tor-browser

mozInlineSpellWordUtil.cpp (41705B)

---

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozInlineSpellWordUtil.h"

#include <algorithm>
#include <utility>

#include "mozilla/BinarySearch.h"
#include "mozilla/EditorBase.h"
#include "mozilla/HTMLEditor.h"
#include "mozilla/Logging.h"
#include "mozilla/dom/CharacterDataBuffer.h"
#include "mozilla/dom/Element.h"

#include "nsDebug.h"
#include "nsAtom.h"
#include "nsComponentManagerUtils.h"
#include "nsUnicodeProperties.h"
#include "nsServiceManagerUtils.h"
#include "nsIContent.h"
#include "nsRange.h"
#include "nsContentUtils.h"
#include "nsIFrame.h"

using namespace mozilla;

static LazyLogModule sInlineSpellWordUtilLog{"InlineSpellWordUtil"};

// IsIgnorableCharacter
//
//    These characters are ones that we should ignore in input.

inline bool IsIgnorableCharacter(char ch) {
 return (ch == static_cast<char>(0xAD));  // SOFT HYPHEN
}

inline bool IsIgnorableCharacter(char16_t ch) {
 return (ch == 0xAD ||   // SOFT HYPHEN
         ch == 0x1806);  // MONGOLIAN TODO SOFT HYPHEN
}

// IsConditionalPunctuation
//
//    Some characters (like apostrophes) require characters on each side to be
//    part of a word, and are otherwise punctuation.

inline bool IsConditionalPunctuation(char ch) {
 return (ch == '\'' ||                    // RIGHT SINGLE QUOTATION MARK
         ch == static_cast<char>(0xB7));  // MIDDLE DOT
}

inline bool IsConditionalPunctuation(char16_t ch) {
 return (ch == '\'' || ch == 0x2019 ||  // RIGHT SINGLE QUOTATION MARK
         ch == 0x00B7);                 // MIDDLE DOT
}

static bool IsAmbiguousDOMWordSeprator(char16_t ch) {
 // This class may be CHAR_CLASS_SEPARATOR, but it depends on context.
 return (ch == '@' || ch == ':' || ch == '.' || ch == '/' || ch == '-' ||
         IsConditionalPunctuation(ch));
}

static bool IsAmbiguousDOMWordSeprator(char ch) {
 // This class may be CHAR_CLASS_SEPARATOR, but it depends on context.
 return IsAmbiguousDOMWordSeprator(static_cast<char16_t>(ch));
}

// IsDOMWordSeparator
//
//    Determines if the given character should be considered as a DOM Word
//    separator. Basically, this is whitespace, although it could also have
//    certain punctuation that we know ALWAYS breaks words. This is important.
//    For example, we can't have any punctuation that could appear in a URL
//    or email address in this, because those need to always fit into a single
//    DOM word.

static bool IsDOMWordSeparator(char ch) {
 // simple spaces or no-break space
 return (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' ||
         ch == static_cast<char>(0xA0));
}

static bool IsDOMWordSeparator(char16_t ch) {
 // simple spaces
 if (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r') return true;

 // complex spaces - check only if char isn't ASCII (uncommon)
 if (ch >= 0xA0 && (ch == 0x00A0 ||  // NO-BREAK SPACE
                    ch == 0x2002 ||  // EN SPACE
                    ch == 0x2003 ||  // EM SPACE
                    ch == 0x2009 ||  // THIN SPACE
                    ch == 0x3000))   // IDEOGRAPHIC SPACE
   return true;

 // otherwise not a space
 return false;
}

bool NodeOffset::operator==(
   const mozilla::RangeBoundary& aRangeBoundary) const {
 if (aRangeBoundary.GetContainer() != mNode) {
   return false;
 }

 const Maybe<uint32_t> rangeBoundaryOffset =
     aRangeBoundary.Offset(RangeBoundary::OffsetFilter::kValidOffsets);

 MOZ_ASSERT(mOffset >= 0);
 return rangeBoundaryOffset &&
        (*rangeBoundaryOffset == static_cast<uint32_t>(mOffset));
}

bool NodeOffsetRange::operator==(const nsRange& aRange) const {
 return mBegin == aRange.StartRef() && mEnd == aRange.EndRef();
}

// static
Maybe<mozInlineSpellWordUtil> mozInlineSpellWordUtil::Create(
   const EditorBase& aEditorBase) {
 dom::Document* document = aEditorBase.GetDocument();
 if (NS_WARN_IF(!document)) {
   return Nothing();
 }

 const bool isContentEditableOrDesignMode = aEditorBase.IsHTMLEditor();

 // Find the root node for the editor. For contenteditable the mRootNode could
 // change to shadow root if the begin and end are inside the shadowDOM.
 nsINode* rootNode = aEditorBase.GetRoot();
 if (NS_WARN_IF(!rootNode)) {
   return Nothing();
 }

 mozInlineSpellWordUtil util{*document, isContentEditableOrDesignMode,
                             *rootNode};
 return Some(std::move(util));
}

static inline bool IsSpellCheckingTextNode(nsINode* aNode) {
 nsIContent* parent = aNode->GetParent();
 if (parent &&
     parent->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style))
   return false;
 return aNode->IsText();
}

typedef void (*OnLeaveNodeFunPtr)(nsINode* aNode, void* aClosure);

// Find the next node in the DOM tree in preorder.
// Calls OnLeaveNodeFunPtr when the traversal leaves a node, which is
// why we can't just use GetNextNode here, sadly.
static nsINode* FindNextNode(nsINode* aNode, const nsINode* aRoot,
                            OnLeaveNodeFunPtr aOnLeaveNode, void* aClosure) {
 MOZ_ASSERT(aNode, "Null starting node?");

 nsINode* next = aNode->GetFirstChild();
 if (next) return next;

