Expand the Material Design hover as it fades out when a ripple is triggered.

ui/views/animation/ink_drop_animation_controller_impl.cc

Index: ui/views/animation/ink_drop_animation_controller_impl.cc
diff --git a/ui/views/animation/ink_drop_animation_controller_impl.cc b/ui/views/animation/ink_drop_animation_controller_impl.cc
index 963440d909e6478c60690c7374745207bc219dea..d28a280868bca12e92ff55b783360651ff2fbbaa 100644
--- a/ui/views/animation/ink_drop_animation_controller_impl.cc
+++ b/ui/views/animation/ink_drop_animation_controller_impl.cc
@@ -29,7 +29,7 @@ const int kHoverFadeInAfterAnimationDurationInMs = 250;
 
 // The duration, in milliseconds, of the hover state fade out animation when it
 // is triggered by an ink drop ripple animation starting.
-const int kHoverFadeOutBeforeAnimationDurationInMs = 300;
+const int kHoverFadeOutBeforeAnimationDurationInMs = 120;
 
 // The amount of time in milliseconds that |hover_| should delay after a ripple
 // animation before fading in.
@@ -85,7 +85,8 @@ void InkDropAnimationControllerImpl::AnimateToState(
 
   if (ink_drop_state != views::InkDropState::HIDDEN) {
     SetHoveredInternal(false, base::TimeDelta::FromMilliseconds(
-                                  kHoverFadeOutBeforeAnimationDurationInMs));
+                                  kHoverFadeOutBeforeAnimationDurationInMs),

[varkha, 2016/04/21 16:16:49]

nitty nit: I thought the second argument to SetHoveredInternal would look better
on its own line.

[bruthig, 2016/04/21 21:14:03]

I agree, but this is how 'git cl format' formats it.

+                       true);
   }
 
   ink_drop_animation_->AnimateToState(ink_drop_state);
@@ -96,7 +97,7 @@ void InkDropAnimationControllerImpl::SnapToActivated() {
   if (!ink_drop_animation_)
     CreateInkDropAnimation();
 
-  SetHoveredInternal(false, base::TimeDelta());
+  SetHoveredInternal(false, base::TimeDelta(), false);
 
   ink_drop_animation_->SnapToActivated();
 }
@@ -107,7 +108,8 @@ void InkDropAnimationControllerImpl::SetHovered(bool is_hovered) {
                      is_hovered ? base::TimeDelta::FromMilliseconds(
                                       kHoverFadeInFromUserInputDurationInMs)
                                 : base::TimeDelta::FromMilliseconds(
-                                      kHoverFadeOutFromUserInputDurationInMs));
+                                      kHoverFadeOutFromUserInputDurationInMs),
+                     false);
 }
 
 void InkDropAnimationControllerImpl::DestroyHiddenTargetedAnimations() {
@@ -175,7 +177,8 @@ void InkDropAnimationControllerImpl::InkDropAnimationEnded(
 
 void InkDropAnimationControllerImpl::SetHoveredInternal(
     bool is_hovered,
-    base::TimeDelta animation_duration) {
+    base::TimeDelta animation_duration,
+    bool explode) {
   StopHoverAfterAnimationTimer();
 
   if (IsHoverFadingInOrVisible() == is_hovered)
@@ -186,7 +189,7 @@ void InkDropAnimationControllerImpl::SetHoveredInternal(
     if (hover_ && !IsVisible())
       hover_->FadeIn(animation_duration);
   } else {
-    hover_->FadeOut(animation_duration);
+    hover_->FadeOut(animation_duration, explode);

[varkha, 2016/04/21 16:16:49]

This seems to be the only place where |hover_| is not null-checked. Is it
guaranteed to be non-null? Line 141 suggests that it might not but I am not
sure.

[bruthig, 2016/04/21 21:14:03]

The check on line 184 should short circuit return if |hover_| is null and the
InkDropAnimationControllerImplTest.SetHoveredFalseWorksWhenNoInkDropHoverExists
test confirms this ;)

[varkha, 2016/04/22 19:57:20]

nit: Yes I see the logic now. It is somewhat hidden behind
IsHoverFadingInOrVisible and the reasoning that it !ishovered then
IsHoverFadingInOrVisible() must have returned true and so hover_ must have been
non-NULL. Maybe a DCHECK?

[bruthig, 2016/04/22 21:08:20]

Where would you suggest I put the DCHECK?  I'd think it would have to go before
line 192 and I've been told not to include the DCHECK if it's going to
de-reference shortly after anyway.

[varkha, 2016/04/22 23:05:55]

Right.

   }
 }
 
@@ -210,7 +213,8 @@ void InkDropAnimationControllerImpl::StopHoverAfterAnimationTimer() {
 
 void InkDropAnimationControllerImpl::HoverAfterAnimationTimerFired() {
   SetHoveredInternal(true, base::TimeDelta::FromMilliseconds(
-                               kHoverFadeInAfterAnimationDurationInMs));
+                               kHoverFadeInAfterAnimationDurationInMs),
+                     true);
   hover_after_animation_timer_.reset();
 }