Add MD Ink Drop Layers to InkDropHost only when a ripple/hover is active.

ui/views/animation/ink_drop_animation_controller_impl.h

 // Copyright 2015 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_VIEWS_ANIMATION_INK_DROP_ANIMATION_CONTROLLER_IMPL_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_ANIMATION_CONTROLLER_IMPL_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/views/animation/ink_drop_animation_controller.h"
 #include "ui/views/animation/ink_drop_animation_observer.h"
+#include "ui/views/animation/ink_drop_hover_observer.h"
 #include "ui/views/views_export.h"
 
 namespace base {
 class Timer;
 }  // namespace base
 
 namespace views {
 namespace test {
 class InkDropAnimationControllerImplTestApi;
 }  // namespace test
 
 class InkDropAnimation;
 class InkDropHost;
 class InkDropHover;
 class InkDropAnimationControllerFactoryTest;
 
 // A functional implementation of an InkDropAnimationController.
 class VIEWS_EXPORT InkDropAnimationControllerImpl
     : public InkDropAnimationController,
-      public InkDropAnimationObserver {
+      public InkDropAnimationObserver,
+      public InkDropHoverObserver {
  public:
   // Constructs an ink drop controller that will attach the ink drop to the
   // given |ink_drop_host|.
   explicit InkDropAnimationControllerImpl(InkDropHost* ink_drop_host);
   ~InkDropAnimationControllerImpl() override;
 
   // InkDropAnimationController:
   InkDropState GetTargetInkDropState() const override;
   bool IsVisible() const override;
   void AnimateToState(InkDropState ink_drop_state) override;
@@ skipping 14 matching lines @@
   // Destroys the current |ink_drop_animation_|.
   void DestroyInkDropAnimation();
 
   // Creates a new InkDropHover and sets it to |hover_|. If |hover_| wasn't null
   // then it will be destroyed using DestroyInkDropHover().
   void CreateInkDropHover();
 
   // Destroys the current |hover_|.
   void DestroyInkDropHover();
 
+  // Adds the |root_layer_| to the |ink_drop_host_| if it hasn't already been
+  // added.
+  void AddRootLayerToHostIfNeeded();
+
+  // Removes the |root_layer_| from the |ink_drop_host_| if no ink drop ripple
+  // or hover is active.
+  void RemoveRootLayerFromHostIfNeeded();
+
   // Returns true if the hover animation is in the process of fading in or
   // is visible.
   bool IsHoverFadingInOrVisible() const;
 
   // views::InkDropAnimationObserver:
   void AnimationStarted(InkDropState ink_drop_state) override;
   void AnimationEnded(InkDropState ink_drop_state,
                       InkDropAnimationEndedReason reason) override;
 
+  // views::InkDropHoverObserver:
+  void AnimationStarted(InkDropHover::AnimationType animation_type) override;
+  void AnimationEnded(InkDropHover::AnimationType animation_type,
+                      InkDropAnimationEndedReason reason) override;
+
   // Enables or disables the hover state based on |is_hovered| and if an
   // animation is triggered it will be scheduled to have the given
   // |animation_duration|. If |explode| is true the hover will expand as it
   // fades out. |explode| is ignored when |is_hovered| is true.
   void SetHoveredInternal(bool is_hovered,
                           base::TimeDelta animation_duration,
                           bool explode);
 
   // Starts the |hover_after_animation_timer_| timer. This will stop the current
   // |hover_after_animation_timer_| instance if it exists.
   void StartHoverAfterAnimationTimer();
 
   // Stops and destroys the current |hover_after_animation_timer_| instance.
   void StopHoverAfterAnimationTimer();
 
   // Callback for when the |hover_after_animation_timer_| fires.
   void HoverAfterAnimationTimerFired();
 
   // The host of the ink drop. Used to poll for information such as whether the
   // hover should be shown or not.
   InkDropHost* ink_drop_host_;
 
   // The root Layer that parents the InkDropAnimation layers and the
   // InkDropHover layers. The |root_layer_| is the one that is added and removed
   // from the InkDropHost.
   std::unique_ptr<ui::Layer> root_layer_;
 
+  // True when the |root_layer_| has been added to the |ink_drop_host_|.
+  bool root_layer_added_to_host_;
+
   // The current InkDropHover. Lazily created using CreateInkDropHover();
   std::unique_ptr<InkDropHover> hover_;
 
   // Tracks the logical hovered state of |this| as manipulated by the public
   // SetHovered() function.
   bool is_hovered_;
 
   // The current InkDropAnimation. Created on demand using
   // CreateInkDropAnimation().
   std::unique_ptr<InkDropAnimation> ink_drop_animation_;
 
   // The timer used to delay the hover fade in after an ink drop animation.
   std::unique_ptr<base::Timer> hover_after_animation_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(InkDropAnimationControllerImpl);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_ANIMATION_CONTROLLER_IMPL_H_