEffectiveCommandValue(node, "subscript") == "subscript" })
           && nodes.some(function(node) { return getEffectiveCommandValue(node, "subscript") != "subscript" }))
           || nodes.some(function(node) { return getEffectiveCommandValue(node, "subscript") == "mixed" });
   }, inlineCommandActivatedValues: ["subscript"],
};

//@}
///// The superscript command /////
//@{
commands.superscript = {
   action: function() {
       // "Call queryCommandState("superscript"), and let state be the
       // result."
       var state = myQueryCommandState("superscript");

       // "Set the selection's value to null."
       setSelectionValue("superscript", null);

       // "If state is false, set the selection's value to "superscript"."
       if (!state) {
           setSelectionValue("superscript", "superscript");
       }

       // "Return true."
       return true;
   }, indeterm: function() {
       // "True if either among formattable nodes that are effectively
       // contained in the active range, there is at least one with effective
       // command value "superscript" and at least one with some other
       // effective command value; or if there is some formattable node
       // effectively contained in the active range with effective command
       // value "mixed".  Otherwise false."
       var nodes = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode);
       return (nodes.some(function(node) { return getEffectiveCommandValue(node, "superscript") == "superscript" })
           && nodes.some(function(node) { return getEffectiveCommandValue(node, "superscript") != "superscript" }))
           || nodes.some(function(node) { return getEffectiveCommandValue(node, "superscript") == "mixed" });
   }, inlineCommandActivatedValues: ["superscript"],
};

//@}
///// The underline command /////
//@{
commands.underline = {
   action: function() {
       // "If queryCommandState("underline") returns true, set the selection's
       // value to null. Otherwise set the selection's value to "underline".
       // Either way, return true."
       if (myQueryCommandState("underline")) {
           setSelectionValue("underline", null);
       } else {
           setSelectionValue("underline", "underline");
       }
       return true;
   }, inlineCommandActivatedValues: ["underline"]
};

//@}
///// The unlink command /////
//@{
commands.unlink = {
   action: function() {
       // "Let hyperlinks be a list of every a element that has an href
       // attribute and is contained in the active range or is an ancestor of
       // one of its boundary points."
       //
       // As usual, take care to ensure it's tree order.  The correctness of
       // the following is left as an exercise for the reader.
       var range = getActiveRange();
       var hyperlinks = [];
       for (
           var node = range.startContainer;
           node;
           node = node.parentNode
       ) {
           if (isHtmlElement(node, "A")
           && node.hasAttribute("href")) {
               hyperlinks.unshift(node);
           }
       }
       for (
           var node = range.startContainer;
           node != nextNodeDescendants(range.endContainer);
           node = nextNode(node)
       ) {
           if (isHtmlElement(node, "A")
           && node.hasAttribute("href")
           && (isContained(node, range)
           || isAncestor(node, range.endContainer)
           || node == range.endContainer)) {
               hyperlinks.push(node);
           }
       }

       // "Clear the value of each member of hyperlinks."
       for (var i = 0; i < hyperlinks.length; i++) {
           clearValue(hyperlinks[i], "unlink");
       }

       // "Return true."
       return true;
   }
};

//@}

/////////////////////////////////////
///// Block formatting commands /////
/////////////////////////////////////

///// Block formatting command definitions /////
//@{

// "An indentation element is either a blockquote, or a div that has a style
// attribute that sets "margin" or some subproperty of it."
function isIndentationElement(node) {
   if (!isHtmlElement(node)) {
       return false;
   }

   if (node.tagName == "BLOCKQUOTE") {
       return true;
   }

   if (node.tagName != "DIV") {
       return false;
   }

   for (var i = 0; i < node.style.length; i++) {
       // Approximate check
       if (/^(-[a-z]+-)?margin/.test(node.style[i])) {
           return true;
       }
   }

   return false;
}

// "A simple indentation element is an indentation element that has no
// attributes except possibly
//
//   * "a style attribute that sets no properties other than "margin",
//     "border", "padding", or subproperties of those; and/or
//   * "a dir attribute."
function isSimpleIndentationElement(node) {
   if (!isIndentationElement(node)) {
       return false;
   }

   for (var i = 0; i < node.attributes.length; i++) {
       if (!isHtmlNamespace(node.attributes[i].namespaceURI)
       || ["style", "dir"].indexOf(node.attributes[i].name) == -1) {
           return false;
       }
   }

   for (var i = 0; i < node.style.length; i++) {
       // This is approximate, but it works well enough for my purposes.
       if (!/^(-[a-z]+-)?(margin|border|padding)/.test(node.style[i])) {
           return false;
       }
   }

   return true;
}

// "A non-list single-line container is an HTML element with local name
// "address", "div", "h1", "h2", "h3", "h4", "h5", "h6", "listing", "p", "pre",
// or "xmp"."
function isNonListSingleLineContainer(node) {
   return isHtmlElement(node, ["address", "div", "h1", "h2", "h3", "h4", "h5",
       "h6", "listing", "p", "pre", "xmp"]);
}

// "A single-line container is either a non-list single-line container, or an
// HTML element with local name "li", "dt", or "dd"."
function isSingleLineContainer(node) {
   return isNonListSingleLineContainer(node)
       || isHtmlElement(node, ["li", "dt", "dd"]);
}

function getBlockNodeOf(node) {
   // "While node is an inline node, set node to its parent."
   while (isInlineNode(node)) {
       node = node.parentNode;
   }

   // "Return node."
   return node;
}

//@}
///// Assorted block formatting command algorithms /////
//@{

function fixDisallowedAncestors(node) {
   // "If node is not editable, abort these steps."
   if (!isEditable(node)) {
       return;
   }

   // "If node is not an allowed child of any of its ancestors in the same
   // editing host:"
   if (getAncestors(node).every(function(ancestor) {
       return !inSameEditingHost(node, ancestor)
           || !isAllowedChild(node, ancestor)
   })) {
       // "If node is a dd or dt, wrap the one-node list consisting of node,
       // with sibling criteria returning true for any dl with no attributes
       // and false otherwise, and new parent instructions returning the
       // result of calling createElement("dl") on the context object. Then
       // abort these steps."
       if (isHtmlElement(node, ["dd", "dt"])) {
           wrap([node],
               function(sibling) { return isHtmlElement(sibling, "dl") && !sibling.attributes.length },
               function() { return document.createElement("dl") });
           return;
       }

       // "If "p" is not an allowed child of the editing host of node, abort
       // these steps."
       if (!isAllowedChild("p", getEditingHostOf(node))) {
           return;
       }

       // "If node is not a prohibited paragraph child, abort these steps."
       if (!isProhibitedParagraphChild(node)) {
           return;
       }

       // "Set the tag name of node to the default single-line container name,
       // and let node be the result."
       node = setTagName(node, defaultSingleLineContainerName);

       // "Fix disallowed ancestors of node."
       fixDisallowedAncestors(node);

       // "Let children be node's children."
       var children = [].slice.call(node.childNodes);

       // "For each child in children, if child is a prohibited paragraph
       // child:"
       children.filter(isProhibitedParagraphChild)
       .forEach(function(child) {
           // "Record the values of the one-node list consisting of child, and
           // let values be the result."
           var values = recordValues([child]);

           // "Split the parent of the one-node list consisting of child."
           splitParent([child]);

           // "Restore the values from values."
           restoreValues(values);
       });

       // "Abort these steps."
       return;
   }

   // "Record the values of the one-node list consisting of node, and let
   // values be the result."
   var values = recordValues([node]);

   // "While node is not an allowed child of its parent, split the parent of
   // the one-node list consisting of node."
   while (!isAllowedChild(node, node.parentNode)) {
       splitParent([node]);
   }

   // "Restore the values from values."
   restoreValues(values);
}

function normalizeSublists(item) {
   // "If item is not an li or it is not editable or its parent is not
   // editable, abort these steps."
   if (!isHtmlElement(item, "LI")
   || !isEditable(item)
   || !isEditable(item.parentNode)) {
       return;
   }

   // "Let new item be null."
   var newItem = null;

   // "While item has an ol or ul child:"
   while ([].some.call(item.childNodes, function (node) { return isHtmlElement(node, ["OL", "UL"]) })) {
       // "Let child be the last child of item."
       var child = item.lastChild;

       // "If child is an ol or ul, or new item is null and child is a Text
       // node whose data consists of zero of more space characters:"
       if (isHtmlElement(child, ["OL", "UL"])
       || (!newItem && child.nodeType == Node.TEXT_NODE && /^[ \t\n\f\r]*$/.test(child.data))) {
           // "Set new item to null."
           newItem = null;

           // "Insert child into the parent of item immediately following
           // item, preserving ranges."
           movePreservingRanges(child, item.parentNode, 1 + getNodeIndex(item));

       // "Otherwise:"
       } else {
           // "If new item is null, let new item be the result of calling
           // createElement("li") on the ownerDocument of item, then insert
           // new item into the parent of item immediately after item."
           if (!newItem) {
               newItem = item.ownerDocument.createElement("li");
               item.parentNode.insertBefore(newItem, item.nextSibling);
           }

           // "Insert child into new item as its first child, preserving
           // ranges."
           movePreservingRanges(child, newItem, 0);
       }
   }
}

function getSelectionListState() {
   // "If the active range is null, return "none"."
   if (!getActiveRange()) {
       return "none";
   }

   // "Block-extend the active range, and let new range be the result."
   var newRange = blockExtend(getActiveRange());

   // "Let node list be a list of nodes, initially empty."
   //
   // "For each node contained in new range, append node to node list if the
   // last member of node list (if any) is not an ancestor of node; node is
   // editable; node is not an indentation element; and node is either an ol
   // or ul, or the child of an ol or ul, or an allowed child of "li"."
   var nodeList = getContainedNodes(newRange, function(node) {
       return isEditable(node)
           && !isIndentationElement(node)
           && (isHtmlElement(node, ["ol", "ul"])
           || isHtmlElement(node.parentNode, ["ol", "ul"])
           || isAllowedChild(node, "li"));
   });

   // "If node list is empty, return "none"."
   if (!nodeList.length) {
       return "none";
   }

   // "If every member of node list is either an ol or the child of an ol or
   // the child of an li child of an ol, and none is a ul or an ancestor of a
   // ul, return "ol"."
   if (nodeList.every(function(node) {
       return isHtmlElement(node, "ol")
           || isHtmlElement(node.parentNode, "ol")
           || (isHtmlElement(node.parentNode, "li") && isHtmlElement(node.parentNode.parentNode, "ol"));
   })
   && !nodeList.some(function(node) { return isHtmlElement(node, "ul") || ("querySelector" in node && node.querySelector("ul")) })) {
       return "ol";
   }

   // "If every member of node list is either a ul or the child of a ul or the
   // child of an li child of a ul, and none is an ol or an ancestor of an ol,
   // return "ul"."
   if (nodeList.every(function(node) {
       return isHtmlElement(node, "ul")
           || isHtmlElement(node.parentNode, "ul")
           || (isHtmlElement(node.parentNode, "li") && isHtmlElement(node.parentNode.parentNode, "ul"));
   })
   && !nodeList.some(function(node) { return isHtmlElement(node, "ol") || ("querySelector" in node && node.querySelector("ol")) })) {
       return "ul";
   }

   var hasOl = nodeList.some(function(node) {
       return isHtmlElement(node, "ol")
           || isHtmlElement(node.parentNode, "ol")
           || ("querySelector" in node && node.querySelector("ol"))
           || (isHtmlElement(node.parentNode, "li") && isHtmlElement(node.parentNode.parentNode, "ol"));
   });
   var hasUl = nodeList.some(function(node) {
       return isHtmlElement(node, "ul")
           || isHtmlElement(node.parentNode, "ul")
           || ("querySelector" in node && node.querySelector("ul"))
           || (isHtmlElement(node.parentNode, "li") && isHtmlElement(node.parentNode.parentNode, "ul"));
   });
   // "If some member of node list is either an ol or the child or ancestor of
   // an ol or the child of an li child of an ol, and some member of node list
   // is either a ul or the child or ancestor of a ul or the child of an li
   // child of a ul, return "mixed"."
   if (hasOl && hasUl) {
       return "mixed";
   }

   // "If some member of node list is either an ol or the child or ancestor of
   // an ol or the child of an li child of an ol, return "mixed ol"."
   if (hasOl) {
       return "mixed ol";
   }

   // "If some member of node list is either a ul or the child or ancestor of
   // a ul or the child of an li child of a ul, return "mixed ul"."
   if (hasUl) {
       return "mixed ul";
   }

   // "Return "none"."
   return "none";
}

function getAlignmentValue(node) {
   // "While node is neither null nor an Element, or it is an Element but its
   // "display" property has resolved value "inline" or "none", set node to
   // its parent."
   while ((node && node.nodeType != Node.ELEMENT_NODE)
   || (node.nodeType == Node.ELEMENT_NODE
   && ["inline", "none"].indexOf(getComputedStyle(node).display) != -1)) {
       node = node.parentNode;
   }

   // "If node is not an Element, return "left"."
   if (!node || node.nodeType != Node.ELEMENT_NODE) {
       return "left";
   }

   var resolvedValue = getComputedStyle(node).textAlign
       // Hack around browser non-standardness
       .replace(/^-(moz|webkit)-/, "")
       .replace(/^auto$/, "start");

   // "If node's "text-align" property has resolved value "start", return
   // "left" if the directionality of node is "ltr", "right" if it is "rtl"."
   if (resolvedValue == "start") {
       return getDirectionality(node) == "ltr" ? "left" : "right";
   }

   // "If node's "text-align" property has resolved value "end", return
   // "right" if the directionality of node is "ltr", "left" if it is "rtl"."
   if (resolvedValue == "end") {
       return getDirectionality(node) == "ltr" ? "right" : "left";
   }

   // "If node's "text-align" property has resolved value "center", "justify",
   // "left", or "right", return that value."
   if (["center", "justify", "left", "right"].indexOf(resolvedValue) != -1) {
       return resolvedValue;
   }

   // "Return "left"."
   return "left";
}

function getNextEquivalentPoint(node, offset) {
   // "If node's length is zero, return null."
   if (getNodeLength(node) == 0) {
       return null;
   }

   // "If offset is node's length, and node's parent is not null, and node is
   // an inline node, return (node's parent, 1 + node's index)."
   if (offset == getNodeLength(node)
   && node.parentNode
   && isInlineNode(node)) {
       return [node.parentNode, 1 + getNodeIndex(node)];
   }

   // "If node has a child with index offset, and that child's length is not
   // zero, and that child is an inline node, return (that child, 0)."
   if (0 <= offset
   && offset < node.childNodes.length
   && getNodeLength(node.childNodes[offset]) != 0
   && isInlineNode(node.childNodes[offset])) {
       return [node.childNodes[offset], 0];
   }

   // "Return null."
   return null;
}

function getPreviousEquivalentPoint(node, offset) {
   // "If node's length is zero, return null."
   if (getNodeLength(node) == 0) {
       return null;
   }

   // "If offset is 0, and node's parent is not null, and node is an inline
   // node, return (node's parent, node's index)."
   if (offset == 0
   && node.parentNode
   && isInlineNode(node)) {
       return [node.parentNode, getNodeIndex(node)];
   }

   // "If node has a child with index offset − 1, and that child's length is
   // not zero, and that child is an inline node, return (that child, that
   // child's length)."
   if (0 <= offset - 1
   && offset - 1 < node.childNodes.length
   && getNodeLength(node.childNodes[offset - 1]) != 0
   && isInlineNode(node.childNodes[offset - 1])) {
       return [node.childNodes[offset - 1], getNodeLength(node.childNodes[offset - 1])];
   }

   // "Return null."
   return null;
}

function getFirstEquivalentPoint(node, offset) {
   // "While (node, offset)'s previous equivalent point is not null, set
   // (node, offset) to its previous equivalent point."
   var prev;
   while (prev = getPreviousEquivalentPoint(node, offset)) {
       node = prev[0];
       offset = prev[1];
   }

   // "Return (node, offset)."
   return [node, offset];
}

function getLastEquivalentPoint(node, offset) {
   // "While (node, offset)'s next equivalent point is not null, set (node,
   // offset) to its next equivalent point."
   var next;
   while (next = getNextEquivalentPoint(node, offset)) {
       node = next[0];
       offset = next[1];
   }

   // "Return (node, offset)."
   return [node, offset];
}

//@}
///// Block-extending a range /////
//@{

// "A boundary point (node, offset) is a block start point if either node's
// parent is null and offset is zero; or node has a child with index offset −
// 1, and that child is either a visible block node or a visible br."
function isBlockStartPoint(node, offset) {
   return (!node.parentNode && offset == 0)
       || (0 <= offset - 1
       && offset - 1 < node.childNodes.length
       && isVisible(node.childNodes[offset - 1])
       && (isBlockNode(node.childNodes[offset - 1])
       || isHtmlElement(node.childNodes[offset - 1], "br")));
}

// "A boundary point (node, offset) is a block end point if either node's
// parent is null and offset is node's length; or node has a child with index
// offset, and that child is a visible block node."
function isBlockEndPoint(node, offset) {
   return (!node.parentNode && offset == getNodeLength(node))
       || (offset < node.childNodes.length
       && isVisible(node.childNodes[offset])
       && isBlockNode(node.childNodes[offset]));
}

// "A boundary point is a block boundary point if it is either a block start
// point or a block end point."
function isBlockBoundaryPoint(node, offset) {
   return isBlockStartPoint(node, offset)
       || isBlockEndPoint(node, offset);
}

function blockExtend(range) {
   // "Let start node, start offset, end node, and end offset be the start
   // and end nodes and offsets of the range."
   var startNode = range.startContainer;
   var startOffset = range.startOffset;
   var endNode = range.endContainer;
   var endOffset = range.endOffset;

   // "If some ancestor container of start node is an li, set start offset to
   // the index of the last such li in tree order, and set start node to that
   // li's parent."
   var liAncestors = getAncestors(startNode).concat(startNode)
       .filter(function(ancestor) { return isHtmlElement(ancestor, "li") })
       .slice(-1);
   if (liAncestors.length) {
       startOffset = getNodeIndex(liAncestors[0]);
       startNode = liAncestors[0].parentNode;
   }

   // "If (start node, start offset) is not a block start point, repeat the
   // following steps:"
   if (!isBlockStartPoint(startNode, startOffset)) do {
       // "If start offset is zero, set it to start node's index, then set
       // start node to its parent."
       if (startOffset == 0) {
           startOffset = getNodeIndex(startNode);
           startNode = startNode.parentNode;

       // "Otherwise, subtract one from start offset."
       } else {
           startOffset--;
       }

       // "If (start node, start offset) is a block boundary point, break from
       // this loop."
   } while (!isBlockBoundaryPoint(startNode, startOffset));

   // "While start offset is zero and start node's parent is not null, set
   // start offset to start node's index, then set start node to its parent."
   while (startOffset == 0
   && startNode.parentNode) {
       startOffset = getNodeIndex(startNode);
       startNode = startNode.parentNode;
   }

   // "If some ancestor container of end node is an li, set end offset to one
   // plus the index of the last such li in tree order, and set end node to
   // that li's parent."
   var liAncestors = getAncestors(endNode).concat(endNode)
       .filter(function(ancestor) { return isHtmlElement(ancestor, "li") })
       .slice(-1);
   if (liAncestors.length) {
       endOffset = 1 + getNodeIndex(liAncestors[0]);
       endNode = liAncestors[0].parentNode;
   }

