uniscribecontroller.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

/*
 * Copyright (C) 2007 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 UniscribeController_h
#define UniscribeController_h

#include <usp10.h>
#include "Font.h"
#include "GlyphBuffer.h"
#include "Vector.h"

namespace WebCore {

class UniscribeController {
public:
    UniscribeController(const Font*, const TextRun&);

    // Advance and measure/place up to the specified character.
    void advance(unsigned to, GlyphBuffer* = 0);

    // Compute the character offset for a given x coordinate.
    int offsetForPosition(int x, bool includePartialGlyphs);

    // Returns the width of everything we've consumed so far.
    float runWidthSoFar() const { return m_runWidthSoFar; }

private:    
    void resetControlAndState();

    void itemizeShapeAndPlace(const UChar*, unsigned length, const SimpleFontData*, GlyphBuffer*);
    bool shapeAndPlaceItem(const UChar*, unsigned index, const SimpleFontData*, GlyphBuffer*);
    bool shape(const UChar* str, int len, SCRIPT_ITEM item, const SimpleFontData* fontData,
               Vector<WORD>& glyphs, Vector<WORD>& clusters,
               Vector<SCRIPT_VISATTR>& visualAttributes);

    const Font& m_font;
    const TextRun& m_run;

    SCRIPT_CONTROL m_control;
    SCRIPT_STATE m_state;
    Vector<SCRIPT_ITEM> m_items;
 
    unsigned m_currentCharacter;
    int m_end;

    float m_runWidthSoFar;
    float m_padding;
    float m_padPerSpace;

    bool m_computingOffsetPosition;
    bool m_includePartialGlyphs;
    float m_offsetX;
    int m_offsetPosition;
};

}
#endif