Unify all types of overflow-related clips for paint and hit testing.

third_party/WebKit/Source/core/paint/PaintLayerClipper.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 29 matching lines @@
  * other provisions required by the MPL or the GPL, as the case may be.
  * If you do not delete the provisions above, a recipient may use your
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
 #include "core/paint/PaintLayerClipper.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutView.h"
-#include "core/layout/svg/LayoutSVGRoot.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintLayer.h"
 
 namespace blink {
 
 static void adjustClipRectsForChildren(const LayoutBoxModelObject& layoutObject,
                                        ClipRects& clipRects) {
   EPosition position = layoutObject.styleRef().position();
   // A fixed object is essentially the root of its containing block hierarchy,
   // so when we encounter such an object, we reset our clip rects to the
   // fixedClipRect.
   if (position == FixedPosition) {
     clipRects.setPosClipRect(clipRects.fixedClipRect());
     clipRects.setOverflowClipRect(clipRects.fixedClipRect());
     clipRects.setFixed(true);
   } else if (position == RelativePosition) {
     clipRects.setPosClipRect(clipRects.overflowClipRect());
   } else if (position == AbsolutePosition) {
     clipRects.setOverflowClipRect(clipRects.posClipRect());
   }
 }
 
-// TODO(chrishtr): move this to LayoutBox.
-static LayoutRect overflowOrControlClip(const LayoutBox& box,
-                                        const LayoutPoint& location,
-                                        OverlayScrollbarClipBehavior behavior) {
-  if (box.hasControlClip())
-    return box.controlClipRect(location);
-  return box.overflowClipRect(location, behavior);
-}
-
 static void applyClipRects(const ClipRectsContext& context,
                            const LayoutBoxModelObject& layoutObject,
                            LayoutPoint offset,
                            ClipRects& clipRects) {
   DCHECK(layoutObject.isBox());
   const LayoutBox& box = *toLayoutBox(&layoutObject);
 
-  DCHECK(box.hasClipRelatedProperty() || box.hasControlClip() ||
-         (box.isSVGRoot() && toLayoutSVGRoot(&box)->shouldApplyViewportClip()));
+  DCHECK(box.shouldClipOverflow() || box.hasClip());
   LayoutView* view = box.view();
   DCHECK(view);
   if (clipRects.fixed() && context.rootLayer->layoutObject() == view)
     offset -= LayoutSize(view->frameView()->getScrollOffset());
 
-  if (box.hasOverflowClip() ||
-      (box.isSVGRoot() && toLayoutSVGRoot(&box)->shouldApplyViewportClip()) ||
-      box.styleRef().containsPaint() || box.hasControlClip()) {
-    ClipRect newOverflowClip = overflowOrControlClip(
-        box, offset, context.overlayScrollbarClipBehavior);
+  if (box.shouldClipOverflow()) {
+    ClipRect newOverflowClip =
+        box.overflowClipRect(offset, context.overlayScrollbarClipBehavior);
     newOverflowClip.setHasRadius(box.styleRef().hasBorderRadius());
     clipRects.setOverflowClipRect(
         intersection(newOverflowClip, clipRects.overflowClipRect()));
     if (box.isPositioned())
       clipRects.setPosClipRect(
           intersection(newOverflowClip, clipRects.posClipRect()));
     if (box.isLayoutView() || box.hasTransformRelatedProperty())
       clipRects.setFixedClipRect(
           intersection(newOverflowClip, clipRects.fixedClipRect()));
     if (box.styleRef().containsPaint()) {
@@ skipping 243 matching lines @@
 
   LayoutPoint offset;
   if (offsetFromRoot)
     offset = *offsetFromRoot;
   else
     m_layer.convertToLayerCoords(context.rootLayer, offset);
   layerBounds = LayoutRect(offset, LayoutSize(m_layer.size()));
 
   // Update the clip rects that will be passed to child layers.
   if (shouldClipOverflow(context)) {
-    LayoutRect overflowOrControlClipRect =
-        overflowOrControlClip(toLayoutBox(layoutObject), offset,
-                              context.overlayScrollbarClipBehavior);
-    foregroundRect.intersect(overflowOrControlClipRect);
+    LayoutRect overflowAndClipRect =
+        toLayoutBox(layoutObject)
+            .overflowClipRect(offset, context.overlayScrollbarClipBehavior);
+    foregroundRect.intersect(overflowAndClipRect);
     if (layoutObject.styleRef().hasBorderRadius())
       foregroundRect.setHasRadius(true);
 
     // FIXME: Does not do the right thing with columns yet, since we don't yet
     // factor in the individual column boxes as overflow.
 
     // The LayoutView is special since its overflow clipping rect may be larger
     // than its box rect (crbug.com/492871).
     LayoutRect layerBoundsWithVisualOverflow =
         layoutObject.isLayoutView()
@@ skipping 176 matching lines @@
 
 bool PaintLayerClipper::shouldClipOverflow(
     const ClipRectsContext& context) const {
   if (!m_layer.layoutObject()->isBox())
     return false;
   const LayoutBox& box = *toLayoutBox(m_layer.layoutObject());
 
   if (!shouldRespectOverflowClip(context))
     return false;
 
-  return box.hasOverflowClip() || box.styleRef().containsPaint() ||
-         box.hasControlClip() ||
-         (box.isSVGRoot() && toLayoutSVGRoot(&box)->shouldApplyViewportClip());
+  return box.shouldClipOverflow();
 }
 
 bool PaintLayerClipper::shouldRespectOverflowClip(
     const ClipRectsContext& context) const {
   if (&m_layer != context.rootLayer)
     return true;
 
   if (context.respectOverflowClip == IgnoreOverflowClip)
     return false;
 
@@ skipping 10 matching lines @@
     const LayoutSize& subpixelAccumulation) const {
   DCHECK(!m_geometryMapper);
   ClipRectsContext context(rootLayer, PaintingClipRects,
                            IgnoreOverlayScrollbarSize, subpixelAccumulation);
   if (respectOverflowClip == IgnoreOverflowClip)
     context.setIgnoreOverflowClip();
   return getClipRects(context);
 }
 
 }  // namespace blink