 // Don't look at siblings or otherwise outside of aRoot
 if (aNode == aRoot) return nullptr;

 next = aNode->GetNextSibling();
 if (next) return next;

 // Go up
 for (;;) {
   if (aOnLeaveNode) {
     aOnLeaveNode(aNode, aClosure);
   }

   next = aNode->GetParent();
   if (next == aRoot || !next) return nullptr;
   aNode = next;

   next = aNode->GetNextSibling();
   if (next) return next;
 }
}

// aNode is not a text node. Find the first text node starting at aNode/aOffset
// in a preorder DOM traversal.
static nsINode* FindNextTextNode(nsINode* aNode, int32_t aOffset,
                                const nsINode* aRoot) {
 MOZ_ASSERT(aNode, "Null starting node?");
 MOZ_ASSERT(!IsSpellCheckingTextNode(aNode),
            "FindNextTextNode should start with a non-text node");

 nsINode* checkNode;
 // Need to start at the aOffset'th child
 nsIContent* child = aNode->GetChildAt_Deprecated(aOffset);

 if (child) {
   checkNode = child;
 } else {
   // aOffset was beyond the end of the child list.
   // goto next node after the last descendant of aNode in
   // a preorder DOM traversal.
   checkNode = aNode->GetNextNonChildNode(aRoot);
 }

 while (checkNode && !IsSpellCheckingTextNode(checkNode)) {
   checkNode = checkNode->GetNextNode(aRoot);
 }
 return checkNode;
}

// mozInlineSpellWordUtil::SetPositionAndEnd
//
//    We have two ranges "hard" and "soft". The hard boundary is simply
//    the scope of the root node. The soft boundary is that which is set
//    by the caller of this class by calling this function. If this function is
//    not called, the soft boundary is the same as the hard boundary.
//
//    When we reach the soft boundary (mSoftText.GetEnd()), we keep
//    going until we reach the end of a word. This allows the caller to set the
//    end of the range to anything, and we will always check whole multiples of
//    words. When we reach the hard boundary we stop no matter what.
//
//    There is no beginning soft boundary. This is because we only go to the
//    previous node once, when finding the previous word boundary in
//    SetPosition(). You might think of the soft boundary as being this initial
//    position.

nsresult mozInlineSpellWordUtil::SetPositionAndEnd(nsINode* aPositionNode,
                                                  int32_t aPositionOffset,
                                                  nsINode* aEndNode,
                                                  int32_t aEndOffset) {
 MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
         ("%s: pos=(%p, %i), end=(%p, %i)", __FUNCTION__, aPositionNode,
          aPositionOffset, aEndNode, aEndOffset));

 MOZ_ASSERT(aPositionNode, "Null begin node?");
 MOZ_ASSERT(aEndNode, "Null end node?");

 MOZ_ASSERT(mRootNode, "Not initialized");

 // Find a appropriate root if we are dealing with contenteditable nodes which
 // are in the shadow DOM.
 if (mIsContentEditableOrDesignMode) {
   nsINode* rootNode = aPositionNode->SubtreeRoot();
   if (rootNode != aEndNode->SubtreeRoot()) {
     return NS_ERROR_FAILURE;
   }

   if (mozilla::dom::ShadowRoot::FromNode(rootNode)) {
     mRootNode = rootNode;
   }
 }

 mSoftText.Invalidate();

 if (!IsSpellCheckingTextNode(aPositionNode)) {
   // Start at the start of the first text node after aNode/aOffset.
   aPositionNode = FindNextTextNode(aPositionNode, aPositionOffset, mRootNode);
   aPositionOffset = 0;
 }
 NodeOffset softBegin = NodeOffset(aPositionNode, aPositionOffset);

 if (!IsSpellCheckingTextNode(aEndNode)) {
   // End at the start of the first text node after aEndNode/aEndOffset.
   aEndNode = FindNextTextNode(aEndNode, aEndOffset, mRootNode);
   aEndOffset = 0;
 }
 NodeOffset softEnd = NodeOffset(aEndNode, aEndOffset);

 nsresult rv = EnsureWords(std::move(softBegin), std::move(softEnd));
 if (NS_FAILED(rv)) {
   return rv;
 }

 int32_t textOffset = MapDOMPositionToSoftTextOffset(mSoftText.GetBegin());
 if (textOffset < 0) {
   return NS_OK;
 }

 mNextWordIndex = FindRealWordContaining(textOffset, HINT_END, true);
 return NS_OK;
}

nsresult mozInlineSpellWordUtil::EnsureWords(NodeOffset aSoftBegin,
                                            NodeOffset aSoftEnd) {
 if (mSoftText.mIsValid) return NS_OK;
 mSoftText.AdjustBeginAndBuildText(std::move(aSoftBegin), std::move(aSoftEnd),
                                   mRootNode);

 mRealWords.Clear();
 Result<RealWords, nsresult> realWords = BuildRealWords();
 if (realWords.isErr()) {
   return realWords.unwrapErr();
 }

 mRealWords = realWords.unwrap();
 mSoftText.mIsValid = true;
 return NS_OK;
}

nsresult mozInlineSpellWordUtil::MakeRangeForWord(const RealWord& aWord,
                                                 nsRange** aRange) const {
 NodeOffset begin =
     MapSoftTextOffsetToDOMPosition(aWord.mSoftTextOffset, HINT_BEGIN);
 NodeOffset end = MapSoftTextOffsetToDOMPosition(aWord.EndOffset(), HINT_END);
 return MakeRange(begin, end, aRange);
}
void mozInlineSpellWordUtil::MakeNodeOffsetRangeForWord(
   const RealWord& aWord, NodeOffsetRange* aNodeOffsetRange) {
 NodeOffset begin =
     MapSoftTextOffsetToDOMPosition(aWord.mSoftTextOffset, HINT_BEGIN);
 NodeOffset end = MapSoftTextOffsetToDOMPosition(aWord.EndOffset(), HINT_END);
 *aNodeOffsetRange = NodeOffsetRange(begin, end);
}

