Source/WebCore/rendering/RenderHTMLCanvas.cpp

/*
 * Copyright (C) 2004, 2006, 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:
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 *    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
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#include "config.h"
#include "RenderHTMLCanvas.h"

#include "CanvasRenderingContext.h"
#include "Document.h"
#include "FrameView.h"
#include "GraphicsContext.h"
#include "HTMLCanvasElement.h"
#include "HTMLNames.h"
#include "PaintInfo.h"
#include "RenderView.h"

namespace WebCore {

using namespace HTMLNames;

RenderHTMLCanvas::RenderHTMLCanvas(HTMLCanvasElement* element)
    : RenderReplaced(element, element->size())
{
    view()->frameView()->setIsVisuallyNonEmpty();
}

bool RenderHTMLCanvas::requiresLayer() const
{
#if PLATFORM(ANDROID)
    // All Canvas are drawn on their own composited layer
    // This improves performances a lot (as this simplify
    // the repaint/inval chain dealing with the PictureSet)
    return true;
#endif

    if (RenderReplaced::requiresLayer())
        return true;
    
    HTMLCanvasElement* canvas = static_cast<HTMLCanvasElement*>(node());
    return canvas && canvas->renderingContext() && canvas->renderingContext()->isAccelerated();
}

void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, int tx, int ty)
{
    IntRect rect = contentBoxRect();
    rect.move(tx, ty);
    static_cast<HTMLCanvasElement*>(node())->paint(paintInfo.context, rect);
}

void RenderHTMLCanvas::canvasSizeChanged()
{
    IntSize canvasSize = static_cast<HTMLCanvasElement*>(node())->size();
    IntSize zoomedSize(canvasSize.width() * style()->effectiveZoom(), canvasSize.height() * style()->effectiveZoom());

    if (zoomedSize == intrinsicSize())
        return;

    setIntrinsicSize(zoomedSize);

    if (!parent())
        return;

    if (!preferredLogicalWidthsDirty())
        setPreferredLogicalWidthsDirty(true);

    IntSize oldSize = size();
    computeLogicalWidth();
    computeLogicalHeight();
    if (oldSize == size())
        return;

    if (!selfNeedsLayout())
        setNeedsLayout(true);
}

} // namespace WebCore