tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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util.js (6598B)

      1 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
      2 /* This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 // The possible values of the "align" component of preserveAspectRatio.
      7 const ALIGN_VALS = ["none",
      8                    "xMinYMin", "xMinYMid", "xMinYMax",
      9                    "xMidYMin", "xMidYMid", "xMidYMax",
     10                    "xMaxYMin", "xMaxYMid", "xMaxYMax"];
     11 
     12 // The possible values of the "meetOrSlice" component of preserveAspectRatio.
     13 const MEETORSLICE_VALS = [ "meet", "slice" ];
     14 
     15 const SVGNS   = "http://www.w3.org/2000/svg";
     16 const XLINKNS = "http://www.w3.org/1999/xlink";
     17 
     18 // This is the separation between the x & y values of each <image> in a
     19 // generated grid.
     20 const IMAGE_OFFSET = 50;
     21 
     22 function generateBorderRect(aX, aY, aWidth, aHeight) {
     23  var rect = document.createElementNS(SVGNS, "rect");
     24  rect.setAttribute("x", aX);
     25  rect.setAttribute("y", aY);
     26  rect.setAttribute("width", aWidth);
     27  rect.setAttribute("height", aHeight);
     28  rect.setAttribute("fill", "none");
     29  rect.setAttribute("stroke", "black");
     30  rect.setAttribute("stroke-width", "2");
     31  rect.setAttribute("stroke-dasharray", "3 2");
     32  return rect;
     33 }
     34 
     35 // Returns an SVG <image> element with the given xlink:href, width, height,
     36 // and preserveAspectRatio=[aAlign aMeetOrSlice] attributes
     37 function generateImageElementForParams(aX, aY, aWidth, aHeight,
     38                                       aHref, aAlign, aMeetOrSlice) {
     39  var image = document.createElementNS(SVGNS, "image");
     40  image.setAttribute("x", aX);
     41  image.setAttribute("y", aY);
     42  image.setAttribute("width", aWidth);
     43  image.setAttribute("height", aHeight);
     44  image.setAttributeNS(XLINKNS, "href", aHref);
     45  image.setAttribute("preserveAspectRatio", aAlign + " " + aMeetOrSlice);
     46  return image;
     47 }
     48 
     49 // Returns a <g> element filled with a grid of <image> elements which each
     50 // have the specified aWidth & aHeight and which use all possible values of
     51 // preserveAspectRatio.
     52 //
     53 // The final "aBonusPARVal" argument (if specified) is used as the
     54 // preserveAspectRatio value on a bonus <image> element, added at the end.
     55 function generateImageGrid(aHref, aWidth, aHeight, aBonusPARVal) {
     56  var grid = document.createElementNS(SVGNS, "g");
     57  var y = 0;
     58  var x = 0;
     59  for (var i = 0; i < ALIGN_VALS.length; i++) {
     60    // Jump to next line of grid, for every other "i" value.
     61    // (every fourth entry)
     62    if (i && i % 2 == 0) {
     63      y += IMAGE_OFFSET;
     64      x = 0;
     65    }
     66    var alignVal = ALIGN_VALS[i];
     67    for (var j = 0; j < MEETORSLICE_VALS.length; j++) {
     68      var meetorsliceVal = MEETORSLICE_VALS[j];
     69      var border = generateBorderRect(x, y, aWidth, aHeight);
     70      var image  = generateImageElementForParams(x, y, aWidth, aHeight,
     71                                                 aHref, alignVal,
     72                                                 meetorsliceVal);
     73      grid.appendChild(border);
     74      grid.appendChild(image);
     75      x += IMAGE_OFFSET;
     76    }
     77  }
     78 
     79  if (aBonusPARVal) {
     80    // Add one final entry with "bonus" pAR value.
     81    y += IMAGE_OFFSET;
     82    x = 0;
     83    var border = generateBorderRect(x, y, aWidth, aHeight);
     84    var image  = generateImageElementForParams(x, y, aWidth, aHeight,
     85                                               aHref, aBonusPARVal, "");
     86    grid.appendChild(border);
     87    grid.appendChild(image);
     88  }
     89 
     90  return grid;
     91 }
     92 
     93 // Returns an SVG <symbol> element that...
