gfx/thebes/gfxDWriteTextAnalysis.h

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   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
   6 #ifndef GFX_DWRITETEXTANALYSIS_H
   7 #define GFX_DWRITETEXTANALYSIS_H
   8
   9 #include "gfxDWriteCommon.h"
  10
  11 // Helper source/sink class for text analysis.
  12 class TextAnalysis
  13     :   public IDWriteTextAnalysisSource,
  14         public IDWriteTextAnalysisSink
  15 {
  16 public:
  17
  18     // IUnknown interface
  19     IFACEMETHOD(QueryInterface)(IID const& iid, OUT void** ppObject)
  20     {
  21         if (iid == __uuidof(IDWriteTextAnalysisSource)) {
  22             *ppObject = static_cast<IDWriteTextAnalysisSource*>(this);
  23             return S_OK;
  24         } else if (iid == __uuidof(IDWriteTextAnalysisSink)) {
  25             *ppObject = static_cast<IDWriteTextAnalysisSink*>(this);
  26             return S_OK;
  27         } else if (iid == __uuidof(IUnknown)) {
  28             *ppObject =
  29                 static_cast<IUnknown*>(static_cast<IDWriteTextAnalysisSource*>(this));
  30             return S_OK;
  31         } else {
  32             return E_NOINTERFACE;
  33         }
  34     }
  35
  36     IFACEMETHOD_(ULONG, AddRef)()
  37     {
  38         return 1;
  39     }
  40
  41     IFACEMETHOD_(ULONG, Release)()
  42     {
  43         return 1;
  44     }
  45
  46     // A single contiguous run of characters containing the same analysis
  47     // results.
  48     struct Run
  49     {
  50         UINT32 mTextStart;   // starting text position of this run
  51         UINT32 mTextLength;  // number of contiguous code units covered
  52         UINT32 mGlyphStart;  // starting glyph in the glyphs array
  53         UINT32 mGlyphCount;  // number of glyphs associated with this run of
  54                              // text
  55         DWRITE_SCRIPT_ANALYSIS mScript;
  56         UINT8 mBidiLevel;
  57         bool mIsSideways;
  58
  59         inline bool ContainsTextPosition(UINT32 aTextPosition) const
  60         {
  61             return aTextPosition >= mTextStart
  62                 && aTextPosition <  mTextStart + mTextLength;
  63         }
  64
  65         Run *nextRun;
  66     };
  67
  68 public:
  69     TextAnalysis(const wchar_t* text,
  70                  UINT32 textLength,
  71                  const wchar_t* localeName,
  72                  DWRITE_READING_DIRECTION readingDirection);
  73
  74     ~TextAnalysis();
  75
  76     STDMETHODIMP GenerateResults(IDWriteTextAnalyzer* textAnalyzer,
  77                                  Run **runHead);
  78
  79     // IDWriteTextAnalysisSource implementation
  80
  81     IFACEMETHODIMP GetTextAtPosition(UINT32 textPosition,
  82                                      OUT WCHAR const** textString,
  83                                      OUT UINT32* textLength);
  84
  85     IFACEMETHODIMP GetTextBeforePosition(UINT32 textPosition,
  86                                          OUT WCHAR const** textString,
  87                                          OUT UINT32* textLength);
  88
  89     IFACEMETHODIMP_(DWRITE_READING_DIRECTION)
  90         GetParagraphReadingDirection() throw();
  91
  92     IFACEMETHODIMP GetLocaleName(UINT32 textPosition,
  93                                  OUT UINT32* textLength,
  94                                  OUT WCHAR const** localeName);
  95
  96     IFACEMETHODIMP
  97         GetNumberSubstitution(UINT32 textPosition,
  98                               OUT UINT32* textLength,
  99                               OUT IDWriteNumberSubstitution** numberSubstitution);
 100
 101     // IDWriteTextAnalysisSink implementation
 102
 103     IFACEMETHODIMP
 104         SetScriptAnalysis(UINT32 textPosition,
 105                           UINT32 textLength,
 106                           DWRITE_SCRIPT_ANALYSIS const* scriptAnalysis);
 107
 108     IFACEMETHODIMP
 109         SetLineBreakpoints(UINT32 textPosition,
 110                            UINT32 textLength,
 111                            const DWRITE_LINE_BREAKPOINT* lineBreakpoints);
 112
 113     IFACEMETHODIMP SetBidiLevel(UINT32 textPosition,
 114                                 UINT32 textLength,
 115                                 UINT8 explicitLevel,
 116                                 UINT8 resolvedLevel);
 117
 118     IFACEMETHODIMP
 119         SetNumberSubstitution(UINT32 textPosition,
 120                               UINT32 textLength,
 121                               IDWriteNumberSubstitution* numberSubstitution);
 122
 123 protected:
 124     Run *FetchNextRun(IN OUT UINT32* textLength);
 125
 126     void SetCurrentRun(UINT32 textPosition);
 127
 128     void SplitCurrentRun(UINT32 splitPosition);
 129
 130 protected:
 131     // Input
 132     // (weak references are fine here, since this class is a transient
 133     //  stack-based helper that doesn't need to copy data)
 134     UINT32 mTextLength;
 135     const wchar_t* mText;
 136     const wchar_t* mLocaleName;
 137     DWRITE_READING_DIRECTION mReadingDirection;
 138
 139     // Current processing state.
 140     Run *mCurrentRun;
 141
 142     // Output is a list of runs starting here
 143     Run  mRunHead;
 144 };
 145
 146 #endif /* GFX_DWRITETEXTANALYSIS_H */