icuSources/layout/CharSubstitutionFilter.h

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
   4  *
   5  */
   6
   7 #ifndef __CHARSUBSTITUTIONFILTER_H
   8 #define __CHARSUBSTITUTIONFILTER_H
   9
  10 #include "LETypes.h"
  11 #include "LEGlyphFilter.h"
  12
  13 U_NAMESPACE_BEGIN
  14
  15 class LEFontInstance;
  16
  17 /**
  18  * This filter is used by character-based GSUB processors. It
  19  * accepts only those characters which the given font can display.
  20  *
  21  * @internal
  22  */
  23 class CharSubstitutionFilter : public UMemory, public LEGlyphFilter
  24 {
  25 private:
  26     /**
  27      * Holds the font which is used to test the characters.
  28      *
  29      * @internal
  30      */
  31     const LEFontInstance *fFontInstance;
  32
  33     /**
  34      * The copy constructor. Not allowed!
  35      *
  36      * @internal
  37      */
  38     CharSubstitutionFilter(const CharSubstitutionFilter &other); // forbid copying of this class
  39
  40     /**
  41      * The replacement operator. Not allowed!
  42      *
  43      * @internal
  44      */
  45     CharSubstitutionFilter &operator=(const CharSubstitutionFilter &other); // forbid copying of this class
  46
  47 public:
  48     /**
  49      * The constructor.
  50      *
  51      * @param fontInstance - the font to use to test the characters.
  52      *
  53      * @internal
  54      */
  55     CharSubstitutionFilter(const LEFontInstance *fontInstance);
  56
  57     /**
  58      * The destructor.
  59      *
  60      * @internal
  61      */
  62     ~CharSubstitutionFilter();
  63
  64     /**
  65      * This method is used to test if a particular
  66      * character can be displayed by the filter's
  67      * font.
  68      *
  69      * @param glyph - the Unicode character code to be tested
  70      *
  71      * @return TRUE if the filter's font can display this character.
  72      *
  73      * @internal
  74      */
  75     le_bool accept(LEGlyphID glyph) const;
  76 };
  77
  78 U_NAMESPACE_END
  79 #endif
  80
  81