1/*
2 * Copyright (C) 2011 Google, 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 GOOGLE 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 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 FrameDestructionObserver_h
27#define FrameDestructionObserver_h
28
29#include "platform/heap/Handle.h"
30
31namespace blink {
32
33class LocalFrame;
34
35class FrameDestructionObserver : public WillBeGarbageCollectedMixin {
36public:
37    explicit FrameDestructionObserver(LocalFrame*);
38
39#if !ENABLE(OILPAN)
40    // Oilpan: there is no known need for directly observing
41    // frameDestroyed() with Oilpan enabled, as its clearing is
42    // handled by keeping a weak reference.
43    //
44    // A weak callback version of frameDestroyed() can be reintroduced
45    // later, should the need arise.
46    virtual void frameDestroyed();
47#endif
48    virtual void willDetachFrameHost();
49
50    LocalFrame* frame() const { return m_frame; }
51
52    virtual void trace(Visitor*);
53
54protected:
55#if !ENABLE(OILPAN)
56    virtual ~FrameDestructionObserver();
57#endif
58
59    void observeFrame(LocalFrame*);
60
61    RawPtrWillBeWeakMember<LocalFrame> m_frame;
62};
63
64}
65
66#endif
67