ui/events/gestures/gesture_recognizer_impl.h

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_
#define UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_

#include <map>
#include <vector>

#include "base/memory/linked_ptr.h"
#include "base/memory/scoped_ptr.h"
#include "ui/events/event_constants.h"
#include "ui/events/events_export.h"
#include "ui/events/gestures/gesture_provider_impl.h"
#include "ui/events/gestures/gesture_recognizer.h"
#include "ui/gfx/point.h"

namespace ui {
class GestureConsumer;
class GestureEvent;
class GestureEventHelper;
class TouchEvent;

// TODO(tdresser): Once the unified gesture recognition process sticks
// (crbug.com/332418), GestureRecognizerImpl can be cleaned up
// significantly.
class EVENTS_EXPORT GestureRecognizerImpl : public GestureRecognizer,
                                            public GestureProviderImplClient {
 public:
  typedef std::map<int, GestureConsumer*> TouchIdToConsumerMap;

  GestureRecognizerImpl();
  ~GestureRecognizerImpl() override;

  std::vector<GestureEventHelper*>& helpers() { return helpers_; }

  // Overridden from GestureRecognizer
  GestureConsumer* GetTouchLockedTarget(
      const TouchEvent& event) override;
  GestureConsumer* GetTargetForGestureEvent(
      const GestureEvent& event) override;
  GestureConsumer* GetTargetForLocation(
      const gfx::PointF& location, int source_device_id) override;
  void TransferEventsTo(GestureConsumer* current_consumer,
                        GestureConsumer* new_consumer) override;
  bool GetLastTouchPointForTarget(GestureConsumer* consumer,
                                  gfx::PointF* point) override;
  bool CancelActiveTouches(GestureConsumer* consumer) override;

 protected:
  virtual GestureProviderImpl* GetGestureProviderForConsumer(
      GestureConsumer* c);

 private:
  // Sets up the target consumer for gestures based on the touch-event.
  void SetupTargets(const TouchEvent& event, GestureConsumer* consumer);

  void DispatchGestureEvent(GestureEvent* event);

  // Overridden from GestureRecognizer
  bool ProcessTouchEventPreDispatch(const TouchEvent& event,
                                    GestureConsumer* consumer) override;

  Gestures* ProcessTouchEventPostDispatch(
      const TouchEvent& event,
      ui::EventResult result,
      GestureConsumer* consumer) override;

  Gestures* ProcessTouchEventOnAsyncAck(
      const TouchEvent& event,
      ui::EventResult result,
      GestureConsumer* consumer) override;

  bool CleanupStateForConsumer(GestureConsumer* consumer) override;
  void AddGestureEventHelper(GestureEventHelper* helper) override;
  void RemoveGestureEventHelper(GestureEventHelper* helper) override;

  // Overridden from GestureProviderImplClient
  void OnGestureEvent(GestureEvent* event) override;

  // Convenience method to find the GestureEventHelper that can dispatch events
  // to a specific |consumer|.
  GestureEventHelper* FindDispatchHelperForConsumer(GestureConsumer* consumer);
  std::map<GestureConsumer*, GestureProviderImpl*> consumer_gesture_provider_;

  // Both |touch_id_target_| and |touch_id_target_for_gestures_| map a touch-id
  // to its target window.  touch-ids are removed from |touch_id_target_| on
  // ET_TOUCH_RELEASE and ET_TOUCH_CANCEL. |touch_id_target_for_gestures_| are
  // removed in ConsumerDestroyed().
  TouchIdToConsumerMap touch_id_target_;
  TouchIdToConsumerMap touch_id_target_for_gestures_;

  std::vector<GestureEventHelper*> helpers_;

  DISALLOW_COPY_AND_ASSIGN(GestureRecognizerImpl);
};

// Provided only for testing:
EVENTS_EXPORT void SetGestureRecognizerForTesting(
    GestureRecognizer* gesture_recognizer);

}  // namespace ui

#endif  // UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_