   // "If (end node, end offset) is not a block end point, repeat the
   // following steps:"
   if (!isBlockEndPoint(endNode, endOffset)) do {
       // "If end offset is end node's length, set it to one plus end node's
       // index, then set end node to its parent."
       if (endOffset == getNodeLength(endNode)) {
           endOffset = 1 + getNodeIndex(endNode);
           endNode = endNode.parentNode;

       // "Otherwise, add one to end offset.
       } else {
           endOffset++;
       }

       // "If (end node, end offset) is a block boundary point, break from
       // this loop."
   } while (!isBlockBoundaryPoint(endNode, endOffset));

   // "While end offset is end node's length and end node's parent is not
   // null, set end offset to one plus end node's index, then set end node to
   // its parent."
   while (endOffset == getNodeLength(endNode)
   && endNode.parentNode) {
       endOffset = 1 + getNodeIndex(endNode);
       endNode = endNode.parentNode;
   }

   // "Let new range be a new range whose start and end nodes and offsets
   // are start node, start offset, end node, and end offset."
   var newRange = startNode.ownerDocument.createRange();
   newRange.setStart(startNode, startOffset);
   newRange.setEnd(endNode, endOffset);

   // "Return new range."
   return newRange;
}

function followsLineBreak(node) {
   // "Let offset be zero."
   var offset = 0;

   // "While (node, offset) is not a block boundary point:"
   while (!isBlockBoundaryPoint(node, offset)) {
       // "If node has a visible child with index offset minus one, return
       // false."
       if (0 <= offset - 1
       && offset - 1 < node.childNodes.length
       && isVisible(node.childNodes[offset - 1])) {
           return false;
       }

       // "If offset is zero or node has no children, set offset to node's
       // index, then set node to its parent."
       if (offset == 0
       || !node.hasChildNodes()) {
           offset = getNodeIndex(node);
           node = node.parentNode;

       // "Otherwise, set node to its child with index offset minus one, then
       // set offset to node's length."
       } else {
           node = node.childNodes[offset - 1];
           offset = getNodeLength(node);
       }
   }

   // "Return true."
   return true;
}

function precedesLineBreak(node) {
   // "Let offset be node's length."
   var offset = getNodeLength(node);

   // "While (node, offset) is not a block boundary point:"
   while (!isBlockBoundaryPoint(node, offset)) {
       // "If node has a visible child with index offset, return false."
       if (offset < node.childNodes.length
       && isVisible(node.childNodes[offset])) {
           return false;
       }

       // "If offset is node's length or node has no children, set offset to
       // one plus node's index, then set node to its parent."
       if (offset == getNodeLength(node)
       || !node.hasChildNodes()) {
           offset = 1 + getNodeIndex(node);
           node = node.parentNode;

       // "Otherwise, set node to its child with index offset and set offset
       // to zero."
       } else {
           node = node.childNodes[offset];
           offset = 0;
       }
   }

   // "Return true."
   return true;
}

//@}
///// Recording and restoring overrides /////
//@{

function recordCurrentOverrides() {
   // "Let overrides be a list of (string, string or boolean) ordered pairs,
   // initially empty."
   var overrides = [];

   // "If there is a value override for "createLink", add ("createLink", value
   // override for "createLink") to overrides."
   if (getValueOverride("createlink") !== undefined) {
       overrides.push(["createlink", getValueOverride("createlink")]);
   }

   // "For each command in the list "bold", "italic", "strikethrough",
   // "subscript", "superscript", "underline", in order: if there is a state
   // override for command, add (command, command's state override) to
   // overrides."
   ["bold", "italic", "strikethrough", "subscript", "superscript",
   "underline"].forEach(function(command) {
       if (getStateOverride(command) !== undefined) {
           overrides.push([command, getStateOverride(command)]);
       }
   });

   // "For each command in the list "fontName", "fontSize", "foreColor",
   // "hiliteColor", in order: if there is a value override for command, add
   // (command, command's value override) to overrides."
   ["fontname", "fontsize", "forecolor",
   "hilitecolor"].forEach(function(command) {
       if (getValueOverride(command) !== undefined) {
           overrides.push([command, getValueOverride(command)]);
       }
   });

   // "Return overrides."
   return overrides;
}

function recordCurrentStatesAndValues() {
   // "Let overrides be a list of (string, string or boolean) ordered pairs,
   // initially empty."
   var overrides = [];

   // "Let node be the first formattable node effectively contained in the
   // active range, or null if there is none."
   var node = getAllEffectivelyContainedNodes(getActiveRange())
       .filter(isFormattableNode)[0];

   // "If node is null, return overrides."
   if (!node) {
       return overrides;
   }

   // "Add ("createLink", node's effective command value for "createLink") to
   // overrides."
   overrides.push(["createlink", getEffectiveCommandValue(node, "createlink")]);

   // "For each command in the list "bold", "italic", "strikethrough",
   // "subscript", "superscript", "underline", in order: if node's effective
   // command value for command is one of its inline command activated values,
   // add (command, true) to overrides, and otherwise add (command, false) to
   // overrides."
   ["bold", "italic", "strikethrough", "subscript", "superscript",
   "underline"].forEach(function(command) {
       if (commands[command].inlineCommandActivatedValues
       .indexOf(getEffectiveCommandValue(node, command)) != -1) {
           overrides.push([command, true]);
       } else {
           overrides.push([command, false]);
       }
   });

   // "For each command in the list "fontName", "foreColor", "hiliteColor", in
   // order: add (command, command's value) to overrides."
   ["fontname", "fontsize", "forecolor", "hilitecolor"].forEach(function(command) {
       overrides.push([command, commands[command].value()]);
   });

   // "Add ("fontSize", node's effective command value for "fontSize") to
   // overrides."
   overrides.push(["fontsize", getEffectiveCommandValue(node, "fontsize")]);

   // "Return overrides."
   return overrides;
}

function restoreStatesAndValues(overrides) {
   // "Let node be the first formattable node effectively contained in the
   // active range, or null if there is none."
   var node = getAllEffectivelyContainedNodes(getActiveRange())
       .filter(isFormattableNode)[0];

   // "If node is not null, then for each (command, override) pair in
   // overrides, in order:"
   if (node) {
       for (var i = 0; i < overrides.length; i++) {
           var command = overrides[i][0];
           var override = overrides[i][1];

           // "If override is a boolean, and queryCommandState(command)
           // returns something different from override, take the action for
           // command, with value equal to the empty string."
           if (typeof override == "boolean"
           && myQueryCommandState(command) != override) {
               commands[command].action("");

           // "Otherwise, if override is a string, and command is neither
           // "createLink" nor "fontSize", and queryCommandValue(command)
           // returns something not equivalent to override, take the action
           // for command, with value equal to override."
           } else if (typeof override == "string"
           && command != "createlink"
           && command != "fontsize"
           && !areEquivalentValues(command, myQueryCommandValue(command), override)) {
               commands[command].action(override);

           // "Otherwise, if override is a string; and command is
           // "createLink"; and either there is a value override for
           // "createLink" that is not equal to override, or there is no value
           // override for "createLink" and node's effective command value for
           // "createLink" is not equal to override: take the action for
           // "createLink", with value equal to override."
           } else if (typeof override == "string"
           && command == "createlink"
           && (
               (
                   getValueOverride("createlink") !== undefined
                   && getValueOverride("createlink") !== override
               ) || (
                   getValueOverride("createlink") === undefined
                   && getEffectiveCommandValue(node, "createlink") !== override
               )
           )) {
               commands.createlink.action(override);

           // "Otherwise, if override is a string; and command is "fontSize";
           // and either there is a value override for "fontSize" that is not
           // equal to override, or there is no value override for "fontSize"
           // and node's effective command value for "fontSize" is not loosely
           // equivalent to override:"
           } else if (typeof override == "string"
           && command == "fontsize"
           && (
               (
                   getValueOverride("fontsize") !== undefined
                   && getValueOverride("fontsize") !== override
               ) || (
                   getValueOverride("fontsize") === undefined
                   && !areLooselyEquivalentValues(command, getEffectiveCommandValue(node, "fontsize"), override)
               )
           )) {
               // "Convert override to an integer number of pixels, and set
               // override to the legacy font size for the result."
               override = getLegacyFontSize(override);

               // "Take the action for "fontSize", with value equal to
               // override."
               commands.fontsize.action(override);

           // "Otherwise, continue this loop from the beginning."
           } else {
               continue;
           }

           // "Set node to the first formattable node effectively contained in
           // the active range, if there is one."
           node = getAllEffectivelyContainedNodes(getActiveRange())
               .filter(isFormattableNode)[0]
               || node;
       }

   // "Otherwise, for each (command, override) pair in overrides, in order:"
   } else {
       for (var i = 0; i < overrides.length; i++) {
           var command = overrides[i][0];
           var override = overrides[i][1];

           // "If override is a boolean, set the state override for command to
           // override."
           if (typeof override == "boolean") {
               setStateOverride(command, override);
           }

           // "If override is a string, set the value override for command to
           // override."
           if (typeof override == "string") {
               setValueOverride(command, override);
           }
       }
   }
}

//@}
///// Deleting the selection /////
//@{

// The flags argument is a dictionary that can have blockMerging,
// stripWrappers, and/or direction as keys.
function deleteSelection(flags) {
   if (flags === undefined) {
       flags = {};
   }

   var blockMerging = "blockMerging" in flags ? Boolean(flags.blockMerging) : true;
   var stripWrappers = "stripWrappers" in flags ? Boolean(flags.stripWrappers) : true;
   var direction = "direction" in flags ? flags.direction : "forward";

   // "If the active range is null, abort these steps and do nothing."
   if (!getActiveRange()) {
       return;
   }

   // "Canonicalize whitespace at the active range's start."
   canonicalizeWhitespace(getActiveRange().startContainer, getActiveRange().startOffset);

   // "Canonicalize whitespace at the active range's end."
   canonicalizeWhitespace(getActiveRange().endContainer, getActiveRange().endOffset);

   // "Let (start node, start offset) be the last equivalent point for the
   // active range's start."
   var start = getLastEquivalentPoint(getActiveRange().startContainer, getActiveRange().startOffset);
   var startNode = start[0];
   var startOffset = start[1];

   // "Let (end node, end offset) be the first equivalent point for the active
   // range's end."
   var end = getFirstEquivalentPoint(getActiveRange().endContainer, getActiveRange().endOffset);
   var endNode = end[0];
   var endOffset = end[1];

   // "If (end node, end offset) is not after (start node, start offset):"
   if (getPosition(endNode, endOffset, startNode, startOffset) !== "after") {
       // "If direction is "forward", call collapseToStart() on the context
       // object's Selection."
       //
       // Here and in a few other places, we check rangeCount to work around a
       // WebKit bug: it will sometimes incorrectly remove ranges from the
       // selection if nodes are removed, so collapseToStart() will throw.
       // This will break everything if we're using an actual selection, but
       // if getActiveRange() is really just returning globalRange and that's
       // all we care about, it will work fine.  I only add the extra check
       // for errors I actually hit in testing.
       if (direction == "forward") {
           if (getSelection().rangeCount) {
               getSelection().collapseToStart();
           }
           getActiveRange().collapse(true);

       // "Otherwise, call collapseToEnd() on the context object's Selection."
       } else {
           getSelection().collapseToEnd();
           getActiveRange().collapse(false);
       }

       // "Abort these steps."
       return;
   }

   // "If start node is a Text node and start offset is 0, set start offset to
   // the index of start node, then set start node to its parent."
   if (startNode.nodeType == Node.TEXT_NODE
   && startOffset == 0) {
       startOffset = getNodeIndex(startNode);
       startNode = startNode.parentNode;
   }

   // "If end node is a Text node and end offset is its length, set end offset
   // to one plus the index of end node, then set end node to its parent."
   if (endNode.nodeType == Node.TEXT_NODE
   && endOffset == getNodeLength(endNode)) {
       endOffset = 1 + getNodeIndex(endNode);
       endNode = endNode.parentNode;
   }

   // "Call collapse(start node, start offset) on the context object's
   // Selection."
   getSelection().collapse(startNode, startOffset);
   getActiveRange().setStart(startNode, startOffset);

   // "Call extend(end node, end offset) on the context object's Selection."
   getSelection().extend(endNode, endOffset);
   getActiveRange().setEnd(endNode, endOffset);

   // "Let start block be the active range's start node."
   var startBlock = getActiveRange().startContainer;

   // "While start block's parent is in the same editing host and start block
   // is an inline node, set start block to its parent."
   while (inSameEditingHost(startBlock, startBlock.parentNode)
   && isInlineNode(startBlock)) {
       startBlock = startBlock.parentNode;
   }

   // "If start block is neither a block node nor an editing host, or "span"
   // is not an allowed child of start block, or start block is a td or th,
   // set start block to null."
   if ((!isBlockNode(startBlock) && !isEditingHost(startBlock))
   || !isAllowedChild("span", startBlock)
   || isHtmlElement(startBlock, ["td", "th"])) {
       startBlock = null;
   }

   // "Let end block be the active range's end node."
   var endBlock = getActiveRange().endContainer;

   // "While end block's parent is in the same editing host and end block is
   // an inline node, set end block to its parent."
   while (inSameEditingHost(endBlock, endBlock.parentNode)
   && isInlineNode(endBlock)) {
       endBlock = endBlock.parentNode;
   }

   // "If end block is neither a block node nor an editing host, or "span" is
   // not an allowed child of end block, or end block is a td or th, set end
   // block to null."
   if ((!isBlockNode(endBlock) && !isEditingHost(endBlock))
   || !isAllowedChild("span", endBlock)
   || isHtmlElement(endBlock, ["td", "th"])) {
       endBlock = null;
   }

   // "Record current states and values, and let overrides be the result."
   var overrides = recordCurrentStatesAndValues();

   // "If start node and end node are the same, and start node is an editable
   // Text node:"
   if (startNode == endNode
   && isEditable(startNode)
   && startNode.nodeType == Node.TEXT_NODE) {
       // "Call deleteData(start offset, end offset − start offset) on start
       // node."
       startNode.deleteData(startOffset, endOffset - startOffset);

       // "Canonicalize whitespace at (start node, start offset), with fix
       // collapsed space false."
       canonicalizeWhitespace(startNode, startOffset, false);

       // "If direction is "forward", call collapseToStart() on the context
       // object's Selection."
       if (direction == "forward") {
           if (getSelection().rangeCount) {
               getSelection().collapseToStart();
           }
           getActiveRange().collapse(true);

       // "Otherwise, call collapseToEnd() on the context object's Selection."
       } else {
           getSelection().collapseToEnd();
           getActiveRange().collapse(false);
       }

       // "Restore states and values from overrides."
       restoreStatesAndValues(overrides);

       // "Abort these steps."
       return;
   }

   // "If start node is an editable Text node, call deleteData() on it, with
   // start offset as the first argument and (length of start node − start
   // offset) as the second argument."
   if (isEditable(startNode)
   && startNode.nodeType == Node.TEXT_NODE) {
       startNode.deleteData(startOffset, getNodeLength(startNode) - startOffset);
   }

   // "Let node list be a list of nodes, initially empty."
   //
   // "For each node contained in the active range, append node to node list
   // if the last member of node list (if any) is not an ancestor of node;
   // node is editable; and node is not a thead, tbody, tfoot, tr, th, or td."
   var nodeList = getContainedNodes(getActiveRange(),
       function(node) {
           return isEditable(node)
               && !isHtmlElement(node, ["thead", "tbody", "tfoot", "tr", "th", "td"]);
       }
   );

   // "For each node in node list:"
   for (var i = 0; i < nodeList.length; i++) {
       var node = nodeList[i];

       // "Let parent be the parent of node."
       var parent_ = node.parentNode;

       // "Remove node from parent."
       parent_.removeChild(node);

       // "If the block node of parent has no visible children, and parent is
       // editable or an editing host, call createElement("br") on the context
       // object and append the result as the last child of parent."
       if (![].some.call(getBlockNodeOf(parent_).childNodes, isVisible)
       && (isEditable(parent_) || isEditingHost(parent_))) {
           parent_.appendChild(document.createElement("br"));
       }

       // "If strip wrappers is true or parent is not an ancestor container of
       // start node, while parent is an editable inline node with length 0,
       // let grandparent be the parent of parent, then remove parent from
       // grandparent, then set parent to grandparent."
       if (stripWrappers
       || (!isAncestor(parent_, startNode) && parent_ != startNode)) {
           while (isEditable(parent_)
           && isInlineNode(parent_)
           && getNodeLength(parent_) == 0) {
               var grandparent = parent_.parentNode;
               grandparent.removeChild(parent_);
               parent_ = grandparent;
           }
       }
   }

   // "If end node is an editable Text node, call deleteData(0, end offset) on
   // it."
   if (isEditable(endNode)
   && endNode.nodeType == Node.TEXT_NODE) {
       endNode.deleteData(0, endOffset);
   }

   // "Canonicalize whitespace at the active range's start, with fix collapsed
   // space false."
   canonicalizeWhitespace(getActiveRange().startContainer, getActiveRange().startOffset, false);

   // "Canonicalize whitespace at the active range's end, with fix collapsed
   // space false."
   canonicalizeWhitespace(getActiveRange().endContainer, getActiveRange().endOffset, false);

   // "If block merging is false, or start block or end block is null, or
   // start block is not in the same editing host as end block, or start block
   // and end block are the same:"
   if (!blockMerging
   || !startBlock
   || !endBlock
   || !inSameEditingHost(startBlock, endBlock)
   || startBlock == endBlock) {
       // "If direction is "forward", call collapseToStart() on the context
       // object's Selection."
       if (direction == "forward") {
           if (getSelection().rangeCount) {
               getSelection().collapseToStart();
           }
           getActiveRange().collapse(true);

       // "Otherwise, call collapseToEnd() on the context object's Selection."
       } else {
           if (getSelection().rangeCount) {
               getSelection().collapseToEnd();
           }
           getActiveRange().collapse(false);
       }

       // "Restore states and values from overrides."
       restoreStatesAndValues(overrides);

       // "Abort these steps."
       return;
   }

   // "If start block has one child, which is a collapsed block prop, remove
   // its child from it."
   if (startBlock.children.length == 1
   && isCollapsedBlockProp(startBlock.firstChild)) {
       startBlock.removeChild(startBlock.firstChild);
   }

   // "If start block is an ancestor of end block:"
   if (isAncestor(startBlock, endBlock)) {
       // "Let reference node be end block."
       var referenceNode = endBlock;

       // "While reference node is not a child of start block, set reference
       // node to its parent."
       while (referenceNode.parentNode != startBlock) {
           referenceNode = referenceNode.parentNode;
       }

       // "Call collapse() on the context object's Selection, with first
       // argument start block and second argument the index of reference
       // node."
       getSelection().collapse(startBlock, getNodeIndex(referenceNode));
       getActiveRange().setStart(startBlock, getNodeIndex(referenceNode));
       getActiveRange().collapse(true);

       // "If end block has no children:"
       if (!endBlock.hasChildNodes()) {
           // "While end block is editable and is the only child of its parent
           // and is not a child of start block, let parent equal end block,
           // then remove end block from parent, then set end block to
           // parent."
           while (isEditable(endBlock)
           && endBlock.parentNode.childNodes.length == 1
           && endBlock.parentNode != startBlock) {
               var parent_ = endBlock;
               parent_.removeChild(endBlock);
               endBlock = parent_;
           }

