1 files changed, 37 insertions, 21 deletions

diff --git a/Source/WebCore/rendering/RenderHTMLCanvas.cpp b/Source/WebCore/rendering/RenderHTMLCanvas.cpp
index e68927033..f2de75d52 100644
--- a/Source/WebCore/rendering/RenderHTMLCanvas.cpp
+++ b/Source/WebCore/rendering/RenderHTMLCanvas.cpp
@@ -10,10 +10,10 @@
  *    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
+ * THIS SOFTWARE IS PROVIDED BY APPLE 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
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE 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
@@ -33,6 +33,7 @@
 #include "GraphicsContext.h"
 #include "HTMLCanvasElement.h"
 #include "HTMLNames.h"
+#include "ImageQualityController.h"
 #include "Page.h"
 #include "PaintInfo.h"
 #include "RenderView.h"
@@ -41,42 +42,57 @@ namespace WebCore {
 
 using namespace HTMLNames;
 
-RenderHTMLCanvas::RenderHTMLCanvas(HTMLCanvasElement* element)
-    : RenderReplaced(element, element->size())
+RenderHTMLCanvas::RenderHTMLCanvas(HTMLCanvasElement& element, Ref<RenderStyle>&& style)
+    : RenderReplaced(element, WTFMove(style), element.size())
 {
     // Actual size is not known yet, report the default intrinsic size.
-    view()->frameView()->incrementVisuallyNonEmptyPixelCount(roundedIntSize(intrinsicSize()));
+    view().frameView().incrementVisuallyNonEmptyPixelCount(roundedIntSize(intrinsicSize()));
+}
+
+HTMLCanvasElement& RenderHTMLCanvas::canvasElement() const
+{
+    return downcast<HTMLCanvasElement>(nodeForNonAnonymous());
 }
 
 bool RenderHTMLCanvas::requiresLayer() const
 {
     if (RenderReplaced::requiresLayer())
         return true;
-    
-    HTMLCanvasElement* canvas = static_cast<HTMLCanvasElement*>(node());
-    return canvas && canvas->renderingContext() && canvas->renderingContext()->isAccelerated();
+
+    if (CanvasRenderingContext* context = canvasElement().renderingContext())
+        return context->isAccelerated();
+
+    return false;
 }
 
 void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
-    LayoutRect rect = contentBoxRect();
-    rect.moveBy(paintOffset);
-
-    if (Frame* frame = this->frame()) {
-        if (Page* page = frame->page()) {
-            if (paintInfo.phase == PaintPhaseForeground)
-                page->addRelevantRepaintedObject(this, rect);
-        }
+    GraphicsContext& context = paintInfo.context();
+
+    LayoutRect contentBoxRect = this->contentBoxRect();
+    contentBoxRect.moveBy(paintOffset);
+    LayoutRect replacedContentRect = this->replacedContentRect(intrinsicSize());
+    replacedContentRect.moveBy(paintOffset);
+
+    // Not allowed to overflow the content box.
+    bool clip = !contentBoxRect.contains(replacedContentRect);
+    GraphicsContextStateSaver stateSaver(paintInfo.context(), clip);
+    if (clip)
+        paintInfo.context().clip(snappedIntRect(contentBoxRect));
+
+    if (Page* page = frame().page()) {
+        if (paintInfo.phase == PaintPhaseForeground)
+            page->addRelevantRepaintedObject(this, intersection(replacedContentRect, contentBoxRect));
     }
 
-    bool useLowQualityScale = style()->imageRendering() == ImageRenderingCrispEdges || style()->imageRendering() == ImageRenderingOptimizeSpeed;
-    static_cast<HTMLCanvasElement*>(node())->paint(paintInfo.context, rect, useLowQualityScale);
+    InterpolationQualityMaintainer interpolationMaintainer(context, ImageQualityController::interpolationQualityFromStyle(style()));
+    canvasElement().paint(context, replacedContentRect);
 }
 
 void RenderHTMLCanvas::canvasSizeChanged()
 {
-    IntSize canvasSize = static_cast<HTMLCanvasElement*>(node())->size();
-    LayoutSize zoomedSize(canvasSize.width() * style()->effectiveZoom(), canvasSize.height() * style()->effectiveZoom());
+    IntSize canvasSize = canvasElement().size();
+    LayoutSize zoomedSize(canvasSize.width() * style().effectiveZoom(), canvasSize.height() * style().effectiveZoom());
 
     if (zoomedSize == intrinsicSize())
         return;
@@ -96,7 +112,7 @@ void RenderHTMLCanvas::canvasSizeChanged()
         return;
 
     if (!selfNeedsLayout())
-        setNeedsLayout(true);
+        setNeedsLayout();
 }
 
 } // namespace WebCore