// mozInlineSpellWordUtil::GetRangeForWord

nsresult mozInlineSpellWordUtil::GetRangeForWord(nsINode* aWordNode,
                                                int32_t aWordOffset,
                                                nsRange** aRange) {
 // Set our soft end and start
 NodeOffset pt(aWordNode, aWordOffset);

 if (!mSoftText.mIsValid || pt != mSoftText.GetBegin() ||
     pt != mSoftText.GetEnd()) {
   mSoftText.Invalidate();
   NodeOffset softBegin = pt;
   NodeOffset softEnd = pt;
   nsresult rv = EnsureWords(std::move(softBegin), std::move(softEnd));
   if (NS_FAILED(rv)) {
     return rv;
   }
 }

 int32_t offset = MapDOMPositionToSoftTextOffset(pt);
 if (offset < 0) return MakeRange(pt, pt, aRange);
 int32_t wordIndex = FindRealWordContaining(offset, HINT_BEGIN, false);
 if (wordIndex < 0) return MakeRange(pt, pt, aRange);
 return MakeRangeForWord(mRealWords[wordIndex], aRange);
}

// This is to fix characters that the spellchecker may not like
static void NormalizeWord(const nsAString& aInput, int32_t aPos, int32_t aLen,
                         nsAString& aOutput) {
 aOutput.Truncate();
 for (int32_t i = 0; i < aLen; i++) {
   char16_t ch = aInput.CharAt(i + aPos);

   // remove ignorable characters from the word
   if (IsIgnorableCharacter(ch)) continue;

   // the spellchecker doesn't handle curly apostrophes in all languages
   if (ch == 0x2019) {  // RIGHT SINGLE QUOTATION MARK
     ch = '\'';
   }

   aOutput.Append(ch);
 }
}

// mozInlineSpellWordUtil::GetNextWord
//
//    FIXME-optimization: we shouldn't have to generate a range every single
//    time. It would be better if the inline spellchecker didn't require a
//    range unless the word was misspelled. This may or may not be possible.

bool mozInlineSpellWordUtil::GetNextWord(Word& aWord) {
 MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
         ("%s: mNextWordIndex=%d", __FUNCTION__, mNextWordIndex));

 if (mNextWordIndex < 0 || mNextWordIndex >= int32_t(mRealWords.Length())) {
   mNextWordIndex = -1;
   aWord.mSkipChecking = true;
   return false;
 }

 const RealWord& realWord = mRealWords[mNextWordIndex];
 MakeNodeOffsetRangeForWord(realWord, &aWord.mNodeOffsetRange);
 ++mNextWordIndex;
 aWord.mSkipChecking = !realWord.mCheckableWord;
 ::NormalizeWord(mSoftText.GetValue(), realWord.mSoftTextOffset,
                 realWord.mLength, aWord.mText);

 MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
         ("%s: returning: %s (skip=%d)", __FUNCTION__,
          NS_ConvertUTF16toUTF8(aWord.mText).get(), aWord.mSkipChecking));

 return true;
}

// mozInlineSpellWordUtil::MakeRange
//
//    Convenience function for creating a range over the current document.

nsresult mozInlineSpellWordUtil::MakeRange(NodeOffset aBegin, NodeOffset aEnd,
                                          nsRange** aRange) const {
 NS_ENSURE_ARG_POINTER(aBegin.mNode);
 if (!mDocument) {
   return NS_ERROR_NOT_INITIALIZED;
 }

 ErrorResult error;
 RefPtr<nsRange> range = nsRange::Create(aBegin.mNode, aBegin.mOffset,
                                         aEnd.mNode, aEnd.mOffset, error);
 if (NS_WARN_IF(error.Failed())) {
   return error.StealNSResult();
 }
 MOZ_ASSERT(range);
 range.forget(aRange);
 return NS_OK;
}

// static
already_AddRefed<nsRange> mozInlineSpellWordUtil::MakeRange(
   const NodeOffsetRange& aRange) {
 IgnoredErrorResult ignoredError;
 RefPtr<nsRange> range =
     nsRange::Create(aRange.Begin().Node(), aRange.Begin().Offset(),
                     aRange.End().Node(), aRange.End().Offset(), ignoredError);
 NS_WARNING_ASSERTION(!ignoredError.Failed(), "Creating a range failed");
 return range.forget();
}

/*********** Word Splitting ************/

// classifies a given character in the DOM word
enum CharClass {
 CHAR_CLASS_WORD,
 CHAR_CLASS_SEPARATOR,
 CHAR_CLASS_END_OF_INPUT
};

// Encapsulates DOM-word to real-word splitting
template <class T>
struct MOZ_STACK_CLASS WordSplitState {
 const T& mDOMWordText;
 int32_t mDOMWordOffset;
 CharClass mCurCharClass;

 explicit WordSplitState(const T& aString)
     : mDOMWordText(aString),
       mDOMWordOffset(0),
       mCurCharClass(CHAR_CLASS_END_OF_INPUT) {}

 CharClass ClassifyCharacter(int32_t aIndex, bool aRecurse) const;
 void Advance();
 void AdvanceThroughSeparators();
 void AdvanceThroughWord();

 // Finds special words like email addresses and URLs that may start at the
 // current position, and returns their length, or 0 if not found. This allows
 // arbitrary word breaking rules to be used for these special entities, as
 // long as they can not contain whitespace.
 bool IsSpecialWord() const;

