[ash-md] Added different highlighting modes to the InkDropImpl.

ui/views/animation/ink_drop_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_IMPL_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_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.h"
 #include "ui/views/animation/ink_drop_highlight_observer.h"
 #include "ui/views/animation/ink_drop_ripple_observer.h"
 #include "ui/views/views_export.h"
 
-namespace base {
-class Timer;
-}  // namespace base
-
 namespace views {
 namespace test {
 class InkDropImplTestApi;
 }  // namespace test
 
 class InkDropRipple;
 class InkDropHost;
 class InkDropHighlight;
 class InkDropFactoryTest;
 
 // A functional implementation of an InkDrop.
 class VIEWS_EXPORT InkDropImpl : public InkDrop,
                                  public InkDropRippleObserver,
                                  public InkDropHighlightObserver {
  public:
+  // The different auto highlight behaviors.
+  enum class AutoHighlightMode {
+    // No auto-highlighting is done. The highlight will only be shown/hidden as
+    // per the hover/focus settings.
+    NONE,
+    // The highlight will be hidden when a ripple becomes visible. After the
+    // ripple is hidden the highlight will be made visible again if the
+    // hover/focus settings deem it should be.
+    HIDE_ON_RIPPLE,
+    // The highlight is made visible when the ripple becomes visible. After the
+    // ripple is hidden the highlight will be hidden again if the hover/focus
+    // settings deem it should be.
+    SHOW_ON_RIPPLE,
+  };
+
   // Constructs an ink drop that will attach the ink drop to the given
   // |ink_drop_host|.
+  //
+  // By default the highlight will be made visible while |this| is hovered but
+  // not focused and the NONE AutoHighlightMode will be used.
   explicit InkDropImpl(InkDropHost* ink_drop_host);
   ~InkDropImpl() override;
 
+  void SetShowHighlightOnHover(bool show_highlight_on_hover);
+
+  void SetShowHighlightOnFocus(bool show_highlight_on_focus);
+
+  // Auto highlighting is a mechanism to show/hide the highlight based on the
+  // visibility of the ripple. See the documentation of the AutoHighlightMode
+  // for more info on the different modes.
+  //
+  // This method is intended as a configuration option to be used after
+  // construction. Behavior is undefined if |this| has already handled any
+  // InkDrop inherited functions.
+  void SetAutoHighlightMode(AutoHighlightMode auto_highlight_mode);
+
   // InkDrop:
   InkDropState GetTargetInkDropState() const override;
   void AnimateToState(InkDropState ink_drop_state) override;
   void SnapToActivated() override;
   void SetHovered(bool is_hovered) override;
   void SetFocused(bool is_focused) override;
 
  private:
+  friend class InkDropImplTest;
   friend class test::InkDropImplTestApi;
 
+  // Forward declaration for use by the HighlightState class definition.
+  class HighlightStateFactory;
+
+  // Base HighlightState defines functions to handle all state changes that may
+  // affect the highlight state.
+  //
+  // Subclasses are expected to handle state changes and transition the
+  // InkDropImpl::highlight_state_ to new states as desired via the
+  // InkDropImpl::SetHighlightState() method.
+  //
+  // New states should be created via the HighlightStateFactory and not
+  // directly. This makes it possible for highlighting strategies to extend the
+  // behavior of existing states and re-use existing state behavior.
+  //
+  // Subclasses are also expected to trigger the appropriate highlight
+  // animations (e.g. fade in/out) via GetInkDrop()->SetHighlight(). Typically
+  // this is done in the Enter()/Exit() functions. Triggering animations
+  // anywhere else may be a sign that a new state should exist.
+  class HighlightState {
+   public:
+    virtual ~HighlightState() {}
+
+    // Called when |this| becomes the current state. Allows subclasses to
+    // perform any work that should not be done in the constructor. It is ok for
+    // subclass implementations to trigger state changes from within Enter().
+    virtual void Enter() {}
+
+    // Called just before |this| is removed as the current state. Allows
+    // subclasses to perform any work that should not be done in the destructor
+    // but is required before exiting |this| state (e.g. releasing resources).
+    //
+    // Subclass implementations should NOT do any work that may trigger another
+    // state change since a state change is already in progress.
+    virtual void Exit() {}
+
+    // Input state change handlers.
+
+    // Called when the value of InkDropImpl::show_highlight_on_hover_ changes.
+    virtual void ShowOnHoverChanged() = 0;
+
+    // Called when the value of InkDropImpl::is_hovered_ changes.
+    virtual void OnHoverChanged() = 0;
+
+    // Called when the value of InkDropImpl::show_highlight_on_focus_ changes.
+    virtual void ShowOnFocusChanged() = 0;
+
+    // Called when the value of InkDropImpl::is_focused_ changes.
+    virtual void OnFocusChanged() = 0;
+
+    // Called when an ink drop ripple animation is started.
+    virtual void AnimationStarted(InkDropState ink_drop_state) = 0;
+
+    // Called when an ink drop ripple animation has ended.
+    virtual void AnimationEnded(InkDropState ink_drop_state,
+                                InkDropAnimationEndedReason reason) = 0;
+
+   protected:
+    explicit HighlightState(HighlightStateFactory* state_factory)
+        : state_factory_(state_factory) {}
+
+    HighlightStateFactory* state_factory() { return state_factory_; }
+
+    // Returns the ink drop that has |this| as the current state.
+    InkDropImpl* GetInkDrop();
+
+   private:
+    // Used by |this| to create the new states to transition to.
+    HighlightStateFactory* state_factory_;
+
+    DISALLOW_COPY_AND_ASSIGN(HighlightState);
+  };
+
+  // Creates the different HighlightStates instances. A factory is used to make
+  // it easier for states to extend and re-use existing state logic.
+  class HighlightStateFactory {
+   public:
+    HighlightStateFactory(AutoHighlightMode highlight_mode,
+                          InkDropImpl* ink_drop);
+
+    // Returns the initial state.
+    std::unique_ptr<HighlightState> CreateStartState();
+
+    std::unique_ptr<HighlightState> CreateHiddenState(
+        base::TimeDelta animation_duration,
+        bool explode);
+
+    std::unique_ptr<HighlightState> CreateVisibleState(
+        base::TimeDelta animation_duration,
+        bool explode);
+
+    InkDropImpl* ink_drop() { return ink_drop_; }
+
+   private:
+    // Defines which concrete state types to create.
+    AutoHighlightMode highlight_mode_;
+
+    // The ink drop to invoke highlight changes on.
+    InkDropImpl* ink_drop_;
+
+    DISALLOW_COPY_AND_ASSIGN(HighlightStateFactory);
+  };
+
+  // AutoHighlightMode::NONE
+  class NoAutoHighlightHiddenState;
+  class NoAutoHighlightVisibleState;
+
+  // AutoHighlightMode::HIDE_ON_RIPPLE
+  class HideHighlightOnRippleHiddenState;
+  class HideHighlightOnRippleVisibleState;
+
+  // AutoHighlightMode::SHOW_ON_RIPPLE states
+  class ShowHighlightOnRippleHiddenState;
+  class ShowHighlightOnRippleVisibleState;
+
   // Destroys |ink_drop_ripple_| if it's targeted to the HIDDEN state.
   void DestroyHiddenTargetedAnimations();
 
