ash/shelf/back_button.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_SHELF_BACK_BUTTON_H_
#define ASH_SHELF_BACK_BUTTON_H_

#include <memory>

#include "ash/ash_export.h"
#include "ash/shelf/shelf_control_button.h"
#include "base/macros.h"

namespace ash {

// The back button shown on the shelf when tablet mode is enabled. Its opacity
// and visiblity are handled by its parent, ShelfView, to ensure the fade
// in/out of the icon matches the movement of ShelfView's items.
class ASH_EXPORT BackButton : public ShelfControlButton {
 public:
  static const char kViewClassName[];

  explicit BackButton(ShelfView* shelf_view);
  ~BackButton() override;

 protected:
  // views::Button:
  void OnGestureEvent(ui::GestureEvent* event) override;
  void OnMouseReleased(const ui::MouseEvent& event) override;
  void PaintButtonContents(gfx::Canvas* canvas) override;
  const char* GetClassName() const override;

 private:
  // Generate and send a VKEY_BROWSER_BACK key event sequence when the back
  // button is pressed. This should on be called on a tap down or mouse release
  // event, and will only send a key down event since that is the one which
  // triggers the back event.
  void GenerateAndSendBackEvent();

  DISALLOW_COPY_AND_ASSIGN(BackButton);
};

}  // namespace ash

#endif  // ASH_SHELF_BACK_BUTTON_H_