 // Similar to IsSpecialWord except that this takes a split word as
 // input. This checks for things that do not require special word-breaking
 // rules.
 bool ShouldSkipWord(int32_t aStart, int32_t aLength) const;

 // Finds the last sequence of DOM word separators before aBeforeOffset and
 // returns the offset to its first element.
 Maybe<int32_t> FindOffsetOfLastDOMWordSeparatorSequence(
     int32_t aBeforeOffset) const;

 char16_t GetUnicharAt(int32_t aIndex) const;
};

// WordSplitState::ClassifyCharacter
template <class T>
CharClass WordSplitState<T>::ClassifyCharacter(int32_t aIndex,
                                              bool aRecurse) const {
 MOZ_ASSERT(aIndex >= 0 && aIndex <= int32_t(mDOMWordText.Length()),
            "Index out of range");
 if (aIndex == int32_t(mDOMWordText.Length())) return CHAR_CLASS_SEPARATOR;

 // this will classify the character, we want to treat "ignorable" characters
 // such as soft hyphens, and also ZWJ and ZWNJ as word characters.
 nsUGenCategory charCategory =
     mozilla::unicode::GetGenCategory(GetUnicharAt(aIndex));
 if (charCategory == nsUGenCategory::kLetter ||
     IsIgnorableCharacter(mDOMWordText[aIndex]) ||
     mDOMWordText[aIndex] == 0x200C /* ZWNJ */ ||
     mDOMWordText[aIndex] == 0x200D /* ZWJ */)
   return CHAR_CLASS_WORD;

 // If conditional punctuation is surrounded immediately on both sides by word
 // characters it also counts as a word character.
 if (IsConditionalPunctuation(mDOMWordText[aIndex])) {
   if (!aRecurse) {
     // not allowed to look around, this punctuation counts like a separator
     return CHAR_CLASS_SEPARATOR;
   }

   // check the left-hand character
   if (aIndex == 0) return CHAR_CLASS_SEPARATOR;
   if (ClassifyCharacter(aIndex - 1, false) != CHAR_CLASS_WORD)
     return CHAR_CLASS_SEPARATOR;
   // If the previous charatcer is a word-char, make sure that it's not a
   // special dot character.
   if (mDOMWordText[aIndex - 1] == '.') return CHAR_CLASS_SEPARATOR;

   // now we know left char is a word-char, check the right-hand character
   if (aIndex == int32_t(mDOMWordText.Length() - 1)) {
     return CHAR_CLASS_SEPARATOR;
   }

   if (ClassifyCharacter(aIndex + 1, false) != CHAR_CLASS_WORD)
     return CHAR_CLASS_SEPARATOR;
   // If the next charatcer is a word-char, make sure that it's not a
   // special dot character.
   if (mDOMWordText[aIndex + 1] == '.') return CHAR_CLASS_SEPARATOR;

   // char on either side is a word, this counts as a word
   return CHAR_CLASS_WORD;
 }

 // The dot character, if appearing at the end of a word, should
 // be considered part of that word.  Example: "etc.", or
 // abbreviations
 if (aIndex > 0 && mDOMWordText[aIndex] == '.' &&
     mDOMWordText[aIndex - 1] != '.' &&
     ClassifyCharacter(aIndex - 1, false) != CHAR_CLASS_WORD) {
   return CHAR_CLASS_WORD;
 }

 // all other punctuation
 if (charCategory == nsUGenCategory::kSeparator ||
     charCategory == nsUGenCategory::kOther ||
     charCategory == nsUGenCategory::kPunctuation ||
     charCategory == nsUGenCategory::kSymbol) {
   // Don't break on hyphens, as hunspell handles them on its own.
   if (aIndex > 0 && mDOMWordText[aIndex] == '-' &&
       mDOMWordText[aIndex - 1] != '-' &&
       ClassifyCharacter(aIndex - 1, false) == CHAR_CLASS_WORD) {
     // A hyphen is only meaningful as a separator inside a word
     // if the previous and next characters are a word character.
     if (aIndex == int32_t(mDOMWordText.Length()) - 1)
       return CHAR_CLASS_SEPARATOR;
     if (mDOMWordText[aIndex + 1] != '.' &&
         ClassifyCharacter(aIndex + 1, false) == CHAR_CLASS_WORD)
       return CHAR_CLASS_WORD;
   }
   return CHAR_CLASS_SEPARATOR;
 }

 // any other character counts as a word
 return CHAR_CLASS_WORD;
}

// WordSplitState::Advance
template <class T>
void WordSplitState<T>::Advance() {
 MOZ_ASSERT(mDOMWordOffset >= 0, "Negative word index");
 MOZ_ASSERT(mDOMWordOffset < (int32_t)mDOMWordText.Length(),
            "Length beyond end");

 mDOMWordOffset++;
 if (mDOMWordOffset >= (int32_t)mDOMWordText.Length())
   mCurCharClass = CHAR_CLASS_END_OF_INPUT;
 else
   mCurCharClass = ClassifyCharacter(mDOMWordOffset, true);
}

// WordSplitState::AdvanceThroughSeparators
template <class T>
void WordSplitState<T>::AdvanceThroughSeparators() {
 while (mCurCharClass == CHAR_CLASS_SEPARATOR) Advance();
}

// WordSplitState::AdvanceThroughWord
template <class T>
void WordSplitState<T>::AdvanceThroughWord() {
 while (mCurCharClass == CHAR_CLASS_WORD) Advance();
}

// WordSplitState::IsSpecialWord
template <class T>
bool WordSplitState<T>::IsSpecialWord() const {
 // Search for email addresses. We simply define these as any sequence of
 // characters with an '@' character in the middle. The DOM word is already
 // split on whitepace, so we know that everything to the end is the address
 int32_t firstColon = -1;
 for (int32_t i = mDOMWordOffset; i < int32_t(mDOMWordText.Length()); i++) {
   if (mDOMWordText[i] == '@') {
     // only accept this if there are unambiguous word characters (don't bother
     // recursing to disambiguate apostrophes) on each side. This prevents
     // classifying, e.g. "@home" as an email address

