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      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 PlatformGestureRecognizer_h
     32 #define PlatformGestureRecognizer_h
     33 
     34 namespace WebCore {
     35 
     36 class EventHandler;
     37 class PlatformGestureRecognizer;
     38 class PlatformTouchEvent;
     39 
     40 // A GestureRecognizer detects gestures occurring in the touch event.
     41 // In response to a given touch event, the GestureRecognizer, updates
     42 // its internal state and optionally dispatches synthetic events to the
     43 // invoking EventHandler instance.
     44 class PlatformGestureRecognizer {
     45 protected:
     46     PlatformGestureRecognizer();
     47 
     48 public:
     49     virtual ~PlatformGestureRecognizer();
     50 
     51     // Invoked for each touch event that could contribute to the current gesture.
     52     // Takes a PlatformTouchEvent and the EventHandler that originated it and which will also
     53     // be the target of any generated synthetic event. Finally, |handled|
     54     // specifies if the |event| was actually handled by |source| (by the JavaScript)
     55     // Returns true if the event resulted in firing a synthetic event.
     56     virtual bool processTouchEventForGesture(const PlatformTouchEvent&, EventHandler*, bool handled) = 0;
     57 
     58     // Factory method for GestureManagers.
     59     static PlatformGestureRecognizer* create();
     60 };
     61 
     62 } // namespace WebCore
     63 
     64 #endif // PlatformGestureRecognizer_h
     65