layout/generic/nsTextFrameUtils.cpp@b8a032363ba2
layout/generic/nsTextFrameUtils.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
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */
6 #include "nsTextFrameUtils.h"
8 #include "nsUnicharUtils.h"
9 #include "nsBidiUtils.h"
10 #include "nsIContent.h"
11 #include "nsStyleStruct.h"
12 #include "nsTextFragment.h"
13 #include <algorithm>
15 static bool IsDiscardable(char16_t ch, uint32_t* aFlags)
16 {
17 // Unlike IS_DISCARDABLE, we don't discard \r. \r will be ignored by gfxTextRun
18 // and discarding it would force us to copy text in many cases of preformatted
19 // text containing \r\n.
20 if (ch == CH_SHY) {
21 *aFlags |= nsTextFrameUtils::TEXT_HAS_SHY;
22 return true;
23 }
24 return IsBidiControl(ch);
25 }
27 static bool IsDiscardable(uint8_t ch, uint32_t* aFlags)
28 {
29 if (ch == CH_SHY) {
30 *aFlags |= nsTextFrameUtils::TEXT_HAS_SHY;
31 return true;
32 }
33 return false;
34 }
36 char16_t*
37 nsTextFrameUtils::TransformText(const char16_t* aText, uint32_t aLength,
38 char16_t* aOutput,
39 CompressionMode aCompression,
40 uint8_t* aIncomingFlags,
41 gfxSkipChars* aSkipChars,
42 uint32_t* aAnalysisFlags)
43 {
44 uint32_t flags = 0;
45 char16_t* outputStart = aOutput;
47 bool lastCharArabic = false;
49 if (aCompression == COMPRESS_NONE ||
50 aCompression == DISCARD_NEWLINE) {
51 // Skip discardables.
52 uint32_t i;
53 for (i = 0; i < aLength; ++i) {
54 char16_t ch = *aText++;
55 if (IsDiscardable(ch, &flags) ||
56 (ch == '\n' && aCompression == DISCARD_NEWLINE)) {
57 aSkipChars->SkipChar();
58 } else {
59 aSkipChars->KeepChar();
60 if (ch > ' ') {
61 lastCharArabic = IS_ARABIC_CHAR(ch);
62 } else if (ch == '\t') {
63 flags |= TEXT_HAS_TAB;
64 }
65 *aOutput++ = ch;
66 }
67 }
68 if (lastCharArabic) {
69 *aIncomingFlags |= INCOMING_ARABICCHAR;
70 } else {
71 *aIncomingFlags &= ~INCOMING_ARABICCHAR;
72 }
73 *aIncomingFlags &= ~INCOMING_WHITESPACE;
74 } else {
75 bool inWhitespace = (*aIncomingFlags & INCOMING_WHITESPACE) != 0;
76 uint32_t i;
77 for (i = 0; i < aLength; ++i) {
78 char16_t ch = *aText++;
79 bool nowInWhitespace;
80 if (ch == ' ' &&
81 (i + 1 >= aLength ||
82 !IsSpaceCombiningSequenceTail(aText, aLength - (i + 1)))) {
83 nowInWhitespace = true;
84 } else if (ch == '\n' && aCompression == COMPRESS_WHITESPACE_NEWLINE) {
85 if (i > 0 && IS_CJ_CHAR(aText[-1]) &&
86 i + 1 < aLength && IS_CJ_CHAR(aText[1])) {
87 // Discard newlines between CJK chars.
88 // XXX this really requires more context to get right!
89 aSkipChars->SkipChar();
90 continue;
91 }
92 nowInWhitespace = true;
93 } else {
94 nowInWhitespace = ch == '\t';
95 }
97 if (!nowInWhitespace) {
98 if (IsDiscardable(ch, &flags)) {
99 aSkipChars->SkipChar();
100 nowInWhitespace = inWhitespace;
101 } else {
102 *aOutput++ = ch;
103 aSkipChars->KeepChar();
104 lastCharArabic = IS_ARABIC_CHAR(ch);
105 }
106 } else {
107 if (inWhitespace) {
108 aSkipChars->SkipChar();
109 } else {
110 if (ch != ' ') {
111 flags |= TEXT_WAS_TRANSFORMED;
112 }
113 *aOutput++ = ' ';
114 aSkipChars->KeepChar();
115 }
116 }
117 inWhitespace = nowInWhitespace;
118 }
119 if (lastCharArabic) {
120 *aIncomingFlags |= INCOMING_ARABICCHAR;
121 } else {
122 *aIncomingFlags &= ~INCOMING_ARABICCHAR;
123 }
124 if (inWhitespace) {
125 *aIncomingFlags |= INCOMING_WHITESPACE;
126 } else {
127 *aIncomingFlags &= ~INCOMING_WHITESPACE;
128 }
129 }
131 if (outputStart + aLength != aOutput) {
132 flags |= TEXT_WAS_TRANSFORMED;
133 }
134 *aAnalysisFlags = flags;
135 return aOutput;
136 }
138 uint8_t*
139 nsTextFrameUtils::TransformText(const uint8_t* aText, uint32_t aLength,
140 uint8_t* aOutput,
141 CompressionMode aCompression,
142 uint8_t* aIncomingFlags,
143 gfxSkipChars* aSkipChars,
144 uint32_t* aAnalysisFlags)
145 {
146 uint32_t flags = 0;
147 uint8_t* outputStart = aOutput;
149 if (aCompression == COMPRESS_NONE ||
150 aCompression == DISCARD_NEWLINE) {
151 // Skip discardables.
