intl/lwbrk/LineBreaker.h

   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/. */
   5 #ifndef mozilla_intl_LineBreaker_h__
   6 #define mozilla_intl_LineBreaker_h__
   7
   8 #include "nscore.h"
   9 #include "nsISupports.h"
  10
  11 #define NS_LINEBREAKER_NEED_MORE_TEXT -1
  12
  13 namespace mozilla {
  14 namespace intl {
  15
  16 class LineBreaker {
  17  public:
  18   NS_INLINE_DECL_REFCOUNTING(LineBreaker)
  19
  20   enum class WordBreak : uint8_t {
  21     Normal = 0,    // default
  22     BreakAll = 1,  // break all
  23     KeepAll = 2    // always keep
  24   };
  25
  26   enum class Strictness : uint8_t {
  27     Auto = 0,
  28     Loose = 1,
  29     Normal = 2,
  30     Strict = 3,
  31     Anywhere = 4
  32   };
  33
  34   static already_AddRefed<LineBreaker> Create();
  35
  36   int32_t Next(const char16_t* aText, uint32_t aLen, uint32_t aPos);
  37
  38   int32_t Prev(const char16_t* aText, uint32_t aLen, uint32_t aPos);
  39
  40   // Call this on a word with whitespace at either end. We will apply JISx4051
  41   // rules to find breaks inside the word. aBreakBefore is set to the break-
  42   // before status of each character; aBreakBefore[0] will always be false
  43   // because we never return a break before the first character.
  44   // aLength is the length of the aText array and also the length of the
  45   // aBreakBefore output array.
  46   void GetJISx4051Breaks(const char16_t* aText, uint32_t aLength,
  47                          WordBreak aWordBreak, Strictness aLevel,
  48                          bool aIsChineseOrJapanese, uint8_t* aBreakBefore);
  49   void GetJISx4051Breaks(const uint8_t* aText, uint32_t aLength,
  50                          WordBreak aWordBreak, Strictness aLevel,
  51                          bool aIsChineseOrJapanese, uint8_t* aBreakBefore);
  52
  53  private:
  54   ~LineBreaker() = default;
  55
  56   int32_t WordMove(const char16_t* aText, uint32_t aLen, uint32_t aPos,
  57                    int8_t aDirection);
  58 };
  59
  60 static inline bool NS_IsSpace(char16_t u) {
  61   return u == 0x0020 ||                   // SPACE
  62          u == 0x0009 ||                   // CHARACTER TABULATION
  63          u == 0x000D ||                   // CARRIAGE RETURN
  64          (0x2000 <= u && u <= 0x2006) ||  // EN QUAD, EM QUAD, EN SPACE,
  65                                           // EM SPACE, THREE-PER-EM SPACE,
  66                                           // FOUR-PER-SPACE, SIX-PER-EM SPACE,
  67          (0x2008 <= u && u <= 0x200B) ||  // PUNCTUATION SPACE, THIN SPACE,
  68                                           // HAIR SPACE, ZERO WIDTH SPACE
  69          u == 0x1361 ||                   // ETHIOPIC WORDSPACE
  70          u == 0x1680 ||                   // OGHAM SPACE MARK
  71          u == 0x205F;                     // MEDIUM MATHEMATICAL SPACE
  72 }
  73
  74 static inline bool NS_NeedsPlatformNativeHandling(char16_t aChar) {
  75   return
  76 #if ANDROID  // Bug 1647377: no "platform native" support for Tibetan;
  77              // better to just use our class-based breaker.
  78       (0x0e01 <= aChar && aChar <= 0x0eff) ||  // Thai, Lao
  79 #else
  80       (0x0e01 <= aChar && aChar <= 0x0fff) ||  // Thai, Lao, Tibetan
  81 #endif
  82       (0x1780 <= aChar && aChar <= 0x17ff);  // Khmer
  83 }
  84
  85 }  // namespace intl
  86 }  // namespace mozilla
  87
  88 #endif /* mozilla_intl_LineBreaker_h__ */