     // Use this condition to only accept words with '@' in the middle of
     // them. It works, but the inlinespellcker doesn't like this. The problem
     // is that you type "fhsgfh@" that's a misspelled word followed by a
     // symbol, but when you type another letter "fhsgfh@g" that first word
     // need to be unmarked misspelled. It doesn't do this. it only checks the
     // current position for potentially removing a spelling range.
     if (i > 0 && ClassifyCharacter(i - 1, false) == CHAR_CLASS_WORD &&
         i < (int32_t)mDOMWordText.Length() - 1 &&
         ClassifyCharacter(i + 1, false) == CHAR_CLASS_WORD) {
       return true;
     }
   } else if (mDOMWordText[i] == ':' && firstColon < 0) {
     firstColon = i;

     // If the first colon is followed by a slash, consider it a URL
     // This will catch things like asdf://foo.com
     if (firstColon < (int32_t)mDOMWordText.Length() - 1 &&
         mDOMWordText[firstColon + 1] == '/') {
       return true;
     }
   }
 }

 // Check the text before the first colon against some known protocols. It
 // is impossible to check against all protocols, especially since you can
 // plug in new protocols. We also don't want to waste time here checking
 // against a lot of obscure protocols.
 if (firstColon > mDOMWordOffset) {
   nsString protocol(
       Substring(mDOMWordText, mDOMWordOffset, firstColon - mDOMWordOffset));
   if (protocol.EqualsIgnoreCase("http") ||
       protocol.EqualsIgnoreCase("https") ||
       protocol.EqualsIgnoreCase("news") ||
       protocol.EqualsIgnoreCase("file") ||
       protocol.EqualsIgnoreCase("javascript") ||
       protocol.EqualsIgnoreCase("data") || protocol.EqualsIgnoreCase("ftp")) {
     return true;
   }
 }

 // not anything special
 return false;
}

// WordSplitState::ShouldSkipWord
template <class T>
bool WordSplitState<T>::ShouldSkipWord(int32_t aStart, int32_t aLength) const {
 int32_t last = aStart + aLength;

 // check to see if the word contains a digit
 for (int32_t i = aStart; i < last; i++) {
   if (mozilla::unicode::GetGenCategory(GetUnicharAt(i)) ==
       nsUGenCategory::kNumber) {
     return true;
   }
 }

 // not special
 return false;
}

template <class T>
Maybe<int32_t> WordSplitState<T>::FindOffsetOfLastDOMWordSeparatorSequence(
   const int32_t aBeforeOffset) const {
 for (int32_t i = aBeforeOffset - 1; i >= 0; --i) {
   if (IsDOMWordSeparator(mDOMWordText[i]) ||
       (!IsAmbiguousDOMWordSeprator(mDOMWordText[i]) &&
        ClassifyCharacter(i, true) == CHAR_CLASS_SEPARATOR)) {
     // Be greedy, find as many separators as we can
     for (int32_t j = i - 1; j >= 0; --j) {
       if (IsDOMWordSeparator(mDOMWordText[j]) ||
           (!IsAmbiguousDOMWordSeprator(mDOMWordText[j]) &&
            ClassifyCharacter(j, true) == CHAR_CLASS_SEPARATOR)) {
         i = j;
       } else {
         break;
       }
     }
     return Some(i);
   }
 }
 return Nothing();
}

template <>
char16_t WordSplitState<nsDependentSubstring>::GetUnicharAt(
   int32_t aIndex) const {
 return mDOMWordText[aIndex];
}

template <>
char16_t WordSplitState<nsDependentCSubstring>::GetUnicharAt(
   int32_t aIndex) const {
 return static_cast<char16_t>(static_cast<uint8_t>(mDOMWordText[aIndex]));
}

static inline bool IsBRElement(nsINode* aNode) {
 return aNode->IsHTMLElement(nsGkAtoms::br);
}

/**
* Given a TextNode, finds the last sequence of DOM word separators before
* aBeforeOffset and returns the offset to its first element.
*
* @param aContent the TextNode to check.
* @param aBeforeOffset the offset in the TextNode before which we will search
*        for the DOM separator. You can pass INT32_MAX to search the entire
*        length of the string.
*/
static Maybe<int32_t> FindOffsetOfLastDOMWordSeparatorSequence(
   nsIContent* aContent, int32_t aBeforeOffset) {
 const dom::CharacterDataBuffer* characterDataBuffer =
     aContent->GetCharacterDataBuffer();
 MOZ_ASSERT(characterDataBuffer, "Where is our text?");
 int32_t end =
     std::min(aBeforeOffset, int32_t(characterDataBuffer->GetLength()));

 if (characterDataBuffer->Is2b()) {
   nsDependentSubstring targetText(characterDataBuffer->Get2b(), end);
   WordSplitState<nsDependentSubstring> state(targetText);
   return state.FindOffsetOfLastDOMWordSeparatorSequence(end);
 }

 nsDependentCSubstring targetText(characterDataBuffer->Get1b(), end);
 WordSplitState<nsDependentCSubstring> state(targetText);
 return state.FindOffsetOfLastDOMWordSeparatorSequence(end);
}