152 uint32_t i;
153 for (i = 0; i < aLength; ++i) {
154 uint8_t ch = *aText++;
155 if (IsDiscardable(ch, &flags) ||
156 (ch == '\n' && aCompression == DISCARD_NEWLINE)) {
157 aSkipChars->SkipChar();
158 } else {
159 aSkipChars->KeepChar();
160 if (ch == '\t') {
161 flags |= TEXT_HAS_TAB;
162 }
163 *aOutput++ = ch;
164 }
165 }
166 *aIncomingFlags &= ~(INCOMING_ARABICCHAR | INCOMING_WHITESPACE);
167 } else {
168 bool inWhitespace = (*aIncomingFlags & INCOMING_WHITESPACE) != 0;
169 uint32_t i;
170 for (i = 0; i < aLength; ++i) {
171 uint8_t ch = *aText++;
172 bool nowInWhitespace = ch == ' ' || ch == '\t' ||
173 (ch == '\n' && aCompression == COMPRESS_WHITESPACE_NEWLINE);
174 if (!nowInWhitespace) {
175 if (IsDiscardable(ch, &flags)) {
176 aSkipChars->SkipChar();
177 nowInWhitespace = inWhitespace;
178 } else {
179 *aOutput++ = ch;
180 aSkipChars->KeepChar();
181 }
182 } else {
183 if (inWhitespace) {
184 aSkipChars->SkipChar();
185 } else {
186 if (ch != ' ') {
187 flags |= TEXT_WAS_TRANSFORMED;
188 }
189 *aOutput++ = ' ';
190 aSkipChars->KeepChar();
191 }
192 }
193 inWhitespace = nowInWhitespace;
194 }
195 *aIncomingFlags &= ~INCOMING_ARABICCHAR;
196 if (inWhitespace) {
197 *aIncomingFlags |= INCOMING_WHITESPACE;
198 } else {
199 *aIncomingFlags &= ~INCOMING_WHITESPACE;
200 }
201 }
203 if (outputStart + aLength != aOutput) {
204 flags |= TEXT_WAS_TRANSFORMED;
205 }
206 *aAnalysisFlags = flags;
207 return aOutput;
208 }
210 uint32_t
211 nsTextFrameUtils::ComputeApproximateLengthWithWhitespaceCompression(
212 nsIContent *aContent, const nsStyleText *aStyleText)
213 {
214 const nsTextFragment *frag = aContent->GetText();
215 // This is an approximation so we don't really need anything
216 // too fancy here.
217 uint32_t len;
218 if (aStyleText->WhiteSpaceIsSignificant()) {
219 len = frag->GetLength();
220 } else {
221 bool is2b = frag->Is2b();
222 union {
223 const char *s1b;
224 const char16_t *s2b;
225 } u;
226 if (is2b) {
227 u.s2b = frag->Get2b();
228 } else {
229 u.s1b = frag->Get1b();
230 }
231 bool prevWS = true; // more important to ignore blocks with
232 // only whitespace than get inline boundaries
233 // exactly right
234 len = 0;
235 for (uint32_t i = 0, i_end = frag->GetLength(); i < i_end; ++i) {
236 char16_t c = is2b ? u.s2b[i] : u.s1b[i];
237 if (c == ' ' || c == '\n' || c == '\t' || c == '\r') {
238 if (!prevWS) {
239 ++len;
240 }
241 prevWS = true;
242 } else {
243 ++len;
244 prevWS = false;
245 }
246 }
247 }
248 return len;
249 }
251 bool nsSkipCharsRunIterator::NextRun() {
252 do {
253 if (mRunLength) {
254 mIterator.AdvanceOriginal(mRunLength);
255 NS_ASSERTION(mRunLength > 0, "No characters in run (initial length too large?)");
256 if (!mSkipped || mLengthIncludesSkipped) {
257 mRemainingLength -= mRunLength;
258 }
259 }
260 if (!mRemainingLength)
261 return false;
262 int32_t length;
263 mSkipped = mIterator.IsOriginalCharSkipped(&length);
264 mRunLength = std::min(length, mRemainingLength);
265 } while (!mVisitSkipped && mSkipped);
267 return true;
268 }