           // "If end block is editable and is not an inline node, and its
           // previousSibling and nextSibling are both inline nodes, call
           // createElement("br") on the context object and insert it into end
           // block's parent immediately after end block."
           if (isEditable(endBlock)
           && !isInlineNode(endBlock)
           && isInlineNode(endBlock.previousSibling)
           && isInlineNode(endBlock.nextSibling)) {
               endBlock.parentNode.insertBefore(document.createElement("br"), endBlock.nextSibling);
           }

           // "If end block is editable, remove it from its parent."
           if (isEditable(endBlock)) {
               endBlock.parentNode.removeChild(endBlock);
           }

           // "Restore states and values from overrides."
           restoreStatesAndValues(overrides);

           // "Abort these steps."
           return;
       }

       // "If end block's firstChild is not an inline node, restore states and
       // values from overrides, then abort these steps."
       if (!isInlineNode(endBlock.firstChild)) {
           restoreStatesAndValues(overrides);
           return;
       }

       // "Let children be a list of nodes, initially empty."
       var children = [];

       // "Append the first child of end block to children."
       children.push(endBlock.firstChild);

       // "While children's last member is not a br, and children's last
       // member's nextSibling is an inline node, append children's last
       // member's nextSibling to children."
       while (!isHtmlElement(children[children.length - 1], "br")
       && isInlineNode(children[children.length - 1].nextSibling)) {
           children.push(children[children.length - 1].nextSibling);
       }

       // "Record the values of children, and let values be the result."
       var values = recordValues(children);

       // "While children's first member's parent is not start block, split
       // the parent of children."
       while (children[0].parentNode != startBlock) {
           splitParent(children);
       }

       // "If children's first member's previousSibling is an editable br,
       // remove that br from its parent."
       if (isEditable(children[0].previousSibling)
       && isHtmlElement(children[0].previousSibling, "br")) {
           children[0].parentNode.removeChild(children[0].previousSibling);
       }

   // "Otherwise, if start block is a descendant of end block:"
   } else if (isDescendant(startBlock, endBlock)) {
       // "Call collapse() on the context object's Selection, with first
       // argument start block and second argument start block's length."
       getSelection().collapse(startBlock, getNodeLength(startBlock));
       getActiveRange().setStart(startBlock, getNodeLength(startBlock));
       getActiveRange().collapse(true);

       // "Let reference node be start block."
       var referenceNode = startBlock;

       // "While reference node is not a child of end block, set reference
       // node to its parent."
       while (referenceNode.parentNode != endBlock) {
           referenceNode = referenceNode.parentNode;
       }

       // "If reference node's nextSibling is an inline node and start block's
       // lastChild is a br, remove start block's lastChild from it."
       if (isInlineNode(referenceNode.nextSibling)
       && isHtmlElement(startBlock.lastChild, "br")) {
           startBlock.removeChild(startBlock.lastChild);
       }

       // "Let nodes to move be a list of nodes, initially empty."
       var nodesToMove = [];

       // "If reference node's nextSibling is neither null nor a block node,
       // append it to nodes to move."
       if (referenceNode.nextSibling
       && !isBlockNode(referenceNode.nextSibling)) {
           nodesToMove.push(referenceNode.nextSibling);
       }

       // "While nodes to move is nonempty and its last member isn't a br and
       // its last member's nextSibling is neither null nor a block node,
       // append its last member's nextSibling to nodes to move."
       if (nodesToMove.length
       && !isHtmlElement(nodesToMove[nodesToMove.length - 1], "br")
       && nodesToMove[nodesToMove.length - 1].nextSibling
       && !isBlockNode(nodesToMove[nodesToMove.length - 1].nextSibling)) {
           nodesToMove.push(nodesToMove[nodesToMove.length - 1].nextSibling);
       }

       // "Record the values of nodes to move, and let values be the result."
       var values = recordValues(nodesToMove);

       // "For each node in nodes to move, append node as the last child of
       // start block, preserving ranges."
       nodesToMove.forEach(function(node) {
           movePreservingRanges(node, startBlock, -1);
       });

   // "Otherwise:"
   } else {
       // "Call collapse() on the context object's Selection, with first
       // argument start block and second argument start block's length."
       getSelection().collapse(startBlock, getNodeLength(startBlock));
       getActiveRange().setStart(startBlock, getNodeLength(startBlock));
       getActiveRange().collapse(true);

       // "If end block's firstChild is an inline node and start block's
       // lastChild is a br, remove start block's lastChild from it."
       if (isInlineNode(endBlock.firstChild)
       && isHtmlElement(startBlock.lastChild, "br")) {
           startBlock.removeChild(startBlock.lastChild);
       }

       // "Record the values of end block's children, and let values be the
       // result."
       var values = recordValues([].slice.call(endBlock.childNodes));

       // "While end block has children, append the first child of end block
       // to start block, preserving ranges."
       while (endBlock.hasChildNodes()) {
           movePreservingRanges(endBlock.firstChild, startBlock, -1);
       }

       // "While end block has no children, let parent be the parent of end
       // block, then remove end block from parent, then set end block to
       // parent."
       while (!endBlock.hasChildNodes()) {
           var parent_ = endBlock.parentNode;
           parent_.removeChild(endBlock);
           endBlock = parent_;
       }
   }

   // "Let ancestor be start block."
   var ancestor = startBlock;

   // "While ancestor has an inclusive ancestor ol in the same editing host
   // whose nextSibling is also an ol in the same editing host, or an
   // inclusive ancestor ul in the same editing host whose nextSibling is also
   // a ul in the same editing host:"
   while (getInclusiveAncestors(ancestor).some(function(node) {
       return inSameEditingHost(ancestor, node)
           && (
               (isHtmlElement(node, "ol") && isHtmlElement(node.nextSibling, "ol"))
               || (isHtmlElement(node, "ul") && isHtmlElement(node.nextSibling, "ul"))
           ) && inSameEditingHost(ancestor, node.nextSibling);
   })) {
       // "While ancestor and its nextSibling are not both ols in the same
       // editing host, and are also not both uls in the same editing host,
       // set ancestor to its parent."
       while (!(
           isHtmlElement(ancestor, "ol")
           && isHtmlElement(ancestor.nextSibling, "ol")
           && inSameEditingHost(ancestor, ancestor.nextSibling)
       ) && !(
           isHtmlElement(ancestor, "ul")
           && isHtmlElement(ancestor.nextSibling, "ul")
           && inSameEditingHost(ancestor, ancestor.nextSibling)
       )) {
           ancestor = ancestor.parentNode;
       }

       // "While ancestor's nextSibling has children, append ancestor's
       // nextSibling's firstChild as the last child of ancestor, preserving
       // ranges."
       while (ancestor.nextSibling.hasChildNodes()) {
           movePreservingRanges(ancestor.nextSibling.firstChild, ancestor, -1);
       }

       // "Remove ancestor's nextSibling from its parent."
       ancestor.parentNode.removeChild(ancestor.nextSibling);
   }

   // "Restore the values from values."
   restoreValues(values);

   // "If start block has no children, call createElement("br") on the context
   // object and append the result as the last child of start block."
   if (!startBlock.hasChildNodes()) {
       startBlock.appendChild(document.createElement("br"));
   }

   // "Remove extraneous line breaks at the end of start block."
   removeExtraneousLineBreaksAtTheEndOf(startBlock);

   // "Restore states and values from overrides."
   restoreStatesAndValues(overrides);
}


//@}
///// Splitting a node list's parent /////
//@{

function splitParent(nodeList) {
   // "Let original parent be the parent of the first member of node list."
   var originalParent = nodeList[0].parentNode;

   // "If original parent is not editable or its parent is null, do nothing
   // and abort these steps."
   if (!isEditable(originalParent)
   || !originalParent.parentNode) {
       return;
   }

   // "If the first child of original parent is in node list, remove
   // extraneous line breaks before original parent."
   if (nodeList.indexOf(originalParent.firstChild) != -1) {
       removeExtraneousLineBreaksBefore(originalParent);
   }

   // "If the first child of original parent is in node list, and original
   // parent follows a line break, set follows line break to true. Otherwise,
   // set follows line break to false."
   var followsLineBreak_ = nodeList.indexOf(originalParent.firstChild) != -1
       && followsLineBreak(originalParent);

   // "If the last child of original parent is in node list, and original
   // parent precedes a line break, set precedes line break to true.
   // Otherwise, set precedes line break to false."
   var precedesLineBreak_ = nodeList.indexOf(originalParent.lastChild) != -1
       && precedesLineBreak(originalParent);

   // "If the first child of original parent is not in node list, but its last
   // child is:"
   if (nodeList.indexOf(originalParent.firstChild) == -1
   && nodeList.indexOf(originalParent.lastChild) != -1) {
       // "For each node in node list, in reverse order, insert node into the
       // parent of original parent immediately after original parent,
       // preserving ranges."
       for (var i = nodeList.length - 1; i >= 0; i--) {
           movePreservingRanges(nodeList[i], originalParent.parentNode, 1 + getNodeIndex(originalParent));
       }

       // "If precedes line break is true, and the last member of node list
       // does not precede a line break, call createElement("br") on the
       // context object and insert the result immediately after the last
       // member of node list."
       if (precedesLineBreak_
       && !precedesLineBreak(nodeList[nodeList.length - 1])) {
           nodeList[nodeList.length - 1].parentNode.insertBefore(document.createElement("br"), nodeList[nodeList.length - 1].nextSibling);
       }

       // "Remove extraneous line breaks at the end of original parent."
       removeExtraneousLineBreaksAtTheEndOf(originalParent);

       // "Abort these steps."
       return;
   }

   // "If the first child of original parent is not in node list:"
   if (nodeList.indexOf(originalParent.firstChild) == -1) {
       // "Let cloned parent be the result of calling cloneNode(false) on
       // original parent."
       var clonedParent = originalParent.cloneNode(false);

       // "If original parent has an id attribute, unset it."
       originalParent.removeAttribute("id");

       // "Insert cloned parent into the parent of original parent immediately
       // before original parent."
       originalParent.parentNode.insertBefore(clonedParent, originalParent);

       // "While the previousSibling of the first member of node list is not
       // null, append the first child of original parent as the last child of
       // cloned parent, preserving ranges."
       while (nodeList[0].previousSibling) {
           movePreservingRanges(originalParent.firstChild, clonedParent, clonedParent.childNodes.length);
       }
   }

   // "For each node in node list, insert node into the parent of original
   // parent immediately before original parent, preserving ranges."
   for (var i = 0; i < nodeList.length; i++) {
       movePreservingRanges(nodeList[i], originalParent.parentNode, getNodeIndex(originalParent));
   }

   // "If follows line break is true, and the first member of node list does
   // not follow a line break, call createElement("br") on the context object
   // and insert the result immediately before the first member of node list."
   if (followsLineBreak_
   && !followsLineBreak(nodeList[0])) {
       nodeList[0].parentNode.insertBefore(document.createElement("br"), nodeList[0]);
   }

   // "If the last member of node list is an inline node other than a br, and
   // the first child of original parent is a br, and original parent is not
   // an inline node, remove the first child of original parent from original
   // parent."
   if (isInlineNode(nodeList[nodeList.length - 1])
   && !isHtmlElement(nodeList[nodeList.length - 1], "br")
   && isHtmlElement(originalParent.firstChild, "br")
   && !isInlineNode(originalParent)) {
       originalParent.removeChild(originalParent.firstChild);
   }

   // "If original parent has no children:"
   if (!originalParent.hasChildNodes()) {
       // "Remove original parent from its parent."
       originalParent.parentNode.removeChild(originalParent);

       // "If precedes line break is true, and the last member of node list
       // does not precede a line break, call createElement("br") on the
       // context object and insert the result immediately after the last
       // member of node list."
       if (precedesLineBreak_
       && !precedesLineBreak(nodeList[nodeList.length - 1])) {
           nodeList[nodeList.length - 1].parentNode.insertBefore(document.createElement("br"), nodeList[nodeList.length - 1].nextSibling);
       }

   // "Otherwise, remove extraneous line breaks before original parent."
   } else {
       removeExtraneousLineBreaksBefore(originalParent);
   }

   // "If node list's last member's nextSibling is null, but its parent is not
   // null, remove extraneous line breaks at the end of node list's last
   // member's parent."
   if (!nodeList[nodeList.length - 1].nextSibling
   && nodeList[nodeList.length - 1].parentNode) {
       removeExtraneousLineBreaksAtTheEndOf(nodeList[nodeList.length - 1].parentNode);
   }
}

// "To remove a node node while preserving its descendants, split the parent of
// node's children if it has any. If it has no children, instead remove it from
// its parent."
function removePreservingDescendants(node) {
   if (node.hasChildNodes()) {
       splitParent([].slice.call(node.childNodes));
   } else {
       node.parentNode.removeChild(node);
   }
}


//@}
///// Canonical space sequences /////
//@{

function canonicalSpaceSequence(n, nonBreakingStart, nonBreakingEnd) {
   // "If n is zero, return the empty string."
   if (n == 0) {
       return "";
   }

   // "If n is one and both non-breaking start and non-breaking end are false,
   // return a single space (U+0020)."
   if (n == 1 && !nonBreakingStart && !nonBreakingEnd) {
       return " ";
   }

   // "If n is one, return a single non-breaking space (U+00A0)."
   if (n == 1) {
       return "\xa0";
   }

   // "Let buffer be the empty string."
   var buffer = "";

   // "If non-breaking start is true, let repeated pair be U+00A0 U+0020.
   // Otherwise, let it be U+0020 U+00A0."
   var repeatedPair;
   if (nonBreakingStart) {
       repeatedPair = "\xa0 ";
   } else {
       repeatedPair = " \xa0";
   }

   // "While n is greater than three, append repeated pair to buffer and
   // subtract two from n."
   while (n > 3) {
       buffer += repeatedPair;
       n -= 2;
   }

   // "If n is three, append a three-element string to buffer depending on
   // non-breaking start and non-breaking end:"
   if (n == 3) {
       buffer +=
           !nonBreakingStart && !nonBreakingEnd ? " \xa0 "
           : nonBreakingStart && !nonBreakingEnd ? "\xa0\xa0 "
           : !nonBreakingStart && nonBreakingEnd ? " \xa0\xa0"
           : nonBreakingStart && nonBreakingEnd ? "\xa0 \xa0"
           : "impossible";

   // "Otherwise, append a two-element string to buffer depending on
   // non-breaking start and non-breaking end:"
   } else {
       buffer +=
           !nonBreakingStart && !nonBreakingEnd ? "\xa0 "
           : nonBreakingStart && !nonBreakingEnd ? "\xa0 "
           : !nonBreakingStart && nonBreakingEnd ? " \xa0"
           : nonBreakingStart && nonBreakingEnd ? "\xa0\xa0"
           : "impossible";
   }

   // "Return buffer."
   return buffer;
}

function canonicalizeWhitespace(node, offset, fixCollapsedSpace) {
   if (fixCollapsedSpace === undefined) {
       // "an optional boolean argument fix collapsed space that defaults to
       // true"
       fixCollapsedSpace = true;
   }

   // "If node is neither editable nor an editing host, abort these steps."
   if (!isEditable(node) && !isEditingHost(node)) {
       return;
   }

   // "Let start node equal node and let start offset equal offset."
   var startNode = node;
   var startOffset = offset;

   // "Repeat the following steps:"
   while (true) {
       // "If start node has a child in the same editing host with index start
       // offset minus one, set start node to that child, then set start
       // offset to start node's length."
       if (0 <= startOffset - 1
       && inSameEditingHost(startNode, startNode.childNodes[startOffset - 1])) {
           startNode = startNode.childNodes[startOffset - 1];
           startOffset = getNodeLength(startNode);

       // "Otherwise, if start offset is zero and start node does not follow a
       // line break and start node's parent is in the same editing host, set
       // start offset to start node's index, then set start node to its
       // parent."
       } else if (startOffset == 0
       && !followsLineBreak(startNode)
       && inSameEditingHost(startNode, startNode.parentNode)) {
           startOffset = getNodeIndex(startNode);
           startNode = startNode.parentNode;

       // "Otherwise, if start node is a Text node and its parent's resolved
       // value for "white-space" is neither "pre" nor "pre-wrap" and start
       // offset is not zero and the (start offset − 1)st element of start
       // node's data is a space (0x0020) or non-breaking space (0x00A0),
       // subtract one from start offset."
       } else if (startNode.nodeType == Node.TEXT_NODE
       && ["pre", "pre-wrap"].indexOf(getComputedStyle(startNode.parentNode).whiteSpace) == -1
       && startOffset != 0
       && /[ \xa0]/.test(startNode.data[startOffset - 1])) {
           startOffset--;

       // "Otherwise, break from this loop."
       } else {
           break;
       }
   }

   // "Let end node equal start node and end offset equal start offset."
   var endNode = startNode;
   var endOffset = startOffset;

   // "Let length equal zero."
   var length = 0;

   // "Let collapse spaces be true if start offset is zero and start node
   // follows a line break, otherwise false."
   var collapseSpaces = startOffset == 0 && followsLineBreak(startNode);

   // "Repeat the following steps:"
   while (true) {
       // "If end node has a child in the same editing host with index end
       // offset, set end node to that child, then set end offset to zero."
       if (endOffset < endNode.childNodes.length
       && inSameEditingHost(endNode, endNode.childNodes[endOffset])) {
           endNode = endNode.childNodes[endOffset];
           endOffset = 0;

       // "Otherwise, if end offset is end node's length and end node does not
       // precede a line break and end node's parent is in the same editing
       // host, set end offset to one plus end node's index, then set end node
       // to its parent."
       } else if (endOffset == getNodeLength(endNode)
       && !precedesLineBreak(endNode)
       && inSameEditingHost(endNode, endNode.parentNode)) {
           endOffset = 1 + getNodeIndex(endNode);
           endNode = endNode.parentNode;

       // "Otherwise, if end node is a Text node and its parent's resolved
       // value for "white-space" is neither "pre" nor "pre-wrap" and end
       // offset is not end node's length and the end offsetth element of
       // end node's data is a space (0x0020) or non-breaking space (0x00A0):"
       } else if (endNode.nodeType == Node.TEXT_NODE
       && ["pre", "pre-wrap"].indexOf(getComputedStyle(endNode.parentNode).whiteSpace) == -1
       && endOffset != getNodeLength(endNode)
       && /[ \xa0]/.test(endNode.data[endOffset])) {
           // "If fix collapsed space is true, and collapse spaces is true,
           // and the end offsetth code unit of end node's data is a space
           // (0x0020): call deleteData(end offset, 1) on end node, then
           // continue this loop from the beginning."
           if (fixCollapsedSpace
           && collapseSpaces
           && " " == endNode.data[endOffset]) {
               endNode.deleteData(endOffset, 1);
               continue;
           }

           // "Set collapse spaces to true if the end offsetth element of end
           // node's data is a space (0x0020), false otherwise."
           collapseSpaces = " " == endNode.data[endOffset];

           // "Add one to end offset."
           endOffset++;

           // "Add one to length."
           length++;

       // "Otherwise, break from this loop."
       } else {
           break;
       }
   }

   // "If fix collapsed space is true, then while (start node, start offset)
   // is before (end node, end offset):"
   if (fixCollapsedSpace) {
       while (getPosition(startNode, startOffset, endNode, endOffset) == "before") {
           // "If end node has a child in the same editing host with index end
           // offset − 1, set end node to that child, then set end offset to end
           // node's length."
           if (0 <= endOffset - 1
           && endOffset - 1 < endNode.childNodes.length
           && inSameEditingHost(endNode, endNode.childNodes[endOffset - 1])) {
               endNode = endNode.childNodes[endOffset - 1];
               endOffset = getNodeLength(endNode);

