Make the material design ripple effect more visible on a quick action (single click or single tap)

ui/views/animation/ink_drop_animation.cc

 // 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.
 
 #include "ui/views/animation/ink_drop_animation.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/compositor/callback_layer_animation_observer.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/geometry/point3_f.h"
 #include "ui/gfx/geometry/point_conversions.h"
+#include "ui/gfx/geometry/point_f.h"
+#include "ui/gfx/geometry/vector3d_f.h"
 #include "ui/gfx/transform_util.h"
 #include "ui/views/animation/ink_drop_animation_observer.h"
 #include "ui/views/animation/ink_drop_painted_layer_delegates.h"
 #include "ui/views/view.h"
 
 namespace {
 
 // The minimum scale factor to use when scaling rectangle layers. Smaller values
 // were causing visual anomalies.
 const float kMinimumRectScale = 0.0001f;
 
 // The minimum scale factor to use when scaling circle layers. Smaller values
 // were causing visual anomalies.
 const float kMinimumCircleScale = 0.001f;
 
 // The ink drop color.
 const SkColor kInkDropColor = SK_ColorBLACK;
 
 // The opacity of the ink drop when it is visible.
-const float kVisibleOpacity = 0.14f;
+const float kVisibleOpacity = 0.11f;
 
 // The opacity of the ink drop when it is not visible.
 const float kHiddenOpacity = 0.0f;
 
-// Durations for the different InkDropState animations in milliseconds.
-const int kHiddenStateAnimationDurationMs = 1;
-const int kActionPendingStateAnimationDurationMs = 500;
-const int kQuickActionStateAnimationDurationMs = 250;
-const int kSlowActionPendingStateAnimationDurationMs = 500;
-const int kSlowActionStateAnimationDurationMs = 250;
-const int kActivatedStateAnimationDurationMs = 125;
-const int kDeactivatedStateAnimationDurationMs = 250;
+// All the sub animations that are used to animate each of the InkDropStates.
+// These are used to get time durations with
+// GetAnimationDuration(InkDropSubAnimations). Note that in general a sub
+// animation defines the duration for either a transformation animation or an
+// opacity animation but there are some exceptions where an entire InkDropState
+// animation consists of only 1 sub animation and it defines the duration for
+// both the transformation and opacity animations.
+enum InkDropSubAnimations {
+  // HIDDEN sub animations.
+
+  // The HIDDEN sub animation that is fading out to a hidden opacity.
+  HIDDEN_FADE_OUT,
+
+  // The HIDDEN sub animation that transforms the shape to a |small_size_|
+  // circle.
+  HIDDEN_TRANSFORM,
+
+  // ACTION_PENDING sub animations.
+
+  // The ACTION_PENDING sub animation that fades in to the visible opacity.
+  ACTION_PENDING_FADE_IN,
+
+  // The ACTION_PENDING sub animation that transforms the shape to a
+  // |large_size_| circle.
+  ACTION_PENDING_TRANSFORM,
+
+  // QUICK_ACTION sub animations.
+
+  // The QUICK_ACTION sub animation that is fading out to a hidden opacity.
+  QUICK_ACTION_FADE_OUT,
+
+  // The QUICK_ACTION sub animation that transforms the shape to a |large_size_|
+  // circle.
+  QUICK_ACTION_TRANSFORM,
+
+  // SLOW_ACTION_PENDING sub animations.
+
+  // The SLOW_ACTION_PENDING animation has only one sub animation which animates
+  // to a |small_size_| rounded rectangle at visible opacity.
+  SLOW_ACTION_PENDING,
+
+  // SLOW_ACTION sub animations.
+
+  // The SLOW_ACTION sub animation that is fading out to a hidden opacity.
+  SLOW_ACTION_FADE_OUT,
+
+  // The SLOW_ACTION sub animation that transforms the shape to a |large_size_|
+  // rounded rectangle.
+  SLOW_ACTION_TRANSFORM,
+
+  // ACTIVATED sub animations.
+
+  // The ACTIVATED sub animation that transforms the shape to a |large_size_|
+  // circle. This is used when the ink drop is in a HIDDEN state prior to
+  // animating to the ACTIVATED state.
+  ACTIVATED_CIRCLE_TRANSFORM,
+
+  // The ACTIVATED sub animation that transforms the shape to a |small_size_|
+  // rounded rectangle.
+  ACTIVATED_RECT_TRANSFORM,
+
+  // DEACTIVATED sub animations.
+
+  // The DEACTIVATED sub animation that is fading out to a hidden opacity.
+  DEACTIVATED_FADE_OUT,
+
+  // The DEACTIVATED sub animation that transforms the shape to a |large_size_|
+  // rounded rectangle.
+  DEACTIVATED_TRANSFORM,
+};
+
+// Duration constants for InkDropStateSubAnimations. See the
+// InkDropStateSubAnimations enum documentation for more info.
+const int kHiddenFadeOutDurationMs = 150;
+const int kHiddenTransformDurationMs = 200;
+const int kActionPendingFadeInDurationMs = 0;
+const int kActionPendingTransformDurationMs = 160;
+const int kQuickActionFadeOutDurationMs = 150;
+const int kQuickActionTransformDurationMs = 160;
+const int kSlowActionPendingDurationMs = 200;
+const int kSlowActionFadeOutDurationMs = 150;
+const int kSlowActionTransformDurationMs = 200;
+const int kActivatedCircleTransformDurationMs = 200;
+const int kActivatedRectTransformDurationMs = 160;
+const int kDeactivatedFadeOutDurationMs = 150;
+const int kDeactivatedTransformDurationMs = 200;
+
+// The scale factor used to burst the QUICK_ACTION bubble as it fades out.
+const float kQuickActionBurstScale = 1.3f;
 
