[ash-md] Fades overview header in and out

ash/common/wm/overview/window_selector_item.cc

Index: ash/common/wm/overview/window_selector_item.cc
diff --git a/ash/common/wm/overview/window_selector_item.cc b/ash/common/wm/overview/window_selector_item.cc
index 91d08e97c7bf56069619e81a3fe30c6f596d2c6e..27286d15b658f06e3a43f1eea57e784bc7a499b7 100644
--- a/ash/common/wm/overview/window_selector_item.cc
+++ b/ash/common/wm/overview/window_selector_item.cc
@@ -10,6 +10,7 @@
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/shell_window_ids.h"
+#include "ash/common/wm/overview/cleanup_animation_observer.h"
 #include "ash/common/wm/overview/overview_animation_type.h"
 #include "ash/common/wm/overview/scoped_overview_animation_settings.h"
 #include "ash/common/wm/overview/scoped_overview_animation_settings_factory.h"
@@ -30,7 +31,10 @@
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/compositor/layer_animation_sequence.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/color_utils.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ -39,7 +43,6 @@
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
-#include "ui/views/controls/button/image_button.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/window/non_client_view.h"
 #include "ui/wm/core/shadow.h"
@@ -66,10 +69,12 @@ static const SkColor kLabelColor = SK_ColorWHITE;
 // TODO(tdanderson): Move this to a central location.
 static const SkColor kCloseButtonColor = SK_ColorWHITE;
 
-// Label background color used with Material Design.
-// TODO(varkha): Make background color conform to window header.
+// Label background color used with Material Design once in overview mode.
 static const SkColor kLabelBackgroundColor = SkColorSetARGB(25, 255, 255, 255);
 
+// Label background color used with Material Design when exiting overview mode.
+static const SkColor kLabelExitColor = SkColorSetARGB(255, 90, 90, 90);
+
 // Corner radius for the selection tiles used with Material Design.
 static int kLabelBackgroundRadius = 2;
 
@@ -97,9 +102,20 @@ static const float kDimmedItemOpacity = 0.5f;
 // Opacity for fading out during closing a window.
 static const float kClosingItemOpacity = 0.8f;
 
+// Opacity for the item header.
+static const float kHeaderOpacity =
+    (SkColorGetA(kLabelBackgroundColor) / 255.f);
+
+// Duration it takes for the header to shift from opaque header color to
+// |kLabelBackgroundColor|.
+static const int kSelectorColorSlideMilliseconds = 240;
+
 // Duration of background opacity transition for the selected label.
 static const int kSelectorFadeInMilliseconds = 350;
 
+// Duration of background opacity transition when exiting overview mode.
+static const int kExitFadeInMilliseconds = 30;
+
 // Before closing a window animate both the window and the caption to shrink by
 // this fraction of size.
 static const float kPreCloseScale = 0.02f;
@@ -120,19 +136,10 @@ void SetupFadeInAfterLayout(views::Widget* widget) {
   window->SetOpacity(1.0f);
 }
 
-// An image button with a close window icon.
-class OverviewCloseButton : public views::ImageButton {
- public:
-  explicit OverviewCloseButton(views::ButtonListener* listener);
-  ~OverviewCloseButton() override;
-
- private:
-  gfx::ImageSkia icon_image_;
-
-  DISALLOW_COPY_AND_ASSIGN(OverviewCloseButton);
-};
+}  // namespace
 
-OverviewCloseButton::OverviewCloseButton(views::ButtonListener* listener)
+WindowSelectorItem::OverviewCloseButton::OverviewCloseButton(
+    views::ButtonListener* listener)
     : views::ImageButton(listener) {
   if (ash::MaterialDesignController::IsOverviewMaterial()) {
     icon_image_ = gfx::CreateVectorIcon(gfx::VectorIconId::WINDOW_CONTROL_CLOSE,
@@ -154,45 +161,176 @@ OverviewCloseButton::OverviewCloseButton(views::ButtonListener* listener)
   }
 }
 