           // "Otherwise, if end offset is zero and end node's parent is in the
           // same editing host, set end offset to end node's index, then set end
           // node to its parent."
           } else if (endOffset == 0
           && inSameEditingHost(endNode, endNode.parentNode)) {
               endOffset = getNodeIndex(endNode);
               endNode = endNode.parentNode;

           // "Otherwise, if end node is a Text node and its parent's resolved
           // value for "white-space" is neither "pre" nor "pre-wrap" and end
           // offset is end node's length and the last code unit of end node's
           // data is a space (0x0020) and end node precedes a line break:"
           } else if (endNode.nodeType == Node.TEXT_NODE
           && ["pre", "pre-wrap"].indexOf(getComputedStyle(endNode.parentNode).whiteSpace) == -1
           && endOffset == getNodeLength(endNode)
           && endNode.data[endNode.data.length - 1] == " "
           && precedesLineBreak(endNode)) {
               // "Subtract one from end offset."
               endOffset--;

               // "Subtract one from length."
               length--;

               // "Call deleteData(end offset, 1) on end node."
               endNode.deleteData(endOffset, 1);

           // "Otherwise, break from this loop."
           } else {
               break;
           }
       }
   }

   // "Let replacement whitespace be the canonical space sequence of length
   // length. non-breaking start is true if start offset is zero and start
   // node follows a line break, and false otherwise. non-breaking end is true
   // if end offset is end node's length and end node precedes a line break,
   // and false otherwise."
   var replacementWhitespace = canonicalSpaceSequence(length,
       startOffset == 0 && followsLineBreak(startNode),
       endOffset == getNodeLength(endNode) && precedesLineBreak(endNode));

   // "While (start node, start offset) is before (end node, end offset):"
   while (getPosition(startNode, startOffset, endNode, endOffset) == "before") {
       // "If start node has a child with index start offset, set start node
       // to that child, then set start offset to zero."
       if (startOffset < startNode.childNodes.length) {
           startNode = startNode.childNodes[startOffset];
           startOffset = 0;

       // "Otherwise, if start node is not a Text node or if start offset is
       // start node's length, set start offset to one plus start node's
       // index, then set start node to its parent."
       } else if (startNode.nodeType != Node.TEXT_NODE
       || startOffset == getNodeLength(startNode)) {
           startOffset = 1 + getNodeIndex(startNode);
           startNode = startNode.parentNode;

       // "Otherwise:"
       } else {
           // "Remove the first element from replacement whitespace, and let
           // element be that element."
           var element = replacementWhitespace[0];
           replacementWhitespace = replacementWhitespace.slice(1);

           // "If element is not the same as the start offsetth element of
           // start node's data:"
           if (element != startNode.data[startOffset]) {
               // "Call insertData(start offset, element) on start node."
               startNode.insertData(startOffset, element);

               // "Call deleteData(start offset + 1, 1) on start node."
               startNode.deleteData(startOffset + 1, 1);
           }

           // "Add one to start offset."
           startOffset++;
       }
   }
}


//@}
///// Indenting and outdenting /////
//@{

function indentNodes(nodeList) {
   // "If node list is empty, do nothing and abort these steps."
   if (!nodeList.length) {
       return;
   }

   // "Let first node be the first member of node list."
   var firstNode = nodeList[0];

   // "If first node's parent is an ol or ul:"
   if (isHtmlElement(firstNode.parentNode, ["OL", "UL"])) {
       // "Let tag be the local name of the parent of first node."
       var tag = firstNode.parentNode.tagName;

       // "Wrap node list, with sibling criteria returning true for an HTML
       // element with local name tag and false otherwise, and new parent
       // instructions returning the result of calling createElement(tag) on
       // the ownerDocument of first node."
       wrap(nodeList,
           function(node) { return isHtmlElement(node, tag) },
           function() { return firstNode.ownerDocument.createElement(tag) });

       // "Abort these steps."
       return;
   }

   // "Wrap node list, with sibling criteria returning true for a simple
   // indentation element and false otherwise, and new parent instructions
   // returning the result of calling createElement("blockquote") on the
   // ownerDocument of first node. Let new parent be the result."
   var newParent = wrap(nodeList,
       function(node) { return isSimpleIndentationElement(node) },
       function() { return firstNode.ownerDocument.createElement("blockquote") });

   // "Fix disallowed ancestors of new parent."
   fixDisallowedAncestors(newParent);
}

function outdentNode(node) {
   // "If node is not editable, abort these steps."
   if (!isEditable(node)) {
       return;
   }

   // "If node is a simple indentation element, remove node, preserving its
   // descendants.  Then abort these steps."
   if (isSimpleIndentationElement(node)) {
       removePreservingDescendants(node);
       return;
   }

   // "If node is an indentation element:"
   if (isIndentationElement(node)) {
       // "Unset the dir attribute of node, if any."
       node.removeAttribute("dir");

       // "Unset the margin, padding, and border CSS properties of node."
       node.style.margin = "";
       node.style.padding = "";
       node.style.border = "";
       if (node.getAttribute("style") == ""
       // Crazy WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=68551
       || node.getAttribute("style") == "border-width: initial; border-color: initial; ") {
           node.removeAttribute("style");
       }

       // "Set the tag name of node to "div"."
       setTagName(node, "div");

       // "Abort these steps."
       return;
   }

   // "Let current ancestor be node's parent."
   var currentAncestor = node.parentNode;

   // "Let ancestor list be a list of nodes, initially empty."
   var ancestorList = [];

   // "While current ancestor is an editable Element that is neither a simple
   // indentation element nor an ol nor a ul, append current ancestor to
   // ancestor list and then set current ancestor to its parent."
   while (isEditable(currentAncestor)
   && currentAncestor.nodeType == Node.ELEMENT_NODE
   && !isSimpleIndentationElement(currentAncestor)
   && !isHtmlElement(currentAncestor, ["ol", "ul"])) {
       ancestorList.push(currentAncestor);
       currentAncestor = currentAncestor.parentNode;
   }

   // "If current ancestor is not an editable simple indentation element:"
   if (!isEditable(currentAncestor)
   || !isSimpleIndentationElement(currentAncestor)) {
       // "Let current ancestor be node's parent."
       currentAncestor = node.parentNode;

       // "Let ancestor list be the empty list."
       ancestorList = [];

       // "While current ancestor is an editable Element that is neither an
       // indentation element nor an ol nor a ul, append current ancestor to
       // ancestor list and then set current ancestor to its parent."
       while (isEditable(currentAncestor)
       && currentAncestor.nodeType == Node.ELEMENT_NODE
       && !isIndentationElement(currentAncestor)
       && !isHtmlElement(currentAncestor, ["ol", "ul"])) {
           ancestorList.push(currentAncestor);
           currentAncestor = currentAncestor.parentNode;
       }
   }

   // "If node is an ol or ul and current ancestor is not an editable
   // indentation element:"
   if (isHtmlElement(node, ["OL", "UL"])
   && (!isEditable(currentAncestor)
   || !isIndentationElement(currentAncestor))) {
       // "Unset the reversed, start, and type attributes of node, if any are
       // set."
       node.removeAttribute("reversed");
       node.removeAttribute("start");
       node.removeAttribute("type");

       // "Let children be the children of node."
       var children = [].slice.call(node.childNodes);

       // "If node has attributes, and its parent is not an ol or ul, set the
       // tag name of node to "div"."
       if (node.attributes.length
       && !isHtmlElement(node.parentNode, ["OL", "UL"])) {
           setTagName(node, "div");

       // "Otherwise:"
       } else {
           // "Record the values of node's children, and let values be the
           // result."
           var values = recordValues([].slice.call(node.childNodes));

           // "Remove node, preserving its descendants."
           removePreservingDescendants(node);

           // "Restore the values from values."
           restoreValues(values);
       }

       // "Fix disallowed ancestors of each member of children."
       for (var i = 0; i < children.length; i++) {
           fixDisallowedAncestors(children[i]);
       }

       // "Abort these steps."
       return;
   }

   // "If current ancestor is not an editable indentation element, abort these
   // steps."
   if (!isEditable(currentAncestor)
   || !isIndentationElement(currentAncestor)) {
       return;
   }

   // "Append current ancestor to ancestor list."
   ancestorList.push(currentAncestor);

   // "Let original ancestor be current ancestor."
   var originalAncestor = currentAncestor;

   // "While ancestor list is not empty:"
   while (ancestorList.length) {
       // "Let current ancestor be the last member of ancestor list."
       //
       // "Remove the last member of ancestor list."
       currentAncestor = ancestorList.pop();

       // "Let target be the child of current ancestor that is equal to either
       // node or the last member of ancestor list."
       var target = node.parentNode == currentAncestor
           ? node
           : ancestorList[ancestorList.length - 1];

       // "If target is an inline node that is not a br, and its nextSibling
       // is a br, remove target's nextSibling from its parent."
       if (isInlineNode(target)
       && !isHtmlElement(target, "BR")
       && isHtmlElement(target.nextSibling, "BR")) {
           target.parentNode.removeChild(target.nextSibling);
       }

       // "Let preceding siblings be the preceding siblings of target, and let
       // following siblings be the following siblings of target."
       var precedingSiblings = [].slice.call(currentAncestor.childNodes, 0, getNodeIndex(target));
       var followingSiblings = [].slice.call(currentAncestor.childNodes, 1 + getNodeIndex(target));

       // "Indent preceding siblings."
       indentNodes(precedingSiblings);

       // "Indent following siblings."
       indentNodes(followingSiblings);
   }

   // "Outdent original ancestor."
   outdentNode(originalAncestor);
}


//@}
///// Toggling lists /////
//@{

function toggleLists(tagName) {
   // "Let mode be "disable" if the selection's list state is tag name, and
   // "enable" otherwise."
   var mode = getSelectionListState() == tagName ? "disable" : "enable";

   var range = getActiveRange();
   tagName = tagName.toUpperCase();

   // "Let other tag name be "ol" if tag name is "ul", and "ul" if tag name is
   // "ol"."
   var otherTagName = tagName == "OL" ? "UL" : "OL";

   // "Let items be a list of all lis that are ancestor containers of the
   // range's start and/or end node."
   //
   // It's annoying to get this in tree order using functional stuff without
   // doing getDescendants(document), which is slow, so I do it imperatively.
   var items = [];
   (function(){
       for (
           var ancestorContainer = range.endContainer;
           ancestorContainer != range.commonAncestorContainer;
           ancestorContainer = ancestorContainer.parentNode
       ) {
           if (isHtmlElement(ancestorContainer, "li")) {
               items.unshift(ancestorContainer);
           }
       }
       for (
           var ancestorContainer = range.startContainer;
           ancestorContainer;
           ancestorContainer = ancestorContainer.parentNode
       ) {
           if (isHtmlElement(ancestorContainer, "li")) {
               items.unshift(ancestorContainer);
           }
       }
   })();

   // "For each item in items, normalize sublists of item."
   items.forEach(normalizeSublists);

   // "Block-extend the range, and let new range be the result."
   var newRange = blockExtend(range);

   // "If mode is "enable", then let lists to convert consist of every
   // editable HTML element with local name other tag name that is contained
   // in new range, and for every list in lists to convert:"
   if (mode == "enable") {
       getAllContainedNodes(newRange, function(node) {
           return isEditable(node)
               && isHtmlElement(node, otherTagName);
       }).forEach(function(list) {
           // "If list's previousSibling or nextSibling is an editable HTML
           // element with local name tag name:"
           if ((isEditable(list.previousSibling) && isHtmlElement(list.previousSibling, tagName))
           || (isEditable(list.nextSibling) && isHtmlElement(list.nextSibling, tagName))) {
               // "Let children be list's children."
               var children = [].slice.call(list.childNodes);

               // "Record the values of children, and let values be the
               // result."
               var values = recordValues(children);

               // "Split the parent of children."
               splitParent(children);

               // "Wrap children, with sibling criteria returning true for an
               // HTML element with local name tag name and false otherwise."
               wrap(children, function(node) { return isHtmlElement(node, tagName) });

               // "Restore the values from values."
               restoreValues(values);

           // "Otherwise, set the tag name of list to tag name."
           } else {
               setTagName(list, tagName);
           }
       });
   }

   // "Let node list be a list of nodes, initially empty."
   //
   // "For each node node contained in new range, if node is editable; the
   // last member of node list (if any) is not an ancestor of node; node
   // is not an indentation element; and either node is an ol or ul, or its
   // parent is an ol or ul, or it is an allowed child of "li"; then append
   // node to node list."
   var nodeList = getContainedNodes(newRange, function(node) {
       return isEditable(node)
       && !isIndentationElement(node)
       && (isHtmlElement(node, ["OL", "UL"])
       || isHtmlElement(node.parentNode, ["OL", "UL"])
       || isAllowedChild(node, "li"));
   });

   // "If mode is "enable", remove from node list any ol or ul whose parent is
   // not also an ol or ul."
   if (mode == "enable") {
       nodeList = nodeList.filter(function(node) {
           return !isHtmlElement(node, ["ol", "ul"])
               || isHtmlElement(node.parentNode, ["ol", "ul"]);
       });
   }

   // "If mode is "disable", then while node list is not empty:"
   if (mode == "disable") {
       while (nodeList.length) {
           // "Let sublist be an empty list of nodes."
           var sublist = [];

           // "Remove the first member from node list and append it to
           // sublist."
           sublist.push(nodeList.shift());

           // "If the first member of sublist is an HTML element with local
           // name tag name, outdent it and continue this loop from the
           // beginning."
           if (isHtmlElement(sublist[0], tagName)) {
               outdentNode(sublist[0]);
               continue;
           }

           // "While node list is not empty, and the first member of node list
           // is the nextSibling of the last member of sublist and is not an
           // HTML element with local name tag name, remove the first member
           // from node list and append it to sublist."
           while (nodeList.length
           && nodeList[0] == sublist[sublist.length - 1].nextSibling
           && !isHtmlElement(nodeList[0], tagName)) {
               sublist.push(nodeList.shift());
           }

           // "Record the values of sublist, and let values be the result."
           var values = recordValues(sublist);

           // "Split the parent of sublist."
           splitParent(sublist);

           // "Fix disallowed ancestors of each member of sublist."
           for (var i = 0; i < sublist.length; i++) {
               fixDisallowedAncestors(sublist[i]);
           }

           // "Restore the values from values."
           restoreValues(values);
       }

   // "Otherwise, while node list is not empty:"
   } else {
       while (nodeList.length) {
           // "Let sublist be an empty list of nodes."
           var sublist = [];

           // "While either sublist is empty, or node list is not empty and
           // its first member is the nextSibling of sublist's last member:"
           while (!sublist.length
           || (nodeList.length
           && nodeList[0] == sublist[sublist.length - 1].nextSibling)) {
               // "If node list's first member is a p or div, set the tag name
               // of node list's first member to "li", and append the result
               // to sublist. Remove the first member from node list."
               if (isHtmlElement(nodeList[0], ["p", "div"])) {
                   sublist.push(setTagName(nodeList[0], "li"));
                   nodeList.shift();

               // "Otherwise, if the first member of node list is an li or ol
               // or ul, remove it from node list and append it to sublist."
               } else if (isHtmlElement(nodeList[0], ["li", "ol", "ul"])) {
                   sublist.push(nodeList.shift());

               // "Otherwise:"
               } else {
                   // "Let nodes to wrap be a list of nodes, initially empty."
                   var nodesToWrap = [];

                   // "While nodes to wrap is empty, or node list is not empty
                   // and its first member is the nextSibling of nodes to
                   // wrap's last member and the first member of node list is
                   // an inline node and the last member of nodes to wrap is
                   // an inline node other than a br, remove the first member
                   // from node list and append it to nodes to wrap."
                   while (!nodesToWrap.length
                   || (nodeList.length
                   && nodeList[0] == nodesToWrap[nodesToWrap.length - 1].nextSibling
                   && isInlineNode(nodeList[0])
                   && isInlineNode(nodesToWrap[nodesToWrap.length - 1])
                   && !isHtmlElement(nodesToWrap[nodesToWrap.length - 1], "br"))) {
                       nodesToWrap.push(nodeList.shift());
                   }

                   // "Wrap nodes to wrap, with new parent instructions
                   // returning the result of calling createElement("li") on
                   // the context object. Append the result to sublist."
                   sublist.push(wrap(nodesToWrap,
                       undefined,
                       function() { return document.createElement("li") }));
               }
           }

           // "If sublist's first member's parent is an HTML element with
           // local name tag name, or if every member of sublist is an ol or
           // ul, continue this loop from the beginning."
           if (isHtmlElement(sublist[0].parentNode, tagName)
           || sublist.every(function(node) { return isHtmlElement(node, ["ol", "ul"]) })) {
               continue;
           }

           // "If sublist's first member's parent is an HTML element with
           // local name other tag name:"
           if (isHtmlElement(sublist[0].parentNode, otherTagName)) {
               // "Record the values of sublist, and let values be the
               // result."
               var values = recordValues(sublist);

               // "Split the parent of sublist."
               splitParent(sublist);

               // "Wrap sublist, with sibling criteria returning true for an
               // HTML element with local name tag name and false otherwise,
               // and new parent instructions returning the result of calling
               // createElement(tag name) on the context object."
               wrap(sublist,
                   function(node) { return isHtmlElement(node, tagName) },
                   function() { return document.createElement(tagName) });

               // "Restore the values from values."
               restoreValues(values);

               // "Continue this loop from the beginning."
               continue;
           }

           // "Wrap sublist, with sibling criteria returning true for an HTML
           // element with local name tag name and false otherwise, and new
           // parent instructions being the following:"
           // . . .
           // "Fix disallowed ancestors of the previous step's result."
           fixDisallowedAncestors(wrap(sublist,
               function(node) { return isHtmlElement(node, tagName) },
               function() {
                   // "If sublist's first member's parent is not an editable
                   // simple indentation element, or sublist's first member's
                   // parent's previousSibling is not an editable HTML element
                   // with local name tag name, call createElement(tag name)
                   // on the context object and return the result."
                   if (!isEditable(sublist[0].parentNode)
                   || !isSimpleIndentationElement(sublist[0].parentNode)
                   || !isEditable(sublist[0].parentNode.previousSibling)
                   || !isHtmlElement(sublist[0].parentNode.previousSibling, tagName)) {
                       return document.createElement(tagName);
                   }

                   // "Let list be sublist's first member's parent's
                   // previousSibling."
                   var list = sublist[0].parentNode.previousSibling;

                   // "Normalize sublists of list's lastChild."
                   normalizeSublists(list.lastChild);

                   // "If list's lastChild is not an editable HTML element
                   // with local name tag name, call createElement(tag name)
                   // on the context object, and append the result as the last
                   // child of list."
                   if (!isEditable(list.lastChild)
                   || !isHtmlElement(list.lastChild, tagName)) {
                       list.appendChild(document.createElement(tagName));
                   }

                   // "Return the last child of list."
                   return list.lastChild;
               }
           ));
       }
   }
}


//@}
///// Justifying the selection /////
//@{

function justifySelection(alignment) {
   // "Block-extend the active range, and let new range be the result."
   var newRange = blockExtend(globalRange);