 // A multiplicative factor used to slow down InkDropState animations.
 const int kSlowAnimationDurationFactor = 3;
 
 // Checks CommandLine switches to determine if the visual feedback should have
 // a fast animations speed.
 bool UseFastAnimations() {
   static bool fast =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           (::switches::kMaterialDesignInkDropAnimationSpeed)) !=
       ::switches::kMaterialDesignInkDropAnimationSpeedSlow;
   return fast;
 }
 
-// Returns the InkDropState animation duration for the given |state|.
-base::TimeDelta GetAnimationDuration(views::InkDropState state) {
+// Returns the InkDropState sub animation duration for the given |state|.
+base::TimeDelta GetAnimationDuration(InkDropSubAnimations state) {
   int duration = 0;
   switch (state) {
-    case views::InkDropState::HIDDEN:
-      duration = kHiddenStateAnimationDurationMs;
+    case HIDDEN_FADE_OUT:
+      duration = kHiddenFadeOutDurationMs;
       break;
-    case views::InkDropState::ACTION_PENDING:
-      duration = kActionPendingStateAnimationDurationMs;
+    case HIDDEN_TRANSFORM:
+      duration = kHiddenTransformDurationMs;
       break;
-    case views::InkDropState::QUICK_ACTION:
-      duration = kQuickActionStateAnimationDurationMs;
+    case ACTION_PENDING_FADE_IN:
+      duration = kActionPendingFadeInDurationMs;
       break;
-    case views::InkDropState::SLOW_ACTION_PENDING:
-      duration = kSlowActionPendingStateAnimationDurationMs;
+    case ACTION_PENDING_TRANSFORM:
+      duration = kActionPendingTransformDurationMs;
       break;
-    case views::InkDropState::SLOW_ACTION:
-      duration = kSlowActionStateAnimationDurationMs;
+    case QUICK_ACTION_FADE_OUT:
+      duration = kQuickActionFadeOutDurationMs;
       break;
-    case views::InkDropState::ACTIVATED:
-      duration = kActivatedStateAnimationDurationMs;
+    case QUICK_ACTION_TRANSFORM:
+      duration = kQuickActionTransformDurationMs;
       break;
-    case views::InkDropState::DEACTIVATED:
-      duration = kDeactivatedStateAnimationDurationMs;
+    case SLOW_ACTION_PENDING:
+      duration = kSlowActionPendingDurationMs;
+      break;
+    case SLOW_ACTION_TRANSFORM:
+      duration = kSlowActionTransformDurationMs;
+      break;
+    case SLOW_ACTION_FADE_OUT:
+      duration = kSlowActionFadeOutDurationMs;
+      break;
+    case ACTIVATED_CIRCLE_TRANSFORM:
+      duration = kActivatedCircleTransformDurationMs;
+      break;
+    case ACTIVATED_RECT_TRANSFORM:
+      duration = kActivatedRectTransformDurationMs;
+      break;
+    case DEACTIVATED_FADE_OUT:
+      duration = kDeactivatedFadeOutDurationMs;
+      break;
+    case DEACTIVATED_TRANSFORM:
+      duration = kDeactivatedTransformDurationMs;

[varkha, 2016/01/28 20:50:45]

Maybe refactor this into a lookup table in future if |state| can be easily made
into an index into a table.