   // Creates a new InkDropRipple and sets it to |ink_drop_ripple_|. If
   // |ink_drop_ripple_| wasn't null then it will be destroyed using
   // DestroyInkDropRipple().
   void CreateInkDropRipple();
 
   // Destroys the current |ink_drop_ripple_|.
   void DestroyInkDropRipple();
@@ skipping 30 matching lines @@
                       InkDropAnimationEndedReason reason) override;
 
   // Enables or disables the highlight state based on |should_highlight| and if
   // an animation is triggered it will be scheduled to have the given
   // |animation_duration|. If |explode| is true the highlight will expand as it
   // fades out. |explode| is ignored when |should_higlight| is true.
   void SetHighlight(bool should_highlight,
                     base::TimeDelta animation_duration,
                     bool explode);
 
-  // Returns true if this ink drop is hovered or focused.
+  // Returns true if |this| the highlight should be visible based on the
+  // hover/focus status.
   bool ShouldHighlight() const;
 
-  // Starts the |highlight_after_ripple_timer_| timer. This will stop the
-  // current
-  // |highlight_after_ripple_timer_| instance if it exists.
-  void StartHighlightAfterRippleTimer();
+  // Returns true if |this| the hilight should be visible based on the focus
+  // status.
+  bool ShouldHighlightBasedOnFocus() const;
 
-  // Callback for when the |highlight_after_ripple_timer_| fires.
-  void HighlightAfterRippleTimerFired();
+  // Updates the current |highlight_state_|. Calls Exit()/Enter() on the
+  // previous/new state to notify them of the transition.
+  //
+  // Uses ExitHighlightState() to exit the current state.
+  void SetHighlightState(std::unique_ptr<HighlightState> highlight_state);
 
-  // The host of the ink drop. Used to poll for information such as whether the
-  // highlight should be shown or not.
+  // Exits the current |highlight_state_| and sets it to null. Ensures state
+  // transitions are not triggered during HighlightStatae::Exit() calls on debug
+  // builds.
+  void ExitHighlightState();
+
+  // The host of the ink drop. Used to create the ripples and highlights, and to
+  // add/remove the root layer to/from it.
   InkDropHost* ink_drop_host_;
 
   // The root Layer that parents the InkDropRipple layers and the
   // InkDropHighlight layers. The |root_layer_| is the one that is added and
-  // removed from the InkDropHost.
+  // removed from the |ink_drop_host_|.
   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 InkDropHighlight. Lazily created using
   // CreateInkDropHighlight();
   std::unique_ptr<InkDropHighlight> highlight_;
 
+  // True denotes the highlight should be shown when |this| is hovered.
+  bool show_highlight_on_hover_;
+
+  // True denotes the highlight should be shown when |this| is focused.
+  bool show_highlight_on_focus_;
+
   // Tracks the logical hovered state of |this| as manipulated by the public
   // SetHovered() function.
   bool is_hovered_;
 
   // Tracks the logical focused state of |this| as manipulated by the public
   // SetFocused() function.
   bool is_focused_;
 
   // The current InkDropRipple. Created on demand using CreateInkDropRipple().
   std::unique_ptr<InkDropRipple> ink_drop_ripple_;
 
-  // The timer used to delay the highlight fade in after an ink drop ripple
-  // animation.
-  std::unique_ptr<base::Timer> highlight_after_ripple_timer_;
+  // Used by |this| to initialize the starting |highlight_state_| and by the
+  // current |highlight_state_| to create the next state.
+  std::unique_ptr<HighlightStateFactory> highlight_state_factory_;
+
+  // The current state object that handles all inputs that affect the visibility
+  // of the |highlight_|.
+  std::unique_ptr<HighlightState> highlight_state_;
+
+  // Used to ensure highlight state transitions are not triggered when exiting
+  // the current state.
+  bool exiting_highlight_state_;
 
   DISALLOW_COPY_AND_ASSIGN(InkDropImpl);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_IMPL_H_