File: character.h

package info (click to toggle)
chromium 138.0.7204.183-1
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 6,071,908 kB
  • sloc: cpp: 34,937,088; ansic: 7,176,967; javascript: 4,110,704; python: 1,419,953; asm: 946,768; xml: 739,971; pascal: 187,324; sh: 89,623; perl: 88,663; objc: 79,944; sql: 50,304; cs: 41,786; fortran: 24,137; makefile: 21,806; php: 13,980; tcl: 13,166; yacc: 8,925; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (337 lines) | stat: -rw-r--r-- 14,746 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
/*
 * Copyright (C) 2014 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_TEXT_CHARACTER_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_TEXT_CHARACTER_H_

#include <unicode/uchar.h>
#include <unicode/uniset.h>

#include "base/containers/span.h"
#include "base/gtest_prod_util.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/text/character_property.h"
#include "third_party/blink/renderer/platform/text/east_asian_spacing_type.h"
#include "third_party/blink/renderer/platform/text/han_kerning_char_type.h"
#include "third_party/blink/renderer/platform/text/text_direction.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/ascii_ctype.h"
#include "third_party/blink/renderer/platform/wtf/text/character_names.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"

namespace blink {

class PLATFORM_EXPORT Character {
  STATIC_ONLY(Character);

 public:
  static inline bool IsInRange(UChar32 character,
                               UChar32 lower_bound,
                               UChar32 upper_bound) {
    return character >= lower_bound && character <= upper_bound;
  }

  // Commonly used Unicode Blocks in CSS specs.
  // https://www.unicode.org/Public/UNIDATA/Blocks.txt
  static bool IsBlockCjkSymbolsAndPunctuation(UChar32 ch) {
    return IsInRange(ch, 0x3000, 0x303F);
  }
  static bool IsBlockHalfwidthAndFullwidthForms(UChar32 ch) {
    return IsInRange(ch, 0xFF00, 0xFFEF);
  }

  // East Asian Width: https://unicode.org/reports/tr11/
  static UEastAsianWidth EastAsianWidth(UChar32 ch) {
    return static_cast<UEastAsianWidth>(
        u_getIntPropertyValue(ch, UCHAR_EAST_ASIAN_WIDTH));
  }
  static bool IsEastAsianWidthFullwidth(UChar32 ch);

  static inline bool IsUnicodeVariationSelector(UChar32 character) {
    // http://www.unicode.org/Public/UCD/latest/ucd/StandardizedVariants.html
    return IsInRange(character, 0x180B,
                     0x180D)  // MONGOLIAN FREE VARIATION SELECTOR ONE to THREE
           ||
           IsInRange(character, 0xFE00, 0xFE0F)  // VARIATION SELECTOR-1 to 16
           || IsInRange(character, 0xE0100,
                        0xE01EF);  // VARIATION SELECTOR-17 to 256
  }

  static inline bool IsUnicodeEmojiVariationSelector(UChar32 character) {
    // https://www.unicode.org/Public/emoji/5.0/emoji-variation-sequences.txt
    return character == 0xFE0E ||
           character == 0xFE0F;  // VARIATION SELECTOR-15 to 16
  }

  static bool IsCJKIdeographOrSymbol(UChar32 c) {
    // Below U+02C7 is likely a common case.
    return c < 0x2C7 ? false : IsCJKIdeographOrSymbolSlow(c);
  }
  static bool IsCJKIdeographOrSymbolBase(UChar32 c) {
    return IsCJKIdeographOrSymbol(c) &&
           !(U_GET_GC_MASK(c) & (U_GC_M_MASK | U_GC_LM_MASK | U_GC_SK_MASK));
  }

  static bool IsIdeographic(UChar32 c) {
    return u_hasBinaryProperty(c, UCHAR_IDEOGRAPHIC);
  }

  static bool IsHangul(UChar32 c) {
    // Below U+1100 is likely a common case.
    return c < 0x1100 ? false : IsHangulSlow(c);
  }

  static unsigned ExpansionOpportunityCount(base::span<const LChar>,
                                            TextDirection,
                                            bool& is_after_expansion);
  static unsigned ExpansionOpportunityCount(base::span<const UChar>,
                                            TextDirection,
                                            bool& is_after_expansion);

  static bool IsUprightInMixedVertical(UChar32 character);