[bruthig, 2016/01/28 22:38:00]

Done.

       break;
   }
-
   return base::TimeDelta::FromMilliseconds(
       (UseFastAnimations() ? 1 : kSlowAnimationDurationFactor) * duration);
 }
 
 // Calculates a Transform for a circle layer. The transform will be set up to
 // translate the |drawn_center_point| to the origin, scale, and then translate
 // to the target point defined by |target_center_x| and |target_center_y|.
 gfx::Transform CalculateCircleTransform(const gfx::Point& drawn_center_point,
                                         float scale,
                                         float target_center_x,
@@ skipping 73 matching lines @@
   AnimateToStateInternal(ink_drop_state, animation_observer);
   animation_observer->SetActive();
 }
 
 void InkDropAnimation::SetCenterPoint(const gfx::Point& center_point) {
   gfx::Transform transform;
   transform.Translate(center_point.x(), center_point.y());
   root_layer_->SetTransform(transform);
 }
 
+void InkDropAnimation::HideImmediately() {
+  AbortAllAnimations();
+  SetStateToHidden();
+  ink_drop_state_ = InkDropState::HIDDEN;
+}
+
 std::string InkDropAnimation::ToLayerName(PaintedShape painted_shape) {
   switch (painted_shape) {
     case TOP_LEFT_CIRCLE:
       return "TOP_LEFT_CIRCLE";
     case TOP_RIGHT_CIRCLE:
       return "TOP_RIGHT_CIRCLE";
     case BOTTOM_RIGHT_CIRCLE:
       return "BOTTOM_RIGHT_CIRCLE";
     case BOTTOM_LEFT_CIRCLE:
       return "BOTTOM_LEFT_CIRCLE";
     case HORIZONTAL_RECT:
       return "HORIZONTAL_RECT";
     case VERTICAL_RECT:
       return "VERTICAL_RECT";
     case PAINTED_SHAPE_COUNT:
       NOTREACHED() << "The PAINTED_SHAPE_COUNT value should never be used.";
       return "PAINTED_SHAPE_COUNT";
   }
   return "UNKNOWN";
 }
 
 void InkDropAnimation::AnimateToStateInternal(
     InkDropState ink_drop_state,
     ui::LayerAnimationObserver* animation_observer) {
+  InkDropState previous_ink_drop_state = ink_drop_state_;
   ink_drop_state_ = ink_drop_state;
 
-  if (ink_drop_state_ == InkDropState::HIDDEN) {
-    // Animating to the HIDDEN state doesn't actually use any
-    // LayerAnimationSequences so we need to explicitly abort any running ones
-    // so that observers receive an InkDropAnimationEnded() event for the
-    // running animation prior to receiving an InkDropAnimationStarted() event
-    // for the HIDDEN 'animation'.
-    AbortAllAnimations();
-    root_layer_->SetVisible(false);
-    SetStateToHidden();
-    return;
-  }
-
   InkDropTransforms transforms;
   root_layer_->SetVisible(true);
 