   // "Let element list be a list of all editable Elements contained in new
   // range that either has an attribute in the HTML namespace whose local
   // name is "align", or has a style attribute that sets "text-align", or is
   // a center."
   var elementList = getAllContainedNodes(newRange, function(node) {
       return node.nodeType == Node.ELEMENT_NODE
           && isEditable(node)
           // Ignoring namespaces here
           && (
               node.hasAttribute("align")
               || node.style.textAlign != ""
               || isHtmlElement(node, "center")
           );
   });

   // "For each element in element list:"
   for (var i = 0; i < elementList.length; i++) {
       var element = elementList[i];

       // "If element has an attribute in the HTML namespace whose local name
       // is "align", remove that attribute."
       element.removeAttribute("align");

       // "Unset the CSS property "text-align" on element, if it's set by a
       // style attribute."
       element.style.textAlign = "";
       if (element.getAttribute("style") == "") {
           element.removeAttribute("style");
       }

       // "If element is a div or span or center with no attributes, remove
       // it, preserving its descendants."
       if (isHtmlElement(element, ["div", "span", "center"])
       && !element.attributes.length) {
           removePreservingDescendants(element);
       }

       // "If element is a center with one or more attributes, set the tag
       // name of element to "div"."
       if (isHtmlElement(element, "center")
       && element.attributes.length) {
           setTagName(element, "div");
       }
   }

   // "Block-extend the active range, and let new range be the result."
   newRange = blockExtend(globalRange);

   // "Let node list be a list of nodes, initially empty."
   var nodeList = [];

   // "For each node node contained in new range, append node to node list if
   // the last member of node list (if any) is not an ancestor of node; node
   // is editable; node is an allowed child of "div"; and node's alignment
   // value is not alignment."
   nodeList = getContainedNodes(newRange, function(node) {
       return isEditable(node)
           && isAllowedChild(node, "div")
           && getAlignmentValue(node) != alignment;
   });

   // "While node list is not empty:"
   while (nodeList.length) {
       // "Let sublist be a list of nodes, initially empty."
       var sublist = [];

       // "Remove the first member of node list and append it to sublist."
       sublist.push(nodeList.shift());

       // "While node list is not empty, and the first member of node list is
       // the nextSibling of the last member of sublist, remove the first
       // member of node list and append it to sublist."
       while (nodeList.length
       && nodeList[0] == sublist[sublist.length - 1].nextSibling) {
           sublist.push(nodeList.shift());
       }

       // "Wrap sublist. Sibling criteria returns true for any div that has
       // one or both of the following two attributes and no other attributes,
       // and false otherwise:"
       //
       //   * "An align attribute whose value is an ASCII case-insensitive
       //     match for alignment.
       //   * "A style attribute which sets exactly one CSS property
       //     (including unrecognized or invalid attributes), which is
       //     "text-align", which is set to alignment.
       //
       // "New parent instructions are to call createElement("div") on the
       // context object, then set its CSS property "text-align" to alignment
       // and return the result."
       wrap(sublist,
           function(node) {
               return isHtmlElement(node, "div")
                   && [].every.call(node.attributes, function(attr) {
                       return (attr.name == "align" && attr.value.toLowerCase() == alignment)
                           || (attr.name == "style" && node.style.length == 1 && node.style.textAlign == alignment);
                   });
           },
           function() {
               var newParent = document.createElement("div");
               newParent.setAttribute("style", "text-align: " + alignment);
               return newParent;
           }
       );
   }
}


//@}
///// Automatic linking /////
//@{
// "An autolinkable URL is a string of the following form:"
var autolinkableUrlRegexp =
   // "Either a string matching the scheme pattern from RFC 3986 section 3.1
   // followed by the literal string ://, or the literal string mailto:;
   // followed by"
   //
   // From the RFC: scheme      = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
   "([a-zA-Z][a-zA-Z0-9+.-]*://|mailto:)"
   // "Zero or more characters other than space characters; followed by"
   + "[^ \t\n\f\r]*"
   // "A character that is not one of the ASCII characters !"'(),-.:;<>[]`{}."
   + "[^!\"'(),\\-.:;<>[\\]`{}]";

// "A valid e-mail address is a string that matches the ABNF production 1*(
// atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined in RFC
// 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section 3.5."
//
// atext: ALPHA / DIGIT / "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" /
// "/" / "=" / "?" / "^" / "_" / "`" / "{" / "|" / "}" / "~"
//
//<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
//<let-dig-hyp> ::= <let-dig> | "-"
//<let-dig> ::= <letter> | <digit>
var validEmailRegexp =
   "[a-zA-Z0-9!#$%&'*+\\-/=?^_`{|}~.]+@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*";

function autolink(node, endOffset) {
   // "While (node, end offset)'s previous equivalent point is not null, set
   // it to its previous equivalent point."
   while (getPreviousEquivalentPoint(node, endOffset)) {
       var prev = getPreviousEquivalentPoint(node, endOffset);
       node = prev[0];
       endOffset = prev[1];
   }

   // "If node is not a Text node, or has an a ancestor, do nothing and abort
   // these steps."
   if (node.nodeType != Node.TEXT_NODE
   || getAncestors(node).some(function(ancestor) { return isHtmlElement(ancestor, "a") })) {
       return;
   }

   // "Let search be the largest substring of node's data whose end is end
   // offset and that contains no space characters."
   var search = /[^ \t\n\f\r]*$/.exec(node.substringData(0, endOffset))[0];

   // "If some substring of search is an autolinkable URL:"
   if (new RegExp(autolinkableUrlRegexp).test(search)) {
       // "While there is no substring of node's data ending at end offset
       // that is an autolinkable URL, decrement end offset."
       while (!(new RegExp(autolinkableUrlRegexp + "$").test(node.substringData(0, endOffset)))) {
           endOffset--;
       }

       // "Let start offset be the start index of the longest substring of
       // node's data that is an autolinkable URL ending at end offset."
       var startOffset = new RegExp(autolinkableUrlRegexp + "$").exec(node.substringData(0, endOffset)).index;

       // "Let href be the substring of node's data starting at start offset
       // and ending at end offset."
       var href = node.substringData(startOffset, endOffset - startOffset);

   // "Otherwise, if some substring of search is a valid e-mail address:"
   } else if (new RegExp(validEmailRegexp).test(search)) {
       // "While there is no substring of node's data ending at end offset
       // that is a valid e-mail address, decrement end offset."
       while (!(new RegExp(validEmailRegexp + "$").test(node.substringData(0, endOffset)))) {
           endOffset--;
       }

       // "Let start offset be the start index of the longest substring of
       // node's data that is a valid e-mail address ending at end offset."
       var startOffset = new RegExp(validEmailRegexp + "$").exec(node.substringData(0, endOffset)).index;

       // "Let href be "mailto:" concatenated with the substring of node's
       // data starting at start offset and ending at end offset."
       var href = "mailto:" + node.substringData(startOffset, endOffset - startOffset);

   // "Otherwise, do nothing and abort these steps."
   } else {
       return;
   }

   // "Let original range be the active range."
   var originalRange = getActiveRange();

   // "Create a new range with start (node, start offset) and end (node, end
   // offset), and set the context object's selection's range to it."
   var newRange = document.createRange();
   newRange.setStart(node, startOffset);
   newRange.setEnd(node, endOffset);
   getSelection().removeAllRanges();
   getSelection().addRange(newRange);
   globalRange = newRange;

   // "Take the action for "createLink", with value equal to href."
   commands.createlink.action(href);

   // "Set the context object's selection's range to original range."
   getSelection().removeAllRanges();
   getSelection().addRange(originalRange);
   globalRange = originalRange;
}
//@}
///// The delete command /////
//@{
commands["delete"] = {
   preservesOverrides: true,
   action: function() {
       // "If the active range is not collapsed, delete the selection and
       // return true."
       if (!getActiveRange().collapsed) {
           deleteSelection();
           return true;
       }

       // "Canonicalize whitespace at the active range's start."
       canonicalizeWhitespace(getActiveRange().startContainer, getActiveRange().startOffset);

       // "Let node and offset be the active range's start node and offset."
       var node = getActiveRange().startContainer;
       var offset = getActiveRange().startOffset;

       // "Repeat the following steps:"
       while (true) {
           // "If offset is zero and node's previousSibling is an editable
           // invisible node, remove node's previousSibling from its parent."
           if (offset == 0
           && isEditable(node.previousSibling)
           && isInvisible(node.previousSibling)) {
               node.parentNode.removeChild(node.previousSibling);

           // "Otherwise, if node has a child with index offset − 1 and that
           // child is an editable invisible node, remove that child from
           // node, then subtract one from offset."
           } else if (0 <= offset - 1
           && offset - 1 < node.childNodes.length
           && isEditable(node.childNodes[offset - 1])
           && isInvisible(node.childNodes[offset - 1])) {
               node.removeChild(node.childNodes[offset - 1]);
               offset--;

           // "Otherwise, if offset is zero and node is an inline node, or if
           // node is an invisible node, set offset to the index of node, then
           // set node to its parent."
           } else if ((offset == 0
           && isInlineNode(node))
           || isInvisible(node)) {
               offset = getNodeIndex(node);
               node = node.parentNode;

           // "Otherwise, if node has a child with index offset − 1 and that
           // child is an editable a, remove that child from node, preserving
           // its descendants. Then return true."
           } else if (0 <= offset - 1
           && offset - 1 < node.childNodes.length
           && isEditable(node.childNodes[offset - 1])
           && isHtmlElement(node.childNodes[offset - 1], "a")) {
               removePreservingDescendants(node.childNodes[offset - 1]);
               return true;

           // "Otherwise, if node has a child with index offset − 1 and that
           // child is not a block node or a br or an img, set node to that
           // child, then set offset to the length of node."
           } else if (0 <= offset - 1
           && offset - 1 < node.childNodes.length
           && !isBlockNode(node.childNodes[offset - 1])
           && !isHtmlElement(node.childNodes[offset - 1], ["br", "img"])) {
               node = node.childNodes[offset - 1];
               offset = getNodeLength(node);

           // "Otherwise, break from this loop."
           } else {
               break;
           }
       }

       // "If node is a Text node and offset is not zero, or if node is a
       // block node that has a child with index offset − 1 and that child is
       // a br or hr or img:"
       if ((node.nodeType == Node.TEXT_NODE
       && offset != 0)
       || (isBlockNode(node)
       && 0 <= offset - 1
       && offset - 1 < node.childNodes.length
       && isHtmlElement(node.childNodes[offset - 1], ["br", "hr", "img"]))) {
           // "Call collapse(node, offset) on the context object's Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setEnd(node, offset);

           // "Call extend(node, offset − 1) on the context object's
           // Selection."
           getSelection().extend(node, offset - 1);
           getActiveRange().setStart(node, offset - 1);

           // "Delete the selection."
           deleteSelection();

           // "Return true."
           return true;
       }

       // "If node is an inline node, return true."
       if (isInlineNode(node)) {
           return true;
       }

       // "If node is an li or dt or dd and is the first child of its parent,
       // and offset is zero:"
       if (isHtmlElement(node, ["li", "dt", "dd"])
       && node == node.parentNode.firstChild
       && offset == 0) {
           // "Let items be a list of all lis that are ancestors of node."
           //
           // Remember, must be in tree order.
           var items = [];
           for (var ancestor = node.parentNode; ancestor; ancestor = ancestor.parentNode) {
               if (isHtmlElement(ancestor, "li")) {
                   items.unshift(ancestor);
               }
           }

           // "Normalize sublists of each item in items."
           for (var i = 0; i < items.length; i++) {
               normalizeSublists(items[i]);
           }

           // "Record the values of the one-node list consisting of node, and
           // let values be the result."
           var values = recordValues([node]);

           // "Split the parent of the one-node list consisting of node."
           splitParent([node]);

           // "Restore the values from values."
           restoreValues(values);

           // "If node is a dd or dt, and it is not an allowed child of any of
           // its ancestors in the same editing host, set the tag name of node
           // to the default single-line container name and let node be the
           // result."
           if (isHtmlElement(node, ["dd", "dt"])
           && getAncestors(node).every(function(ancestor) {
               return !inSameEditingHost(node, ancestor)
                   || !isAllowedChild(node, ancestor)
           })) {
               node = setTagName(node, defaultSingleLineContainerName);
           }

           // "Fix disallowed ancestors of node."
           fixDisallowedAncestors(node);

           // "Return true."
           return true;
       }

       // "Let start node equal node and let start offset equal offset."
       var startNode = node;
       var startOffset = offset;

       // "Repeat the following steps:"
       while (true) {
           // "If start offset is zero, set start offset to the index of start
           // node and then set start node to its parent."
           if (startOffset == 0) {
               startOffset = getNodeIndex(startNode);
               startNode = startNode.parentNode;

           // "Otherwise, if start node has an editable invisible child with
           // index start offset minus one, remove it from start node and
           // subtract one from start offset."
           } else if (0 <= startOffset - 1
           && startOffset - 1 < startNode.childNodes.length
           && isEditable(startNode.childNodes[startOffset - 1])
           && isInvisible(startNode.childNodes[startOffset - 1])) {
               startNode.removeChild(startNode.childNodes[startOffset - 1]);
               startOffset--;

           // "Otherwise, break from this loop."
           } else {
               break;
           }
       }

       // "If offset is zero, and node has an editable ancestor container in
       // the same editing host that's an indentation element:"
       if (offset == 0
       && getAncestors(node).concat(node).filter(function(ancestor) {
           return isEditable(ancestor)
               && inSameEditingHost(ancestor, node)
               && isIndentationElement(ancestor);
       }).length) {
           // "Block-extend the range whose start and end are both (node, 0),
           // and let new range be the result."
           var newRange = document.createRange();
           newRange.setStart(node, 0);
           newRange = blockExtend(newRange);

           // "Let node list be a list of nodes, initially empty."
           //
           // "For each node current node contained in new range, append
           // current node to node list if the last member of node list (if
           // any) is not an ancestor of current node, and current node is
           // editable but has no editable descendants."
           var nodeList = getContainedNodes(newRange, function(currentNode) {
               return isEditable(currentNode)
                   && !hasEditableDescendants(currentNode);
           });

           // "Outdent each node in node list."
           for (var i = 0; i < nodeList.length; i++) {
               outdentNode(nodeList[i]);
           }

           // "Return true."
           return true;
       }

       // "If the child of start node with index start offset is a table,
       // return true."
       if (isHtmlElement(startNode.childNodes[startOffset], "table")) {
           return true;
       }

       // "If start node has a child with index start offset − 1, and that
       // child is a table:"
       if (0 <= startOffset - 1
       && startOffset - 1 < startNode.childNodes.length
       && isHtmlElement(startNode.childNodes[startOffset - 1], "table")) {
           // "Call collapse(start node, start offset − 1) on the context
           // object's Selection."
           getSelection().collapse(startNode, startOffset - 1);
           getActiveRange().setStart(startNode, startOffset - 1);

           // "Call extend(start node, start offset) on the context object's
           // Selection."
           getSelection().extend(startNode, startOffset);
           getActiveRange().setEnd(startNode, startOffset);

           // "Return true."
           return true;
       }

       // "If offset is zero; and either the child of start node with index
       // start offset minus one is an hr, or the child is a br whose
       // previousSibling is either a br or not an inline node:"
       if (offset == 0
       && (isHtmlElement(startNode.childNodes[startOffset - 1], "hr")
           || (
               isHtmlElement(startNode.childNodes[startOffset - 1], "br")
               && (
                   isHtmlElement(startNode.childNodes[startOffset - 1].previousSibling, "br")
                   || !isInlineNode(startNode.childNodes[startOffset - 1].previousSibling)
               )
           )
       )) {
           // "Call collapse(start node, start offset − 1) on the context
           // object's Selection."
           getSelection().collapse(startNode, startOffset - 1);
           getActiveRange().setStart(startNode, startOffset - 1);

           // "Call extend(start node, start offset) on the context object's
           // Selection."
           getSelection().extend(startNode, startOffset);
           getActiveRange().setEnd(startNode, startOffset);

           // "Delete the selection."
           deleteSelection();

           // "Call collapse(node, offset) on the Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setStart(node, offset);
           getActiveRange().collapse(true);

           // "Return true."
           return true;
       }

       // "If the child of start node with index start offset is an li or dt
       // or dd, and that child's firstChild is an inline node, and start
       // offset is not zero:"
       if (isHtmlElement(startNode.childNodes[startOffset], ["li", "dt", "dd"])
       && isInlineNode(startNode.childNodes[startOffset].firstChild)
       && startOffset != 0) {
           // "Let previous item be the child of start node with index start
           // offset minus one."
           var previousItem = startNode.childNodes[startOffset - 1];

           // "If previous item's lastChild is an inline node other than a br,
           // call createElement("br") on the context object and append the
           // result as the last child of previous item."
           if (isInlineNode(previousItem.lastChild)
           && !isHtmlElement(previousItem.lastChild, "br")) {
               previousItem.appendChild(document.createElement("br"));
           }

           // "If previous item's lastChild is an inline node, call
           // createElement("br") on the context object and append the result
           // as the last child of previous item."
           if (isInlineNode(previousItem.lastChild)) {
               previousItem.appendChild(document.createElement("br"));
           }
       }

       // "If start node's child with index start offset is an li or dt or dd,
       // and that child's previousSibling is also an li or dt or dd:"
       if (isHtmlElement(startNode.childNodes[startOffset], ["li", "dt", "dd"])
       && isHtmlElement(startNode.childNodes[startOffset].previousSibling, ["li", "dt", "dd"])) {
           // "Call cloneRange() on the active range, and let original range
           // be the result."
           //
           // We need to add it to extraRanges so it will actually get updated
           // when moving preserving ranges.
           var originalRange = getActiveRange().cloneRange();
           extraRanges.push(originalRange);

           // "Set start node to its child with index start offset − 1."
           startNode = startNode.childNodes[startOffset - 1];

           // "Set start offset to start node's length."
           startOffset = getNodeLength(startNode);

           // "Set node to start node's nextSibling."
           node = startNode.nextSibling;

           // "Call collapse(start node, start offset) on the context object's
           // Selection."
           getSelection().collapse(startNode, startOffset);
           getActiveRange().setStart(startNode, startOffset);

           // "Call extend(node, 0) on the context object's Selection."
           getSelection().extend(node, 0);
           getActiveRange().setEnd(node, 0);

           // "Delete the selection."
           deleteSelection();

           // "Call removeAllRanges() on the context object's Selection."
           getSelection().removeAllRanges();

           // "Call addRange(original range) on the context object's
           // Selection."
           getSelection().addRange(originalRange);
           getActiveRange().setStart(originalRange.startContainer, originalRange.startOffset);
           getActiveRange().setEnd(originalRange.endContainer, originalRange.endOffset);

           // "Return true."
           extraRanges.pop();
           return true;
       }

       // "While start node has a child with index start offset minus one:"
       while (0 <= startOffset - 1
       && startOffset - 1 < startNode.childNodes.length) {
           // "If start node's child with index start offset minus one is
           // editable and invisible, remove it from start node, then subtract
           // one from start offset."
           if (isEditable(startNode.childNodes[startOffset - 1])
           && isInvisible(startNode.childNodes[startOffset - 1])) {
               startNode.removeChild(startNode.childNodes[startOffset - 1]);
               startOffset--;

           // "Otherwise, set start node to its child with index start offset
           // minus one, then set start offset to the length of start node."
           } else {
               startNode = startNode.childNodes[startOffset - 1];
               startOffset = getNodeLength(startNode);
           }
       }

       // "Call collapse(start node, start offset) on the context object's
       // Selection."
       getSelection().collapse(startNode, startOffset);
       getActiveRange().setStart(startNode, startOffset);