  // https://html.spec.whatwg.org/C/#prod-potentialcustomelementname
  static bool IsPotentialCustomElementName8BitChar(LChar ch) {
    return IsASCIILower(ch) || IsASCIIDigit(ch) || ch == '-' || ch == '.' ||
           ch == '_' || ch == 0xb7 || (0xc0 <= ch && ch != 0xd7 && ch != 0xf7);
  }
  static bool IsPotentialCustomElementNameChar(UChar32 character);

  // http://unicode.org/reports/tr9/#Directional_Formatting_Characters
  static bool IsBidiControl(UChar32 character);
  static bool MaybeBidiRtlUtf16(base::StrictNumeric<UChar> ch);
  static bool MaybeBidiRtl(UChar32 ch);
  static bool MaybeBidiRtl(const String&);

  static HanKerningCharType GetHanKerningCharType(UChar32 character);
  static EastAsianSpacingType GetEastAsianSpacingType(UChar32 character);
  // Check the `HanKerningCharType` of a character without knowing the font.
  // It depends on fonts, so it may not be `kOpen` or `kClose` even when this
  // function returns `true`. See `HanKerning::GetCharType`.
  static bool MaybeHanKerningOpen(UChar32 ch) {
    return MaybeHanKerningOpenOrCloseFast(ch) && MaybeHanKerningOpenSlow(ch);
  }
  static bool MaybeHanKerningClose(UChar32 ch) {
    return MaybeHanKerningOpenOrCloseFast(ch) && MaybeHanKerningCloseSlow(ch);
  }
  // Check if the character may be `kOpen` or `kClose` only by ranges, without
  // getting the Unicode property. Faster than `MaybeHanKerningOpen` and
  // `MaybeHanKerningClose` but has more cases where it returns `true` for other
  // characters.
  static bool MaybeHanKerningOpenOrCloseFast(UChar32 character) {
    return IsInRange(character, kLeftSingleQuotationMarkCharacter, 0x301F) ||
           IsInRange(character, 0xFF08, 0xFF60);
  }
  static bool MayNeedEastAsianSpacing(UChar32);

  // Collapsible white space characters defined in CSS:
  // https://drafts.csswg.org/css-text-3/#collapsible-white-space
  static bool IsCollapsibleSpace(UChar c) {
    return c == kSpaceCharacter || c == kNewlineCharacter ||
           c == kTabulationCharacter || c == kCarriageReturnCharacter;
  }
  static bool IsLineFeed(UChar c) { return c == kNewlineCharacter; }
  template <typename CharacterType>
  static bool IsOtherSpaceSeparator(CharacterType c) {
    return c == kIdeographicSpaceCharacter;
  }
  static bool TreatAsSpace(UChar32 c) {
    return c == kSpaceCharacter || c == kTabulationCharacter ||
           c == kNewlineCharacter || c == kNoBreakSpaceCharacter;
  }
  static bool TreatAsZeroWidthSpace(UChar32 c) {
    return TreatAsZeroWidthSpaceInComplexScript(c) ||
           c == kZeroWidthNonJoinerCharacter || c == kZeroWidthJoinerCharacter;
  }
  static bool TreatAsZeroWidthSpaceInComplexScriptLegacy(UChar32 c) {
    return c == kFormFeedCharacter || c == kCarriageReturnCharacter ||
           c == kSoftHyphenCharacter || c == kZeroWidthSpaceCharacter ||
           (c >= kLeftToRightMarkCharacter && c <= kRightToLeftMarkCharacter) ||
           (c >= kLeftToRightEmbedCharacter &&
            c <= kRightToLeftOverrideCharacter) ||
           c == kZeroWidthNoBreakSpaceCharacter ||
           c == kObjectReplacementCharacter;
  }
  static bool TreatAsZeroWidthSpaceInComplexScript(UChar32 c) {
    if (c == kFormFeedCharacter || c == kCarriageReturnCharacter ||
        c == kObjectReplacementCharacter) {
      return true;
    }
    return IsDefaultIgnorable(c);
  }
  // https://unicode.org/reports/tr44/#Default_Ignorable_Code_Point
  static bool IsDefaultIgnorable(UChar32 c) {
    if (c < 0x0100) {
      return c == kSoftHyphenCharacter;
    }
    return u_hasBinaryProperty(c, UCHAR_DEFAULT_IGNORABLE_CODE_POINT);
  }
  static bool CanTextDecorationSkipInk(UChar32);
  static bool CanReceiveTextEmphasis(UChar32);

