1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4 * Copyright (C) 2003, 2006, 2007, 2009 Apple Inc. All rights reserved.
5 * Copyright (C) 2010, 2012 Google Inc. All rights reserved.
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public License
18 * along with this library; see the file COPYING.LIB.  If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
21 */
22
23#ifndef RenderLayerModelObject_h
24#define RenderLayerModelObject_h
25
26#include "core/rendering/RenderObject.h"
27
28namespace WebCore {
29
30class RenderLayer;
31
32class RenderLayerModelObject : public RenderObject {
33public:
34    explicit RenderLayerModelObject(ContainerNode*);
35    virtual ~RenderLayerModelObject();
36
37    // Called by RenderObject::willBeDestroyed() and is the only way layers should ever be destroyed
38    void destroyLayer();
39
40    bool hasSelfPaintingLayer() const;
41    RenderLayer* layer() const { return m_layer; }
42
43    virtual void styleWillChange(StyleDifference, const RenderStyle* newStyle) OVERRIDE;
44    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
45    virtual void updateFromStyle() { }
46
47    virtual bool requiresLayer() const = 0;
48
49    // Returns true if the background is painted opaque in the given rect.
50    // The query rect is given in local coordinate system.
51    virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const { return false; }
52
53    // This is null for anonymous renderers.
54    ContainerNode* node() const { return toContainerNode(RenderObject::node()); }
55
56protected:
57    void ensureLayer();
58
59    virtual void willBeDestroyed() OVERRIDE;
60
61    virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer*, const LayoutPoint&, const LayoutRect&) const OVERRIDE;
62
63private:
64    virtual bool isLayerModelObject() const OVERRIDE FINAL { return true; }
65
66    RenderLayer* m_layer;
67
68    // Used to store state between styleWillChange and styleDidChange
69    static bool s_wasFloating;
70    static bool s_hadLayer;
71    static bool s_hadTransform;
72    static bool s_layerWasSelfPainting;
73};
74
75inline RenderLayerModelObject* toRenderLayerModelObject(RenderObject* object)
76{
77    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isLayerModelObject());
78    return static_cast<RenderLayerModelObject*>(object);
79}
80
81inline const RenderLayerModelObject* toRenderLayerModelObject(const RenderObject* object)
82{
83    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isLayerModelObject());
84    return static_cast<const RenderLayerModelObject*>(object);
85}
86
87// This will catch anyone doing an unnecessary cast.
88void toRenderLayerModelObject(const RenderLayerModelObject*);
89
90} // namespace WebCore
91
92#endif // RenderLayerModelObject_h
93