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..cf23bfe146bf7a754b742edabb1d43462716fcc1 100644
--- a/ash/system/tray/tray_background_view.cc
+++ b/ash/system/tray/tray_background_view.cc
@@ -22,12 +22,15 @@
 #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/scoped_layer_animation_settings.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"
 
@@ -38,6 +41,7 @@ const int kTrayBackgroundHoverAlpha = 150;
 const SkColor kTrayBackgroundPressedColor = SkColorSetRGB(66, 129, 244);
 
 const int kAnimationDurationForPopupMS = 200;
+const int kAnimationDurationForVisibility = 200;
 
 }  // namespace
 
@@ -307,6 +311,9 @@ 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 +326,41 @@ void TrayBackgroundView::Initialize() {
   SetTrayBorder();
 }
 
+void TrayBackgroundView::SetVisible(bool set_visible) {

[flackr, 2014/04/30 16:06:40]

s/set_visible/visible to match the variable name in definition in .h file and
overridden method.

[jonross, 2014/04/30 21:25:38]

Done.

+  if (set_visible == visible())
+    return;
+
+  if (set_visible)
+    views::View::SetVisible(set_visible);

[flackr, 2014/04/30 16:06:40]

I believe you should be able to SetVisible(false) in the scope of the
ScopedLayerAnimationSettings, and then it will automagically keep the layer
visible until the animation is complete and you won't need the animation
observer.

[jonross, 2014/04/30 21:25:38]

In order to user layer()->SetVisibility(false) I would need to detach the layer
from the tree. This is typically done when a window is about to be destroyed.

Other areas use the pattern of an animation listener. For this change we will
stick with this pattern.

+
+  layer()->GetAnimator()->StopAnimating();
+  ui::ScopedLayerAnimationSettings animation(layer()->GetAnimator());
+  animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
+      kAnimationDurationForVisibility));
+  animation.SetPreemptionStrategy(
+      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+  animation.AddObserver(this);
+
+  if (set_visible) {
+    layer()->SetOpacity(1.0f);
+    gfx::Transform transform;
+    transform.Translate(0.0f, 0.0f);
+    transform.Scale(1.0f, 1.0f);
+    layer()->SetTransform(transform);
+  } else {
+    layer()->SetOpacity(0.0f);
+    gfx::Transform transform;
+    if (shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM ||
+         shelf_alignment_ == SHELF_ALIGNMENT_TOP) {

[flackr, 2014/04/30 16:06:40]

nit: bad indent, should line up with above line.

[jonross, 2014/04/30 21:25:38]

Done.

+      transform.Translate(width(), height() / 2.0f);
+    } else {
+      transform.Translate(width() / 2.0f, height());
+    }
+    transform.Scale(0.01f, 0.01f);

[flackr, 2014/04/30 16:06:40]

Use constants for non 0 or 1 values.

[jonross, 2014/04/30 21:25:38]

Done.

+    layer()->SetTransform(transform);
+  }
+}
+
 const char* TrayBackgroundView::GetClassName() const {
   return kViewClassName;
 }
@@ -387,6 +429,18 @@ ShelfLayoutManager* TrayBackgroundView::GetShelfLayoutManager() {
 }
 
 void TrayBackgroundView::SetShelfAlignment(ShelfAlignment alignment) {
+  if (!visible() && shelf_alignment_ != alignment) {
+    // A translation transform was applied when becoming hidden. Swap the
+    // transform to be the offscreen position for the new alignment.

[flackr, 2014/04/30 16:06:40]

It'd probably make more sense to set the correct transform to transition in from
in Show before the scope of the ScopedLayerAnimationSettings object.

[jonross, 2014/04/30 21:25:38]

Done.

+    gfx::Transform transform;
+    if (alignment == SHELF_ALIGNMENT_BOTTOM || alignment == SHELF_ALIGNMENT_TOP)
+      transform.Translate(width(), height() /  2.0f);
+    else
+      transform.Translate(width() /2.0f, height());
+    transform.Scale(0.01f, 0.01f);
+    layer()->SetTransform(transform);
+  }
+
   shelf_alignment_ = alignment;
   SetTrayBorder();
   tray_container_->SetAlignment(alignment);
@@ -420,6 +474,11 @@ void TrayBackgroundView::SetTrayBorder() {
       top_edge, left_edge, bottom_edge, right_edge));
 }
 
+void TrayBackgroundView::OnImplicitAnimationsCompleted() {
+  if (layer()->opacity() == 0.0f)
+    views::View::SetVisible(false);
+}
+
 void TrayBackgroundView::InitializeBubbleAnimations(
     views::Widget* bubble_widget) {
   wm::SetWindowVisibilityAnimationType(