Animate the OverviewButtonTray

ash/system/tray/tray_background_view.cc

Index: ash/system/tray/tray_background_view.cc
diff --git a/ash/system/tray/tray_background_view.cc b/ash/system/tray/tray_background_view.cc
index fc24c14932af7c4673e9a46c1d195ce8701d965a..f0e88d3b5c9770a18625b3c908ecef2571949874 100644
--- a/ash/system/tray/tray_background_view.cc
+++ b/ash/system/tray/tray_background_view.cc
@@ -22,12 +22,17 @@
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/compositor/layer.h"
+#include "ui/compositor/layer_animation_element.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/animation/tween.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/skia_util.h"
+#include "ui/gfx/transform.h"
 #include "ui/views/background.h"
 #include "ui/views/layout/box_layout.h"
 
@@ -37,7 +42,15 @@ const int kTrayBackgroundAlpha = 100;
 const int kTrayBackgroundHoverAlpha = 150;
 const SkColor kTrayBackgroundPressedColor = SkColorSetRGB(66, 129, 244);
 
-const int kAnimationDurationForPopupMS = 200;
+const int kAnimationDurationForPopupMs = 200;
+
+// Duration of opacity animation for visibility changes.
+const int kAnimationDurationForVisibilityMs = 250;
+
+// When becoming visible delay the animation so that StatusAreaWidgetDelegate
+// can animate sibling views out of the position to be occuped by the
+// TrayBackgroundView.
+const int kShowAnimationDelayMs = 100;
 
 }  // namespace
 
@@ -307,6 +320,9 @@ TrayBackgroundView::TrayBackgroundView(StatusAreaWidget* status_area_widget)
   tray_container_ = new TrayContainer(shelf_alignment_);
   SetContents(tray_container_);
   tray_event_filter_.reset(new TrayEventFilter);
+
+  SetPaintToLayer(true);
+  SetFillsBoundsOpaquely(false);
 }
 
 TrayBackgroundView::~TrayBackgroundView() {
@@ -319,6 +335,51 @@ void TrayBackgroundView::Initialize() {
   SetTrayBorder();
 }
 
+void TrayBackgroundView::SetVisible(bool visible) {
+  if (visible == this->visible())
+    return;
+
+  if (visible) {
+    // A translation transform was applied when becoming hidden. However the
+    // alignment of the shelf can change. Reset the offscreen transform so that
+    // the animation to becoming visible reflects the changed layout.
+    HideTransformation();

[oshima, 2014/05/08 17:38:42]

If you need this, don't you also need to set the opacity/visibility here as
well?

[jonross, 2014/05/08 17:50:07]

No, the setting of position is because the tray can be rotated while the button
is hidden. So the position it animated to could be invalid for the animation to
visibility.

The rotation changes won't affect opacity, which will be off.

[oshima, 2014/05/08 18:30:54]

I see, make sense. Can you update the description a bit like "the self can
change while hidden."

[jonross, 2014/05/08 18:44:27]

Done.

+    // SetVisible(false) is defered until the animation for hiding is done.
+    // Otherwise the view is immediately hidden and the animation does not
+    // render.
+    views::View::SetVisible(visible);
+  }
+
+  layer()->GetAnimator()->StopAnimating();
+  ui::ScopedLayerAnimationSettings animation(layer()->GetAnimator());
+  animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
+      kAnimationDurationForVisibilityMs));
+  animation.SetPreemptionStrategy(
+      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+
+  if (visible) {
+    animation.SetTweenType(gfx::Tween::EASE_OUT);
+    // Show is delayed so as to allow time for other children of
+    // StatusAreaWidget to begin animating to their new positions.
+    layer()->GetAnimator()->SchedulePauseForProperties(
+        base::TimeDelta::FromMilliseconds(kShowAnimationDelayMs),
+        ui::LayerAnimationElement::OPACITY |
+        ui::LayerAnimationElement::TRANSFORM);
+    layer()->SetOpacity(1.0f);

[oshima, 2014/05/08 17:38:42]

don't you have to set layer()->SetVisible(true); ?

[jonross, 2014/05/08 17:50:07]

The setting of the view to visible at line 350 turns the layer visibility back
on.

[oshima, 2014/05/08 18:30:54]

can you document it? The code that looks to cause opacity / visibility
inconsistency may confuse us later.

[jonross, 2014/05/08 18:44:27]

Done.

+    gfx::Transform transform;
+    transform.Translate(0.0f, 0.0f);
+    layer()->SetTransform(transform);
+  } else {
+    // Listen only to the hide animation. As we cannot turn off visibility
+    // until the animation is over.
+    animation.AddObserver(this);
+    animation.SetTweenType(gfx::Tween::EASE_IN);
+    layer()->SetOpacity(0.0f);
+    layer()->SetVisible(false);
+    HideTransformation();
+  }
+}
+
 const char* TrayBackgroundView::GetClassName() const {
   return kViewClassName;
 }
@@ -420,6 +481,20 @@ void TrayBackgroundView::SetTrayBorder() {
       top_edge, left_edge, bottom_edge, right_edge));
 }
 
+void TrayBackgroundView::OnImplicitAnimationsCompleted() {
+  views::View::SetVisible(false);
+}
+
+void TrayBackgroundView::HideTransformation() {

[oshima, 2014/05/08 17:38:42]

Set/ApplyHideTransformation ?

+  gfx::Transform transform;
+  if (shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM ||
+      shelf_alignment_ == SHELF_ALIGNMENT_TOP)
+    transform.Translate(width(), 0.0f);
+  else
+    transform.Translate(0.0f, height());
+  layer()->SetTransform(transform);
+}
+
 void TrayBackgroundView::InitializeBubbleAnimations(
     views::Widget* bubble_widget) {
   wm::SetWindowVisibilityAnimationType(
@@ -430,7 +505,7 @@ void TrayBackgroundView::InitializeBubbleAnimations(
       wm::ANIMATE_HIDE);
   wm::SetWindowVisibilityAnimationDuration(
       bubble_widget->GetNativeWindow(),
-      base::TimeDelta::FromMilliseconds(kAnimationDurationForPopupMS));
+      base::TimeDelta::FromMilliseconds(kAnimationDurationForPopupMs));
 }
 
 aura::Window* TrayBackgroundView::GetBubbleWindowContainer() const {