The Tor Browser: gfx/thebes/gfxDWriteTextAnalysis.cpp@b8a032363ba2 (annotated)

gfx/thebes/gfxDWriteTextAnalysis.cpp@b8a032363ba2 (annotated)

gfx/thebes/gfxDWriteTextAnalysis.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * 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 "gfxDWriteTextAnalysis.h"
 TextAnalysis::TextAnalysis(const wchar_t* text,
                            UINT32 textLength,
                            const wchar_t* localeName,
                            DWRITE_READING_DIRECTION readingDirection)
   : mText(text)
   , mTextLength(textLength)
   , mLocaleName(localeName)
   , mReadingDirection(readingDirection)
   , mCurrentRun(nullptr)
 {
 }
 TextAnalysis::~TextAnalysis()
 {
     // delete runs, except mRunHead which is part of the TextAnalysis object
     for (Run *run = mRunHead.nextRun; run;) {
         Run *origRun = run;
         run = run->nextRun;
         delete origRun;
     }
 }
 STDMETHODIMP
 TextAnalysis::GenerateResults(IDWriteTextAnalyzer* textAnalyzer,
                               OUT Run **runHead)
 {
     // Analyzes the text using the script analyzer and returns
     // the result as a series of runs.
     HRESULT hr = S_OK;
     // Initially start out with one result that covers the entire range.
     // This result will be subdivided by the analysis processes.
     mRunHead.mTextStart = 0;
     mRunHead.mTextLength = mTextLength;
     mRunHead.mBidiLevel =
         (mReadingDirection == DWRITE_READING_DIRECTION_RIGHT_TO_LEFT);
     mRunHead.nextRun = nullptr;
     mCurrentRun = &mRunHead;
     // Call each of the analyzers in sequence, recording their results.
     if (SUCCEEDED(hr = textAnalyzer->AnalyzeScript(this,
 ,
                                                    mTextLength,
                                                    this))) {
         *runHead = &mRunHead;
     }
     return hr;
 }
 ////////////////////////////////////////////////////////////////////////////////
 // IDWriteTextAnalysisSource source implementation
 IFACEMETHODIMP
 TextAnalysis::GetTextAtPosition(UINT32 textPosition,
                                 OUT WCHAR const** textString,
                                 OUT UINT32* textLength)
 {
     if (textPosition >= mTextLength) {
         // No text at this position, valid query though.
         *textString = nullptr;
         *textLength = 0;
     } else {
         *textString = mText + textPosition;
         *textLength = mTextLength - textPosition;
     }
     return S_OK;
 }
 IFACEMETHODIMP
 TextAnalysis::GetTextBeforePosition(UINT32 textPosition,
                                     OUT WCHAR const** textString,
                                     OUT UINT32* textLength)
 {
     if (textPosition == 0 || textPosition > mTextLength) {
         // Either there is no text before here (== 0), or this
         // is an invalid position. The query is considered valid thouh.
         *textString = nullptr;
         *textLength = 0;
     } else {
         *textString = mText;
         *textLength = textPosition;
     }
     return S_OK;
 }
 DWRITE_READING_DIRECTION STDMETHODCALLTYPE
 TextAnalysis::GetParagraphReadingDirection()
 {
     // We support only a single reading direction.
     return mReadingDirection;
 }
 IFACEMETHODIMP
 TextAnalysis::GetLocaleName(UINT32 textPosition,
                             OUT UINT32* textLength,
                             OUT WCHAR const** localeName)
 {
     // Single locale name is used, valid until the end of the string.
     *localeName = mLocaleName;
     *textLength = mTextLength - textPosition;
     return S_OK;
 }
 IFACEMETHODIMP
 TextAnalysis::GetNumberSubstitution(UINT32 textPosition,
                                     OUT UINT32* textLength,
                                     OUT IDWriteNumberSubstitution** numberSubstitution)
 {
     // We do not support number substitution.
     *numberSubstitution = nullptr;
     *textLength = mTextLength - textPosition;
