third_party/WebKit/Source/platform/fonts/Character.h

   1 /*
   2  * Copyright (C) 2014 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
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   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef Character_h
  32 #define Character_h
  33
  34 #include "platform/PlatformExport.h"
  35 #include "platform/text/TextDirection.h"
  36 #include "platform/text/TextPath.h"
  37 #include "platform/text/TextRun.h"
  38 #include "wtf/HashSet.h"
  39 #include "wtf/text/CharacterNames.h"
  40 #include "wtf/text/WTFString.h"
  41
  42 namespace blink {
  43
  44 class PLATFORM_EXPORT Character {
  45 public:
  46     static CodePath characterRangeCodePath(const LChar*, unsigned) { return SimplePath; }
  47     static CodePath characterRangeCodePath(const UChar*, unsigned len);
  48
  49     static inline bool isInRange(UChar32 character, UChar32 lowerBound, UChar32 upperBound)
  50     {
  51         return character >= lowerBound && character <= upperBound;
  52     }
  53
  54     static inline bool isUnicodeVariationSelector(UChar32 character)
  55     {
  56         // http://www.unicode.org/Public/UCD/latest/ucd/StandardizedVariants.html
  57         return isInRange(character, 0x180B, 0x180D) // MONGOLIAN FREE VARIATION SELECTOR ONE to THREE
  58             || isInRange(character, 0xFE00, 0xFE0F) // VARIATION SELECTOR-1 to 16
  59             || isInRange(character, 0xE0100, 0xE01EF); // VARIATION SELECTOR-17 to 256
  60     }
  61
  62     static bool isCJKIdeograph(UChar32);
  63     static bool isCJKIdeographOrSymbol(UChar32);
  64
  65     static unsigned expansionOpportunityCount(const LChar*, size_t length, TextDirection, bool& isAfterExpansion, const TextJustify);
  66     static unsigned expansionOpportunityCount(const UChar*, size_t length, TextDirection, bool& isAfterExpansion, const TextJustify);
  67
  68     static bool isUprightInMixedVertical(UChar32 character);
  69
  70     static bool treatAsSpace(UChar c)
  71     {
  72         return c == spaceCharacter
  73             || c == tabulationCharacter
  74             || c == newlineCharacter
  75             || c == noBreakSpaceCharacter;
  76     }
  77     static bool treatAsZeroWidthSpace(UChar c)
  78     {
  79         return treatAsZeroWidthSpaceInComplexScript(c)
  80             || c == zeroWidthNonJoinerCharacter
  81             || c == zeroWidthJoinerCharacter;
  82     }
  83     static bool treatAsZeroWidthSpaceInComplexScript(UChar c)
  84     {
  85         return c < 0x20 // ASCII Control Characters
  86             || (c >= 0x7F && c < 0xA0) // ASCII Delete .. No-break spaceCharacter
  87             || c == softHyphenCharacter
  88             || c == zeroWidthSpaceCharacter
  89             || (c >= leftToRightMarkCharacter && c <= rightToLeftMarkCharacter)
  90             || (c >= leftToRightEmbedCharacter && c <= rightToLeftOverrideCharacter)
  91             || c == zeroWidthNoBreakSpaceCharacter
  92             || c == objectReplacementCharacter;
  93     }
  94     static bool canReceiveTextEmphasis(UChar32);
  95
  96     static inline UChar normalizeSpaces(UChar character)
  97     {
  98         if (treatAsSpace(character))
  99             return spaceCharacter;
 100
 101         if (treatAsZeroWidthSpace(character))
 102             return zeroWidthSpaceCharacter;
 103
 104         return character;
 105     }
 106
 107     static inline bool isNormalizedCanvasSpaceCharacter(UChar c)
 108     {
 109         // According to specification all space characters should be replaced with 0x0020 space character.
 110         // http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#text-preparation-algorithm
 111         // The space characters according to specification are : U+0020, U+0009, U+000A, U+000C, and U+000D.
 112         // http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#space-character
 113         // This function returns true for 0x000B also, so that this is backward compatible.
 114         // Otherwise, the test LayoutTests/canvas/philip/tests/2d.text.draw.space.collapse.space.html will fail
 115         return c == 0x0009 || (c >= 0x000A && c <= 0x000D);
 116     }
 117
 118     static String normalizeSpaces(const LChar*, unsigned length);
 119     static String normalizeSpaces(const UChar*, unsigned length);
 120
 121 private:
 122     Character();
 123 };
 124
 125 } // namespace blink
 126
 127 #endif