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 blink {
29
30class RenderLayer;
31class ScrollableArea;
32
33enum LayerType {
34    NoLayer,
35    NormalLayer,
36    // A forced or overflow clip layer is required for bookkeeping purposes,
37    // but does not force a layer to be self painting.
38    OverflowClipLayer,
39    ForcedLayer
40};
41
42class RenderLayerModelObject : public RenderObject {
43public:
44    explicit RenderLayerModelObject(ContainerNode*);
45    virtual ~RenderLayerModelObject();
46
47    // This is the only way layers should ever be destroyed.
48    void destroyLayer();
49
50    bool hasSelfPaintingLayer() const;
51    RenderLayer* layer() const { return m_layer.get(); }
52    ScrollableArea* scrollableArea() const;
53
54    virtual void styleWillChange(StyleDifference, const RenderStyle& newStyle) OVERRIDE;
55    virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
56    virtual void updateFromStyle() { }
57
58    virtual LayerType layerTypeRequired() const = 0;
59
60    // Returns true if the background is painted opaque in the given rect.
61    // The query rect is given in local coordinate system.
62    virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const { return false; }
63
64    // This is null for anonymous renderers.
65    ContainerNode* node() const { return toContainerNode(RenderObject::node()); }
66
67    virtual void invalidateTreeIfNeeded(const PaintInvalidationState&) OVERRIDE;
68
69    // Indicate that the contents of this renderer need to be repainted. Only has an effect if compositing is being used,
70    void setBackingNeedsPaintInvalidationInRect(const LayoutRect&) const; // r is in the coordinate space of this render object
71
72protected:
73    void createLayer(LayerType);
74
75    virtual void willBeDestroyed() OVERRIDE;
76
77    virtual void addLayerHitTestRects(LayerHitTestRects&, const RenderLayer*, const LayoutPoint&, const LayoutRect&) const OVERRIDE;
78
79private:
80    virtual bool isLayerModelObject() const OVERRIDE FINAL { return true; }
81
82    OwnPtr<RenderLayer> m_layer;
83
84    // Used to store state between styleWillChange and styleDidChange
85    static bool s_wasFloating;
86};
87
88DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderLayerModelObject, isLayerModelObject());
89
90} // namespace blink
91
92#endif // RenderLayerModelObject_h
93