headers/private/interface/WidthBuffer.h

   1 /*
   2  * Copyright 2003-2010, Haiku, Inc.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef __WIDTHBUFFER_H
   6 #define __WIDTHBUFFER_H
   7
   8
   9 #include <Locker.h>
  10 #include <TextView.h>
  11
  12 #include "TextViewSupportBuffer.h"
  13
  14
  15 class BFont;
  16
  17
  18 namespace BPrivate {
  19
  20
  21 class TextGapBuffer;
  22
  23
  24 struct _width_table_ {
  25         BFont font;                             // corresponding font
  26         int32 hashCount;                // number of hashed items
  27         int32 tableCount;               // size of table
  28         void* widths;                   // width table
  29 };
  30
  31
  32 class WidthBuffer : public _BTextViewSupportBuffer_<_width_table_> {
  33 public:
  34                                                                 WidthBuffer();
  35         virtual                                         ~WidthBuffer();
  36
  37                         float                           StringWidth(const char* inText,
  38                                                                         int32 fromOffset, int32 length,
  39                                                                         const BFont* inStyle);
  40                         float                           StringWidth(TextGapBuffer& gapBuffer,
  41                                                                         int32 fromOffset, int32 length,
  42                                                                         const BFont* inStyle);
  43
  44 private:
  45                         bool                            FindTable(const BFont* font, int32* outIndex);
  46                         int32                           InsertTable(const BFont* font);
  47
  48                         bool                            GetEscapement(uint32 value, int32 index,
  49                                                                         float* escapement);
  50                         float                           HashEscapements(const char* chars,
  51                                                                         int32 numChars, int32 numBytes,
  52                                                                         int32 tableIndex, const BFont* font);
  53
  54         static  uint32                          Hash(uint32);
  55
  56 private:
  57                         BLocker                         fLock;
  58 };
  59
  60
  61 extern WidthBuffer* gWidthBuffer;
  62
  63
  64 } // namespace BPrivate
  65
  66
  67 using BPrivate::WidthBuffer;
  68
  69
  70 #if __GNUC__ < 3
  71 //! NetPositive binary compatibility support
  72
  73 class _BWidthBuffer_ : public _BTextViewSupportBuffer_<BPrivate::_width_table_> {
  74         _BWidthBuffer_();
  75         virtual ~_BWidthBuffer_();
  76 };
  77
  78 extern
  79 _BWidthBuffer_* gCompatibilityWidthBuffer;
  80
  81 #endif // __GNUC__ < 3
  82
  83
  84 #endif // __WIDTHBUFFER_H