   switch (ink_drop_state_) {
     case InkDropState::HIDDEN:
-      // This case is handled above in a short circuit return.
+      if (GetCurrentOpacity() == kHiddenOpacity) {
+        AbortAllAnimations();
+        break;
+      } else {
+        AnimateToOpacity(kHiddenOpacity, GetAnimationDuration(HIDDEN_FADE_OUT),
+                         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                         gfx::Tween::EASE_IN_OUT, animation_observer);
+        CalculateCircleTransforms(small_size_, &transforms);
+        AnimateToTransforms(
+            transforms, GetAnimationDuration(HIDDEN_TRANSFORM),
+            ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+            gfx::Tween::EASE_IN_OUT, animation_observer);
+      }
       break;
     case InkDropState::ACTION_PENDING:
+      DCHECK(previous_ink_drop_state == InkDropState::HIDDEN);
+      AnimateToOpacity(kVisibleOpacity,
+                       GetAnimationDuration(ACTION_PENDING_FADE_IN),
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN, animation_observer);
+      AnimateToOpacity(kVisibleOpacity,
+                       GetAnimationDuration(ACTION_PENDING_TRANSFORM),
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN, animation_observer);
       CalculateCircleTransforms(large_size_, &transforms);
-      AnimateToTransforms(transforms, kVisibleOpacity,
-                          GetAnimationDuration(InkDropState::ACTION_PENDING),
+      AnimateToTransforms(transforms,
+                          GetAnimationDuration(ACTION_PENDING_TRANSFORM),
                           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                          animation_observer);
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
       break;
-    case InkDropState::QUICK_ACTION:
-      CalculateCircleTransforms(large_size_, &transforms);
-      AnimateToTransforms(transforms, kHiddenOpacity,
-                          GetAnimationDuration(InkDropState::QUICK_ACTION),
+    case InkDropState::QUICK_ACTION: {
+      DCHECK(previous_ink_drop_state == InkDropState::HIDDEN ||
+             previous_ink_drop_state == InkDropState::ACTION_PENDING);
+      AnimateToOpacity(kHiddenOpacity,
+                       GetAnimationDuration(QUICK_ACTION_FADE_OUT),
+                       ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
+      gfx::Size s = ScaleToRoundedSize(large_size_, kQuickActionBurstScale);
+      CalculateCircleTransforms(s, &transforms);
+      AnimateToTransforms(transforms,
+                          GetAnimationDuration(QUICK_ACTION_TRANSFORM),
+                          ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
+      break;
+    }
+    case InkDropState::SLOW_ACTION_PENDING:
+      DCHECK(previous_ink_drop_state == InkDropState::ACTION_PENDING);
+      AnimateToOpacity(kVisibleOpacity,
+                       GetAnimationDuration(SLOW_ACTION_PENDING),
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN, animation_observer);
+      CalculateRectTransforms(small_size_, small_corner_radius_, &transforms);
+      AnimateToTransforms(transforms, GetAnimationDuration(SLOW_ACTION_PENDING),
                           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                          animation_observer);
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
       break;
-    case InkDropState::SLOW_ACTION_PENDING:
+    case InkDropState::SLOW_ACTION: {
+      DCHECK(previous_ink_drop_state == InkDropState::SLOW_ACTION_PENDING);
+      base::TimeDelta visible_duration =
+          GetAnimationDuration(SLOW_ACTION_TRANSFORM) -
+          GetAnimationDuration(SLOW_ACTION_FADE_OUT);
+      AnimateToOpacity(kVisibleOpacity, visible_duration,
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
+      AnimateToOpacity(kHiddenOpacity,
+                       GetAnimationDuration(SLOW_ACTION_FADE_OUT),
+                       ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
+      CalculateRectTransforms(large_size_, large_corner_radius_, &transforms);
+      AnimateToTransforms(transforms,
+                          GetAnimationDuration(SLOW_ACTION_TRANSFORM),
+                          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
+      break;
+    }
+    case InkDropState::ACTIVATED: {
+      // Animate the opacity so that it cancels any opacity animations already
+      // in progress.
+      AnimateToOpacity(kVisibleOpacity, base::TimeDelta(),
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
+
+      ui::LayerAnimator::PreemptionStrategy rect_transform_preemption_strategy =
+          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET;
+      if (previous_ink_drop_state == InkDropState::HIDDEN) {
+        rect_transform_preemption_strategy =
+            ui::LayerAnimator::ENQUEUE_NEW_ANIMATION;
+        CalculateCircleTransforms(large_size_, &transforms);
+        AnimateToTransforms(
+            transforms, GetAnimationDuration(ACTIVATED_CIRCLE_TRANSFORM),
+            ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+            gfx::Tween::EASE_IN_OUT, animation_observer);
+      } else if (previous_ink_drop_state == InkDropState::ACTION_PENDING) {
+        rect_transform_preemption_strategy =
+            ui::LayerAnimator::ENQUEUE_NEW_ANIMATION;
+      }
+
       CalculateRectTransforms(small_size_, small_corner_radius_, &transforms);
-      AnimateToTransforms(
-          transforms, kVisibleOpacity,
-          GetAnimationDuration(InkDropState::SLOW_ACTION_PENDING),
-          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-          animation_observer);
+      AnimateToTransforms(transforms,
+                          GetAnimationDuration(ACTIVATED_RECT_TRANSFORM),
+                          rect_transform_preemption_strategy,
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
       break;
-    case InkDropState::SLOW_ACTION:
+    }
+    case InkDropState::DEACTIVATED: {
+      base::TimeDelta visible_duration =
+          GetAnimationDuration(DEACTIVATED_TRANSFORM) -
+          GetAnimationDuration(DEACTIVATED_FADE_OUT);
+      AnimateToOpacity(kVisibleOpacity, visible_duration,
+                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
       CalculateRectTransforms(large_size_, large_corner_radius_, &transforms);
-      AnimateToTransforms(transforms, kHiddenOpacity,
-                          GetAnimationDuration(InkDropState::SLOW_ACTION),
+      AnimateToOpacity(kHiddenOpacity,
+                       GetAnimationDuration(DEACTIVATED_FADE_OUT),
+                       ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
+                       gfx::Tween::EASE_IN_OUT, animation_observer);
+      CalculateRectTransforms(large_size_, large_corner_radius_, &transforms);
+      AnimateToTransforms(transforms,
+                          GetAnimationDuration(DEACTIVATED_TRANSFORM),
                           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                          animation_observer);
+                          gfx::Tween::EASE_IN_OUT, animation_observer);
       break;
-    case InkDropState::ACTIVATED:
-      CalculateRectTransforms(small_size_, small_corner_radius_, &transforms);
-      AnimateToTransforms(transforms, kVisibleOpacity,
-                          GetAnimationDuration(InkDropState::ACTIVATED),
-                          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                          animation_observer);
-      break;
-    case InkDropState::DEACTIVATED:
-      CalculateRectTransforms(large_size_, large_corner_radius_, &transforms);
-      AnimateToTransforms(transforms, kHiddenOpacity,
-                          GetAnimationDuration(InkDropState::DEACTIVATED),
-                          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                          animation_observer);
-      break;
+    }
   }
 }
 