-OverviewCloseButton::~OverviewCloseButton() {}
+WindowSelectorItem::OverviewCloseButton::~OverviewCloseButton() {}
 
-// A View having rounded corners and a specified background color which is
+// A View having rounded top corners and a specified background color which is
 // only painted within the bounds defined by the rounded corners.
-// TODO(varkha): This duplicates code from RoundedImageView. Refactor these
-//               classes and move into ui/views.
-class RoundedContainerView : public views::View {
+// This class coordinates the transitions of the overview mode header when
+// entering the overview mode. Those animations are:
+// - Opacity animation. The header is initially same color as the original
+//   window's header. It starts as transparent and is faded in. When the full
+//   opacity is reached the original header is hidden (which is nearly
+//   imperceptable because this view obscures the original header) and a color
+//   animation starts.
+// - Color animation is used to change the color from the opaque color of the
+//   original window's header to semi-transparent color of the overview mode
+//   header (on entry to overview). It is also used on exit from overview to
+//   quickly change the color to a close opaque color in parallel with an
+//   opacity transition to mask the original header reappearing.
+class WindowSelectorItem::RoundedContainerView
+    : public views::View,
+      public gfx::AnimationDelegate,
+      public ui::LayerAnimationObserver {
  public:
-  RoundedContainerView(int corner_radius, SkColor background)
-      : corner_radius_(corner_radius), background_(background) {}
+  RoundedContainerView(WindowSelectorItem* item,
+                       WmWindow* item_window,
+                       int corner_radius,
+                       SkColor background)
+      : item_(item),
+        item_window_(item_window),
+        corner_radius_(corner_radius),
+        initial_color_(background),
+        target_color_(background),
+        current_value_(0),
+        layer_(nullptr),
+        animation_(new gfx::SlideAnimation(this)) {}
+
+  ~RoundedContainerView() override { StopObservingLayerAnimations(); }
+
+  void OnItemRestored() { item_ = nullptr; }
+
+  // Starts observing layer animations so that actions can be taken when
+  // particular animations (opacity) complete. It should only be called once
+  // when the initial fade in animation is started.
+  void ObserveLayerAnimations(ui::Layer* layer) {
+    DCHECK(!layer_);
+    layer_ = layer;
+    layer_->GetAnimator()->AddObserver(this);
+  }
 
-  ~RoundedContainerView() override {}
+  // Stops observing layer animations
+  void StopObservingLayerAnimations() {
+    if (!layer_)
+      return;
+    layer_->GetAnimator()->RemoveObserver(this);
+    layer_ = nullptr;
+  }
 
+  void set_color(SkColor target_color) { target_color_ = target_color; }
+
+  // Starts a color animation using |tween_type|. The animation will change the
+  // color from |initial_color_| to |target_color_| over |duration| specified
+  // in milliseconds.
+  // This animation can start once the implicit layer fade-in opacity animation
+  // is completed. It is used to transition color from the opaque original
+  // window header color to |kLabelBackgroundColor| on entry into overview mode
+  // and from |kLabelBackgroundColor| back to the original window header color
+  // on exit from the overview mode.
+  void AnimateColor(gfx::Tween::Type tween_type, int duration) {
+    DCHECK(!layer_);  // layer animations should be completed.
+    animation_->SetSlideDuration(duration);
+    animation_->SetTweenType(tween_type);
+    animation_->Reset(0);
+    animation_->Show();
+
+    // Tests complete animations immediately. Emulate by invoking the callback.
+    if (ui::ScopedAnimationDurationScaleMode::duration_scale_mode() ==
+        ui::ScopedAnimationDurationScaleMode::ZERO_DURATION) {
+      AnimationEnded(animation_.get());
+    }
+  }
+
+  // Changes the view opacity by animating its background color. The animation
+  // will change the alpha value in |target_color_| from its current value to
+  // |opacity| * 255 but preserve the RGB values.
+  void AnimateBackgroundOpacity(float opacity) {
+    animation_->SetSlideDuration(kSelectorFadeInMilliseconds);
+    animation_->SetTweenType(gfx::Tween::EASE_OUT);
+    animation_->Reset(0);
+    animation_->Show();
+    target_color_ = SkColorSetA(target_color_, opacity * 255);
+  }
+
+  // views::View:
   void OnPaint(gfx::Canvas* canvas) override {
     views::View::OnPaint(canvas);
-
     SkScalar radius = SkIntToScalar(corner_radius_);
-    const SkScalar kRadius[8] = {radius, radius, radius, radius,
-                                 radius, radius, radius, radius};
+    const SkScalar kRadius[8] = {radius, radius, radius, radius, 0, 0, 0, 0};
     SkPath path;
     gfx::Rect bounds(size());
-    bounds.set_height(bounds.height() + radius);
     path.addRoundRect(gfx::RectToSkRect(bounds), kRadius);
 