       // "Call extend(node, offset) on the context object's Selection."
       getSelection().extend(node, offset);
       getActiveRange().setEnd(node, offset);

       // "Delete the selection, with direction "backward"."
       deleteSelection({direction: "backward"});

       // "Return true."
       return true;
   }
};

//@}
///// The formatBlock command /////
//@{
// "A formattable block name is "address", "dd", "div", "dt", "h1", "h2", "h3",
// "h4", "h5", "h6", "p", or "pre"."
var formattableBlockNames = ["address", "dd", "div", "dt", "h1", "h2", "h3",
   "h4", "h5", "h6", "p", "pre"];

commands.formatblock = {
   preservesOverrides: true,
   action: function(value) {
       // "If value begins with a "<" character and ends with a ">" character,
       // remove the first and last characters from it."
       if (/^<.*>$/.test(value)) {
           value = value.slice(1, -1);
       }

       // "Let value be converted to ASCII lowercase."
       value = value.toLowerCase();

       // "If value is not a formattable block name, return false."
       if (formattableBlockNames.indexOf(value) == -1) {
           return false;
       }

       // "Block-extend the active range, and let new range be the result."
       var newRange = blockExtend(getActiveRange());

       // "Let node list be an empty list of nodes."
       //
       // "For each node node contained in new range, append node to node list
       // if it is editable, the last member of original node list (if any) is
       // not an ancestor of node, node is either a non-list single-line
       // container or an allowed child of "p" or a dd or dt, and node is not
       // the ancestor of a prohibited paragraph child."
       var nodeList = getContainedNodes(newRange, function(node) {
           return isEditable(node)
               && (isNonListSingleLineContainer(node)
               || isAllowedChild(node, "p")
               || isHtmlElement(node, ["dd", "dt"]))
               && !getDescendants(node).some(isProhibitedParagraphChild);
       });

       // "Record the values of node list, and let values be the result."
       var values = recordValues(nodeList);

       // "For each node in node list, while node is the descendant of an
       // editable HTML element in the same editing host, whose local name is
       // a formattable block name, and which is not the ancestor of a
       // prohibited paragraph child, split the parent of the one-node list
       // consisting of node."
       for (var i = 0; i < nodeList.length; i++) {
           var node = nodeList[i];
           while (getAncestors(node).some(function(ancestor) {
               return isEditable(ancestor)
                   && inSameEditingHost(ancestor, node)
                   && isHtmlElement(ancestor, formattableBlockNames)
                   && !getDescendants(ancestor).some(isProhibitedParagraphChild);
           })) {
               splitParent([node]);
           }
       }

       // "Restore the values from values."
       restoreValues(values);

       // "While node list is not empty:"
       while (nodeList.length) {
           var sublist;

           // "If the first member of node list is a single-line
           // container:"
           if (isSingleLineContainer(nodeList[0])) {
               // "Let sublist be the children of the first member of node
               // list."
               sublist = [].slice.call(nodeList[0].childNodes);

               // "Record the values of sublist, and let values be the
               // result."
               var values = recordValues(sublist);

               // "Remove the first member of node list from its parent,
               // preserving its descendants."
               removePreservingDescendants(nodeList[0]);

               // "Restore the values from values."
               restoreValues(values);

               // "Remove the first member from node list."
               nodeList.shift();

           // "Otherwise:"
           } else {
               // "Let sublist be an empty list of nodes."
               sublist = [];

               // "Remove the first member of node list and append it to
               // sublist."
               sublist.push(nodeList.shift());

               // "While node list is not empty, and the first member of
               // node list is the nextSibling of the last member of
               // sublist, and the first member of node list is not a
               // single-line container, and the last member of sublist is
               // not a br, remove the first member of node list and
               // append it to sublist."
               while (nodeList.length
               && nodeList[0] == sublist[sublist.length - 1].nextSibling
               && !isSingleLineContainer(nodeList[0])
               && !isHtmlElement(sublist[sublist.length - 1], "BR")) {
                   sublist.push(nodeList.shift());
               }
           }

           // "Wrap sublist. If value is "div" or "p", sibling criteria
           // returns false; otherwise it returns true for an HTML element
           // with local name value and no attributes, and false otherwise.
           // New parent instructions return the result of running
           // createElement(value) on the context object. Then fix disallowed
           // ancestors of the result."
           fixDisallowedAncestors(wrap(sublist,
               ["div", "p"].indexOf(value) == - 1
                   ? function(node) { return isHtmlElement(node, value) && !node.attributes.length }
                   : function() { return false },
               function() { return document.createElement(value) }));
       }

       // "Return true."
       return true;
   }, indeterm: function() {
       // "If the active range is null, return false."
       if (!getActiveRange()) {
           return false;
       }

       // "Block-extend the active range, and let new range be the result."
       var newRange = blockExtend(getActiveRange());

       // "Let node list be all visible editable nodes that are contained in
       // new range and have no children."
       var nodeList = getAllContainedNodes(newRange, function(node) {
           return isVisible(node)
               && isEditable(node)
               && !node.hasChildNodes();
       });

       // "If node list is empty, return false."
       if (!nodeList.length) {
           return false;
       }

       // "Let type be null."
       var type = null;

       // "For each node in node list:"
       for (var i = 0; i < nodeList.length; i++) {
           var node = nodeList[i];

           // "While node's parent is editable and in the same editing host as
           // node, and node is not an HTML element whose local name is a
           // formattable block name, set node to its parent."
           while (isEditable(node.parentNode)
           && inSameEditingHost(node, node.parentNode)
           && !isHtmlElement(node, formattableBlockNames)) {
               node = node.parentNode;
           }

           // "Let current type be the empty string."
           var currentType = "";

           // "If node is an editable HTML element whose local name is a
           // formattable block name, and node is not the ancestor of a
           // prohibited paragraph child, set current type to node's local
           // name."
           if (isEditable(node)
           && isHtmlElement(node, formattableBlockNames)
           && !getDescendants(node).some(isProhibitedParagraphChild)) {
               currentType = node.tagName;
           }

           // "If type is null, set type to current type."
           if (type === null) {
               type = currentType;

           // "Otherwise, if type does not equal current type, return true."
           } else if (type != currentType) {
               return true;
           }
       }

       // "Return false."
       return false;
   }, value: function() {
       // "If the active range is null, return the empty string."
       if (!getActiveRange()) {
           return "";
       }

       // "Block-extend the active range, and let new range be the result."
       var newRange = blockExtend(getActiveRange());

       // "Let node be the first visible editable node that is contained in
       // new range and has no children. If there is no such node, return the
       // empty string."
       var nodes = getAllContainedNodes(newRange, function(node) {
           return isVisible(node)
               && isEditable(node)
               && !node.hasChildNodes();
       });
       if (!nodes.length) {
           return "";
       }
       var node = nodes[0];

       // "While node's parent is editable and in the same editing host as
       // node, and node is not an HTML element whose local name is a
       // formattable block name, set node to its parent."
       while (isEditable(node.parentNode)
       && inSameEditingHost(node, node.parentNode)
       && !isHtmlElement(node, formattableBlockNames)) {
           node = node.parentNode;
       }

       // "If node is an editable HTML element whose local name is a
       // formattable block name, and node is not the ancestor of a prohibited
       // paragraph child, return node's local name, converted to ASCII
       // lowercase."
       if (isEditable(node)
       && isHtmlElement(node, formattableBlockNames)
       && !getDescendants(node).some(isProhibitedParagraphChild)) {
           return node.tagName.toLowerCase();
       }

       // "Return the empty string."
       return "";
   }
};

//@}
///// The forwardDelete command /////
//@{
commands.forwarddelete = {
   preservesOverrides: true,
   action: function() {
       // "If the active range is not collapsed, delete the selection and
       // return true."
       if (!getActiveRange().collapsed) {
           deleteSelection();
           return true;
       }

       // "Canonicalize whitespace at the active range's start."
       canonicalizeWhitespace(getActiveRange().startContainer, getActiveRange().startOffset);

       // "Let node and offset be the active range's start node and offset."
       var node = getActiveRange().startContainer;
       var offset = getActiveRange().startOffset;

       // "Repeat the following steps:"
       while (true) {
           // "If offset is the length of node and node's nextSibling is an
           // editable invisible node, remove node's nextSibling from its
           // parent."
           if (offset == getNodeLength(node)
           && isEditable(node.nextSibling)
           && isInvisible(node.nextSibling)) {
               node.parentNode.removeChild(node.nextSibling);

           // "Otherwise, if node has a child with index offset and that child
           // is an editable invisible node, remove that child from node."
           } else if (offset < node.childNodes.length
           && isEditable(node.childNodes[offset])
           && isInvisible(node.childNodes[offset])) {
               node.removeChild(node.childNodes[offset]);

           // "Otherwise, if offset is the length of node and node is an
           // inline node, or if node is invisible, set offset to one plus the
           // index of node, then set node to its parent."
           } else if ((offset == getNodeLength(node)
           && isInlineNode(node))
           || isInvisible(node)) {
               offset = 1 + getNodeIndex(node);
               node = node.parentNode;

           // "Otherwise, if node has a child with index offset and that child
           // is neither a block node nor a br nor an img nor a collapsed
           // block prop, set node to that child, then set offset to zero."
           } else if (offset < node.childNodes.length
           && !isBlockNode(node.childNodes[offset])
           && !isHtmlElement(node.childNodes[offset], ["br", "img"])
           && !isCollapsedBlockProp(node.childNodes[offset])) {
               node = node.childNodes[offset];
               offset = 0;

           // "Otherwise, break from this loop."
           } else {
               break;
           }
       }

       // "If node is a Text node and offset is not node's length:"
       if (node.nodeType == Node.TEXT_NODE
       && offset != getNodeLength(node)) {
           // "Let end offset be offset plus one."
           var endOffset = offset + 1;

           // "While end offset is not node's length and the end offsetth
           // element of node's data has general category M when interpreted
           // as a Unicode code point, add one to end offset."
           //
           // TODO: Not even going to try handling anything beyond the most
           // basic combining marks, since I couldn't find a good list.  I
           // special-case a few Hebrew diacritics too to test basic coverage
           // of non-Latin stuff.
           while (endOffset != node.length
           && /^[\u0300-\u036f\u0591-\u05bd\u05c1\u05c2]$/.test(node.data[endOffset])) {
               endOffset++;
           }

           // "Call collapse(node, offset) on the context object's Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setStart(node, offset);

           // "Call extend(node, end offset) on the context object's
           // Selection."
           getSelection().extend(node, endOffset);
           getActiveRange().setEnd(node, endOffset);

           // "Delete the selection."
           deleteSelection();

           // "Return true."
           return true;
       }

       // "If node is an inline node, return true."
       if (isInlineNode(node)) {
           return true;
       }

       // "If node has a child with index offset and that child is a br or hr
       // or img, but is not a collapsed block prop:"
       if (offset < node.childNodes.length
       && isHtmlElement(node.childNodes[offset], ["br", "hr", "img"])
       && !isCollapsedBlockProp(node.childNodes[offset])) {
           // "Call collapse(node, offset) on the context object's Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setStart(node, offset);

           // "Call extend(node, offset + 1) on the context object's
           // Selection."
           getSelection().extend(node, offset + 1);
           getActiveRange().setEnd(node, offset + 1);

           // "Delete the selection."
           deleteSelection();

           // "Return true."
           return true;
       }

       // "Let end node equal node and let end offset equal offset."
       var endNode = node;
       var endOffset = offset;

       // "If end node has a child with index end offset, and that child is a
       // collapsed block prop, add one to end offset."
       if (endOffset < endNode.childNodes.length
       && isCollapsedBlockProp(endNode.childNodes[endOffset])) {
           endOffset++;
       }

       // "Repeat the following steps:"
       while (true) {
           // "If end offset is the length of end node, set end offset to one
           // plus the index of end node and then set end node to its parent."
           if (endOffset == getNodeLength(endNode)) {
               endOffset = 1 + getNodeIndex(endNode);
               endNode = endNode.parentNode;

           // "Otherwise, if end node has a an editable invisible child with
           // index end offset, remove it from end node."
           } else if (endOffset < endNode.childNodes.length
           && isEditable(endNode.childNodes[endOffset])
           && isInvisible(endNode.childNodes[endOffset])) {
               endNode.removeChild(endNode.childNodes[endOffset]);

           // "Otherwise, break from this loop."
           } else {
               break;
           }
       }

       // "If the child of end node with index end offset minus one is a
       // table, return true."
       if (isHtmlElement(endNode.childNodes[endOffset - 1], "table")) {
           return true;
       }

       // "If the child of end node with index end offset is a table:"
       if (isHtmlElement(endNode.childNodes[endOffset], "table")) {
           // "Call collapse(end node, end offset) on the context object's
           // Selection."
           getSelection().collapse(endNode, endOffset);
           getActiveRange().setStart(endNode, endOffset);

           // "Call extend(end node, end offset + 1) on the context object's
           // Selection."
           getSelection().extend(endNode, endOffset + 1);
           getActiveRange().setEnd(endNode, endOffset + 1);

           // "Return true."
           return true;
       }

       // "If offset is the length of node, and the child of end node with
       // index end offset is an hr or br:"
       if (offset == getNodeLength(node)
       && isHtmlElement(endNode.childNodes[endOffset], ["br", "hr"])) {
           // "Call collapse(end node, end offset) on the context object's
           // Selection."
           getSelection().collapse(endNode, endOffset);
           getActiveRange().setStart(endNode, endOffset);

           // "Call extend(end node, end offset + 1) on the context object's
           // Selection."
           getSelection().extend(endNode, endOffset + 1);
           getActiveRange().setEnd(endNode, endOffset + 1);

           // "Delete the selection."
           deleteSelection();

           // "Call collapse(node, offset) on the Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setStart(node, offset);
           getActiveRange().collapse(true);

           // "Return true."
           return true;
       }

       // "While end node has a child with index end offset:"
       while (endOffset < endNode.childNodes.length) {
           // "If end node's child with index end offset is editable and
           // invisible, remove it from end node."
           if (isEditable(endNode.childNodes[endOffset])
           && isInvisible(endNode.childNodes[endOffset])) {
               endNode.removeChild(endNode.childNodes[endOffset]);

           // "Otherwise, set end node to its child with index end offset and
           // set end offset to zero."
           } else {
               endNode = endNode.childNodes[endOffset];
               endOffset = 0;
           }
       }

       // "Call collapse(node, offset) on the context object's Selection."
       getSelection().collapse(node, offset);
       getActiveRange().setStart(node, offset);

       // "Call extend(end node, end offset) on the context object's
       // Selection."
       getSelection().extend(endNode, endOffset);
       getActiveRange().setEnd(endNode, endOffset);

       // "Delete the selection."
       deleteSelection();

       // "Return true."
       return true;
   }
};

//@}
///// The indent command /////
//@{
commands.indent = {
   preservesOverrides: true,
   action: function() {
       // "Let items be a list of all lis that are ancestor containers of the
       // active range's start and/or end node."
       //
       // Has to be in tree order, remember!
       var items = [];
       for (var node = getActiveRange().endContainer; node != getActiveRange().commonAncestorContainer; node = node.parentNode) {
           if (isHtmlElement(node, "LI")) {
               items.unshift(node);
           }
       }
       for (var node = getActiveRange().startContainer; node != getActiveRange().commonAncestorContainer; node = node.parentNode) {
           if (isHtmlElement(node, "LI")) {
               items.unshift(node);
           }
       }
       for (var node = getActiveRange().commonAncestorContainer; node; node = node.parentNode) {
           if (isHtmlElement(node, "LI")) {
               items.unshift(node);
           }
       }

       // "For each item in items, normalize sublists of item."
       for (var i = 0; i < items.length; i++) {
           normalizeSublists(items[i]);
       }

       // "Block-extend the active range, and let new range be the result."
       var newRange = blockExtend(getActiveRange());

       // "Let node list be a list of nodes, initially empty."
       var nodeList = [];

       // "For each node node contained in new range, if node is editable and
       // is an allowed child of "div" or "ol" and if the last member of node
       // list (if any) is not an ancestor of node, append node to node list."
       nodeList = getContainedNodes(newRange, function(node) {
           return isEditable(node)
               && (isAllowedChild(node, "div")
               || isAllowedChild(node, "ol"));
       });

       // "If the first visible member of node list is an li whose parent is
       // an ol or ul:"
       if (isHtmlElement(nodeList.filter(isVisible)[0], "li")
       && isHtmlElement(nodeList.filter(isVisible)[0].parentNode, ["ol", "ul"])) {
           // "Let sibling be node list's first visible member's
           // previousSibling."
           var sibling = nodeList.filter(isVisible)[0].previousSibling;

           // "While sibling is invisible, set sibling to its
           // previousSibling."
           while (isInvisible(sibling)) {
               sibling = sibling.previousSibling;
           }

           // "If sibling is an li, normalize sublists of sibling."
           if (isHtmlElement(sibling, "li")) {
               normalizeSublists(sibling);
           }
       }

       // "While node list is not empty:"
       while (nodeList.length) {
           // "Let sublist be a list of nodes, initially empty."
           var sublist = [];

           // "Remove the first member of node list and append it to sublist."
           sublist.push(nodeList.shift());

           // "While the first member of node list is the nextSibling of the
           // last member of sublist, remove the first member of node list and
           // append it to sublist."
           while (nodeList.length
           && nodeList[0] == sublist[sublist.length - 1].nextSibling) {
               sublist.push(nodeList.shift());
           }

           // "Indent sublist."
           indentNodes(sublist);
       }

       // "Return true."
       return true;
   }
};

//@}
///// The insertHorizontalRule command /////
//@{
commands.inserthorizontalrule = {
   preservesOverrides: true,
   action: function() {
       // "Let start node, start offset, end node, and end offset be the
       // active range's start and end nodes and offsets."
       var startNode = getActiveRange().startContainer;
       var startOffset = getActiveRange().startOffset;
       var endNode = getActiveRange().endContainer;
       var endOffset = getActiveRange().endOffset;

       // "While start offset is 0 and start node's parent is not null, set
       // start offset to start node's index, then set start node to its
       // parent."
       while (startOffset == 0
       && startNode.parentNode) {
           startOffset = getNodeIndex(startNode);
           startNode = startNode.parentNode;
       }

       // "While end offset is end node's length, and end node's parent is not
       // null, set end offset to one plus end node's index, then set end node
       // to its parent."
       while (endOffset == getNodeLength(endNode)
       && endNode.parentNode) {
           endOffset = 1 + getNodeIndex(endNode);
           endNode = endNode.parentNode;
       }

       // "Call collapse(start node, start offset) on the context object's
       // Selection."
       getSelection().collapse(startNode, startOffset);
       getActiveRange().setStart(startNode, startOffset);

       // "Call extend(end node, end offset) on the context object's
       // Selection."
       getSelection().extend(endNode, endOffset);
       getActiveRange().setEnd(endNode, endOffset);

       // "Delete the selection, with block merging false."
       deleteSelection({blockMerging: false});

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "If the active range's start node is a Text node and its start
       // offset is zero, call collapse() on the context object's Selection,
       // with first argument the active range's start node's parent and
       // second argument the active range's start node's index."
       if (getActiveRange().startContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().startOffset == 0) {
           var newNode = getActiveRange().startContainer.parentNode;
           var newOffset = getNodeIndex(getActiveRange().startContainer);
           getSelection().collapse(newNode, newOffset);
           getActiveRange().setStart(newNode, newOffset);
           getActiveRange().collapse(true);
       }

