Compact layout mananger animates windows rather than the default container layer.

ash/wm/compact_layout_manager.cc

Index: ash/wm/compact_layout_manager.cc
diff --git a/ash/wm/compact_layout_manager.cc b/ash/wm/compact_layout_manager.cc
index eacfbcd21036d2063d69b1954db51c91c9ce0578..49924746af4e4c3fd4f42f48434bb2586aef2900 100644
--- a/ash/wm/compact_layout_manager.cc
+++ b/ash/wm/compact_layout_manager.cc
@@ -10,6 +10,7 @@
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/window_util.h"
+#include "base/memory/scoped_vector.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/compositor/scoped_layer_animation_settings.h"
@@ -39,14 +40,6 @@ bool ShouldAnimateOnEntrance(aura::Window* window) {
       window_util::IsWindowMaximized(window);
 }
 
-// Adjust layer bounds to grow or shrink in |delta_width|.
-void AdjustContainerLayerWidth(int delta_width) {
-  gfx::Rect bounds(GetDefaultContainerLayer()->bounds());
-  bounds.set_width(bounds.width() + delta_width);
-  GetDefaultContainerLayer()->SetBounds(bounds);
-  GetDefaultContainerLayer()->GetCompositor()->WidgetSizeChanged(
-      GetDefaultContainerLayer()->bounds().size());
-}
 }  // namespace
 
 /////////////////////////////////////////////////////////////////////////////
@@ -66,20 +59,11 @@ CompactLayoutManager::~CompactLayoutManager() {
 void CompactLayoutManager::OnWindowAddedToLayout(aura::Window* child) {
   BaseLayoutManager::OnWindowAddedToLayout(child);
   UpdateStatusAreaVisibility();
-  if (windows().size() > 1 &&
-      child->type() == aura::client::WINDOW_TYPE_NORMAL) {
-    // The first window is already contained in the current layer,
-    // add subsequent windows to layer bounds calculation.
-    AdjustContainerLayerWidth(child->bounds().width());
-  }
 }
 
 void CompactLayoutManager::OnWillRemoveWindowFromLayout(aura::Window* child) {
   BaseLayoutManager::OnWillRemoveWindowFromLayout(child);
   UpdateStatusAreaVisibility();
-  if (windows().size() > 1 && ShouldAnimateOnEntrance(child))
-    AdjustContainerLayerWidth(-child->bounds().width());
-
   if (child == current_window_) {
     LayoutWindows(current_window_);
     SwitchToReplacementWindow();
@@ -144,8 +128,7 @@ void CompactLayoutManager::OnWindowStackingChanged(aura::Window* window) {
 // CompactLayoutManager, AnimationDelegate overrides:
 
 void CompactLayoutManager::OnImplicitAnimationsCompleted() {
-  if (!GetDefaultContainerLayer()->GetAnimator()->is_animating())
-    HideWindows();
+  HideWindows();
 }
 
 //////////////////////////////////////////////////////////////////////////////
@@ -164,12 +147,24 @@ void CompactLayoutManager::UpdateStatusAreaVisibility() {
 }
 
 void CompactLayoutManager::AnimateSlideTo(int offset_x) {
-  ui::ScopedLayerAnimationSettings settings(
-      GetDefaultContainerLayer()->GetAnimator());
-  settings.AddObserver(this);
+  // If we were waiting for another implicit animation to complete, forget
+  // about it since we're about to start observing a new animation.
+  StopObservingImplicitAnimations();
+  ScopedVector<ui::ScopedLayerAnimationSettings> settings;

[sky, 2012/02/13 22:21:13]

Is there a reason you're creating this outside the for loop? Shouldn't it be
simpler to declare on the stack around line 163ish?

   ui::Transform transform;
-  transform.ConcatTranslate(-offset_x, 0);
-  GetDefaultContainerLayer()->SetTransform(transform);  // Will be animated!
+  transform.SetTranslateX(-offset_x);
+  ShellDelegate* shell_delegate = ash::Shell::GetInstance()->delegate();
+  const WindowList& windows_list = shell_delegate->GetCycleWindowList(
+      ShellDelegate::SOURCE_KEYBOARD,
+      ShellDelegate::ORDER_LINEAR);
+  for (WindowListConstIter const_it = windows_list.begin();
+       const_it != windows_list.end();
+       ++const_it) {
+    settings.push_back(new ui::ScopedLayerAnimationSettings(
+        (*const_it)->layer()->GetAnimator()));
+    settings[settings.size() - 1]->AddObserver(this);
+    (*const_it)->layer()->SetTransform(transform);

[alicet1, 2012/02/13 22:32:46]

I'm not sure this will work properly -- this will set all windows in the cycle
list to slide to -offset_x. if you have 3 windows, how does alt-tabbing through
them shows the fast sliding from window 3 -> window 1?

+  }
 }
 
 void CompactLayoutManager::LayoutWindows(aura::Window* skip) {