1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsTextFrameUtils.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,268 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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 "nsTextFrameUtils.h"
1.10 +
1.11 +#include "nsUnicharUtils.h"
1.12 +#include "nsBidiUtils.h"
1.13 +#include "nsIContent.h"
1.14 +#include "nsStyleStruct.h"
1.15 +#include "nsTextFragment.h"
1.16 +#include <algorithm>
1.17 +
1.18 +static bool IsDiscardable(char16_t ch, uint32_t* aFlags)
1.19 +{
1.20 + // Unlike IS_DISCARDABLE, we don't discard \r. \r will be ignored by gfxTextRun
1.21 + // and discarding it would force us to copy text in many cases of preformatted
1.22 + // text containing \r\n.
1.23 + if (ch == CH_SHY) {
1.24 + *aFlags |= nsTextFrameUtils::TEXT_HAS_SHY;
1.25 + return true;
1.26 + }
1.27 + return IsBidiControl(ch);
1.28 +}
1.29 +
1.30 +static bool IsDiscardable(uint8_t ch, uint32_t* aFlags)
1.31 +{
1.32 + if (ch == CH_SHY) {
1.33 + *aFlags |= nsTextFrameUtils::TEXT_HAS_SHY;
1.34 + return true;
1.35 + }
1.36 + return false;
1.37 +}
1.38 +
1.39 +char16_t*
1.40 +nsTextFrameUtils::TransformText(const char16_t* aText, uint32_t aLength,
1.41 + char16_t* aOutput,
1.42 + CompressionMode aCompression,
1.43 + uint8_t* aIncomingFlags,
1.44 + gfxSkipChars* aSkipChars,
1.45 + uint32_t* aAnalysisFlags)
1.46 +{
1.47 + uint32_t flags = 0;
1.48 + char16_t* outputStart = aOutput;
1.49 +
1.50 + bool lastCharArabic = false;
1.51 +
1.52 + if (aCompression == COMPRESS_NONE ||
1.53 + aCompression == DISCARD_NEWLINE) {
1.54 + // Skip discardables.
1.55 + uint32_t i;
1.56 + for (i = 0; i < aLength; ++i) {
1.57 + char16_t ch = *aText++;
1.58 + if (IsDiscardable(ch, &flags) ||
1.59 + (ch == '\n' && aCompression == DISCARD_NEWLINE)) {
1.60 + aSkipChars->SkipChar();
1.61 + } else {
1.62 + aSkipChars->KeepChar();
1.63 + if (ch > ' ') {
1.64 + lastCharArabic = IS_ARABIC_CHAR(ch);
1.65 + } else if (ch == '\t') {
1.66 + flags |= TEXT_HAS_TAB;
1.67 + }
1.68 + *aOutput++ = ch;
1.69 + }
1.70 + }
1.71 + if (lastCharArabic) {
1.72 + *aIncomingFlags |= INCOMING_ARABICCHAR;
1.73 + } else {
1.74 + *aIncomingFlags &= ~INCOMING_ARABICCHAR;
1.75 + }
1.76 + *aIncomingFlags &= ~INCOMING_WHITESPACE;
1.77 + } else {
1.78 + bool inWhitespace = (*aIncomingFlags & INCOMING_WHITESPACE) != 0;
1.79 + uint32_t i;
1.80 + for (i = 0; i < aLength; ++i) {
1.81 + char16_t ch = *aText++;
1.82 + bool nowInWhitespace;
1.83 + if (ch == ' ' &&
1.84 + (i + 1 >= aLength ||
1.85 + !IsSpaceCombiningSequenceTail(aText, aLength - (i + 1)))) {
1.86 + nowInWhitespace = true;
1.87 + } else if (ch == '\n' && aCompression == COMPRESS_WHITESPACE_NEWLINE) {
1.88 + if (i > 0 && IS_CJ_CHAR(aText[-1]) &&
1.89 + i + 1 < aLength && IS_CJ_CHAR(aText[1])) {
1.90 + // Discard newlines between CJK chars.