     SkPaint paint;
     paint.setAntiAlias(true);
     canvas->ClipPath(path, true);
-    canvas->DrawColor(background_);
+
+    SkColor target_color = initial_color_;
+    if (target_color_ != target_color) {
+      target_color = color_utils::AlphaBlend(target_color_, initial_color_,
+                                             current_value_);
+    }
+    canvas->DrawColor(target_color);
   }
 
  private:
+  // gfx::AnimationDelegate:
+  void AnimationEnded(const gfx::Animation* animation) override {
+    initial_color_ = target_color_;
+    // Tabbed browser windows show the overview mode header behind the window
+    // during the initial animation. Once the initial fade-in completes and the
+    // overview header is fully exposed update stacking to keep the label above
+    // the item which prevents input events from reaching the window.
+    WmWindow* label_window = WmLookup::Get()->GetWindowForWidget(GetWidget());
+    if (label_window && item_window_)
+      label_window->GetParent()->StackChildAbove(label_window, item_window_);
+    item_window_ = nullptr;
+  }
+
+  void AnimationProgressed(const gfx::Animation* animation) override {
+    current_value_ = animation_->CurrentValueBetween(0, 255);
+    SchedulePaint();
+  }
+
+  void AnimationCanceled(const gfx::Animation* animation) override {
+    item_window_ = nullptr;
+    initial_color_ = target_color_;
+    current_value_ = 255;
+    SchedulePaint();
+  }
+
+  // ui::LayerAnimationObserver:
+  void OnLayerAnimationEnded(ui::LayerAnimationSequence* sequence) override {
+    if (0 != (sequence->properties() &
+              ui::LayerAnimationElement::AnimatableProperty::OPACITY)) {
+      if (item_)
+        item_->HideHeaderAndSetShape(0);
+      StopObservingLayerAnimations();
+      AnimateColor(gfx::Tween::EASE_IN, kSelectorColorSlideMilliseconds);
+    }
+  }
+
+  void OnLayerAnimationAborted(ui::LayerAnimationSequence* sequence) override {
+    if (0 != (sequence->properties() &
+              ui::LayerAnimationElement::AnimatableProperty::OPACITY)) {
+      StopObservingLayerAnimations();
+    }
+  }
+
+  void OnLayerAnimationScheduled(
+      ui::LayerAnimationSequence* sequence) override {}
+
+  WindowSelectorItem* item_;
+  WmWindow* item_window_;
   int corner_radius_;
-  SkColor background_;
+  SkColor initial_color_;
+  SkColor target_color_;
+  int current_value_;
+  ui::Layer* layer_;
+  std::unique_ptr<gfx::SlideAnimation> animation_;
 
   DISALLOW_COPY_AND_ASSIGN(RoundedContainerView);
 };
 
-}  // namespace
-
 bool WindowSelectorItem::use_mask_ = false;
 bool WindowSelectorItem::use_shape_ = false;
 
