Intersection Observer first draft

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 23 matching lines @@
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/heap/Handle.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "wtf/OwnPtr.h"
 
 namespace blink {
 
 class DeprecatedPaintLayerCompositor;
 class LayoutQuote;
 
+using IntersectionObserverTargetMap = HashMap<LayoutObject*, FloatRect>;
+
 // LayoutView is the root of the layout tree and the Document's LayoutObject.
 //
 // It corresponds to the CSS concept of 'initial containing block' (or ICB).
 // http://www.w3.org/TR/CSS2/visudet.html#containing-block-details
 //
 // Its dimensions match that of the layout viewport. This viewport is used to
 // size elements, in particular fixed positioned elements.
 // LayoutView is always at position (0,0) relative to the document (and so isn't
 // necessarily in view).
 // See
@@ skipping 137 matching lines @@
     void pushLayoutState(LayoutState& layoutState) { m_layoutState = &layoutState; }
     void popLayoutState() { ASSERT(m_layoutState); m_layoutState = m_layoutState->next(); }
     void invalidateTreeIfNeeded(PaintInvalidationState&) final;
 
     LayoutRect visualOverflowRect() const override;
 
     // Invalidates paint for the entire view, including composited descendants, but not including child frames.
     // It is very likely you do not want to call this method.
     void setShouldDoFullPaintInvalidationForViewAndAllDescendants();
 
+    void addIntersectionObserverTarget(LayoutObject*);
+    void removeIntersectionObserverTarget(LayoutObject*);
+    void computeIntersectionObservations(const FloatRect&);
+
 private:
     void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = nullptr, const PaintInvalidationState* = nullptr) const override;
 
     const LayoutObject* pushMappingToContainer(const LayoutBoxModelObject* ancestorToStopAt, LayoutGeometryMap&) const override;
     void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const override;
     void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const override;
 
     void layoutContent();
 #if ENABLE(ASSERT)
     void checkLayoutState();
@@ skipping 42 matching lines @@
 
     OwnPtr<DeprecatedPaintLayerCompositor> m_compositor;
     RefPtr<IntervalArena> m_intervalArena;
 
     LayoutQuote* m_layoutQuoteHead;
     unsigned m_layoutCounterCount;
 
     unsigned m_hitTestCount;
     unsigned m_hitTestCacheHits;
     OwnPtrWillBePersistent<HitTestCache> m_hitTestCache;
+
+    IntersectionObserverTargetMap m_intersectionObserverTargets;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutView, isLayoutView());
 
 // Suspends the PaintInvalidationState cached offset and clipRect optimization. Used under transforms
 // that cannot be represented by PaintInvalidationState (common in SVG) and when paint invalidation
 // containers don't follow the common tree-walk algorithm (e.g. when an absolute positioned descendant
 // is nested under a relatively positioned inline-block child).
 class ForceHorriblySlowRectMapping {
     STACK_ALLOCATED();
@@ skipping 13 matching lines @@
             m_paintInvalidationState->m_cachedOffsetsEnabled = true;
     }
 private:
     const PaintInvalidationState* m_paintInvalidationState;
     bool m_didDisable;
 };
 
 } // namespace blink
 
 #endif // LayoutView_h