       // "If the active range's start node is a Text node and its start
       // offset is the length of its start node, call collapse() on the
       // context object's Selection, with first argument the active range's
       // start node's parent, and the second argument one plus the active
       // range's start node's index."
       if (getActiveRange().startContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().startOffset == getNodeLength(getActiveRange().startContainer)) {
           var newNode = getActiveRange().startContainer.parentNode;
           var newOffset = 1 + getNodeIndex(getActiveRange().startContainer);
           getSelection().collapse(newNode, newOffset);
           getActiveRange().setStart(newNode, newOffset);
           getActiveRange().collapse(true);
       }

       // "Let hr be the result of calling createElement("hr") on the
       // context object."
       var hr = document.createElement("hr");

       // "Run insertNode(hr) on the active range."
       getActiveRange().insertNode(hr);

       // "Fix disallowed ancestors of hr."
       fixDisallowedAncestors(hr);

       // "Run collapse() on the context object's Selection, with first
       // argument hr's parent and the second argument equal to one plus hr's
       // index."
       getSelection().collapse(hr.parentNode, 1 + getNodeIndex(hr));
       getActiveRange().setStart(hr.parentNode, 1 + getNodeIndex(hr));
       getActiveRange().collapse(true);

       // "Return true."
       return true;
   }
};

//@}
///// The insertHTML command /////
//@{
commands.inserthtml = {
   preservesOverrides: true,
   action: function(value) {
       // "Delete the selection."
       deleteSelection();

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "Let frag be the result of calling createContextualFragment(value)
       // on the active range."
       var frag = getActiveRange().createContextualFragment(value);

       // "Let last child be the lastChild of frag."
       var lastChild = frag.lastChild;

       // "If last child is null, return true."
       if (!lastChild) {
           return true;
       }

       // "Let descendants be all descendants of frag."
       var descendants = getDescendants(frag);

       // "If the active range's start node is a block node:"
       if (isBlockNode(getActiveRange().startContainer)) {
           // "Let collapsed block props be all editable collapsed block prop
           // children of the active range's start node that have index
           // greater than or equal to the active range's start offset."
           //
           // "For each node in collapsed block props, remove node from its
           // parent."
           [].filter.call(getActiveRange().startContainer.childNodes, function(node) {
               return isEditable(node)
                   && isCollapsedBlockProp(node)
                   && getNodeIndex(node) >= getActiveRange().startOffset;
           }).forEach(function(node) {
               node.parentNode.removeChild(node);
           });
       }

       // "Call insertNode(frag) on the active range."
       getActiveRange().insertNode(frag);

       // "If the active range's start node is a block node with no visible
       // children, call createElement("br") on the context object and append
       // the result as the last child of the active range's start node."
       if (isBlockNode(getActiveRange().startContainer)
       && ![].some.call(getActiveRange().startContainer.childNodes, isVisible)) {
           getActiveRange().startContainer.appendChild(document.createElement("br"));
       }

       // "Call collapse() on the context object's Selection, with last
       // child's parent as the first argument and one plus its index as the
       // second."
       getActiveRange().setStart(lastChild.parentNode, 1 + getNodeIndex(lastChild));
       getActiveRange().setEnd(lastChild.parentNode, 1 + getNodeIndex(lastChild));

       // "Fix disallowed ancestors of each member of descendants."
       for (var i = 0; i < descendants.length; i++) {
           fixDisallowedAncestors(descendants[i]);
       }

       // "Return true."
       return true;
   }
};

//@}
///// The insertImage command /////
//@{
commands.insertimage = {
   preservesOverrides: true,
   action: function(value) {
       // "If value is the empty string, return false."
       if (value === "") {
           return false;
       }

       // "Delete the selection, with strip wrappers false."
       deleteSelection({stripWrappers: false});

       // "Let range be the active range."
       var range = getActiveRange();

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "If range's start node is a block node whose sole child is a br, and
       // its start offset is 0, remove its start node's child from it."
       if (isBlockNode(range.startContainer)
       && range.startContainer.childNodes.length == 1
       && isHtmlElement(range.startContainer.firstChild, "br")
       && range.startOffset == 0) {
           range.startContainer.removeChild(range.startContainer.firstChild);
       }

       // "Let img be the result of calling createElement("img") on the
       // context object."
       var img = document.createElement("img");

       // "Run setAttribute("src", value) on img."
       img.setAttribute("src", value);

       // "Run insertNode(img) on the range."
       range.insertNode(img);

       // "Run collapse() on the Selection, with first argument equal to the
       // parent of img and the second argument equal to one plus the index of
       // img."
       //
       // Not everyone actually supports collapse(), so we do it manually
       // instead.  Also, we need to modify the actual range we're given as
       // well, for the sake of autoimplementation.html's range-filling-in.
       range.setStart(img.parentNode, 1 + getNodeIndex(img));
       range.setEnd(img.parentNode, 1 + getNodeIndex(img));
       getSelection().removeAllRanges();
       getSelection().addRange(range);

       // IE adds width and height attributes for some reason, so remove those
       // to actually do what the spec says.
       img.removeAttribute("width");
       img.removeAttribute("height");

       // "Return true."
       return true;
   }
};

//@}
///// The insertLineBreak command /////
//@{
commands.insertlinebreak = {
   preservesOverrides: true,
   action: function(value) {
       // "Delete the selection, with strip wrappers false."
       deleteSelection({stripWrappers: false});

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "If the active range's start node is an Element, and "br" is not an
       // allowed child of it, return true."
       if (getActiveRange().startContainer.nodeType == Node.ELEMENT_NODE
       && !isAllowedChild("br", getActiveRange().startContainer)) {
           return true;
       }

       // "If the active range's start node is not an Element, and "br" is not
       // an allowed child of the active range's start node's parent, return
       // true."
       if (getActiveRange().startContainer.nodeType != Node.ELEMENT_NODE
       && !isAllowedChild("br", getActiveRange().startContainer.parentNode)) {
           return true;
       }

       // "If the active range's start node is a Text node and its start
       // offset is zero, call collapse() on the context object's Selection,
       // with first argument equal to the active range's start node's parent
       // and second argument equal to the active range's start node's index."
       if (getActiveRange().startContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().startOffset == 0) {
           var newNode = getActiveRange().startContainer.parentNode;
           var newOffset = getNodeIndex(getActiveRange().startContainer);
           getSelection().collapse(newNode, newOffset);
           getActiveRange().setStart(newNode, newOffset);
           getActiveRange().setEnd(newNode, newOffset);
       }

       // "If the active range's start node is a Text node and its start
       // offset is the length of its start node, call collapse() on the
       // context object's Selection, with first argument equal to the active
       // range's start node's parent and second argument equal to one plus
       // the active range's start node's index."
       if (getActiveRange().startContainer.nodeType == Node.TEXT_NODE
       && getActiveRange().startOffset == getNodeLength(getActiveRange().startContainer)) {
           var newNode = getActiveRange().startContainer.parentNode;
           var newOffset = 1 + getNodeIndex(getActiveRange().startContainer);
           getSelection().collapse(newNode, newOffset);
           getActiveRange().setStart(newNode, newOffset);
           getActiveRange().setEnd(newNode, newOffset);
       }

       // "Let br be the result of calling createElement("br") on the context
       // object."
       var br = document.createElement("br");

       // "Call insertNode(br) on the active range."
       getActiveRange().insertNode(br);

       // "Call collapse() on the context object's Selection, with br's parent
       // as the first argument and one plus br's index as the second
       // argument."
       getSelection().collapse(br.parentNode, 1 + getNodeIndex(br));
       getActiveRange().setStart(br.parentNode, 1 + getNodeIndex(br));
       getActiveRange().setEnd(br.parentNode, 1 + getNodeIndex(br));

       // "If br is a collapsed line break, call createElement("br") on the
       // context object and let extra br be the result, then call
       // insertNode(extra br) on the active range."
       if (isCollapsedLineBreak(br)) {
           getActiveRange().insertNode(document.createElement("br"));

           // Compensate for nonstandard implementations of insertNode
           getSelection().collapse(br.parentNode, 1 + getNodeIndex(br));
           getActiveRange().setStart(br.parentNode, 1 + getNodeIndex(br));
           getActiveRange().setEnd(br.parentNode, 1 + getNodeIndex(br));
       }

       // "Return true."
       return true;
   }
};

//@}
///// The insertOrderedList command /////
//@{
commands.insertorderedlist = {
   preservesOverrides: true,
   // "Toggle lists with tag name "ol", then return true."
   action: function() { toggleLists("ol"); return true },
   // "True if the selection's list state is "mixed" or "mixed ol", false
   // otherwise."
   indeterm: function() { return /^mixed( ol)?$/.test(getSelectionListState()) },
   // "True if the selection's list state is "ol", false otherwise."
   state: function() { return getSelectionListState() == "ol" },
};

//@}
///// The insertParagraph command /////
//@{
commands.insertparagraph = {
   preservesOverrides: true,
   action: function() {
       // "Delete the selection."
       deleteSelection();

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "Let node and offset be the active range's start node and offset."
       var node = getActiveRange().startContainer;
       var offset = getActiveRange().startOffset;

       // "If node is a Text node, and offset is neither 0 nor the length of
       // node, call splitText(offset) on node."
       if (node.nodeType == Node.TEXT_NODE
       && offset != 0
       && offset != getNodeLength(node)) {
           node.splitText(offset);
       }

       // "If node is a Text node and offset is its length, set offset to one
       // plus the index of node, then set node to its parent."
       if (node.nodeType == Node.TEXT_NODE
       && offset == getNodeLength(node)) {
           offset = 1 + getNodeIndex(node);
           node = node.parentNode;
       }

       // "If node is a Text or Comment node, set offset to the index of node,
       // then set node to its parent."
       if (node.nodeType == Node.TEXT_NODE
       || node.nodeType == Node.COMMENT_NODE) {
           offset = getNodeIndex(node);
           node = node.parentNode;
       }

       // "Call collapse(node, offset) on the context object's Selection."
       getSelection().collapse(node, offset);
       getActiveRange().setStart(node, offset);
       getActiveRange().setEnd(node, offset);

       // "Let container equal node."
       var container = node;

       // "While container is not a single-line container, and container's
       // parent is editable and in the same editing host as node, set
       // container to its parent."
       while (!isSingleLineContainer(container)
       && isEditable(container.parentNode)
       && inSameEditingHost(node, container.parentNode)) {
           container = container.parentNode;
       }

       // "If container is an editable single-line container in the same
       // editing host as node, and its local name is "p" or "div":"
       if (isEditable(container)
       && isSingleLineContainer(container)
       && inSameEditingHost(node, container.parentNode)
       && (container.tagName == "P" || container.tagName == "DIV")) {
           // "Let outer container equal container."
           var outerContainer = container;

           // "While outer container is not a dd or dt or li, and outer
           // container's parent is editable, set outer container to its
           // parent."
           while (!isHtmlElement(outerContainer, ["dd", "dt", "li"])
           && isEditable(outerContainer.parentNode)) {
               outerContainer = outerContainer.parentNode;
           }

           // "If outer container is a dd or dt or li, set container to outer
           // container."
           if (isHtmlElement(outerContainer, ["dd", "dt", "li"])) {
               container = outerContainer;
           }
       }

       // "If container is not editable or not in the same editing host as
       // node or is not a single-line container:"
       if (!isEditable(container)
       || !inSameEditingHost(container, node)
       || !isSingleLineContainer(container)) {
           // "Let tag be the default single-line container name."
           var tag = defaultSingleLineContainerName;

           // "Block-extend the active range, and let new range be the
           // result."
           var newRange = blockExtend(getActiveRange());

           // "Let node list be a list of nodes, initially empty."
           //
           // "Append to node list the first node in tree order that is
           // contained in new range and is an allowed child of "p", if any."
           var nodeList = getContainedNodes(newRange, function(node) { return isAllowedChild(node, "p") })
               .slice(0, 1);

           // "If node list is empty:"
           if (!nodeList.length) {
               // "If tag is not an allowed child of the active range's start
               // node, return true."
               if (!isAllowedChild(tag, getActiveRange().startContainer)) {
                   return true;
               }

               // "Set container to the result of calling createElement(tag)
               // on the context object."
               container = document.createElement(tag);

               // "Call insertNode(container) on the active range."
               getActiveRange().insertNode(container);

               // "Call createElement("br") on the context object, and append
               // the result as the last child of container."
               container.appendChild(document.createElement("br"));

               // "Call collapse(container, 0) on the context object's
               // Selection."
               getSelection().collapse(container, 0);
               getActiveRange().setStart(container, 0);
               getActiveRange().setEnd(container, 0);

               // "Return true."
               return true;
           }

           // "While the nextSibling of the last member of node list is not
           // null and is an allowed child of "p", append it to node list."
           while (nodeList[nodeList.length - 1].nextSibling
           && isAllowedChild(nodeList[nodeList.length - 1].nextSibling, "p")) {
               nodeList.push(nodeList[nodeList.length - 1].nextSibling);
           }

           // "Wrap node list, with sibling criteria returning false and new
           // parent instructions returning the result of calling
           // createElement(tag) on the context object. Set container to the
           // result."
           container = wrap(nodeList,
               function() { return false },
               function() { return document.createElement(tag) }
           );
       }

       // "If container's local name is "address", "listing", or "pre":"
       if (container.tagName == "ADDRESS"
       || container.tagName == "LISTING"
       || container.tagName == "PRE") {
           // "Let br be the result of calling createElement("br") on the
           // context object."
           var br = document.createElement("br");

           // "Call insertNode(br) on the active range."
           getActiveRange().insertNode(br);

           // "Call collapse(node, offset + 1) on the context object's
           // Selection."
           getSelection().collapse(node, offset + 1);
           getActiveRange().setStart(node, offset + 1);
           getActiveRange().setEnd(node, offset + 1);

           // "If br is the last descendant of container, let br be the result
           // of calling createElement("br") on the context object, then call
           // insertNode(br) on the active range."
           //
           // Work around browser bugs: some browsers select the
           // newly-inserted node, not per spec.
           if (!isDescendant(nextNode(br), container)) {
               getActiveRange().insertNode(document.createElement("br"));
               getSelection().collapse(node, offset + 1);
               getActiveRange().setEnd(node, offset + 1);
           }

           // "Return true."
           return true;
       }

       // "If container's local name is "li", "dt", or "dd"; and either it has
       // no children or it has a single child and that child is a br:"
       if (["LI", "DT", "DD"].indexOf(container.tagName) != -1
       && (!container.hasChildNodes()
       || (container.childNodes.length == 1
       && isHtmlElement(container.firstChild, "br")))) {
           // "Split the parent of the one-node list consisting of container."
           splitParent([container]);

           // "If container has no children, call createElement("br") on the
           // context object and append the result as the last child of
           // container."
           if (!container.hasChildNodes()) {
               container.appendChild(document.createElement("br"));
           }

           // "If container is a dd or dt, and it is not an allowed child of
           // any of its ancestors in the same editing host, set the tag name
           // of container to the default single-line container name and let
           // container be the result."
           if (isHtmlElement(container, ["dd", "dt"])
           && getAncestors(container).every(function(ancestor) {
               return !inSameEditingHost(container, ancestor)
                   || !isAllowedChild(container, ancestor)
           })) {
               container = setTagName(container, defaultSingleLineContainerName);
           }

           // "Fix disallowed ancestors of container."
           fixDisallowedAncestors(container);

           // "Return true."
           return true;
       }

       // "Let new line range be a new range whose start is the same as
       // the active range's, and whose end is (container, length of
       // container)."
       var newLineRange = document.createRange();
       newLineRange.setStart(getActiveRange().startContainer, getActiveRange().startOffset);
       newLineRange.setEnd(container, getNodeLength(container));

       // "While new line range's start offset is zero and its start node is
       // not a prohibited paragraph child, set its start to (parent of start
       // node, index of start node)."
       while (newLineRange.startOffset == 0
       && !isProhibitedParagraphChild(newLineRange.startContainer)) {
           newLineRange.setStart(newLineRange.startContainer.parentNode, getNodeIndex(newLineRange.startContainer));
       }

       // "While new line range's start offset is the length of its start node
       // and its start node is not a prohibited paragraph child, set its
       // start to (parent of start node, 1 + index of start node)."
       while (newLineRange.startOffset == getNodeLength(newLineRange.startContainer)
       && !isProhibitedParagraphChild(newLineRange.startContainer)) {
           newLineRange.setStart(newLineRange.startContainer.parentNode, 1 + getNodeIndex(newLineRange.startContainer));
       }

       // "Let end of line be true if new line range contains either nothing
       // or a single br, and false otherwise."
       var containedInNewLineRange = getContainedNodes(newLineRange);
       var endOfLine = !containedInNewLineRange.length
           || (containedInNewLineRange.length == 1
           && isHtmlElement(containedInNewLineRange[0], "br"));

       // "If the local name of container is "h1", "h2", "h3", "h4", "h5", or
       // "h6", and end of line is true, let new container name be the default
       // single-line container name."
       var newContainerName;
       if (/^H[1-6]$/.test(container.tagName)
       && endOfLine) {
           newContainerName = defaultSingleLineContainerName;

       // "Otherwise, if the local name of container is "dt" and end of line
       // is true, let new container name be "dd"."
       } else if (container.tagName == "DT"
       && endOfLine) {
           newContainerName = "dd";

       // "Otherwise, if the local name of container is "dd" and end of line
       // is true, let new container name be "dt"."
       } else if (container.tagName == "DD"
       && endOfLine) {
           newContainerName = "dt";

       // "Otherwise, let new container name be the local name of container."
       } else {
           newContainerName = container.tagName.toLowerCase();
       }

       // "Let new container be the result of calling createElement(new
       // container name) on the context object."
       var newContainer = document.createElement(newContainerName);

       // "Copy all attributes of container to new container."
       for (var i = 0; i < container.attributes.length; i++) {
           newContainer.setAttributeNS(container.attributes[i].namespaceURI, container.attributes[i].name, container.attributes[i].value);
       }

       // "If new container has an id attribute, unset it."
       newContainer.removeAttribute("id");

       // "Insert new container into the parent of container immediately after
       // container."
       container.parentNode.insertBefore(newContainer, container.nextSibling);

       // "Let contained nodes be all nodes contained in new line range."
       var containedNodes = getAllContainedNodes(newLineRange);

       // "Let frag be the result of calling extractContents() on new line
       // range."
       var frag = newLineRange.extractContents();

       // "Unset the id attribute (if any) of each Element descendant of frag
       // that is not in contained nodes."
       var descendants = getDescendants(frag);
       for (var i = 0; i < descendants.length; i++) {
           if (descendants[i].nodeType == Node.ELEMENT_NODE
           && containedNodes.indexOf(descendants[i]) == -1) {
               descendants[i].removeAttribute("id");
           }
       }

       // "Call appendChild(frag) on new container."
       newContainer.appendChild(frag);

       // "While container's lastChild is a prohibited paragraph child, set
       // container to its lastChild."
       while (isProhibitedParagraphChild(container.lastChild)) {
           container = container.lastChild;
       }

       // "While new container's lastChild is a prohibited paragraph child,
       // set new container to its lastChild."
       while (isProhibitedParagraphChild(newContainer.lastChild)) {
           newContainer = newContainer.lastChild;
       }

       // "If container has no visible children, call createElement("br") on
       // the context object, and append the result as the last child of
       // container."
       if (![].some.call(container.childNodes, isVisible)) {
           container.appendChild(document.createElement("br"));
       }