@@ -223,8 +361,10 @@ gfx::Rect WindowSelectorItem::OverviewLabelButton::GetChildAreaBounds() {
 class WindowSelectorItem::CaptionContainerView : public views::View {
  public:
   CaptionContainerView(WindowSelectorItem::OverviewLabelButton* label,
-                       views::ImageButton* close_button)
-      : label_(label), close_button_(close_button) {
+                       views::ImageButton* close_button,
+                       WindowSelectorItem::RoundedContainerView* background)
+      : label_(label), close_button_(close_button), background_(background) {
+    AddChildView(background_);
     AddChildView(label_);
     AddChildView(close_button_);
   }
@@ -239,6 +379,10 @@ class WindowSelectorItem::CaptionContainerView : public views::View {
     // events from reaching the transformed window in overview.
     gfx::Rect bounds(GetLocalBounds());
     bounds.Inset(kWindowSelectorMargin, kWindowSelectorMargin);
+    gfx::Rect background_bounds(bounds);
+    background_bounds.set_height(close_button_->GetPreferredSize().height());
+    background_->SetBoundsRect(background_bounds);
+
     const int visible_height = close_button_->GetPreferredSize().height();
     gfx::Insets label_padding(0, 0, bounds.height() - visible_height,
                               visible_height);
@@ -250,11 +394,10 @@ class WindowSelectorItem::CaptionContainerView : public views::View {
     close_button_->SetBoundsRect(bounds);
   }
 
-  void OnBoundsChanged(const gfx::Rect& previous_bounds) override { Layout(); }
-
  private:
   WindowSelectorItem::OverviewLabelButton* label_;
   views::ImageButton* close_button_;
+  WindowSelectorItem::RoundedContainerView* background_;
 
   DISALLOW_COPY_AND_ASSIGN(CaptionContainerView);
 };
@@ -265,10 +408,12 @@ WindowSelectorItem::WindowSelectorItem(WmWindow* window,
       root_window_(window->GetRootWindow()),
       transform_window_(window),
       in_bounds_update_(false),
+      selected_(false),
       caption_container_view_(nullptr),
       window_label_button_view_(nullptr),
       close_button_(new OverviewCloseButton(this)),
-      window_selector_(window_selector) {
+      window_selector_(window_selector),
+      background_view_(nullptr) {
   CreateWindowLabel(window->GetTitle());
   if (!ash::MaterialDesignController::IsOverviewMaterial()) {
     views::Widget::InitParams params;
@@ -300,6 +445,8 @@ WindowSelectorItem::WindowSelectorItem(WmWindow* window,
 }
 
 WindowSelectorItem::~WindowSelectorItem() {
+  if (background_view_)
+    background_view_->OnItemRestored();
   GetWindow()->RemoveObserver(this);
 }
 
@@ -308,7 +455,28 @@ WmWindow* WindowSelectorItem::GetWindow() {
 }
 
 void WindowSelectorItem::RestoreWindow() {
+  window_label_button_view_->ResetListener();
+  close_button_->ResetListener();
   transform_window_.RestoreWindow();
+  if (background_view_)
+    background_view_->OnItemRestored();
+  UpdateHeaderLayout(
+      HeaderFadeInMode::EXIT,
+      OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS);
+}
+
+void WindowSelectorItem::Shutdown() {
+  if (transform_window_.GetTopInset()) {
+    // Activating a window (even when it is the window that was active before
+    // overview) results in stacking it at the top. Maintain the label window
+    // stacking position above the item to make the header transformation more
+    // gradual upon exiting the overview mode.
+    WmWindow* label_window =
+        WmLookup::Get()->GetWindowForWidget(window_label_.get());
+    label_window->GetParent()->StackChildAbove(label_window,
+                                               transform_window_.window());
+  }
+  FadeOut(std::move(window_label_));
 }
 
 void WindowSelectorItem::ShowWindowOnExit() {
@@ -339,7 +507,7 @@ void WindowSelectorItem::SetBounds(const gfx::Rect& target_bounds,
 
