fontwin.cpp

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) 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
 * 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. 
 */

#include "config.h"
#include "Font.h"

#include "FontFallbackList.h"
#include "GlyphBuffer.h"
#include "GraphicsContext.h"
#include "IntRect.h"
#include "NotImplemented.h"
#include "SimpleFontData.h"
#include "UniscribeController.h"
#include <wtf/MathExtras.h>

namespace WebCore {

FloatRect Font::selectionRectForComplexText(const TextRun& run, const IntPoint& point, int h,
                                            int from, int to) const
{
    UniscribeController it(this, run);
    it.advance(from);
    float beforeWidth = it.runWidthSoFar();
    it.advance(to);
    float afterWidth = it.runWidthSoFar();

    // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
    if (run.rtl()) {
        it.advance(run.length());
        float totalWidth = it.runWidthSoFar();
        return FloatRect(point.x() + floorf(totalWidth - afterWidth), point.y(), roundf(totalWidth - beforeWidth) - floorf(totalWidth - afterWidth), h);
    } 
    
    return FloatRect(point.x() + floorf(beforeWidth), point.y(), roundf(afterWidth) - floorf(beforeWidth), h);
}

void Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point,
                           int from, int to) const
{
    // This glyph buffer holds our glyphs + advances + font data for each glyph.
    GlyphBuffer glyphBuffer;

    float startX = point.x();
    UniscribeController controller(this, run);
    controller.advance(from);
    float beforeWidth = controller.runWidthSoFar();
    controller.advance(to, &glyphBuffer);
    
    // We couldn't generate any glyphs for the run.  Give up.
    if (glyphBuffer.isEmpty())
        return;
    
    float afterWidth = controller.runWidthSoFar();

    if (run.rtl()) {
        controller.advance(run.length());
        startX += controller.runWidthSoFar() - afterWidth;
    } else
        startX += beforeWidth;

    // Draw the glyph buffer now at the starting point returned in startX.
    FloatPoint startPoint(startX, point.y());
    drawGlyphBuffer(context, glyphBuffer, run, startPoint);
}

float Font::floatWidthForComplexText(const TextRun& run) const
{
    UniscribeController controller(this, run);
    controller.advance(run.length());
    return controller.runWidthSoFar();
}

int Font::offsetForPositionForComplexText(const TextRun& run, int x, bool includePartialGlyphs) const
{
    UniscribeController controller(this, run);
    return controller.offsetForPosition(x, includePartialGlyphs);
}

}