/**
* Check if there's a DOM word separator before aBeforeOffset in this node.
* Always returns true if it's a BR element.
* aSeparatorOffset is set to the index of the first character in the last
* separator if any is found (0 for BR elements).
*
* This function does not modify aSeparatorOffset when it returns false.
*/
static bool ContainsDOMWordSeparator(nsINode* aNode, int32_t aBeforeOffset,
                                    int32_t* aSeparatorOffset) {
 if (IsBRElement(aNode)) {
   *aSeparatorOffset = 0;
   return true;
 }

 if (!IsSpellCheckingTextNode(aNode)) return false;

 const Maybe<int32_t> separatorOffset =
     FindOffsetOfLastDOMWordSeparatorSequence(aNode->AsContent(),
                                              aBeforeOffset);
 if (separatorOffset) {
   *aSeparatorOffset = *separatorOffset;
   return true;
 }

 return false;
}

static bool IsBreakElement(nsINode* aNode) {
 if (!aNode->IsElement()) {
   return false;
 }

 dom::Element* element = aNode->AsElement();
 if (element->IsHTMLElement(nsGkAtoms::br)) {
   return true;
 }

 // If we don't have a frame, we don't consider ourselves a break
 // element.  In particular, words can span us.
 nsIFrame* frame = element->GetPrimaryFrame();
 if (!frame) {
   return false;
 }

 auto* disp = frame->StyleDisplay();
 // Anything that's not an inline element is a break element.
 // XXXbz should replaced inlines be break elements, though?
 // Also should inline-block and such be break elements?
 //
 // FIXME(emilio): We should teach the spell checker to deal with generated
 // content (it doesn't at all), then remove the IsListItem() check, as there
 // could be no marker, etc...
 return !disp->IsInlineFlow() || disp->IsListItem();
}

struct CheckLeavingBreakElementClosure {
 bool mLeftBreakElement;
};

static void CheckLeavingBreakElement(nsINode* aNode, void* aClosure) {
 CheckLeavingBreakElementClosure* cl =
     static_cast<CheckLeavingBreakElementClosure*>(aClosure);
 if (!cl->mLeftBreakElement && IsBreakElement(aNode)) {
   cl->mLeftBreakElement = true;
 }
}

void mozInlineSpellWordUtil::NormalizeWord(nsAString& aWord) {
 nsAutoString result;
 ::NormalizeWord(aWord, 0, aWord.Length(), result);
 aWord = result;
}

void mozInlineSpellWordUtil::SoftText::AdjustBeginAndBuildText(
   NodeOffset aBegin, NodeOffset aEnd, const nsINode* aRootNode) {
 MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug, ("%s", __FUNCTION__));

 mBegin = std::move(aBegin);
 mEnd = std::move(aEnd);

 // First we have to work backwards from mBegin to find a text node
 // containing a DOM word separator, a non-inline-element
 // boundary, or the hard start node. That's where we'll start building the
 // soft string from.
 nsINode* node = mBegin.mNode;
 int32_t firstOffsetInNode = 0;
 int32_t checkBeforeOffset = mBegin.mOffset;
 while (node) {
   if (ContainsDOMWordSeparator(node, checkBeforeOffset, &firstOffsetInNode)) {
     if (node == mBegin.mNode) {
       // If we find a word separator on the first node, look at the preceding
       // word on the text node as well.
       if (firstOffsetInNode > 0) {
         // Try to find the previous word boundary in the current node. If
         // we can't find one, start checking previous sibling nodes (if any
         // adjacent ones exist) to see if we can find any text nodes with
         // DOM word separators. We bail out as soon as we see a node that is
         // not a text node, or we run out of previous sibling nodes. In the
         // event that we simply cannot find any preceding word separator, the
         // offset is set to 0, and the soft text beginning node is set to the
         // "most previous" text node before the original starting node, or
         // kept at the original starting node if no previous text nodes exist.
         int32_t newOffset = 0;
         if (!ContainsDOMWordSeparator(node, firstOffsetInNode - 1,
                                       &newOffset)) {
           nsIContent* prevNode = node->GetPreviousSibling();
           while (prevNode && IsSpellCheckingTextNode(prevNode)) {
             mBegin.mNode = prevNode;
             const Maybe<int32_t> separatorOffset =
                 FindOffsetOfLastDOMWordSeparatorSequence(prevNode, INT32_MAX);
             if (separatorOffset) {
               newOffset = *separatorOffset;
               break;
             }
             prevNode = prevNode->GetPreviousSibling();
           }
         }
         firstOffsetInNode = newOffset;
       } else {
         firstOffsetInNode = 0;
       }

       MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
               ("%s: adjusting mBegin.mOffset from %i to %i.", __FUNCTION__,
                mBegin.mOffset, firstOffsetInNode));
       mBegin.mOffset = firstOffsetInNode;
     }
     break;
   }
   checkBeforeOffset = INT32_MAX;
   if (IsBreakElement(node)) {
     // Since GerPrevNode follows tree *preorder*, we're about to traverse up
     // out of 'node'. Since node induces breaks (e.g., it's a block), don't
     // bother trying to look outside it, just stop now.
     break;
   }
   // GetPreviousContent below expects aRootNode to be an ancestor of node.
   if (!node->IsInclusiveDescendantOf(aRootNode)) {
     break;
   }
   node = node->GetPrevNode(aRootNode);
 }

