ash/common/shelf/overflow_button.h

// Copyright 2013 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_COMMON_SHELF_OVERFLOW_BUTTON_H_
#define ASH_COMMON_SHELF_OVERFLOW_BUTTON_H_

#include "base/macros.h"
#include "ui/gfx/image/image_skia.h"
#include "ui/views/controls/button/custom_button.h"

namespace ash {
class ShelfView;
class WmShelf;

// Shelf overflow chevron button.
class OverflowButton : public views::CustomButton {
 public:
  // |shelf_view| is the view containing this button.
  OverflowButton(ShelfView* shelf_view, WmShelf* wm_shelf);
  ~OverflowButton() override;

  void OnShelfAlignmentChanged();
  void OnOverflowBubbleShown();
  void OnOverflowBubbleHidden();

  // Sets alpha value of the background and schedules a paint.
  void SetBackgroundAlpha(int alpha);

 private:
  // views::CustomButton:
  void OnPaint(gfx::Canvas* canvas) override;
  std::unique_ptr<views::InkDrop> CreateInkDrop() override;
  std::unique_ptr<views::InkDropRipple> CreateInkDropRipple() const override;
  bool ShouldEnterPushedState(const ui::Event& event) override;
  void NotifyClick(const ui::Event& event) override;

  // Helper functions to paint the background and foreground of the button
  // at |bounds|.
  void PaintBackground(gfx::Canvas* canvas, const gfx::Rect& bounds);
  void PaintForeground(gfx::Canvas* canvas, const gfx::Rect& bounds);

  // Returns the id of the asset to use for the button backgound based on the
  // current shelf state.
  // TODO(tdanderson): Remove this once the material design shelf is enabled
  // by default. See crbug.com/614453.
  int NonMaterialBackgroundImageId() const;

  // Calculates the bounds of the overflow button based on the shelf alignment.
  gfx::Rect CalculateButtonBounds() const;

  // Used for bottom shelf alignment. |bottom_image_| points to
  // |bottom_image_md_| for material design, otherwise it is points to a
  // resource owned by the ResourceBundle.
  // TODO(tdanderson): Remove the non-md code once the material design shelf is
  // enabled by default. See crbug.com/614453.
  const gfx::ImageSkia* bottom_image_;
  gfx::ImageSkia bottom_image_md_;

  // Cached rotations of |bottom_image_| used for left and right shelf
  // alignments.
  gfx::ImageSkia left_image_;
  gfx::ImageSkia right_image_;

  ShelfView* shelf_view_;
  WmShelf* wm_shelf_;

  // Alpha value used to paint the background.
  int background_alpha_;

  DISALLOW_COPY_AND_ASSIGN(OverflowButton);
};

}  // namespace ash

#endif  // ASH_COMMON_SHELF_OVERFLOW_BUTTON_H_