Implement closed shadow adjustment for Element.offsetParent

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 645 matching lines @@
     bool isElementContinuation() const { return node() && node()->layoutObject() != this; }
     bool isInlineElementContinuation() const { return isElementContinuation() && isInline(); }
     virtual LayoutBoxModelObject* virtualContinuation() const { return nullptr; }
 
     bool isFloating() const { return m_bitfields.floating(); }
 
     bool isOutOfFlowPositioned() const { return m_bitfields.isOutOfFlowPositioned(); } // absolute or fixed positioning
     bool isInFlowPositioned() const { return m_bitfields.isInFlowPositioned(); } // relative or sticky positioning
     bool isRelPositioned() const { return m_bitfields.isRelPositioned(); } // relative positioning
     bool isStickyPositioned() const { return m_bitfields.isStickyPositioned(); } // sticky positioning
+    bool isFixedPositioned() const { return isOutOfFlowPositioned() && style()->position() == FixedPosition; } // fixed positioning
     bool isPositioned() const { return m_bitfields.isPositioned(); }
 
     bool isText() const  { return m_bitfields.isText(); }
     bool isBox() const { return m_bitfields.isBox(); }
     bool isInline() const { return m_bitfields.isInline(); } // inline object
     bool isDragging() const { return m_bitfields.isDragging(); }
     bool isAtomicInlineLevel() const { return m_bitfields.isAtomicInlineLevel(); }
     bool isHorizontalWritingMode() const { return m_bitfields.horizontalWritingMode(); }
     bool hasFlippedBlocksWritingMode() const
     {
@@ skipping 132 matching lines @@
     // If |ancestor| and |ancestorSkipped| are not null, on return *ancestorSkipped
     // is true if the layoutObject returned is an ancestor of |ancestor|.
     LayoutObject* container(const LayoutBoxModelObject* ancestor = nullptr, bool* ancestorSkipped = nullptr, bool* filterOrReflectionSkipped = nullptr) const;
     // Finds the container as if this object is fixed-position.
     LayoutBlock* containerForFixedPosition(const LayoutBoxModelObject* ancestor = nullptr, bool* ancestorSkipped = nullptr, bool* filterOrReflectionSkipped = nullptr) const;
     // Finds the containing block as if this object is absolute-position.
     LayoutBlock* containingBlockForAbsolutePosition() const;
 
     virtual LayoutObject* hoverAncestor() const { return parent(); }
 
-    Element* offsetParent() const;
+    Element* offsetParent(const Element* = nullptr) const;
 
     void markContainerChainForLayout(bool scheduleRelayout = true, SubtreeLayoutScope* = nullptr);
     void setNeedsLayout(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
     void setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReasonForTracing, MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
     void clearNeedsLayout();
     void setChildNeedsLayout(MarkingBehavior = MarkContainerChain, SubtreeLayoutScope* = nullptr);
     void setNeedsPositionedMovementLayout();
     void setPreferredLogicalWidthsDirty(MarkingBehavior = MarkContainerChain);
     void clearPreferredLogicalWidthsDirty();
 
@@ skipping 1350 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