 // Now build up the string moving forward through the DOM until we reach
 // the soft end and *then* see a DOM word separator, a non-inline-element
 // boundary, or the hard end node.
 mValue.Truncate();
 mDOMMapping.Clear();
 bool seenSoftEnd = false;
 // Leave this outside the loop so large heap string allocations can be reused
 // across iterations
 while (node) {
   if (node == mEnd.mNode) {
     seenSoftEnd = true;
   }

   bool exit = false;
   if (IsSpellCheckingTextNode(node)) {
     nsIContent* content = static_cast<nsIContent*>(node);
     MOZ_ASSERT(content, "Where is our content?");
     const dom::CharacterDataBuffer* characterDataBuffer =
         content->GetCharacterDataBuffer();
     MOZ_ASSERT(characterDataBuffer, "Where is our text?");
     uint32_t lastOffsetInNode = characterDataBuffer->GetLength();

     if (seenSoftEnd) {
       // check whether we can stop after this
       for (uint32_t i =
                node == mEnd.mNode ? AssertedCast<uint32_t>(mEnd.mOffset) : 0;
            i < characterDataBuffer->GetLength(); ++i) {
         if (IsDOMWordSeparator(characterDataBuffer->CharAt(i))) {
           exit = true;
           // stop at the first separator after the soft end point
           lastOffsetInNode = i;
           break;
         }
       }
     }

     if (firstOffsetInNode >= 0 &&
         static_cast<uint32_t>(firstOffsetInNode) < lastOffsetInNode) {
       const uint32_t len = lastOffsetInNode - firstOffsetInNode;
       mDOMMapping.AppendElement(DOMTextMapping(
           NodeOffset(node, firstOffsetInNode), mValue.Length(), len));

       const bool ok = characterDataBuffer->AppendTo(
           mValue, static_cast<uint32_t>(firstOffsetInNode), len,
           mozilla::fallible);
       if (!ok) {
         // probably out of memory, remove from mDOMMapping
         mDOMMapping.RemoveLastElement();
         exit = true;
       }
     }

     firstOffsetInNode = 0;
   }

   if (exit) break;

   CheckLeavingBreakElementClosure closure = {false};
   node = FindNextNode(node, aRootNode, CheckLeavingBreakElement, &closure);
   if (closure.mLeftBreakElement || (node && IsBreakElement(node))) {
     // We left, or are entering, a break element (e.g., block). Maybe we can
     // stop now.
     if (seenSoftEnd) break;
     // Record the break
     mValue.Append(' ');
   }
 }

 MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
         ("%s: got DOM string: %s", __FUNCTION__,
          NS_ConvertUTF16toUTF8(mValue).get()));
}

auto mozInlineSpellWordUtil::BuildRealWords() const
   -> Result<RealWords, nsresult> {
 // This is pretty simple. We just have to walk mSoftText.GetValue(),
 // tokenizing it into "real words". We do an outer traversal of words
 // delimited by IsDOMWordSeparator, calling SplitDOMWordAndAppendTo on each of
 // those DOM words
 int32_t wordStart = -1;
 RealWords realWords;
 for (int32_t i = 0; i < int32_t(mSoftText.GetValue().Length()); ++i) {
   if (IsDOMWordSeparator(mSoftText.GetValue().CharAt(i))) {
     if (wordStart >= 0) {
       nsresult rv = SplitDOMWordAndAppendTo(wordStart, i, realWords);
       if (NS_FAILED(rv)) {
         return Err(rv);
       }
       wordStart = -1;
     }
   } else {
     if (wordStart < 0) {
       wordStart = i;
     }
   }
 }
 if (wordStart >= 0) {
   nsresult rv = SplitDOMWordAndAppendTo(
       wordStart, mSoftText.GetValue().Length(), realWords);
   if (NS_FAILED(rv)) {
     return Err(rv);
   }
 }

 return realWords;
}

/*********** DOM/realwords<->mSoftText.GetValue() mapping functions
* ************/

int32_t mozInlineSpellWordUtil::MapDOMPositionToSoftTextOffset(
   const NodeOffset& aNodeOffset) const {
 if (!mSoftText.mIsValid) {
   NS_ERROR("Soft text must be valid if we're to map into it");
   return -1;
 }

 for (int32_t i = 0; i < int32_t(mSoftText.GetDOMMapping().Length()); ++i) {
   const DOMTextMapping& map = mSoftText.GetDOMMapping()[i];
   if (map.mNodeOffset.mNode == aNodeOffset.mNode) {
     // Allow offsets at either end of the string, in particular, allow the
     // offset that's at the end of the contributed string
     int32_t offsetInContributedString =
         aNodeOffset.mOffset - map.mNodeOffset.mOffset;
     if (offsetInContributedString >= 0 &&
         offsetInContributedString <= map.mLength)
       return map.mSoftTextOffset + offsetInContributedString;
     return -1;
   }
 }
 return -1;
}

namespace {

template <class T>
class FirstLargerOffset {
 int32_t mSoftTextOffset;

public:
 explicit FirstLargerOffset(int32_t aSoftTextOffset)
     : mSoftTextOffset(aSoftTextOffset) {}
 int operator()(const T& t) const {
   // We want the first larger offset, so never return 0 (which would
   // short-circuit evaluation before finding the last such offset).
   return mSoftTextOffset < t.mSoftTextOffset ? -1 : 1;
 }
};

template <class T>
bool FindLastNongreaterOffset(const nsTArray<T>& aContainer,
                             int32_t aSoftTextOffset, size_t* aIndex) {
 if (aContainer.Length() == 0) {
   return false;
 }

 BinarySearchIf(aContainer, 0, aContainer.Length(),
                FirstLargerOffset<T>(aSoftTextOffset), aIndex);
 if (*aIndex > 0) {
   // There was at least one mapping with offset <= aSoftTextOffset. Step back
   // to find the last element with |mSoftTextOffset <= aSoftTextOffset|.
   *aIndex -= 1;
 } else {
   // Every mapping had offset greater than aSoftTextOffset.
   MOZ_ASSERT(aContainer[*aIndex].mSoftTextOffset > aSoftTextOffset);
 }
 return true;
}

}  // namespace

NodeOffset mozInlineSpellWordUtil::MapSoftTextOffsetToDOMPosition(
   int32_t aSoftTextOffset, DOMMapHint aHint) const {
 MOZ_ASSERT(mSoftText.mIsValid,
            "Soft text must be valid if we're to map out of it");
 if (!mSoftText.mIsValid) return NodeOffset(nullptr, -1);