 void InkDropAnimation::AnimateToTransforms(
     const InkDropTransforms transforms,
-    float opacity,
     base::TimeDelta duration,
     ui::LayerAnimator::PreemptionStrategy preemption_strategy,
+    gfx::Tween::Type tween,
     ui::LayerAnimationObserver* animation_observer) {
-  ui::LayerAnimator* root_animator = root_layer_->GetAnimator();
-  ui::ScopedLayerAnimationSettings root_animation(root_animator);
-  root_animation.SetPreemptionStrategy(preemption_strategy);
-  ui::LayerAnimationElement* root_element =
-      ui::LayerAnimationElement::CreateOpacityElement(opacity, duration);
-  ui::LayerAnimationSequence* root_sequence =
-      new ui::LayerAnimationSequence(root_element);
-
-  if (animation_observer)
-    root_sequence->AddObserver(animation_observer);
-
-  root_animator->StartAnimation(root_sequence);
-
   for (int i = 0; i < PAINTED_SHAPE_COUNT; ++i) {
     ui::LayerAnimator* animator = painted_layers_[i]->GetAnimator();
     ui::ScopedLayerAnimationSettings animation(animator);
     animation.SetPreemptionStrategy(preemption_strategy);
+    animation.SetTweenType(tween);
     ui::LayerAnimationElement* element =
         ui::LayerAnimationElement::CreateTransformElement(transforms[i],
                                                           duration);
     ui::LayerAnimationSequence* sequence =
         new ui::LayerAnimationSequence(element);
 
     if (animation_observer)
       sequence->AddObserver(animation_observer);
 
     animator->StartAnimation(sequence);
   }
 }
 
 void InkDropAnimation::SetStateToHidden() {
   InkDropTransforms transforms;
   // Using a size of 0x0 creates visual anomalies.
   CalculateCircleTransforms(gfx::Size(1, 1), &transforms);
   SetTransforms(transforms);
   SetOpacity(kHiddenOpacity);
+  root_layer_->SetVisible(false);
 }
 
 void InkDropAnimation::SetTransforms(const InkDropTransforms transforms) {
   for (int i = 0; i < PAINTED_SHAPE_COUNT; ++i)
     painted_layers_[i]->SetTransform(transforms[i]);
 }
 
