1 /* 2 * Copyright (C) 2006, 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 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef GlyphPageTreeNode_h 30 #define GlyphPageTreeNode_h 31 32 #include <string.h> 33 #include "core/platform/graphics/GlyphPage.h" 34 #include "wtf/HashMap.h" 35 #include "wtf/OwnPtr.h" 36 #include "wtf/PassRefPtr.h" 37 #include "wtf/RefCounted.h" 38 #include "wtf/unicode/Unicode.h" 39 40 #ifndef NDEBUG 41 void showGlyphPageTrees(); 42 void showGlyphPageTree(unsigned pageNumber); 43 #endif 44 45 namespace WebCore { 46 47 class FontData; 48 class SimpleFontData; 49 50 // The glyph page tree is a data structure that maps (FontData, glyph page number) 51 // to a GlyphPage. Level 0 (the "root") is special. There is one root 52 // GlyphPageTreeNode for each glyph page number. The roots do not have a 53 // GlyphPage associated with them, and their initializePage() function is never 54 // called to fill the glyphs. 55 // 56 // Each root node maps a FontData pointer to another GlyphPageTreeNode at 57 // level 1 (the "root child") that stores the actual glyphs for a specific font data. 58 // These nodes will only have a GlyphPage if they have glyphs for that range. 59 // 60 // Levels greater than one correspond to subsequent levels of the fallback list 61 // for that font. These levels override their parent's page of glyphs by 62 // filling in holes with the new font (thus making a more complete page). 63 // 64 // A NULL FontData pointer corresponds to the system fallback 65 // font. It is tracked separately from the regular pages and overrides so that 66 // the glyph pages do not get polluted with these last-resort glyphs. The 67 // system fallback page is not populated at construction like the other pages, 68 // but on demand for each glyph, because the system may need to use different 69 // fallback fonts for each. This lazy population is done by the Font. 70 class GlyphPageTreeNode { 71 WTF_MAKE_FAST_ALLOCATED; 72 public: 73 static GlyphPageTreeNode* getRootChild(const FontData* fontData, unsigned pageNumber) 74 { 75 return getRoot(pageNumber)->getChild(fontData, pageNumber); 76 } 77 78 static void pruneTreeCustomFontData(const FontData*); 79 static void pruneTreeFontData(const SimpleFontData*); 80 81 void pruneCustomFontData(const FontData*); 82 void pruneFontData(const SimpleFontData*, unsigned level = 0); 83 84 GlyphPageTreeNode* parent() const { return m_parent; } 85 GlyphPageTreeNode* getChild(const FontData*, unsigned pageNumber); 86 87 // Returns a page of glyphs (or NULL if there are no glyphs in this page's character range). 88 GlyphPage* page() const { return m_page.get(); } 89 90 // Returns the level of this node. See class-level comment. 91 unsigned level() const { return m_level; } 92 93 // The system fallback font has special rules (see above). 94 bool isSystemFallback() const { return m_isSystemFallback; } 95 96 static size_t treeGlyphPageCount(); 97 size_t pageCount() const; 98 99 private: 100 GlyphPageTreeNode() 101 : m_parent(0) 102 , m_level(0) 103 , m_isSystemFallback(false) 104 , m_customFontCount(0) 105 #ifndef NDEBUG 106 , m_pageNumber(0) 107 #endif 108 { 109 } 110 111 static GlyphPageTreeNode* getRoot(unsigned pageNumber); 112 void initializePage(const FontData*, unsigned pageNumber); 113 114 #ifndef NDEBUG 115 void showSubtree(); 116 #endif 117 118 static HashMap<int, GlyphPageTreeNode*>* roots; 119 static GlyphPageTreeNode* pageZeroRoot; 120 121 typedef HashMap<const FontData*, OwnPtr<GlyphPageTreeNode> > GlyphPageTreeNodeMap; 122 123 GlyphPageTreeNodeMap m_children; 124 GlyphPageTreeNode* m_parent; 125 RefPtr<GlyphPage> m_page; 126 unsigned m_level : 31; 127 bool m_isSystemFallback : 1; 128 unsigned m_customFontCount; 129 OwnPtr<GlyphPageTreeNode> m_systemFallbackChild; 130 131 #ifndef NDEBUG 132 unsigned m_pageNumber; 133 134 friend void ::showGlyphPageTrees(); 135 friend void ::showGlyphPageTree(unsigned pageNumber); 136 #endif 137 }; 138 139 } // namespace WebCore 140 141 #endif // GlyphPageTreeNode_h 142
