1/*
2 * Copyright (C) 2012 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 APPLE 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 IdTargetObserver_h
27#define IdTargetObserver_h
28
29#include "platform/heap/Handle.h"
30#include "wtf/text/AtomicString.h"
31
32namespace blink {
33
34class IdTargetObserverRegistry;
35
36class IdTargetObserver : public NoBaseWillBeGarbageCollectedFinalized<IdTargetObserver> {
37public:
38    virtual ~IdTargetObserver();
39    virtual void trace(Visitor*);
40    virtual void idTargetChanged() = 0;
41    virtual void unregister();
42
43protected:
44    IdTargetObserver(IdTargetObserverRegistry&, const AtomicString& id);
45
46private:
47    IdTargetObserverRegistry& registry() { return *m_registry; }
48
49    RawPtrWillBeMember<IdTargetObserverRegistry> m_registry;
50    AtomicString m_id;
51};
52
53} // namespace blink
54
55#endif // IdTargetObserver_h
56