Refactoring to make adding ink drop animations easier

ui/views/controls/button/custom_button.cc

Index: ui/views/controls/button/custom_button.cc
diff --git a/ui/views/controls/button/custom_button.cc b/ui/views/controls/button/custom_button.cc
index aafbf2d65a63aa32810d6da8d352f9bf1663f8af..c3d484773946c37005bd2fa00d68f4aa995591c5 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -10,6 +10,7 @@
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/animation/throb_animation.h"
 #include "ui/gfx/screen.h"
+#include "ui/views/animation/ink_drop_delegate.h"
 #include "ui/views/controls/button/blue_button.h"
 #include "ui/views/controls/button/checkbox.h"
 #include "ui/views/controls/button/image_button.h"
@@ -284,6 +285,8 @@ void CustomButton::OnDragDone() {
   // (since disabled buttons may still be able to be dragged).
   if (state_ != STATE_DISABLED)
     SetState(STATE_NORMAL);
+  if (ink_drop_delegate_)
+    ink_drop_delegate_->OnAction(InkDropState::HIDDEN);
 }
 
 void CustomButton::GetAccessibleState(ui::AXViewState* state) {
@@ -371,9 +374,18 @@ bool CustomButton::ShouldEnterHoveredState() {
   return check_mouse_position && IsMouseHovered();
 }
 
+void CustomButton::set_ink_drop_delegate(InkDropDelegate* ink_drop_delegate) {
+  ink_drop_delegate_.reset(ink_drop_delegate);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // CustomButton, View overrides (protected):
 
+void CustomButton::OnBoundsChanged(const gfx::Rect& previous_bounds) {
+  if (ink_drop_delegate_)

[bruthig, 2015/11/26 21:27:33]

Correct me if I'm wrong but the intent here was to set the ink drop centre in
the OnBoundsChange() event, at the request of sadrul@ right?  And the
CustomButton::Layout() method should be removed then?

I tried removing CustomButton::Layout() and noticed that the ripple is
incorrectly centered on the BackButton.  The problem is that the
BackButton->SetLeadingMargin() does not trigger an OnBoundsChange() event.  And
it just so happens that BackButton::SetBounds() is called before
BackButton::SetLeadingMargin() in ToolbarView and thus the ripple will actually
be in the wrong place every time.

[varkha, 2015/11/26 22:12:40]

I have restored override of Layout(). Can you see if this works?

+    ink_drop_delegate_->OnBoundsChanged();
+}
+
 void CustomButton::ViewHierarchyChanged(
     const ViewHierarchyChangedDetails& details) {
   if (!details.is_add && state_ != STATE_DISABLED)