text: /*
   * Copyright (C) 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef ComplexTextController_h
  #define ComplexTextController_h
  
  #include "GlyphBuffer.h"
  #include <wtf/HashSet.h>
  #include <wtf/PassRefPtr.h>
  #include <wtf/RefCounted.h>
  #include <wtf/RetainPtr.h>
  #include <wtf/Vector.h>
  #include <wtf/unicode/Unicode.h>
  
  typedef unsigned short CGGlyph;
  
  #if USE(CORE_TEXT)
  typedef const struct __CTRun * CTRunRef;
  typedef const struct __CTLine * CTLineRef;
  #endif
  #if USE(ATSUI)
  typedef struct OpaqueATSUTextLayout*    ATSUTextLayout;
  typedef struct ATSGlyphVector*          ATSULineRef;
  typedef UInt32 ATSULayoutOperationSelector;
  typedef UInt32 ATSULayoutOperationCallbackStatus;
  #endif
  
  namespace WebCore {
  
  class Font;
  class SimpleFontData;
  class TextRun;
  
  // ComplexTextController is responsible for rendering and measuring glyphs for
  // complex scripts on OS X.
  // The underlying API can be selected at compile time based on USE(ATSUI) and
  // USE(CORE_TEXT).  If both are defined then the Core Text APIs are used for
  // OS Versions >= 10.6, ATSUI is used otherwise.
  class ComplexTextController {
  public:
      ComplexTextController(const Font*, const TextRun&, bool mayUseNaturalWritingDirection = false, HashSet<const SimpleFontData*>* fallbackFonts = 0, bool forTextEmphasis = false);
  
      // Advance and emit glyphs up to the specified character.
      void advance(unsigned to, GlyphBuffer* = 0);
  
      // Compute the character offset for a given x coordinate.
      int offsetForPosition(float x, bool includePartialGlyphs);
  
      // Returns the width of everything we've consumed so far.
      float runWidthSoFar() const { return m_runWidthSoFar; }
  
      float totalWidth() const { return m_totalWidth; }
  
      float finalRoundingWidth() const { return m_finalRoundingWidth; }
  
      float minGlyphBoundingBoxX() const { return m_minGlyphBoundingBoxX; }
      float maxGlyphBoundingBoxX() const { return m_maxGlyphBoundingBoxX; }
      float minGlyphBoundingBoxY() const { return m_minGlyphBoundingBoxY; }
      float maxGlyphBoundingBoxY() const { return m_maxGlyphBoundingBoxY; }
      
  private:
      static const SimpleFontData* systemFallbackFontData() { return reinterpret_cast<const SimpleFontData*>(-1); }
  
      class ComplexTextRun : public RefCounted<ComplexTextRun> {
      public:
  #if USE(CORE_TEXT)
          static PassRefPtr<ComplexTextRun> create(CTRunRef ctRun, const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange)
          {
              return adoptRef(new ComplexTextRun(ctRun, fontData, characters, stringLocation, stringLength, runRange));
          }
  #endif
  #if USE(ATSUI)
          static PassRefPtr<ComplexTextRun> create(ATSUTextLayout atsuTextLayout, const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr, bool directionalOverride)
          {
              return adoptRef(new ComplexTextRun(atsuTextLayout, fontData, characters, stringLocation, stringLength, ltr, directionalOverride));
          }
  #endif
          static PassRefPtr<ComplexTextRun> create(const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr)
          {
              return adoptRef(new ComplexTextRun(fontData, characters, stringLocation, stringLength, ltr));
          }
  
          unsigned glyphCount() const { return m_glyphCount; }
          const SimpleFontData* fontData() const { return m_fontData; }
          const UChar* characters() const { return m_characters; }
          unsigned stringLocation() const { return m_stringLocation; }
          size_t stringLength() const { return m_stringLength; }
          ALWAYS_INLINE CFIndex indexAt(size_t i) const;
          CFIndex indexEnd() const { return m_indexEnd; }
          CFIndex endOffsetAt(size_t i) const { ASSERT(!m_isMonotonic); return m_glyphEndOffsets[i]; }
          const CGGlyph* glyphs() const { return m_glyphs; }
          const CGSize* advances() const { return m_advances; }
          bool isMonotonic() const { return m_isMonotonic; }
          void setIsNonMonotonic();
  
      private:
  #if USE(CORE_TEXT)
          ComplexTextRun(CTRunRef, const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange);
          void createTextRunFromFontDataCoreText(bool ltr);
  #endif
  #if USE(ATSUI)
          ComplexTextRun(ATSUTextLayout, const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr, bool directionalOverride);
          void createTextRunFromFontDataATSUI(bool ltr);
  #endif
          ComplexTextRun(const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr);
  
  #if USE(ATSUI)
          static OSStatus overrideLayoutOperation(ATSULayoutOperationSelector, ATSULineRef, URefCon, void*, ATSULayoutOperationCallbackStatus*);
  #endif
  
          unsigned m_glyphCount;
          const SimpleFontData* m_fontData;
          const UChar* m_characters;
          unsigned m_stringLocation;
          size_t m_stringLength;
  #if USE(CORE_TEXT)
          Vector<CFIndex, 64> m_coreTextIndicesVector;
          const CFIndex* m_coreTextIndices;
  #endif
  #if USE(ATSUI)
          Vector<CFIndex, 64> m_atsuiIndices;
  #endif
          CFIndex m_indexEnd;
          Vector<CFIndex, 64> m_glyphEndOffsets;
          Vector<CGGlyph, 64> m_glyphsVector;
          const CGGlyph* m_glyphs;
          Vector<CGSize, 64> m_advancesVector;
          const CGSize* m_advances;
  #if USE(ATSUI)
          bool m_directionalOverride;
  #endif
          bool m_isMonotonic;
      };
  
      void collectComplexTextRuns();
  
      // collectComplexTextRunsForCharacters() is a stub function that calls through to the ATSUI or Core Text variants based
      // on the API in use.
      void collectComplexTextRunsForCharacters(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
      void collectComplexTextRunsForCharactersATSUI(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
      void collectComplexTextRunsForCharactersCoreText(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
      void adjustGlyphsAndAdvances();
  
      const Font& m_font;
      const TextRun& m_run;
      bool m_mayUseNaturalWritingDirection;
      bool m_forTextEmphasis;
  
      Vector<UChar, 256> m_smallCapsBuffer;
  
  #if USE(CORE_TEXT)
      // Retain lines rather than their runs for better performance.
      Vector<RetainPtr<CTLineRef> > m_coreTextLines;
  #endif
      Vector<RefPtr<ComplexTextRun>, 16> m_complexTextRuns;
      Vector<CGSize, 256> m_adjustedAdvances;
      Vector<CGGlyph, 256> m_adjustedGlyphs;
   
      unsigned m_currentCharacter;
      int m_end;
  
      CGFloat m_totalWidth;
  
      float m_runWidthSoFar;
      unsigned m_numGlyphsSoFar;
      size_t m_currentRun;
      unsigned m_glyphInCurrentRun;
      unsigned m_characterInCurrentGlyph;
      float m_finalRoundingWidth;
      float m_expansion;
      float m_expansionPerOpportunity;
      float m_leadingExpansion;
      bool m_afterExpansion;
  
      HashSet<const SimpleFontData*>* m_fallbackFonts;
  
      float m_minGlyphBoundingBoxX;
      float m_maxGlyphBoundingBoxX;
      float m_minGlyphBoundingBoxY;
      float m_maxGlyphBoundingBoxY;
  
      unsigned m_lastRoundingGlyph;
  };
  
  } // namespace WebCore
  
  #endif // ComplexTextController_h
  