1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/thebes/gfxDWriteTextAnalysis.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,257 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "gfxDWriteTextAnalysis.h"
1.10 +
1.11 +TextAnalysis::TextAnalysis(const wchar_t* text,
1.12 + UINT32 textLength,
1.13 + const wchar_t* localeName,
1.14 + DWRITE_READING_DIRECTION readingDirection)
1.15 + : mText(text)
1.16 + , mTextLength(textLength)
1.17 + , mLocaleName(localeName)
1.18 + , mReadingDirection(readingDirection)
1.19 + , mCurrentRun(nullptr)
1.20 +{
1.21 +}
1.22 +
1.23 +TextAnalysis::~TextAnalysis()
1.24 +{
1.25 + // delete runs, except mRunHead which is part of the TextAnalysis object
1.26 + for (Run *run = mRunHead.nextRun; run;) {
1.27 + Run *origRun = run;
1.28 + run = run->nextRun;
1.29 + delete origRun;
1.30 + }
1.31 +}
1.32 +
1.33 +STDMETHODIMP
1.34 +TextAnalysis::GenerateResults(IDWriteTextAnalyzer* textAnalyzer,
1.35 + OUT Run **runHead)
1.36 +{
1.37 + // Analyzes the text using the script analyzer and returns
1.38 + // the result as a series of runs.
1.39 +
1.40 + HRESULT hr = S_OK;
1.41 +
1.42 + // Initially start out with one result that covers the entire range.
1.43 + // This result will be subdivided by the analysis processes.
1.44 + mRunHead.mTextStart = 0;
1.45 + mRunHead.mTextLength = mTextLength;
1.46 + mRunHead.mBidiLevel =
1.47 + (mReadingDirection == DWRITE_READING_DIRECTION_RIGHT_TO_LEFT);
1.48 + mRunHead.nextRun = nullptr;
1.49 + mCurrentRun = &mRunHead;
1.50 +
1.51 + // Call each of the analyzers in sequence, recording their results.
1.52 + if (SUCCEEDED(hr = textAnalyzer->AnalyzeScript(this,
1.53 + 0,
1.54 + mTextLength,
1.55 + this))) {
1.56 + *runHead = &mRunHead;
1.57 + }
1.58 +
1.59 + return hr;
1.60 +}
1.61 +
1.62 +
1.63 +////////////////////////////////////////////////////////////////////////////////
1.64 +// IDWriteTextAnalysisSource source implementation
1.65 +
1.66 +IFACEMETHODIMP
1.67 +TextAnalysis::GetTextAtPosition(UINT32 textPosition,
1.68 + OUT WCHAR const** textString,
1.69 + OUT UINT32* textLength)
1.70 +{
1.71 + if (textPosition >= mTextLength) {
1.72 + // No text at this position, valid query though.
1.73 + *textString = nullptr;
1.74 + *textLength = 0;
1.75 + } else {
1.76 + *textString = mText + textPosition;
1.77 + *textLength = mTextLength - textPosition;
1.78 + }
1.79 + return S_OK;
1.80 +}
1.81 +
1.82 +
1.83 +IFACEMETHODIMP
1.84 +TextAnalysis::GetTextBeforePosition(UINT32 textPosition,
1.85 + OUT WCHAR const** textString,
1.86 + OUT UINT32* textLength)
1.87 +{
1.88 + if (textPosition == 0 || textPosition > mTextLength) {
1.89 + // Either there is no text before here (== 0), or this
1.90 + // is an invalid position. The query is considered valid thouh.
1.91 + *textString = nullptr;
1.92 + *textLength = 0;
1.93 + } else {
1.94 + *textString = mText;
1.95 + *textLength = textPosition;
1.96 + }
1.97 + return S_OK;
1.98 +}
1.99 +
1.100 +
1.101 +DWRITE_READING_DIRECTION STDMETHODCALLTYPE
1.102 +TextAnalysis::GetParagraphReadingDirection()
1.103 +{
1.104 + // We support only a single reading direction.
1.105 + return mReadingDirection;
1.106 +}
1.107 +
1.108 +
1.109 +IFACEMETHODIMP
1.110 +TextAnalysis::GetLocaleName(UINT32 textPosition,
1.111 + OUT UINT32* textLength,
1.112 + OUT WCHAR const** localeName)
1.113 +{
1.114 + // Single locale name is used, valid until the end of the string.
1.115 + *localeName = mLocaleName;
1.116 + *textLength = mTextLength - textPosition;
1.117 +
1.118 + return S_OK;
1.119 +}
1.120 +
1.121 +
1.122 +IFACEMETHODIMP
1.123 +TextAnalysis::GetNumberSubstitution(UINT32 textPosition,
1.124 + OUT UINT32* textLength,
1.125 + OUT IDWriteNumberSubstitution** numberSubstitution)
1.126 +{
1.127 + // We do not support number substitution.
