Revert of Replaced BackgroundAnimator with ShelfBackgroundAnimator.

ash/common/shelf/shelf_background_animator.h

-// Copyright 2016 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_SHELF_BACKGROUND_ANIMATOR_H_
-#define ASH_COMMON_SHELF_SHELF_BACKGROUND_ANIMATOR_H_
-
-#include <vector>
-
-#include "ash/ash_export.h"
-#include "ash/common/shelf/shelf_types.h"
-#include "ash/common/shelf/wm_shelf_observer.h"
-#include "ash/common/wm/background_animator.h"
-#include "base/macros.h"
-#include "base/observer_list.h"
-
-namespace ash {
-
-class ShelfBackgroundAnimatorObserver;
-class ShelfBackgroundAnimatorTestApi;
-class WmShelf;
-
-// Central controller for the Shelf and Dock opacity animations.
-//
-// The ShelfBackgroundAnimator is capable of observing a WmShelf instance for
-// background type changes or clients can call PaintBackground() directly.
-//
-// The Shelf uses 3 surfaces for the animations:
-//
-//  Non-Material Design:
-//    1. Shelf button backgrounds
-//    2. Opaque overlay for the SHELF_BACKGROUND_MAXIMIZED state.
-//    3. Shelf and Dock assets for the SHELF_BACKGROUND_OVERLAP state.
-//  Material Design:
-//    1. Shelf button backgrounds
-//    2. Opaque overlay for the SHELF_BACKGROUND_OVERLAP and
-//       SHELF_BACKGROUND_MAXIMIZED states.
-class ASH_EXPORT ShelfBackgroundAnimator : public WmShelfObserver,
-                                           public BackgroundAnimatorDelegate {
- public:
-  // Initializes this with the given |background_type|. This will observe the
-  // |wm_shelf| for background type changes if |wm_shelf| is not null.
-  ShelfBackgroundAnimator(ShelfBackgroundType background_type,
-                          WmShelf* wm_shelf);
-  ~ShelfBackgroundAnimator() override;
-
-  ShelfBackgroundType target_background_type() const {
-    return target_background_type_;
-  }
-
-  // |observer| will be notified of the current values when being added.
-  void AddObserver(ShelfBackgroundAnimatorObserver* observer);
-  void RemoveObserver(ShelfBackgroundAnimatorObserver* observer);
-
-  // Conditionally animates the background to the specified |background_type|
-  // and notifies observers of the new background parameters (e.g. alpha).
-  // If |change_type| is BACKGROUND_CHANGE_IMMEDIATE then the
-  // observers will only receive one notification with the final background
-  // state, otherwise the observers will be notified multiple times in order to
-  // animate the changes to the backgrounds.
-  //
-  // NOTE: If a second request to paint the same |background_type| using the
-  // BACKGROUND_CHANGE_ANIMATE change type is received it will be ignored and
-  // observers will NOT be notified.
-  void PaintBackground(ShelfBackgroundType background_type,
-                       BackgroundAnimatorChangeType change_type);
-
- protected:
-  // WmShelfObserver:
-  void OnBackgroundTypeChanged(
-      ShelfBackgroundType background_type,
-      BackgroundAnimatorChangeType change_type) override;
-
-  // BackgroundAnimatorDelegate:
-  void UpdateBackground(BackgroundAnimator* animator, int alpha) override;
-  void BackgroundAnimationEnded(BackgroundAnimator* animator) override;
-
- private:
-  friend class ShelfBackgroundAnimatorTestApi;
-
-  // Helper function used by PaintBackground() to animate the background.
-  void AnimateBackground(ShelfBackgroundType background_type,
-                         BackgroundAnimatorChangeType change_type);
-
-  // Creates new BackgroundAnimators configured with the correct durations and
-  // initial/target alpha values. If any BackgroundAnimators are currently
-  // animating they will be stopped.
-  void CreateAnimators(ShelfBackgroundType background_type,
-                       BackgroundAnimatorChangeType change_type);
-
-  // Stops all existing animators owned by this.
-  void StopAnimators();
-
-  // Called when an alpha value changes and observers need to be notified.
-  void OnAlphaChanged(BackgroundAnimator* animator, int alpha);
-
-  // The background type that this is animating towards or has reached.
-  ShelfBackgroundType target_background_type_ = SHELF_BACKGROUND_DEFAULT;
-
-  // The last background type this is animating away from.
-  ShelfBackgroundType previous_background_type_ = SHELF_BACKGROUND_MAXIMIZED;
-
-  // Animates the solid color background of the Shelf.
-  // TODO(bruthig): Replace all BackgroundAnimators with a single
-  // gfx::SlideAnimation.
-  std::unique_ptr<BackgroundAnimator> opaque_background_animator_;
-
-  // Animates the asset/image based background of the Shelf.
-  // TODO(bruthig): Remove when non-md is no longer needed (crbug.com/614453).
-  std::unique_ptr<BackgroundAnimator> asset_background_animator_;
-
-  // Animates the backgrounds of Shelf child Views.
-  std::unique_ptr<BackgroundAnimator> item_background_animator_;
-
-  base::ObserverList<ShelfBackgroundAnimatorObserver> observers_;
-
-  // True if the existing BackgroundAnimators can be re-used to animate to the
-  // |previous_background_type_|. This allows for pre-empted animations to take
-  // the same amount of time to reverse to the |previous_background_type_|.
-  bool can_reuse_animators_ = false;
-
-  // Tracks how many animators completed successfully since the last
-  // CreateAnimators() call. Used to properly set |can_reuse_animators_|.
-  int successful_animator_count_ = 0;
-
-  // The shelf to observe for changes to the shelf background type, can be null.
-  WmShelf* wm_shelf_;
-
-  DISALLOW_COPY_AND_ASSIGN(ShelfBackgroundAnimator);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SHELF_SHELF_BACKGROUND_ANIMATOR_H_