     94 //  (a) has the given ID
     95 //  (b) contains only a <use> element to the given URI
     96 //  (c) has a hardcoded viewBox="0 0 10 10" attribute
     97 //  (d) has the given preserveAspectRatio=[aAlign aMeetOrSlice] attribute
     98 function generateSymbolElementForParams(aSymbolID, aHref,
     99                                        aAlign, aMeetOrSlice) {
    100  var use = document.createElementNS(SVGNS, "use");
    101  use.setAttributeNS(XLINKNS, "href", aHref);
    102 
    103  var symbol = document.createElementNS(SVGNS, "symbol");
    104  symbol.setAttribute("id", aSymbolID);
    105  symbol.setAttribute("viewBox", "0 0 10 10");
    106  symbol.setAttribute("preserveAspectRatio", aAlign + " " + aMeetOrSlice);
    107 
    108  symbol.appendChild(use);
    109  return symbol;
    110 }
    111 
    112 function generateUseElementForParams(aTargetURI, aX, aY, aWidth, aHeight) {
    113  var use = document.createElementNS(SVGNS, "use");
    114  use.setAttributeNS(XLINKNS, "href", aTargetURI);
    115  use.setAttribute("x", aX);
    116  use.setAttribute("y", aY);
    117  use.setAttribute("width", aWidth);
    118  use.setAttribute("height", aHeight);
    119  return use;
    120 }
    121 
    122 // Returns a <g> element filled with a grid of <use> elements which each
    123 // have the specified aWidth & aHeight and which reference <symbol> elements
    124 // with all possible values of preserveAspectRatio.  Each <symbol> contains
    125 // a <use> that links to the given URI, aHref.
    126 //
    127 // The final "aBonusPARVal" argument (if specified) is used as the
    128 // preserveAspectRatio value on a bonus <symbol> element, added at the end.
    129 function generateSymbolGrid(aHref, aWidth, aHeight, aBonusPARVal) {
    130  var grid = document.createElementNS(SVGNS, "g");
    131  var y = 0;
    132  var x = 0;
    133  for (var i = 0; i < ALIGN_VALS.length; i++) {
    134    // Jump to next line of grid, for every other "i" value.
    135    // (every fourth entry)
    136    if (i && i % 2 == 0) {
    137      y += IMAGE_OFFSET;
    138      x = 0;
    139    }
    140    var alignVal = ALIGN_VALS[i];
    141    for (var j = 0; j < MEETORSLICE_VALS.length; j++) {
    142      var meetorsliceVal = MEETORSLICE_VALS[j];
    143      var border = generateBorderRect(x, y, aWidth, aHeight);
    144 
    145      var symbolID = "symbol_" + alignVal + "_" + meetorsliceVal;
    146      var symbol = generateSymbolElementForParams(symbolID, aHref,
    147                                                  alignVal, meetorsliceVal);
    148      var use = generateUseElementForParams("#" + symbolID,
    149                                            x, y, aWidth, aHeight);
    150      grid.appendChild(symbol); // This isn't painted
    151      grid.appendChild(border);
    152      grid.appendChild(use);
    153      x += IMAGE_OFFSET;
    154    }
    155  }
    156 
    157  if (aBonusPARVal) {
    158    // Add one final entry with "bonus" pAR value.
    159    y += IMAGE_OFFSET;
    160    x = 0;
    161    var border = generateBorderRect(x, y, aWidth, aHeight);
    162    var symbolID = "symbol_Bonus";
    163    var symbol = generateSymbolElementForParams(symbolID, aHref,
    164                                                aBonusPARVal, "");
    165    var use = generateUseElementForParams("#" + symbolID,
    166                                          x, y, aWidth, aHeight);
    167    grid.appendChild(symbol); // This isn't painted
    168    grid.appendChild(border);
    169    grid.appendChild(use);
    170  }
    171 
    172  return grid;
    173 }