1.128 + *numberSubstitution = nullptr;
1.129 + *textLength = mTextLength - textPosition;
1.130 +
1.131 + return S_OK;
1.132 +}
1.133 +
1.134 +
1.135 +////////////////////////////////////////////////////////////////////////////////
1.136 +// IDWriteTextAnalysisSink implementation
1.137 +
1.138 +IFACEMETHODIMP
1.139 +TextAnalysis::SetLineBreakpoints(UINT32 textPosition,
1.140 + UINT32 textLength,
1.141 + DWRITE_LINE_BREAKPOINT const* lineBreakpoints)
1.142 +{
1.143 + // We don't use this for now.
1.144 + return S_OK;
1.145 +}
1.146 +
1.147 +
1.148 +IFACEMETHODIMP
1.149 +TextAnalysis::SetScriptAnalysis(UINT32 textPosition,
1.150 + UINT32 textLength,
1.151 + DWRITE_SCRIPT_ANALYSIS const* scriptAnalysis)
1.152 +{
1.153 + SetCurrentRun(textPosition);
1.154 + SplitCurrentRun(textPosition);
1.155 + while (textLength > 0) {
1.156 + Run *run = FetchNextRun(&textLength);
1.157 + run->mScript = *scriptAnalysis;
1.158 + }
1.159 +
1.160 + return S_OK;
1.161 +}
1.162 +
1.163 +
1.164 +IFACEMETHODIMP
1.165 +TextAnalysis::SetBidiLevel(UINT32 textPosition,
1.166 + UINT32 textLength,
1.167 + UINT8 explicitLevel,
1.168 + UINT8 resolvedLevel)
1.169 +{
1.170 + // We don't use this for now.
1.171 + return S_OK;
1.172 +}
1.173 +
1.174 +
1.175 +IFACEMETHODIMP
1.176 +TextAnalysis::SetNumberSubstitution(UINT32 textPosition,
1.177 + UINT32 textLength,
1.178 + IDWriteNumberSubstitution* numberSubstitution)
1.179 +{
1.180 + // We don't use this for now.
1.181 + return S_OK;
1.182 +}
1.183 +
1.184 +
1.185 +////////////////////////////////////////////////////////////////////////////////
1.186 +// Run modification.
1.187 +
1.188 +TextAnalysis::Run *
1.189 +TextAnalysis::FetchNextRun(IN OUT UINT32* textLength)
1.190 +{
1.191 + // Used by the sink setters, this returns a reference to the next run.
1.192 + // Position and length are adjusted to now point after the current run
1.193 + // being returned.
1.194 +
1.195 + Run *origRun = mCurrentRun;
1.196 + // Split the tail if needed (the length remaining is less than the
1.197 + // current run's size).
1.198 + if (*textLength < mCurrentRun->mTextLength) {
1.199 + SplitCurrentRun(mCurrentRun->mTextStart + *textLength);
1.200 + } else {
1.201 + // Just advance the current run.
1.202 + mCurrentRun = mCurrentRun->nextRun;
1.203 + }
1.204 + *textLength -= origRun->mTextLength;
1.205 +
1.206 + // Return a reference to the run that was just current.
1.207 + return origRun;
1.208 +}
1.209 +
1.210 +
1.211 +void TextAnalysis::SetCurrentRun(UINT32 textPosition)
1.212 +{
1.213 + // Move the current run to the given position.
1.214 + // Since the analyzers generally return results in a forward manner,
1.215 + // this will usually just return early. If not, find the
1.216 + // corresponding run for the text position.
1.217 +
1.218 + if (mCurrentRun && mCurrentRun->ContainsTextPosition(textPosition)) {
1.219 + return;
1.220 + }
1.221 +
1.222 + for (Run *run = &mRunHead; run; run = run->nextRun) {
1.223 + if (run->ContainsTextPosition(textPosition)) {
1.224 + mCurrentRun = run;
1.225 + return;
1.226 + }
1.227 + }
1.228 + NS_NOTREACHED("We should always be able to find the text position in one \
1.229 + of our runs");
1.230 +}
1.231 +
1.232 +
1.233 +void TextAnalysis::SplitCurrentRun(UINT32 splitPosition)
1.234 +{
1.235 + if (!mCurrentRun) {
1.236 + NS_ASSERTION(false, "SplitCurrentRun called without current run.");
1.237 + // Shouldn't be calling this when no current run is set!
1.238 + return;
1.239 + }
1.240 + // Split the current run.
1.241 + if (splitPosition <= mCurrentRun->mTextStart) {
1.242 + // No need to split, already the start of a run
1.243 + // or before it. Usually the first.
1.244 + return;
1.245 + }
1.246 + Run *newRun = new Run;
1.247 +
1.248 + *newRun = *mCurrentRun;
1.249 +
1.250 + // Insert the new run in our linked list.
1.251 + newRun->nextRun = mCurrentRun->nextRun;
1.252 + mCurrentRun->nextRun = newRun;
1.253 +
1.254 + // Adjust runs' text positions and lengths.
1.255 + UINT32 splitPoint = splitPosition - mCurrentRun->mTextStart;
1.256 + newRun->mTextStart += splitPoint;
1.257 + newRun->mTextLength -= splitPoint;
1.258 + mCurrentRun->mTextLength = splitPoint;
1.259 + mCurrentRun = newRun;
1.260 +}
