chromium/ui/events/gesture_detection/gesture_listeners.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_EVENTS_GESTURE_DETECTION_GESTURE_LISTENERS_H_
#define UI_EVENTS_GESTURE_DETECTION_GESTURE_LISTENERS_H_

#include "ui/events/gesture_detection/gesture_detection_export.h"

namespace ui {

class MotionEvent;

// Client through which |GestureDetector| signals gesture detection.
class GESTURE_DETECTION_EXPORT GestureListener { … };

// Client through which |GestureDetector| signals double-tap detection.
class GESTURE_DETECTION_EXPORT DoubleTapListener { … };

// A convenience class to extend when you only want to listen for a subset
// of all the gestures. This implements all methods in the
// |GestureListener| and |DoubleTapListener| but does
// nothing and returns false for all applicable methods.
class GESTURE_DETECTION_EXPORT SimpleGestureListener
    : public GestureListener,
      public DoubleTapListener { … };

}  // namespace ui

#endif  // UI_EVENTS_GESTURE_DETECTION_GESTURE_LISTENERS_H_