1.91 + // XXX this really requires more context to get right!
1.92 + aSkipChars->SkipChar();
1.93 + continue;
1.94 + }
1.95 + nowInWhitespace = true;
1.96 + } else {
1.97 + nowInWhitespace = ch == '\t';
1.98 + }
1.99 +
1.100 + if (!nowInWhitespace) {
1.101 + if (IsDiscardable(ch, &flags)) {
1.102 + aSkipChars->SkipChar();
1.103 + nowInWhitespace = inWhitespace;
1.104 + } else {
1.105 + *aOutput++ = ch;
1.106 + aSkipChars->KeepChar();
1.107 + lastCharArabic = IS_ARABIC_CHAR(ch);
1.108 + }
1.109 + } else {
1.110 + if (inWhitespace) {
1.111 + aSkipChars->SkipChar();
1.112 + } else {
1.113 + if (ch != ' ') {
1.114 + flags |= TEXT_WAS_TRANSFORMED;
1.115 + }
1.116 + *aOutput++ = ' ';
1.117 + aSkipChars->KeepChar();
1.118 + }
1.119 + }
1.120 + inWhitespace = nowInWhitespace;
1.121 + }
1.122 + if (lastCharArabic) {
1.123 + *aIncomingFlags |= INCOMING_ARABICCHAR;
1.124 + } else {
1.125 + *aIncomingFlags &= ~INCOMING_ARABICCHAR;
1.126 + }
1.127 + if (inWhitespace) {
1.128 + *aIncomingFlags |= INCOMING_WHITESPACE;
1.129 + } else {
1.130 + *aIncomingFlags &= ~INCOMING_WHITESPACE;
1.131 + }
1.132 + }
1.133 +
1.134 + if (outputStart + aLength != aOutput) {
1.135 + flags |= TEXT_WAS_TRANSFORMED;
1.136 + }
1.137 + *aAnalysisFlags = flags;
1.138 + return aOutput;
1.139 +}
1.140 +
1.141 +uint8_t*
1.142 +nsTextFrameUtils::TransformText(const uint8_t* aText, uint32_t aLength,
1.143 + uint8_t* aOutput,
1.144 + CompressionMode aCompression,
1.145 + uint8_t* aIncomingFlags,
1.146 + gfxSkipChars* aSkipChars,
1.147 + uint32_t* aAnalysisFlags)
1.148 +{
1.149 + uint32_t flags = 0;
1.150 + uint8_t* outputStart = aOutput;
1.151 +
1.152 + if (aCompression == COMPRESS_NONE ||
1.153 + aCompression == DISCARD_NEWLINE) {
1.154 + // Skip discardables.
1.155 + uint32_t i;
1.156 + for (i = 0; i < aLength; ++i) {
1.157 + uint8_t ch = *aText++;
1.158 + if (IsDiscardable(ch, &flags) ||
1.159 + (ch == '\n' && aCompression == DISCARD_NEWLINE)) {
1.160 + aSkipChars->SkipChar();
1.161 + } else {
1.162 + aSkipChars->KeepChar();
1.163 + if (ch == '\t') {
1.164 + flags |= TEXT_HAS_TAB;
1.165 + }
1.166 + *aOutput++ = ch;
1.167 + }
1.168 + }
1.169 + *aIncomingFlags &= ~(INCOMING_ARABICCHAR | INCOMING_WHITESPACE);
1.170 + } else {
1.171 + bool inWhitespace = (*aIncomingFlags & INCOMING_WHITESPACE) != 0;
1.172 + uint32_t i;
1.173 + for (i = 0; i < aLength; ++i) {
1.174 + uint8_t ch = *aText++;
1.175 + bool nowInWhitespace = ch == ' ' || ch == '\t' ||
1.176 + (ch == '\n' && aCompression == COMPRESS_WHITESPACE_NEWLINE);
1.177 + if (!nowInWhitespace) {
1.178 + if (IsDiscardable(ch, &flags)) {
1.179 + aSkipChars->SkipChar();
