src/third_party/WebKit/Source/core/rendering/RenderHTMLCanvas.cpp

   1 /*
   2  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "core/rendering/RenderHTMLCanvas.h"
  28
  29 #include "core/html/HTMLCanvasElement.h"
  30 #include "core/html/canvas/CanvasRenderingContext.h"
  31 #include "core/frame/FrameView.h"
  32 #include "core/frame/LocalFrame.h"
  33 #include "core/page/Page.h"
  34 #include "core/rendering/PaintInfo.h"
  35 #include "core/rendering/RenderView.h"
  36
  37 namespace WebCore {
  38
  39 using namespace HTMLNames;
  40
  41 RenderHTMLCanvas::RenderHTMLCanvas(HTMLCanvasElement* element)
  42     : RenderReplaced(element, element->size())
  43 {
  44     view()->frameView()->setIsVisuallyNonEmpty();
  45 }
  46
  47 LayerType RenderHTMLCanvas::layerTypeRequired() const
  48 {
  49     return NormalLayer;
  50 }
  51
  52 void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  53 {
  54     GraphicsContext* context = paintInfo.context;
  55
  56     LayoutRect contentRect = contentBoxRect();
  57     contentRect.moveBy(paintOffset);
  58     LayoutRect paintRect = replacedContentRect();
  59     paintRect.moveBy(paintOffset);
  60
  61     bool clip = !contentRect.contains(paintRect);
  62     if (clip) {
  63         // Not allowed to overflow the content box.
  64         paintInfo.context->save();
  65         paintInfo.context->clip(pixelSnappedIntRect(contentRect));
  66     }
  67
  68     // FIXME: InterpolationNone should be used if ImageRenderingOptimizeContrast is set.
  69     // See bug for more details: crbug.com/353716.
  70     InterpolationQuality interpolationQuality = style()->imageRendering() == ImageRenderingOptimizeContrast ? InterpolationLow : CanvasDefaultInterpolationQuality;
  71     InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
  72     context->setImageInterpolationQuality(interpolationQuality);
  73     toHTMLCanvasElement(node())->paint(context, paintRect);
  74     context->setImageInterpolationQuality(previousInterpolationQuality);
  75
  76     if (clip)
  77         context->restore();
  78 }
  79
  80 void RenderHTMLCanvas::canvasSizeChanged()
  81 {
  82     IntSize canvasSize = toHTMLCanvasElement(node())->size();
  83     LayoutSize zoomedSize(canvasSize.width() * style()->effectiveZoom(), canvasSize.height() * style()->effectiveZoom());
  84
  85     if (zoomedSize == intrinsicSize())
  86         return;
  87
  88     setIntrinsicSize(zoomedSize);
  89
  90     if (!parent())
  91         return;
  92
  93     if (!preferredLogicalWidthsDirty())
  94         setPreferredLogicalWidthsDirty();
  95
  96     LayoutSize oldSize = size();
  97     updateLogicalWidth();
  98     updateLogicalHeight();
  99     if (oldSize == size())
 100         return;
 101
 102     if (!selfNeedsLayout())
 103         setNeedsLayout();
 104 }
 105
 106 CompositingReasons RenderHTMLCanvas::additionalCompositingReasons(CompositingTriggerFlags triggers) const
 107 {
 108     if (!(triggers & CanvasTrigger))
 109         return CompositingReasonNone;
 110
 111     HTMLCanvasElement* canvas = toHTMLCanvasElement(node());
 112     if (canvas->renderingContext() && canvas->renderingContext()->isAccelerated())
 113         return CompositingReasonCanvas;
 114
 115     return CompositingReasonNone;
 116 }
 117
 118 } // namespace WebCore