WebCore/CoreTextController.h

   1 /*
   2  * Copyright (C) 2007, 2008 Apple Inc. All Rights Reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef CoreTextController_h
  27 #define CoreTextController_h
  28
  29 #if USE(CORE_TEXT)
  30
  31 #include "Font.h"
  32 #include "GlyphBuffer.h"
  33 #include <wtf/RetainPtr.h>
  34 #include <wtf/Vector.h>
  35
  36 namespace WebCore {
  37
  38 class CoreTextController {
  39 public:
  40     CoreTextController(const Font*, const TextRun&, bool mayUseNaturalWritingDirection = false);
  41
  42     // Advance and emit glyphs up to the specified character.
  43     void advance(unsigned to, GlyphBuffer* = 0);
  44
  45     // Compute the character offset for a given x coordinate.
  46     int offsetForPosition(int x, bool includePartialGlyphs);
  47
  48     // Returns the width of everything we've consumed so far.
  49     float runWidthSoFar() const { return m_runWidthSoFar; }
  50
  51     float totalWidth() const { return m_totalWidth; }
  52
  53     // Extra width to the left of the leftmost glyph.
  54     float finalRoundingWidth() const { return m_finalRoundingWidth; }
  55
  56 private:
  57     class CoreTextRun {
  58     public:
  59         CoreTextRun(CTRunRef, const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength);
  60         CoreTextRun(const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr);
  61
  62         CTRunRef ctRun() const { return m_CTRun.get(); }
  63         unsigned glyphCount() const { return m_glyphCount; }
  64         const SimpleFontData* fontData() const { return m_fontData; }
  65         const UChar* characters() const { return m_characters; }
  66         unsigned stringLocation() const { return m_stringLocation; }
  67         size_t stringLength() const { return m_stringLength; }
  68         CFIndex indexAt(size_t i) const { return m_indices[i]; }
  69
  70     private:
  71         RetainPtr<CTRunRef> m_CTRun;
  72         unsigned m_glyphCount;
  73         const SimpleFontData* m_fontData;
  74         const UChar* m_characters;
  75         unsigned m_stringLocation;
  76         size_t m_stringLength;
  77         const CFIndex* m_indices;
  78         // Used only if CTRunGet*Ptr fails or if this is a missing glyphs run.
  79         RetainPtr<CFMutableDataRef> m_indicesData;
  80     };
  81
  82     void collectCoreTextRuns();
  83     void collectCoreTextRunsForCharacters(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
  84     void adjustGlyphsAndAdvances();
  85
  86     const Font& m_font;
  87     const TextRun& m_run;
  88     bool m_mayUseNaturalWritingDirection;
  89
  90     Vector<UChar, 256> m_smallCapsBuffer;
  91
  92     Vector<CoreTextRun, 16> m_coreTextRuns;
  93     Vector<CGSize, 256> m_adjustedAdvances;
  94     Vector<CGGlyph, 256> m_adjustedGlyphs;
  95
  96     unsigned m_currentCharacter;
  97     int m_end;
  98
  99     CGFloat m_totalWidth;
 100
 101     float m_runWidthSoFar;
 102     unsigned m_numGlyphsSoFar;
 103     size_t m_currentRun;
 104     unsigned m_glyphInCurrentRun;
 105     float m_finalRoundingWidth;
 106     float m_padding;
 107     float m_padPerSpace;
 108
 109     unsigned m_lastRoundingGlyph;
 110 };
 111
 112 } // namespace WebCore
 113 #endif // USE(CORE_TEXT)
 114 #endif // CoreTextController_h