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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef WebScopedUserGesture_h
32#define WebScopedUserGesture_h
33
34#include "../platform/WebPrivateOwnPtr.h"
35
36namespace blink {
37
38class UserGestureIndicator;
39class WebUserGestureToken;
40
41// An instance of this class, while kept alive, will indicate that we are in
42// the context of a known user gesture. To use, create one, perform whatever
43// actions were done under color of a known user gesture, and then delete it.
44// Usually this will be done on the stack.
45//
46// SECURITY WARNING: Do not create several instances of this class for the same
47// user gesture. Doing so might enable malicious code to work around certain
48// restrictions such as opening multiple windows.
49// Instead, obtain the current WebUserGestureToken from the
50// WebUserGestureIndicator, and use this token to create a
51// WebScopedUserGesture. If the token was alrady consumed, the new
52// WebScopedUserGesture will not indicate that we are in the context of a user
53// gesture.
54class WebScopedUserGesture {
55public:
56    explicit WebScopedUserGesture(const WebUserGestureToken& token) { initializeWithToken(token); }
57    WebScopedUserGesture() { initialize(); }
58    ~WebScopedUserGesture() { reset(); }
59
60private:
61    BLINK_EXPORT void initialize();
62    BLINK_EXPORT void initializeWithToken(const WebUserGestureToken&);
63    BLINK_EXPORT void reset();
64
65    WebPrivateOwnPtr<UserGestureIndicator> m_indicator;
66};
67
68} // namespace blink
69
70#endif // WebScopedUserGesture_h
71