 // Find the last mapping, if any, such that mSoftTextOffset <= aSoftTextOffset
 size_t index;
 bool found = FindLastNongreaterOffset(mSoftText.GetDOMMapping(),
                                       aSoftTextOffset, &index);
 if (!found) {
   return NodeOffset(nullptr, -1);
 }

 // 'index' is now the last mapping, if any, such that
 // mSoftTextOffset <= aSoftTextOffset.
 // If we're doing HINT_END, then we may want to return the end of the
 // the previous mapping instead of the start of this mapping
 if (aHint == HINT_END && index > 0) {
   const DOMTextMapping& map = mSoftText.GetDOMMapping()[index - 1];
   if (map.mSoftTextOffset + map.mLength == aSoftTextOffset)
     return NodeOffset(map.mNodeOffset.mNode,
                       map.mNodeOffset.mOffset + map.mLength);
 }

 // We allow ourselves to return the end of this mapping even if we're
 // doing HINT_START. This will only happen if there is no mapping which this
 // point is the start of. I'm not 100% sure this is OK...
 const DOMTextMapping& map = mSoftText.GetDOMMapping()[index];
 int32_t offset = aSoftTextOffset - map.mSoftTextOffset;
 if (offset >= 0 && offset <= map.mLength)
   return NodeOffset(map.mNodeOffset.mNode, map.mNodeOffset.mOffset + offset);

 return NodeOffset(nullptr, -1);
}

// static
void mozInlineSpellWordUtil::ToString(const DOMMapHint aHint,
                                     nsACString& aResult) {
 switch (aHint) {
   case HINT_BEGIN:
     aResult.AssignLiteral("begin");
     break;
   case HINT_END:
     aResult.AssignLiteral("end");
     break;
 }
}

int32_t mozInlineSpellWordUtil::FindRealWordContaining(
   int32_t aSoftTextOffset, DOMMapHint aHint, bool aSearchForward) const {
 if (MOZ_LOG_TEST(sInlineSpellWordUtilLog, LogLevel::Debug)) {
   nsAutoCString hint;
   mozInlineSpellWordUtil::ToString(aHint, hint);

   MOZ_LOG(
       sInlineSpellWordUtilLog, LogLevel::Debug,
       ("%s: offset=%i, hint=%s, searchForward=%i.", __FUNCTION__,
        aSoftTextOffset, hint.get(), static_cast<int32_t>(aSearchForward)));
 }

 MOZ_ASSERT(mSoftText.mIsValid,
            "Soft text must be valid if we're to map out of it");
 if (!mSoftText.mIsValid) return -1;

 // Find the last word, if any, such that mRealWords[index].mSoftTextOffset
 // <= aSoftTextOffset
 size_t index;
 bool found = FindLastNongreaterOffset(mRealWords, aSoftTextOffset, &index);
 if (!found) {
   return -1;
 }

 // 'index' is now the last word, if any, such that
 // mSoftTextOffset <= aSoftTextOffset.
 // If we're doing HINT_END, then we may want to return the end of the
 // the previous word instead of the start of this word
 if (aHint == HINT_END && index > 0) {
   const RealWord& word = mRealWords[index - 1];
   if (word.EndOffset() == aSoftTextOffset) {
     return index - 1;
   }
 }

 // We allow ourselves to return the end of this word even if we're
 // doing HINT_BEGIN. This will only happen if there is no word which this
 // point is the start of. I'm not 100% sure this is OK...
 const RealWord& word = mRealWords[index];
 int32_t offset = aSoftTextOffset - word.mSoftTextOffset;
 if (offset >= 0 && offset <= static_cast<int32_t>(word.mLength)) return index;

 if (aSearchForward) {
   if (mRealWords[0].mSoftTextOffset > aSoftTextOffset) {
     // All words have mSoftTextOffset > aSoftTextOffset
     return 0;
   }
   // 'index' is the last word such that mSoftTextOffset <= aSoftTextOffset.
   // Word index+1, if it exists, will be the first with
   // mSoftTextOffset > aSoftTextOffset.
   if (index + 1 < mRealWords.Length()) return index + 1;
 }

 return -1;
}

// mozInlineSpellWordUtil::SplitDOMWordAndAppendTo

nsresult mozInlineSpellWordUtil::SplitDOMWordAndAppendTo(
   int32_t aStart, int32_t aEnd, nsTArray<RealWord>& aRealWords) const {
 nsDependentSubstring targetText(mSoftText.GetValue(), aStart, aEnd - aStart);
 WordSplitState<nsDependentSubstring> state(targetText);
 state.mCurCharClass = state.ClassifyCharacter(0, true);

 state.AdvanceThroughSeparators();
 if (state.mCurCharClass != CHAR_CLASS_END_OF_INPUT && state.IsSpecialWord()) {
   int32_t specialWordLength =
       state.mDOMWordText.Length() - state.mDOMWordOffset;
   if (!aRealWords.AppendElement(
           RealWord(aStart + state.mDOMWordOffset, specialWordLength, false),
           fallible)) {
     return NS_ERROR_OUT_OF_MEMORY;
   }

   return NS_OK;
 }

 while (state.mCurCharClass != CHAR_CLASS_END_OF_INPUT) {
   state.AdvanceThroughSeparators();
   if (state.mCurCharClass == CHAR_CLASS_END_OF_INPUT) break;

   // save the beginning of the word
   int32_t wordOffset = state.mDOMWordOffset;

   // find the end of the word
   state.AdvanceThroughWord();
   int32_t wordLen = state.mDOMWordOffset - wordOffset;
   if (!aRealWords.AppendElement(
           RealWord(aStart + wordOffset, wordLen,
                    !state.ShouldSkipWord(wordOffset, wordLen)),
           fallible)) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
 }

 return NS_OK;
}