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      1 /*
      2  * Copyright (C) 2003, 2006, 2008, 2011 Apple Inc. All rights reserved.
      3  * Copyright (C) 2008 Holger Hans Peter Freyther
      4  *
      5  * This library is free software; you can redistribute it and/or
      6  * modify it under the terms of the GNU Library General Public
      7  * License as published by the Free Software Foundation; either
      8  * version 2 of the License, or (at your option) any later version.
      9  *
     10  * This library is distributed in the hope that it will be useful,
     11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  * Library General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU Library General Public License
     16  * along with this library; see the file COPYING.LIB.  If not, write to
     17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  * Boston, MA 02110-1301, USA.
     19  *
     20  */
     21 
     22 #ifndef WidthIterator_h
     23 #define WidthIterator_h
     24 
     25 #include "platform/PlatformExport.h"
     26 #include "platform/fonts/Font.h"
     27 #include "platform/fonts/SVGGlyph.h"
     28 #include "platform/text/TextRun.h"
     29 #include "wtf/HashSet.h"
     30 #include "wtf/unicode/Unicode.h"
     31 #include "wtf/Vector.h"
     32 
     33 namespace WebCore {
     34 
     35 class Font;
     36 class GlyphBuffer;
     37 class SimpleFontData;
     38 class TextRun;
     39 struct GlyphData;
     40 
     41 struct PLATFORM_EXPORT WidthIterator {
     42     WTF_MAKE_FAST_ALLOCATED;
     43 public:
     44     WidthIterator(const Font*, const TextRun&, HashSet<const SimpleFontData*>* fallbackFonts = 0, bool accountForGlyphBounds = false, bool forTextEmphasis = false);
     45 
     46     unsigned advance(int to, GlyphBuffer*);
     47     bool advanceOneCharacter(float& width, GlyphBuffer&);
     48 
     49     float maxGlyphBoundingBoxY() const { ASSERT(m_accountForGlyphBounds); return m_maxGlyphBoundingBoxY; }
     50     float minGlyphBoundingBoxY() const { ASSERT(m_accountForGlyphBounds); return m_minGlyphBoundingBoxY; }
     51     float firstGlyphOverflow() const { ASSERT(m_accountForGlyphBounds); return m_firstGlyphOverflow; }
     52     float lastGlyphOverflow() const { ASSERT(m_accountForGlyphBounds); return m_lastGlyphOverflow; }
     53 
     54     const TextRun& run() const { return m_run; }
     55     float runWidthSoFar() const { return m_runWidthSoFar; }
     56 
     57 #if ENABLE(SVG_FONTS)
     58     String lastGlyphName() const { return m_lastGlyphName; }
     59     void setLastGlyphName(const String& name) { m_lastGlyphName = name; }
     60     Vector<SVGGlyph::ArabicForm>& arabicForms() { return m_arabicForms; }
     61 #endif
     62 
     63     static bool supportsTypesettingFeatures(const Font& font)
     64     {
     65 
     66         return !font.typesettingFeatures();
     67     }
     68 
     69     const Font* m_font;
     70 
     71     const TextRun& m_run;
     72 
     73     unsigned m_currentCharacter;
     74     float m_runWidthSoFar;
     75     float m_expansion;
     76     float m_expansionPerOpportunity;
     77     bool m_isAfterExpansion;
     78     float m_finalRoundingWidth;
     79 
     80 #if ENABLE(SVG_FONTS)
     81     String m_lastGlyphName;
     82     Vector<SVGGlyph::ArabicForm> m_arabicForms;
     83 #endif
     84 
     85 private:
     86     GlyphData glyphDataForCharacter(UChar32, bool mirror, int currentCharacter, unsigned& advanceLength);
     87     template <typename TextIterator>
     88     inline unsigned advanceInternal(TextIterator&, GlyphBuffer*);
     89 
     90     bool shouldApplyFontTransforms() const { return m_run.length() > 1 && (m_typesettingFeatures & (Kerning | Ligatures)); }
     91 
     92     TypesettingFeatures m_typesettingFeatures;
     93     HashSet<const SimpleFontData*>* m_fallbackFonts;
     94     bool m_accountForGlyphBounds;
     95     float m_maxGlyphBoundingBoxY;
     96     float m_minGlyphBoundingBoxY;
     97     float m_firstGlyphOverflow;
     98     float m_lastGlyphOverflow;
     99     bool m_forTextEmphasis;
    100 };
    101 
    102 }
    103 
    104 #endif
    105