fontplatformdatalinux.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

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 * 
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 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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 */

#ifndef FontPlatformDataLinux_h
#define FontPlatformDataLinux_h

#include "StringImpl.h"
#include <wtf/RefPtr.h>

class SkPaint;
class SkTypeface;

namespace WebCore {

class FontDescription;

// -----------------------------------------------------------------------------
// FontPlatformData is the handle which WebKit has on a specific face. A face
// is the tuple of (font, size, ...etc). Here we are just wrapping a Skia
// SkTypeface pointer and dealing with the reference counting etc.
// -----------------------------------------------------------------------------
class FontPlatformData {
public:
    // Used for deleted values in the font cache's hash tables. The hash table
    // will create us with this structure, and it will compare other values
    // to this "Deleted" one. It expects the Deleted one to be differentiable
    // from the NULL one (created with the empty constructor), so we can't just
    // set everything to NULL.
    FontPlatformData(WTF::HashTableDeletedValueType)
        : m_typeface(hashTableDeletedFontValue())
        , m_textSize(0)
        , m_fakeBold(false)
        , m_fakeItalic(false)
        { }

    FontPlatformData()
        : m_typeface(0)
        , m_textSize(0)
        , m_fakeBold(false)
        , m_fakeItalic(false)
        { }

    FontPlatformData(float textSize, bool fakeBold, bool fakeItalic)
        : m_typeface(0)
        , m_textSize(textSize)
        , m_fakeBold(fakeBold)
        , m_fakeItalic(fakeItalic)
        { }

    FontPlatformData(const FontPlatformData&);
    FontPlatformData(SkTypeface*, float textSize, bool fakeBold, bool fakeItalic);
    FontPlatformData(const FontPlatformData& src, float textSize);
    ~FontPlatformData();

    // -------------------------------------------------------------------------
    // Return true iff this font is monospaced (i.e. every glyph has an equal x
    // advance)
    // -------------------------------------------------------------------------
    bool isFixedPitch() const;

    // -------------------------------------------------------------------------
    // Setup a Skia painting context to use this font.
    // -------------------------------------------------------------------------
    void setupPaint(SkPaint*) const;

    unsigned hash() const;
    float size() const { return m_textSize; }

    bool operator==(const FontPlatformData&) const;
    FontPlatformData& operator=(const FontPlatformData&);
    bool isHashTableDeletedValue() const { return m_typeface == hashTableDeletedFontValue(); }

private:
    // FIXME: Could SkAutoUnref be used here?
    SkTypeface* m_typeface;
    float m_textSize;
    bool m_fakeBold;
    bool m_fakeItalic;

    SkTypeface* hashTableDeletedFontValue() const { return reinterpret_cast<SkTypeface*>(-1); }
};

}  // namespace WebCore

#endif  // ifdef FontPlatformData_h