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 36 namespace blink { 37 38 class UserGestureIndicator; 39 class 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. 54 class WebScopedUserGesture { 55 public: WebScopedUserGesture(const WebUserGestureToken & token)56 explicit WebScopedUserGesture(const WebUserGestureToken& token) { initializeWithToken(token); } WebScopedUserGesture()57 WebScopedUserGesture() { initialize(); } ~WebScopedUserGesture()58 ~WebScopedUserGesture() { reset(); } 59 60 private: 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