1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef CSSCanvasValue_h
27#define CSSCanvasValue_h
28
29#include "core/css/CSSImageGeneratorValue.h"
30#include "core/html/HTMLCanvasElement.h"
31
32namespace blink {
33
34class Document;
35
36class CSSCanvasValue : public CSSImageGeneratorValue {
37public:
38    static PassRefPtrWillBeRawPtr<CSSCanvasValue> create(const String& name)
39    {
40        return adoptRefWillBeNoop(new CSSCanvasValue(name));
41    }
42    ~CSSCanvasValue();
43
44    String customCSSText() const;
45
46    PassRefPtr<Image> image(RenderObject*, const IntSize&);
47    bool isFixedSize() const { return true; }
48    IntSize fixedSize(const RenderObject*);
49
50    bool isPending() const { return false; }
51    void loadSubimages(ResourceFetcher*) { }
52
53    bool equals(const CSSCanvasValue&) const;
54
55    void traceAfterDispatch(Visitor*);
56
57private:
58    explicit CSSCanvasValue(const String& name)
59        : CSSImageGeneratorValue(CanvasClass)
60        , m_canvasObserver(adoptPtrWillBeNoop(new CanvasObserverProxy(this)))
61        , m_name(name)
62        , m_element(nullptr)
63    {
64    }
65
66    // NOTE: We put the CanvasObserver in a member instead of inheriting from it
67    // to avoid adding a vptr to CSSCanvasValue.
68    class CanvasObserverProxy FINAL : public NoBaseWillBeGarbageCollected<CanvasObserverProxy>, public CanvasObserver {
69        WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(CanvasObserverProxy);
70    public:
71        explicit CanvasObserverProxy(CSSCanvasValue* ownerValue) : m_ownerValue(ownerValue) { }
72
73        virtual void canvasChanged(HTMLCanvasElement* canvas, const FloatRect& changedRect) OVERRIDE
74        {
75            m_ownerValue->canvasChanged(canvas, changedRect);
76        }
77        virtual void canvasResized(HTMLCanvasElement* canvas) OVERRIDE
78        {
79            m_ownerValue->canvasResized(canvas);
80        }
81#if !ENABLE(OILPAN)
82        virtual void canvasDestroyed(HTMLCanvasElement* canvas) OVERRIDE
83        {
84            m_ownerValue->canvasDestroyed(canvas);
85        }
86#endif
87        virtual void trace(Visitor* visitor) OVERRIDE
88        {
89            visitor->trace(m_ownerValue);
90            CanvasObserver::trace(visitor);
91        }
92
93    private:
94        RawPtrWillBeMember<CSSCanvasValue> m_ownerValue;
95    };
96
97    void canvasChanged(HTMLCanvasElement*, const FloatRect& changedRect);
98    void canvasResized(HTMLCanvasElement*);
99
100#if !ENABLE(OILPAN)
101    void canvasDestroyed(HTMLCanvasElement*);
102#endif
103
104    HTMLCanvasElement* element(Document*);
105
106    OwnPtrWillBeMember<CanvasObserverProxy> m_canvasObserver;
107
108    // The name of the canvas.
109    String m_name;
110    // The document supplies the element and owns it.
111    RawPtrWillBeWeakMember<HTMLCanvasElement> m_element;
112};
113
114DEFINE_CSS_VALUE_TYPE_CASTS(CSSCanvasValue, isCanvasValue());
115
116} // namespace blink
117
118#endif // CSSCanvasValue_h
119