1.180 + nowInWhitespace = inWhitespace;
1.181 + } else {
1.182 + *aOutput++ = ch;
1.183 + aSkipChars->KeepChar();
1.184 + }
1.185 + } else {
1.186 + if (inWhitespace) {
1.187 + aSkipChars->SkipChar();
1.188 + } else {
1.189 + if (ch != ' ') {
1.190 + flags |= TEXT_WAS_TRANSFORMED;
1.191 + }
1.192 + *aOutput++ = ' ';
1.193 + aSkipChars->KeepChar();
1.194 + }
1.195 + }
1.196 + inWhitespace = nowInWhitespace;
1.197 + }
1.198 + *aIncomingFlags &= ~INCOMING_ARABICCHAR;
1.199 + if (inWhitespace) {
1.200 + *aIncomingFlags |= INCOMING_WHITESPACE;
1.201 + } else {
1.202 + *aIncomingFlags &= ~INCOMING_WHITESPACE;
1.203 + }
1.204 + }
1.205 +
1.206 + if (outputStart + aLength != aOutput) {
1.207 + flags |= TEXT_WAS_TRANSFORMED;
1.208 + }
1.209 + *aAnalysisFlags = flags;
1.210 + return aOutput;
1.211 +}
1.212 +
1.213 +uint32_t
1.214 +nsTextFrameUtils::ComputeApproximateLengthWithWhitespaceCompression(
1.215 + nsIContent *aContent, const nsStyleText *aStyleText)
1.216 +{
1.217 + const nsTextFragment *frag = aContent->GetText();
1.218 + // This is an approximation so we don't really need anything
1.219 + // too fancy here.
1.220 + uint32_t len;
1.221 + if (aStyleText->WhiteSpaceIsSignificant()) {
1.222 + len = frag->GetLength();
1.223 + } else {
1.224 + bool is2b = frag->Is2b();
1.225 + union {
1.226 + const char *s1b;
1.227 + const char16_t *s2b;
1.228 + } u;
1.229 + if (is2b) {
1.230 + u.s2b = frag->Get2b();
1.231 + } else {
1.232 + u.s1b = frag->Get1b();
1.233 + }
1.234 + bool prevWS = true; // more important to ignore blocks with
1.235 + // only whitespace than get inline boundaries
1.236 + // exactly right
1.237 + len = 0;
1.238 + for (uint32_t i = 0, i_end = frag->GetLength(); i < i_end; ++i) {
1.239 + char16_t c = is2b ? u.s2b[i] : u.s1b[i];
1.240 + if (c == ' ' || c == '\n' || c == '\t' || c == '\r') {
1.241 + if (!prevWS) {
1.242 + ++len;
1.243 + }
1.244 + prevWS = true;
1.245 + } else {
1.246 + ++len;
1.247 + prevWS = false;
1.248 + }
1.249 + }
1.250 + }
1.251 + return len;
1.252 +}
1.253 +
1.254 +bool nsSkipCharsRunIterator::NextRun() {
1.255 + do {
1.256 + if (mRunLength) {
1.257 + mIterator.AdvanceOriginal(mRunLength);
1.258 + NS_ASSERTION(mRunLength > 0, "No characters in run (initial length too large?)");
1.259 + if (!mSkipped || mLengthIncludesSkipped) {
1.260 + mRemainingLength -= mRunLength;
1.261 + }
1.262 + }
1.263 + if (!mRemainingLength)
1.264 + return false;
1.265 + int32_t length;
1.266 + mSkipped = mIterator.IsOriginalCharSkipped(&length);
1.267 + mRunLength = std::min(length, mRemainingLength);
1.268 + } while (!mVisitSkipped && mSkipped);
1.269 +
1.270 + return true;
1.271 +}