       // "If new container has no visible children, call createElement("br")
       // on the context object, and append the result as the last child of
       // new container."
       if (![].some.call(newContainer.childNodes, isVisible)) {
           newContainer.appendChild(document.createElement("br"));
       }

       // "Call collapse(new container, 0) on the context object's Selection."
       getSelection().collapse(newContainer, 0);
       getActiveRange().setStart(newContainer, 0);
       getActiveRange().setEnd(newContainer, 0);

       // "Return true."
       return true;
   }
};

//@}
///// The insertText command /////
//@{
commands.inserttext = {
   action: function(value) {
       // "Delete the selection, with strip wrappers false."
       deleteSelection({stripWrappers: false});

       // "If the active range's start node is neither editable nor an editing
       // host, return true."
       if (!isEditable(getActiveRange().startContainer)
       && !isEditingHost(getActiveRange().startContainer)) {
           return true;
       }

       // "If value's length is greater than one:"
       if (value.length > 1) {
           // "For each element el in value, take the action for the
           // insertText command, with value equal to el."
           for (var i = 0; i < value.length; i++) {
               commands.inserttext.action(value[i]);
           }

           // "Return true."
           return true;
       }

       // "If value is the empty string, return true."
       if (value == "") {
           return true;
       }

       // "If value is a newline (U+00A0), take the action for the
       // insertParagraph command and return true."
       if (value == "\n") {
           commands.insertparagraph.action();
           return true;
       }

       // "Let node and offset be the active range's start node and offset."
       var node = getActiveRange().startContainer;
       var offset = getActiveRange().startOffset;

       // "If node has a child whose index is offset − 1, and that child is a
       // Text node, set node to that child, then set offset to node's
       // length."
       if (0 <= offset - 1
       && offset - 1 < node.childNodes.length
       && node.childNodes[offset - 1].nodeType == Node.TEXT_NODE) {
           node = node.childNodes[offset - 1];
           offset = getNodeLength(node);
       }

       // "If node has a child whose index is offset, and that child is a Text
       // node, set node to that child, then set offset to zero."
       if (0 <= offset
       && offset < node.childNodes.length
       && node.childNodes[offset].nodeType == Node.TEXT_NODE) {
           node = node.childNodes[offset];
           offset = 0;
       }

       // "Record current overrides, and let overrides be the result."
       var overrides = recordCurrentOverrides();

       // "Call collapse(node, offset) on the context object's Selection."
       getSelection().collapse(node, offset);
       getActiveRange().setStart(node, offset);
       getActiveRange().setEnd(node, offset);

       // "Canonicalize whitespace at (node, offset)."
       canonicalizeWhitespace(node, offset);

       // "Let (node, offset) be the active range's start."
       node = getActiveRange().startContainer;
       offset = getActiveRange().startOffset;

       // "If node is a Text node:"
       if (node.nodeType == Node.TEXT_NODE) {
           // "Call insertData(offset, value) on node."
           node.insertData(offset, value);

           // "Call collapse(node, offset) on the context object's Selection."
           getSelection().collapse(node, offset);
           getActiveRange().setStart(node, offset);

           // "Call extend(node, offset + 1) on the context object's
           // Selection."
           //
           // Work around WebKit bug: the extend() can throw if the text we're
           // adding is trailing whitespace.
           try { getSelection().extend(node, offset + 1); } catch(e) {}
           getActiveRange().setEnd(node, offset + 1);

       // "Otherwise:"
       } else {
           // "If node has only one child, which is a collapsed line break,
           // remove its child from it."
           //
           // FIXME: IE incorrectly returns false here instead of true
           // sometimes?
           if (node.childNodes.length == 1
           && isCollapsedLineBreak(node.firstChild)) {
               node.removeChild(node.firstChild);
           }

           // "Let text be the result of calling createTextNode(value) on the
           // context object."
           var text = document.createTextNode(value);

           // "Call insertNode(text) on the active range."
           getActiveRange().insertNode(text);

           // "Call collapse(text, 0) on the context object's Selection."
           getSelection().collapse(text, 0);
           getActiveRange().setStart(text, 0);

           // "Call extend(text, 1) on the context object's Selection."
           getSelection().extend(text, 1);
           getActiveRange().setEnd(text, 1);
       }

       // "Restore states and values from overrides."
       restoreStatesAndValues(overrides);

       // "Canonicalize whitespace at the active range's start, with fix
       // collapsed space false."
       canonicalizeWhitespace(getActiveRange().startContainer, getActiveRange().startOffset, false);

       // "Canonicalize whitespace at the active range's end, with fix
       // collapsed space false."
       canonicalizeWhitespace(getActiveRange().endContainer, getActiveRange().endOffset, false);

       // "If value is a space character, autolink the active range's start."
       if (/^[ \t\n\f\r]$/.test(value)) {
           autolink(getActiveRange().startContainer, getActiveRange().startOffset);
       }

       // "Call collapseToEnd() on the context object's Selection."
       //
       // Work around WebKit bug: sometimes it blows up the selection and
       // throws, which we don't want.
       try { getSelection().collapseToEnd(); } catch(e) {}
       getActiveRange().collapse(false);

       // "Return true."
       return true;
   }
};

//@}
///// The insertUnorderedList command /////
//@{
commands.insertunorderedlist = {
   preservesOverrides: true,
   // "Toggle lists with tag name "ul", then return true."
   action: function() { toggleLists("ul"); return true },
   // "True if the selection's list state is "mixed" or "mixed ul", false
   // otherwise."
   indeterm: function() { return /^mixed( ul)?$/.test(getSelectionListState()) },
   // "True if the selection's list state is "ul", false otherwise."
   state: function() { return getSelectionListState() == "ul" },
};

//@}
///// The justifyCenter command /////
//@{
commands.justifycenter = {
   preservesOverrides: true,
   // "Justify the selection with alignment "center", then return true."
   action: function() { justifySelection("center"); return true },
   indeterm: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if among visible editable nodes that
       // are contained in the result and have no children, at least one has
       // alignment value "center" and at least one does not. Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.some(function(node) { return getAlignmentValue(node) == "center" })
           && nodes.some(function(node) { return getAlignmentValue(node) != "center" });
   }, state: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if there is at least one visible
       // editable node that is contained in the result and has no children,
       // and all such nodes have alignment value "center".  Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.length
           && nodes.every(function(node) { return getAlignmentValue(node) == "center" });
   }, value: function() {
       // "Return the empty string if the active range is null.  Otherwise,
       // block-extend the active range, and return the alignment value of the
       // first visible editable node that is contained in the result and has
       // no children. If there is no such node, return "left"."
       if (!getActiveRange()) {
           return "";
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       if (nodes.length) {
           return getAlignmentValue(nodes[0]);
       } else {
           return "left";
       }
   },
};

//@}
///// The justifyFull command /////
//@{
commands.justifyfull = {
   preservesOverrides: true,
   // "Justify the selection with alignment "justify", then return true."
   action: function() { justifySelection("justify"); return true },
   indeterm: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if among visible editable nodes that
       // are contained in the result and have no children, at least one has
       // alignment value "justify" and at least one does not. Otherwise
       // return false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.some(function(node) { return getAlignmentValue(node) == "justify" })
           && nodes.some(function(node) { return getAlignmentValue(node) != "justify" });
   }, state: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if there is at least one visible
       // editable node that is contained in the result and has no children,
       // and all such nodes have alignment value "justify".  Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.length
           && nodes.every(function(node) { return getAlignmentValue(node) == "justify" });
   }, value: function() {
       // "Return the empty string if the active range is null.  Otherwise,
       // block-extend the active range, and return the alignment value of the
       // first visible editable node that is contained in the result and has
       // no children. If there is no such node, return "left"."
       if (!getActiveRange()) {
           return "";
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       if (nodes.length) {
           return getAlignmentValue(nodes[0]);
       } else {
           return "left";
       }
   },
};

//@}
///// The justifyLeft command /////
//@{
commands.justifyleft = {
   preservesOverrides: true,
   // "Justify the selection with alignment "left", then return true."
   action: function() { justifySelection("left"); return true },
   indeterm: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if among visible editable nodes that
       // are contained in the result and have no children, at least one has
       // alignment value "left" and at least one does not. Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.some(function(node) { return getAlignmentValue(node) == "left" })
           && nodes.some(function(node) { return getAlignmentValue(node) != "left" });
   }, state: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if there is at least one visible
       // editable node that is contained in the result and has no children,
       // and all such nodes have alignment value "left".  Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.length
           && nodes.every(function(node) { return getAlignmentValue(node) == "left" });
   }, value: function() {
       // "Return the empty string if the active range is null.  Otherwise,
       // block-extend the active range, and return the alignment value of the
       // first visible editable node that is contained in the result and has
       // no children. If there is no such node, return "left"."
       if (!getActiveRange()) {
           return "";
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       if (nodes.length) {
           return getAlignmentValue(nodes[0]);
       } else {
           return "left";
       }
   },
};

//@}
///// The justifyRight command /////
//@{
commands.justifyright = {
   preservesOverrides: true,
   // "Justify the selection with alignment "right", then return true."
   action: function() { justifySelection("right"); return true },
   indeterm: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if among visible editable nodes that
       // are contained in the result and have no children, at least one has
       // alignment value "right" and at least one does not. Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.some(function(node) { return getAlignmentValue(node) == "right" })
           && nodes.some(function(node) { return getAlignmentValue(node) != "right" });
   }, state: function() {
       // "Return false if the active range is null.  Otherwise, block-extend
       // the active range. Return true if there is at least one visible
       // editable node that is contained in the result and has no children,
       // and all such nodes have alignment value "right".  Otherwise return
       // false."
       if (!getActiveRange()) {
           return false;
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       return nodes.length
           && nodes.every(function(node) { return getAlignmentValue(node) == "right" });
   }, value: function() {
       // "Return the empty string if the active range is null.  Otherwise,
       // block-extend the active range, and return the alignment value of the
       // first visible editable node that is contained in the result and has
       // no children. If there is no such node, return "left"."
       if (!getActiveRange()) {
           return "";
       }
       var nodes = getAllContainedNodes(blockExtend(getActiveRange()), function(node) {
           return isEditable(node) && isVisible(node) && !node.hasChildNodes();
       });
       if (nodes.length) {
           return getAlignmentValue(nodes[0]);
       } else {
           return "left";
       }
   },
};

//@}
///// The outdent command /////
//@{
commands.outdent = {
   preservesOverrides: true,
   action: function() {
       // "Let items be a list of all lis that are ancestor containers of the
       // range's start and/or end node."
       //
       // It's annoying to get this in tree order using functional stuff
       // without doing getDescendants(document), which is slow, so I do it
       // imperatively.
       var items = [];
       (function(){
           for (
               var ancestorContainer = getActiveRange().endContainer;
               ancestorContainer != getActiveRange().commonAncestorContainer;
               ancestorContainer = ancestorContainer.parentNode
           ) {
               if (isHtmlElement(ancestorContainer, "li")) {
                   items.unshift(ancestorContainer);
               }
           }
           for (
               var ancestorContainer = getActiveRange().startContainer;
               ancestorContainer;
               ancestorContainer = ancestorContainer.parentNode
           ) {
               if (isHtmlElement(ancestorContainer, "li")) {
                   items.unshift(ancestorContainer);
               }
           }
       })();

       // "For each item in items, normalize sublists of item."
       items.forEach(normalizeSublists);

       // "Block-extend the active range, and let new range be the result."
       var newRange = blockExtend(getActiveRange());

       // "Let node list be a list of nodes, initially empty."
       //
       // "For each node node contained in new range, append node to node list
       // if the last member of node list (if any) is not an ancestor of node;
       // node is editable; and either node has no editable descendants, or is
       // an ol or ul, or is an li whose parent is an ol or ul."
       var nodeList = getContainedNodes(newRange, function(node) {
           return isEditable(node)
               && (!getDescendants(node).some(isEditable)
               || isHtmlElement(node, ["ol", "ul"])
               || (isHtmlElement(node, "li") && isHtmlElement(node.parentNode, ["ol", "ul"])));
       });

       // "While node list is not empty:"
       while (nodeList.length) {
           // "While the first member of node list is an ol or ul or is not
           // the child of an ol or ul, outdent it and remove it from node
           // list."
           while (nodeList.length
           && (isHtmlElement(nodeList[0], ["OL", "UL"])
           || !isHtmlElement(nodeList[0].parentNode, ["OL", "UL"]))) {
               outdentNode(nodeList.shift());
           }

           // "If node list is empty, break from these substeps."
           if (!nodeList.length) {
               break;
           }

           // "Let sublist be a list of nodes, initially empty."
           var sublist = [];

           // "Remove the first member of node list and append it to sublist."
           sublist.push(nodeList.shift());

           // "While the first member of node list is the nextSibling of the
           // last member of sublist, and the first member of node list is not
           // an ol or ul, remove the first member of node list and append it
           // to sublist."
           while (nodeList.length
           && nodeList[0] == sublist[sublist.length - 1].nextSibling
           && !isHtmlElement(nodeList[0], ["OL", "UL"])) {
               sublist.push(nodeList.shift());
           }

           // "Record the values of sublist, and let values be the result."
           var values = recordValues(sublist);

           // "Split the parent of sublist, with new parent null."
           splitParent(sublist);

           // "Fix disallowed ancestors of each member of sublist."
           sublist.forEach(fixDisallowedAncestors);

           // "Restore the values from values."
           restoreValues(values);
       }

       // "Return true."
       return true;
   }
};

//@}

//////////////////////////////////
///// Miscellaneous commands /////
//////////////////////////////////

///// The defaultParagraphSeparator command /////
//@{
commands.defaultparagraphseparator = {
   action: function(value) {
       // "Let value be converted to ASCII lowercase. If value is then equal
       // to "p" or "div", set the context object's default single-line
       // container name to value and return true. Otherwise, return false."
       value = value.toLowerCase();
       if (value == "p" || value == "div") {
           defaultSingleLineContainerName = value;
           return true;
       }
       return false;
   }, value: function() {
       // "Return the context object's default single-line container name."
       return defaultSingleLineContainerName;
   },
};

//@}
///// The selectAll command /////
//@{
commands.selectall = {
   // Note, this ignores the whole globalRange/getActiveRange() thing and
   // works with actual selections.  Not suitable for autoimplementation.html.
   action: function() {
       // "Let target be the body element of the context object."
       var target = document.body;

       // "If target is null, let target be the context object's
       // documentElement."
       if (!target) {
           target = document.documentElement;
       }

       // "If target is null, call getSelection() on the context object, and
       // call removeAllRanges() on the result."
       if (!target) {
           getSelection().removeAllRanges();

       // "Otherwise, call getSelection() on the context object, and call
       // selectAllChildren(target) on the result."
       } else {
           getSelection().selectAllChildren(target);
       }

       // "Return true."
       return true;
   }
};

//@}
///// The styleWithCSS command /////
//@{
commands.stylewithcss = {
   action: function(value) {
       // "If value is an ASCII case-insensitive match for the string
       // "false", set the CSS styling flag to false. Otherwise, set the
       // CSS styling flag to true.  Either way, return true."
       cssStylingFlag = String(value).toLowerCase() != "false";
       return true;
   }, state: function() { return cssStylingFlag }
};

//@}
///// The useCSS command /////
//@{
commands.usecss = {
   action: function(value) {
       // "If value is an ASCII case-insensitive match for the string "false",
       // set the CSS styling flag to true. Otherwise, set the CSS styling
       // flag to false.  Either way, return true."
       cssStylingFlag = String(value).toLowerCase() == "false";
       return true;
   }
};
//@}

// Some final setup
//@{
(function() {
// Opera 11.50 doesn't implement Object.keys, so I have to make an explicit
// temporary, which means I need an extra closure to not leak the temporaries
// into the global namespace.  >:(
var commandNames = [];
for (var command in commands) {
   commandNames.push(command);
}
commandNames.forEach(function(command) {
   // "If a command does not have a relevant CSS property specified, it
   // defaults to null."
   if (!("relevantCssProperty" in commands[command])) {
       commands[command].relevantCssProperty = null;
   }

   // "If a command has inline command activated values defined but nothing
   // else defines when it is indeterminate, it is indeterminate if among
   // formattable nodes effectively contained in the active range, there is at
   // least one whose effective command value is one of the given values and
   // at least one whose effective command value is not one of the given
   // values."
   if ("inlineCommandActivatedValues" in commands[command]
   && !("indeterm" in commands[command])) {
       commands[command].indeterm = function() {
           if (!getActiveRange()) {
               return false;
           }

           var values = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode)
               .map(function(node) { return getEffectiveCommandValue(node, command) });

           var matchingValues = values.filter(function(value) {
               return commands[command].inlineCommandActivatedValues.indexOf(value) != -1;
           });

           return matchingValues.length >= 1
               && values.length - matchingValues.length >= 1;
       };
   }

   // "If a command has inline command activated values defined, its state is
   // true if either no formattable node is effectively contained in the
   // active range, and the active range's start node's effective command
   // value is one of the given values; or if there is at least one
   // formattable node effectively contained in the active range, and all of
   // them have an effective command value equal to one of the given values."
   if ("inlineCommandActivatedValues" in commands[command]) {
       commands[command].state = function() {
           if (!getActiveRange()) {
               return false;
           }

           var nodes = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode);

           if (nodes.length == 0) {
               return commands[command].inlineCommandActivatedValues
                   .indexOf(getEffectiveCommandValue(getActiveRange().startContainer, command)) != -1;
           } else {
               return nodes.every(function(node) {
                   return commands[command].inlineCommandActivatedValues
                       .indexOf(getEffectiveCommandValue(node, command)) != -1;
               });
           }
       };
   }

   // "If a command is a standard inline value command, it is indeterminate if
   // among formattable nodes that are effectively contained in the active
   // range, there are two that have distinct effective command values. Its
   // value is the effective command value of the first formattable node that
   // is effectively contained in the active range; or if there is no such
   // node, the effective command value of the active range's start node; or
   // if that is null, the empty string."
   if ("standardInlineValueCommand" in commands[command]) {
       commands[command].indeterm = function() {
           if (!getActiveRange()) {
               return false;
           }

           var values = getAllEffectivelyContainedNodes(getActiveRange())
               .filter(isFormattableNode)
               .map(function(node) { return getEffectiveCommandValue(node, command) });
           for (var i = 1; i < values.length; i++) {
               if (values[i] != values[i - 1]) {
                   return true;
               }
           }
           return false;
       };

       commands[command].value = function() {
           if (!getActiveRange()) {
               return "";
           }

           var refNode = getAllEffectivelyContainedNodes(getActiveRange(), isFormattableNode)[0];

           if (typeof refNode == "undefined") {
               refNode = getActiveRange().startContainer;
           }

           var ret = getEffectiveCommandValue(refNode, command);
           if (ret === null) {
               return "";
           }
           return ret;
       };
   }

   // "If a command preserves overrides, then before taking its action, the
   // user agent must record current overrides. After taking the action, if
   // the active range is collapsed, it must restore states and values from
   // the recorded list."
   if ("preservesOverrides" in commands[command]) {
       var oldAction = commands[command].action;

       commands[command].action = function(value) {
           var overrides = recordCurrentOverrides();
           var ret = oldAction(value);
           if (getActiveRange().collapsed) {
               restoreStatesAndValues(overrides);
           }
           return ret;
       };
   }
});
})();
//@}

// vim: foldmarker=@{,@} foldmethod=marker