  static bool IsGraphemeExtended(UChar32 c) {
    // http://unicode.org/reports/tr29/#Extend
    return u_hasBinaryProperty(c, UCHAR_GRAPHEME_EXTEND);
  }

  // Returns true if the character has a Emoji property.
  // See http://www.unicode.org/Public/emoji/3.0/emoji-data.txt
  static bool IsEmoji(UChar32);
  // Default presentation style according to:
  // http://www.unicode.org/reports/tr51/#Presentation_Style
  static bool IsEmojiTextDefault(UChar32);
  static bool IsEmojiEmojiDefault(UChar32);
  static bool IsEmojiModifierBase(UChar32);
  static inline bool IsEmojiKeycapBase(UChar32 ch) {
    return (ch >= '0' && ch <= '9') || ch == '#' || ch == '*';
  }
  static bool IsRegionalIndicator(UChar32);
  static bool IsModifier(UChar32 c) { return c >= 0x1F3FB && c <= 0x1F3FF; }
  // http://www.unicode.org/reports/tr51/proposed.html#flag-emoji-tag-sequences
  static bool IsEmojiTagSequence(UChar32);
  static bool IsEmojiComponent(UChar32);
  static bool IsExtendedPictographic(UChar32);
  static bool MaybeEmojiPresentation(UChar32);

  static bool IsStandardizedVariationSequence(UChar32, UChar32);
  static bool IsEmojiVariationSequence(UChar32, UChar32);
  static bool IsIdeographicVariationSequence(UChar32 ch, UChar32 vs);
  static bool IsVariationSequence(UChar32, UChar32);

  static inline bool IsNormalizedCanvasSpaceCharacter(UChar32 c) {
    // According to specification all space characters should be replaced with
    // 0x0020 space character.
    // http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#text-preparation-algorithm
    // The space characters according to specification are : U+0020, U+0009,
    // U+000A, U+000C, and U+000D.
    // http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#space-character
    // This function returns true for 0x000B also, so that this is backward
    // compatible.  Otherwise, the test
    // web_tests/canvas/philip/tests/2d.text.draw.space.collapse.space.html
    // will fail
    return c == 0x0009 || (c >= 0x000A && c <= 0x000D);
  }

  static bool IsCommonOrInheritedScript(UChar32);
  static bool IsPrivateUse(UChar32);
  static bool IsNonCharacter(UChar32);

  // Returns whether a script code could be determined for the given character
  // and that script code is not USCRIPT_COMMON or USCRIPT_INHERITED.
  static bool HasDefiniteScript(UChar32);

  static bool IsModernGeorgianUppercase(UChar32 c) {
    return IsInRange(c, 0x1C90, 0x1CBF);
  }

