gfx/thebes/gfxTextRunWordCache.h

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  15  * The Original Code is Mozilla Foundation code.
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  17  * The Initial Developer of the Original Code is Mozilla Foundation.
  18  * Portions created by the Initial Developer are Copyright (C) 2006
  19  * the Initial Developer. All Rights Reserved.
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  21  * Contributor(s):
  22  *   Vladimir Vukicevic <vladimir@pobox.com>
  23  *   Ehsan Akhgari <ehsan.akhgari@gmail.com>
  24  *   Jonathan Kew <jfkthame@gmail.com>
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
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  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #ifndef GFX_TEXT_RUN_WORD_CACHE_H
  41 #define GFX_TEXT_RUN_WORD_CACHE_H
  42
  43 #include "gfxFont.h"
  44
  45 /**
  46  * Cache individual "words" (strings delimited by white-space or white-space-like
  47  * characters that don't involve kerning or ligatures) in textruns.
  48   */
  49 class THEBES_API gfxTextRunWordCache {
  50 public:
  51     enum {
  52       TEXT_IN_CACHE = 0x10000000,
  53
  54       /**
  55        * nsTextFrameThebes sets these, but they're defined here rather than in
  56        * nsTextFrameUtils.h because the cache also needs to check the _INCOMING flag
  57        */
  58       TEXT_TRAILING_ARABICCHAR = 0x20000000,
  59       /**
  60        * When set, the previous character for this textrun was an Arabic
  61        * character.  This is used for the context detection necessary for
  62        * bidi.numeral implementation.
  63        */
  64       TEXT_INCOMING_ARABICCHAR = 0x40000000,
  65
  66       TEXT_UNUSED_FLAGS = 0x80000000
  67     };
  68
  69     /**
  70      * Create a textrun using cached words.
  71      * Invalid characters (see gfxFontGroup::IsInvalidChar) will be automatically
  72      * treated as invisible missing.
  73      * @param aFlags the flag TEXT_IS_ASCII must be set by the caller,
  74      * if applicable; TEXT_IN_CACHE is added if we have a reference to
  75      * the textrun in the cache and RemoveTextRun must be called when the
  76      * textrun dies.
  77      */
  78     static gfxTextRun *MakeTextRun(const PRUnichar *aText, PRUint32 aLength,
  79                                    gfxFontGroup *aFontGroup,
  80                                    const gfxFontGroup::Parameters *aParams,
  81                                    PRUint32 aFlags);
  82     /**
  83      * Create a textrun using cached words.
  84      * Invalid characters (see gfxFontGroup::IsInvalidChar) will be automatically
  85      * treated as invisible missing.
  86      * @param aFlags the flag TEXT_IS_ASCII must be set by the caller,
  87      * if applicable; TEXT_IN_CACHE is added if we have a reference to
  88      * the textrun in the cache and RemoveTextRun must be called when the
  89      * textrun dies.
  90      */
  91     static gfxTextRun *MakeTextRun(const PRUint8 *aText, PRUint32 aLength,
  92                                    gfxFontGroup *aFontGroup,
  93                                    const gfxFontGroup::Parameters *aParams,
  94                                    PRUint32 aFlags);
  95
  96     /**
  97      * Remove a textrun from the cache. This must be called before aTextRun
  98      * is deleted! The text in the textrun must still be valid.
  99      */
 100     static void RemoveTextRun(gfxTextRun *aTextRun);
 101
 102     /**
 103      * Flush the textrun cache. This must be called if a configuration
 104      * change that would affect textruns is applied.
 105      */
 106     static void Flush();
 107
 108 protected:
 109     friend class gfxPlatform;
 110
 111     static nsresult Init();
 112     static void Shutdown();
 113 };
 114
 115 #endif /* GFX_TEXT_RUN_WORD_CACHE_H */