Moving GraphicsContext and dependencies from core to platform.

Source/core/platform/graphics/GlyphPageTreeNode.h

-/*
- * Copyright (C) 2006, 2007, 2008 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.
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE 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 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 GlyphPageTreeNode_h
-#define GlyphPageTreeNode_h
-
-#include "platform/fonts/GlyphPage.h"
-#include <string.h>
-#include "wtf/HashMap.h"
-#include "wtf/OwnPtr.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
-#include "wtf/unicode/Unicode.h"
-
-#ifndef NDEBUG
-void showGlyphPageTrees();
-void showGlyphPageTree(unsigned pageNumber);
-#endif
-
-namespace WebCore {
-
-class FontData;
-class SimpleFontData;
-
-// The glyph page tree is a data structure that maps (FontData, glyph page number)
-// to a GlyphPage.  Level 0 (the "root") is special. There is one root
-// GlyphPageTreeNode for each glyph page number.  The roots do not have a
-// GlyphPage associated with them, and their initializePage() function is never
-// called to fill the glyphs.
-//
-// Each root node maps a FontData pointer to another GlyphPageTreeNode at
-// level 1 (the "root child") that stores the actual glyphs for a specific font data.
-// These nodes will only have a GlyphPage if they have glyphs for that range.
-//
-// Levels greater than one correspond to subsequent levels of the fallback list
-// for that font. These levels override their parent's page of glyphs by
-// filling in holes with the new font (thus making a more complete page).
-//
-// A NULL FontData pointer corresponds to the system fallback
-// font. It is tracked separately from the regular pages and overrides so that
-// the glyph pages do not get polluted with these last-resort glyphs. The
-// system fallback page is not populated at construction like the other pages,
-// but on demand for each glyph, because the system may need to use different
-// fallback fonts for each. This lazy population is done by the Font.
-class GlyphPageTreeNode {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    static GlyphPageTreeNode* getRootChild(const FontData* fontData, unsigned pageNumber)
-    {
-        return getRoot(pageNumber)->getChild(fontData, pageNumber);
-    }
-
-    static void pruneTreeCustomFontData(const FontData*);
-    static void pruneTreeFontData(const SimpleFontData*);
-
-    void pruneCustomFontData(const FontData*);
-    void pruneFontData(const SimpleFontData*, unsigned level = 0);
-
-    GlyphPageTreeNode* parent() const { return m_parent; }
-    GlyphPageTreeNode* getChild(const FontData*, unsigned pageNumber);
-
-    // Returns a page of glyphs (or NULL if there are no glyphs in this page's character range).
-    GlyphPage* page() const { return m_page.get(); }
-
-    // Returns the level of this node. See class-level comment.
-    unsigned level() const { return m_level; }
-
-    // The system fallback font has special rules (see above).
-    bool isSystemFallback() const { return m_isSystemFallback; }
-
-    static size_t treeGlyphPageCount();
-    size_t pageCount() const;
-
-private:
-    GlyphPageTreeNode()
-        : m_parent(0)
-        , m_level(0)
-        , m_isSystemFallback(false)
-        , m_customFontCount(0)
-#ifndef NDEBUG
-        , m_pageNumber(0)
-#endif
-    {
-    }
-
-    static GlyphPageTreeNode* getRoot(unsigned pageNumber);
-    void initializePage(const FontData*, unsigned pageNumber);
-
-#ifndef NDEBUG
-    void showSubtree();
-#endif
-
-    static HashMap<int, GlyphPageTreeNode*>* roots;
-    static GlyphPageTreeNode* pageZeroRoot;
-
-    typedef HashMap<const FontData*, OwnPtr<GlyphPageTreeNode> > GlyphPageTreeNodeMap;
-
-    GlyphPageTreeNodeMap m_children;
-    GlyphPageTreeNode* m_parent;
-    RefPtr<GlyphPage> m_page;
-    unsigned m_level : 31;
-    bool m_isSystemFallback : 1;
-    unsigned m_customFontCount;
-    OwnPtr<GlyphPageTreeNode> m_systemFallbackChild;
-
-#ifndef NDEBUG
-    unsigned m_pageNumber;
-
-    friend void ::showGlyphPageTrees();
-    friend void ::showGlyphPageTree(unsigned pageNumber);
-#endif
-};
-
-} // namespace WebCore
-
-#endif // GlyphPageTreeNode_h