+float InkDropAnimation::GetCurrentOpacity() const {
+  return root_layer_->opacity();
+}
+
 void InkDropAnimation::SetOpacity(float opacity) {
   root_layer_->SetOpacity(opacity);
 }
 
+void InkDropAnimation::AnimateToOpacity(
+    float opacity,
+    base::TimeDelta duration,
+    ui::LayerAnimator::PreemptionStrategy preemption_strategy,
+    gfx::Tween::Type tween,
+    ui::LayerAnimationObserver* animation_observer) {
+  ui::LayerAnimator* animator = root_layer_->GetAnimator();
+  ui::ScopedLayerAnimationSettings animation_settings(animator);
+  animation_settings.SetPreemptionStrategy(preemption_strategy);
+  animation_settings.SetTweenType(tween);
+  ui::LayerAnimationElement* animation_element =
+      ui::LayerAnimationElement::CreateOpacityElement(opacity, duration);
+  ui::LayerAnimationSequence* animation_sequence =
+      new ui::LayerAnimationSequence(animation_element);
+
+  if (animation_observer)
+    animation_sequence->AddObserver(animation_observer);
+
+  animator->StartAnimation(animation_sequence);
+}
+
 void InkDropAnimation::CalculateCircleTransforms(
     const gfx::Size& size,
     InkDropTransforms* transforms_out) const {
   CalculateRectTransforms(size, std::min(size.width(), size.height()) / 2.0f,
                           transforms_out);
 }
 
 void InkDropAnimation::CalculateRectTransforms(
     const gfx::Size& size,
     float corner_radius,
@@ skipping 41 matching lines @@
       std::max(kMinimumRectScale,
                (size.height() - 2.0f * corner_radius) / rect_delegate_height));
 
   (*transforms_out)[VERTICAL_RECT] = CalculateRectTransform(
       ToRoundedPoint(rect_layer_delegate_->GetCenterPoint()),
       std::max(kMinimumRectScale,
                (size.width() - 2.0f * corner_radius) / rect_delegate_width),
       std::max(kMinimumRectScale, size.height() / rect_delegate_height));
 }
 
-void InkDropAnimation::GetCurrentTansforms(
+void InkDropAnimation::GetCurrentTransforms(
     InkDropTransforms* transforms_out) const {
   for (int i = 0; i < PAINTED_SHAPE_COUNT; ++i)
-    (*transforms_out)[i] = painted_layers_[i]->GetTargetTransform();
+    (*transforms_out)[i] = painted_layers_[i]->transform();
 }
 
 void InkDropAnimation::AddPaintLayer(PaintedShape painted_shape) {
   ui::LayerDelegate* delegate = nullptr;
   switch (painted_shape) {
     case TOP_LEFT_CIRCLE:
     case TOP_RIGHT_CIRCLE:
     case BOTTOM_RIGHT_CIRCLE:
     case BOTTOM_LEFT_CIRCLE:
       delegate = circle_layer_delegate_.get();
@@ skipping 30 matching lines @@
 void InkDropAnimation::AnimationStartedCallback(
     InkDropState ink_drop_state,
     const ui::CallbackLayerAnimationObserver& observer) {
   FOR_EACH_OBSERVER(InkDropAnimationObserver, observers_,
                     InkDropAnimationStarted(ink_drop_state));
 }
 
 bool InkDropAnimation::AnimationEndedCallback(
     InkDropState ink_drop_state,
     const ui::CallbackLayerAnimationObserver& observer) {
+  if (ink_drop_state == InkDropState::HIDDEN)
+    SetStateToHidden();
+
   FOR_EACH_OBSERVER(
       InkDropAnimationObserver, observers_,
       InkDropAnimationEnded(ink_drop_state,
                             observer.aborted_count()
                                 ? InkDropAnimationObserver::PRE_EMPTED
                                 : InkDropAnimationObserver::SUCCESS));
   return true;
 }
 
 }  // namespace views