ash/highlighter/highlighter_controller.h

// Copyright 2017 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 ASH_HIGHLIGHTER_HIGHLIGHTER_CONTROLLER_H_
#define ASH_HIGHLIGHTER_HIGHLIGHTER_CONTROLLER_H_

#include <memory>

#include "ash/fast_ink/fast_ink_pointer_controller.h"

namespace base {
class OneShotTimer;
}

namespace ash {

class HighlighterResultView;
class HighlighterSelectionObserver;
class HighlighterView;

// Controller for the highlighter functionality.
// Enables/disables highlighter as well as receives points
// and passes them off to be rendered.
class ASH_EXPORT HighlighterController : public FastInkPointerController {
 public:
  HighlighterController();
  ~HighlighterController() override;

  // Set the observer to handle selection results.
  void SetObserver(HighlighterSelectionObserver* observer);

  // FastInkPointerController:
  void SetEnabled(bool enabled) override;

 private:
  friend class HighlighterControllerTestApi;

  // FastInkPointerController:
  views::View* GetPointerView() const override;
  void CreatePointerView(base::TimeDelta presentation_delay,
                         aura::Window* root_window) override;
  void UpdatePointerView(ui::TouchEvent* event) override;
  void DestroyPointerView() override;
  bool CanStartNewGesture(ui::TouchEvent* event) override;

  // Performs gesture recognition, initiates appropriate visual effects,
  // notifies the observer if necessary.
  void RecognizeGesture();

  // Destroys |highlighter_view_|, if it exists.
  void DestroyHighlighterView();

  // Destroys |result_view_|, if it exists.
  void DestroyResultView();

  // |highlighter_view_| will only hold an instance when the highlighter is
  // enabled and activated (pressed or dragged) and until the fade out
  // animation is done.
  std::unique_ptr<HighlighterView> highlighter_view_;

  // |result_view_| will only hold an instance when the selection result
  // animation is in progress.
  std::unique_ptr<HighlighterResultView> result_view_;

  // |observer_| is not owned by the controller.
  HighlighterSelectionObserver* observer_ = nullptr;

  // Time of the session start (e.g. when the controller was enabled).
  base::TimeTicks session_start_;

  // Time of the previous gesture end, valid after the first gesture
  // within the session is complete.
  base::TimeTicks previous_gesture_end_;

  // Gesture counter withing a session.
  int gesture_counter_ = 0;

  // Recognized gesture counter withing a session.
  int recognized_gesture_counter_ = 0;

  // Not null while waiting for the next event to continue an interrupted
  // stroke.
  std::unique_ptr<base::OneShotTimer> interrupted_stroke_timer_;

  DISALLOW_COPY_AND_ASSIGN(HighlighterController);
};

}  // namespace ash

#endif  // ASH_HIGHLIGHTER_HIGHLIGHTER_CONTROLLER_H_