LayoutObject::invalidatePaintIfNeededForSynchronizedPainting() and plumbing

third_party/WebKit/Source/core/layout/LayoutObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1154 matching lines @@
     {
         ASSERT(!RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled());
         m_previousPositionFromPaintInvalidationBacking = positionFromPaintInvalidationBacking;
     }
 
     bool paintOffsetChanged(const LayoutPoint& newPaintOffset) const
     {
         ASSERT(RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled());
         return m_previousPositionFromPaintInvalidationBacking != uninitializedPaintOffset() && m_previousPositionFromPaintInvalidationBacking != newPaintOffset;
     }
-    void setPreviousPaintOffset(const LayoutPoint& paintOffset) const
+    void setPreviousPaintOffset(const LayoutPoint& paintOffset)
     {
         ASSERT(RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled());
         m_previousPositionFromPaintInvalidationBacking = paintOffset;
     }
 
     PaintInvalidationReason fullPaintInvalidationReason() const { return m_bitfields.fullPaintInvalidationReason(); }
     bool shouldDoFullPaintInvalidation() const { return m_bitfields.fullPaintInvalidationReason() != PaintInvalidationNone; }
     void setShouldDoFullPaintInvalidation(PaintInvalidationReason = PaintInvalidationFull);
     void clearShouldDoFullPaintInvalidation() { m_bitfields.setFullPaintInvalidationReason(PaintInvalidationNone); }
 
@@ skipping 34 matching lines @@
     // to invalidate its descendants which are painted on the same backing. However, for
     // an object (e.g. LayoutScrollbarPart, custom scroll corner, custom resizer) which is
     // not hooked up in the layout tree and not able to find its paint backing, it should
     // let its owning layout object call the following function.
     // FIXME: should we hook up scrollbar parts in the layout tree? crbug.com/484263.
     void invalidateDisplayItemClientForNonCompositingDescendantsOf(const LayoutObject&) const;
 
     // Called before anonymousChild.setStyle(). Override to set custom styles for the child.
     virtual void updateAnonymousChildStyle(const LayoutObject& anonymousChild, ComputedStyle& style) const { }
 
+    // Painters can use const methods only, except for these explicitly declared methods.
+    class MutableForPainting {
+    public:
+        void setPreviousPaintOffset(const LayoutPoint& paintOffset) { m_layoutObject.setPreviousPaintOffset(paintOffset); }
+        void invalidatePaintIfNeeded(const PaintInfo& paintInfo) { m_layoutObject.invalidatePaintIfNeededForSynchronizedPainting(paintInfo); }
+
+    private:
+        friend class LayoutObject;
+        MutableForPainting(const LayoutObject& layoutObject) : m_layoutObject(const_cast<LayoutObject&>(layoutObject)) { }
+
+        LayoutObject& m_layoutObject;
+    };
+    MutableForPainting mutableForPainting() const { return MutableForPainting(*this); }
+
 protected:
     enum LayoutObjectType {
         LayoutObjectBr,
         LayoutObjectCanvas,
         LayoutObjectFieldset,
         LayoutObjectCounter,
         LayoutObjectDetailsMarker,
         LayoutObjectEmbeddedObject,
         LayoutObjectFileUploadControl,
         LayoutObjectFrame,
@@ skipping 111 matching lines @@
 
 #if ENABLE(ASSERT)
     virtual bool paintInvalidationStateIsDirty() const
     {
         return m_bitfields.neededLayoutBecauseOfChildren() || shouldCheckForPaintInvalidationRegardlessOfPaintInvalidationState();
     }
 #endif
 
     virtual void invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState& childPaintInvalidationState);
     virtual PaintInvalidationReason invalidatePaintIfNeeded(PaintInvalidationState&, const LayoutBoxModelObject& paintInvalidationContainer);
+    void invalidatePaintIfNeededForSynchronizedPainting(const PaintInfo&);
 
     // When this object is invalidated for paint, this method is called to invalidate any DisplayItemClients
     // owned by this object, including the object itself, LayoutText/LayoutInline line boxes, etc.,
     // not including children which will be invalidated normally during invalidateTreeIfNeeded() and
     // parts which are invalidated separately (e.g. scrollbars).
     virtual void invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer, PaintInvalidationReason, const LayoutRect& previousPaintInvalidationRect, const LayoutRect& newPaintInvalidationRect) const;
 
     void setIsSlowRepaintObject(bool);
 
     void clearSelfNeedsOverflowRecalcAfterStyleChange() { m_bitfields.setSelfNeedsOverflowRecalcAfterStyleChange(false); }
@@ skipping 344 matching lines @@
 
     // This stores the paint invalidation rect from the previous frame. This rect does *not* account for composited scrolling. See
     // adjustInvalidationRectForCompositedScrolling().
     LayoutRect m_previousPaintInvalidationRect;
 
     // This stores the position in the paint invalidation backing's coordinate.
     // It is used to detect layoutObject shifts that forces a full invalidation.
     // This point does *not* account for composited scrolling. See adjustInvalidationRectForCompositedScrolling().
     // For slimmingPaintOffsetCaching, this stores the previous paint offset.
     // TODO(wangxianzhu): Rename this to m_previousPaintOffset when we enable slimmingPaintOffsetCaching.
-    // TODO(wangxianzhu): Better mutation control for painting.
-    mutable LayoutPoint m_previousPositionFromPaintInvalidationBacking;
+    LayoutPoint m_previousPositionFromPaintInvalidationBacking;
 };
 
 // FIXME: remove this once the layout object lifecycle ASSERTS are no longer hit.
 class DeprecatedDisableModifyLayoutTreeStructureAsserts {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(DeprecatedDisableModifyLayoutTreeStructureAsserts);
 public:
     DeprecatedDisableModifyLayoutTreeStructureAsserts();
 
     static bool canModifyLayoutTreeStateInAnyState();
@@ skipping 218 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h