  // Map modern secular Georgian uppercase letters added in Unicode
  // 11.0 to their corresponding lowercase letters.
  // https://www.unicode.org/charts/PDF/U10A0.pdf
  // https://www.unicode.org/charts/PDF/U1C90.pdf
  static UChar32 LowercaseModernGeorgianUppercase(UChar32 c) {
    return (c - (0x1C90 - 0x10D0));
  }

  static bool IsVerticalMathCharacter(UChar32);

 private:
  FRIEND_TEST_ALL_PREFIXES(CharacterTest, Derived);

  static bool IsCJKIdeographOrSymbolSlow(UChar32);
  static bool IsHangulSlow(UChar32);
  static bool MaybeHanKerningOpenSlow(UChar32);
  static bool MaybeHanKerningCloseSlow(UChar32);
  static void ApplyPatternAndFreezeIfEmpty(icu::UnicodeSet* unicodeSet,
                                           const char* pattern);
};

// True if the character may need the Bidi reordering. If false, the
// `Bidi_Class` of `ch` isn't `R`, `AL`, nor Bidi controls.
// https://util.unicode.org/UnicodeJsps/list-unicodeset.jsp?a=%5B%5B%3Abc%3DR%3A%5D%5B%3Abc%3DAL%3A%5D%5D&g=bc
// https://util.unicode.org/UnicodeJsps/list-unicodeset.jsp?a=[:Bidi_C:]
//
// This function assumes all non-BMP characters may be Bidi.
inline bool Character::MaybeBidiRtlUtf16(base::StrictNumeric<UChar> ch) {
  return ch >= 0x0590 &&
         // `InlineItemsBuilder` may emit U+200B Zero Width Space.
         ch != kZeroWidthSpaceCharacter &&
         // General Punctuation such as curly quotes.
         !IsInRange(ch, 0x2010, 0x2029) &&
         // CJK etc., up to Surrogate Pairs.
         !IsInRange(ch, 0x206A, 0xD7FF) &&
         // Common in CJK.
         !IsInRange(ch, 0xFF00, 0xFFFF);
}

inline bool Character::MaybeBidiRtl(UChar32 ch) {
  return ch >= 0x0590 &&
         // `InlineItemsBuilder` may emit U+200B Zero Width Space.
         ch != kZeroWidthSpaceCharacter &&
         // General Punctuation such as curly quotes.
         !IsInRange(ch, 0x2010, 0x2029) &&
         // CJK etc., up to Surrogate Pairs.
         !IsInRange(ch, 0x206A, 0xD7FF) &&
         // Common in CJK.
         !IsInRange(ch, 0xFF00, 0xFFFF) &&
         // Kana Extended-B, Kana Supplement, Kana Extended-A, Small Kana
         // Extension
         !IsInRange(ch, 0x1AFF0, 0x1B16F) &&
         // CJK Ideographs Extensions
         !IsInRange(ch, 0x20000, 0x323AF);
}

inline bool Character::MaybeBidiRtl(const String& text) {
  return !text.Is8Bit() && !text.IsAllSpecialCharacters<[](UChar c) {
    return !MaybeBidiRtlUtf16(c);
  }>();
}

inline bool Character::IsEastAsianWidthFullwidth(UChar32 ch) {
  // All EAW=F characters are in the "Halfwidth and Fullwidth forms" block,
  // except U+3000 IDEOGRAPHIC SPACE.
  // https://util.unicode.org/UnicodeJsps/list-unicodeset.jsp?a=[:ea=F:]
  return ch == kIdeographicSpaceCharacter ||
         (IsBlockHalfwidthAndFullwidthForms(ch) &&
          EastAsianWidth(ch) == UEastAsianWidth::U_EA_FULLWIDTH);
}

inline bool Character::MayNeedEastAsianSpacing(UChar32 ch) {
  // `EastAsianSpacingType::kWide` may need the spacing. U+02C7 is the minimum
  // code point of `kWide`.
  return ch >= 0x02C7 && ch != kObjectReplacementCharacter &&
         // U+2000-206F General Punctuation has rather popular characters, such
         // as ZWSP and curly quotation marks. Exclude the largest range of
         // non-`kWide` that include them.
         !IsInRange(ch, 0x1200, 0x3004);
}

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_TEXT_CHARACTER_H_