     return S_OK;
 }
 ////////////////////////////////////////////////////////////////////////////////
 // IDWriteTextAnalysisSink implementation
 IFACEMETHODIMP
 TextAnalysis::SetLineBreakpoints(UINT32 textPosition,
                                  UINT32 textLength,
                                  DWRITE_LINE_BREAKPOINT const* lineBreakpoints)
 {
     // We don't use this for now.
     return S_OK;
 }
 IFACEMETHODIMP
 TextAnalysis::SetScriptAnalysis(UINT32 textPosition,
                                 UINT32 textLength,
                                 DWRITE_SCRIPT_ANALYSIS const* scriptAnalysis)
 {
     SetCurrentRun(textPosition);
     SplitCurrentRun(textPosition);
     while (textLength > 0) {
         Run *run = FetchNextRun(&textLength);
         run->mScript = *scriptAnalysis;
     }
     return S_OK;
 }
 IFACEMETHODIMP
 TextAnalysis::SetBidiLevel(UINT32 textPosition,
                            UINT32 textLength,
                            UINT8 explicitLevel,
                            UINT8 resolvedLevel)
 {
     // We don't use this for now.
     return S_OK;
 }
 IFACEMETHODIMP
 TextAnalysis::SetNumberSubstitution(UINT32 textPosition,
                                     UINT32 textLength,
                                     IDWriteNumberSubstitution* numberSubstitution)
 {
     // We don't use this for now.
     return S_OK;
 }
 ////////////////////////////////////////////////////////////////////////////////
 // Run modification.
 TextAnalysis::Run *
 TextAnalysis::FetchNextRun(IN OUT UINT32* textLength)
 {
     // Used by the sink setters, this returns a reference to the next run.
     // Position and length are adjusted to now point after the current run
     // being returned.
     Run *origRun = mCurrentRun;
     // Split the tail if needed (the length remaining is less than the
     // current run's size).
     if (*textLength < mCurrentRun->mTextLength) {
         SplitCurrentRun(mCurrentRun->mTextStart + *textLength);
     } else {
         // Just advance the current run.
         mCurrentRun = mCurrentRun->nextRun;
     }
     *textLength -= origRun->mTextLength;
     // Return a reference to the run that was just current.
     return origRun;
 }
 void TextAnalysis::SetCurrentRun(UINT32 textPosition)
 {
     // Move the current run to the given position.
     // Since the analyzers generally return results in a forward manner,
     // this will usually just return early. If not, find the
     // corresponding run for the text position.
     if (mCurrentRun && mCurrentRun->ContainsTextPosition(textPosition)) {
         return;
     }
     for (Run *run = &mRunHead; run; run = run->nextRun) {
         if (run->ContainsTextPosition(textPosition)) {
             mCurrentRun = run;
             return;
         }
     }
     NS_NOTREACHED("We should always be able to find the text position in one \
         of our runs");
 }
 void TextAnalysis::SplitCurrentRun(UINT32 splitPosition)
 {
     if (!mCurrentRun) {
         NS_ASSERTION(false, "SplitCurrentRun called without current run.");
         // Shouldn't be calling this when no current run is set!
         return;
     }
     // Split the current run.
     if (splitPosition <= mCurrentRun->mTextStart) {
         // No need to split, already the start of a run
         // or before it. Usually the first.
         return;
     }
     Run *newRun = new Run;
     *newRun = *mCurrentRun;
     // Insert the new run in our linked list.
     newRun->nextRun = mCurrentRun->nextRun;
     mCurrentRun->nextRun = newRun;
     // Adjust runs' text positions and lengths.
     UINT32 splitPoint = splitPosition - mCurrentRun->mTextStart;
     newRun->mTextStart += splitPoint;
     newRun->mTextLength -= splitPoint;
     mCurrentRun->mTextLength = splitPoint;
     mCurrentRun = newRun;
 }

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gfx/thebes/gfxDWriteTextAnalysis.cpp@b8a032363ba2 (annotated)

gfx/thebes/gfxDWriteTextAnalysis.cpp