   // SetItemBounds is called before UpdateHeaderLayout so the header can
   // properly use the updated windows bounds.
-  UpdateHeaderLayout(animation_type);
+  UpdateHeaderLayout(HeaderFadeInMode::UPDATE, animation_type);
   if (!ash::MaterialDesignController::IsOverviewMaterial())
     UpdateWindowLabel(target_bounds, animation_type);
 }
@@ -347,28 +515,21 @@ void WindowSelectorItem::SetBounds(const gfx::Rect& target_bounds,
 void WindowSelectorItem::SetSelected(bool selected) {
   if (!ash::MaterialDesignController::IsOverviewMaterial())
     return;
-  WmWindow* window =
-      WmLookup::Get()->GetWindowForWidget(window_label_selector_.get());
-  ui::ScopedLayerAnimationSettings animation_settings(
-      window->GetLayer()->GetAnimator());
-  animation_settings.SetTransitionDuration(
-      base::TimeDelta::FromMilliseconds(kSelectorFadeInMilliseconds));
-  animation_settings.SetTweenType(selected ? gfx::Tween::FAST_OUT_LINEAR_IN
-                                           : gfx::Tween::LINEAR_OUT_SLOW_IN);
-  animation_settings.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-  window->SetOpacity(selected ? 0.0f : 1.0f);
-
-  ui::ScopedLayerAnimationSettings animation_settings_shadow(
-      shadow_->shadow_layer()->GetAnimator());
-  animation_settings_shadow.SetTransitionDuration(
-      base::TimeDelta::FromMilliseconds(kSelectorFadeInMilliseconds));
-  animation_settings_shadow.SetTweenType(selected
-                                             ? gfx::Tween::FAST_OUT_LINEAR_IN
-                                             : gfx::Tween::LINEAR_OUT_SLOW_IN);
-  animation_settings_shadow.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-  shadow_->shadow_layer()->SetOpacity(selected ? 0.0f : 1.0f);
+  selected_ = selected;
+  background_view_->AnimateBackgroundOpacity(selected ? 0.f : kHeaderOpacity);
+
+  if (shadow_) {
+    ui::ScopedLayerAnimationSettings animation_settings_shadow(
+        shadow_->shadow_layer()->GetAnimator());
+    animation_settings_shadow.SetTransitionDuration(
+        base::TimeDelta::FromMilliseconds(kSelectorFadeInMilliseconds));
+    animation_settings_shadow.SetTweenType(
+        selected ? gfx::Tween::FAST_OUT_LINEAR_IN
+                 : gfx::Tween::LINEAR_OUT_SLOW_IN);
+    animation_settings_shadow.SetPreemptionStrategy(
+        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+    shadow_->shadow_layer()->SetOpacity(selected ? 0.0f : 1.0f);
+  }
 }
 
 void WindowSelectorItem::RecomputeWindowTransforms() {
@@ -381,7 +542,8 @@ void WindowSelectorItem::RecomputeWindowTransforms() {
   else
     inset_bounds.Inset(kWindowMargin, kWindowMargin);
   SetItemBounds(inset_bounds, OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
-  UpdateHeaderLayout(OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
+  UpdateHeaderLayout(HeaderFadeInMode::UPDATE,
+                     OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
 }
 
 void WindowSelectorItem::SendAccessibleSelectionEvent() {
@@ -409,6 +571,10 @@ void WindowSelectorItem::CloseWindow() {
   transform_window_.Close();
 }
 
+void WindowSelectorItem::HideHeaderAndSetShape(int radius) {
+  transform_window_.HideHeaderAndSetShape(use_mask_, use_shape_, radius);
+}
+
 void WindowSelectorItem::SetDimmed(bool dimmed) {
   dimmed_ = dimmed;
   SetOpacity(dimmed ? kDimmedItemOpacity : 1.0f);
@@ -473,17 +639,17 @@ void WindowSelectorItem::SetItemBounds(const gfx::Rect& target_bounds,
       screen_rect, selector_item_bounds);
   ScopedTransformOverviewWindow::ScopedAnimationSettings animation_settings;
   transform_window_.BeginScopedAnimation(animation_type, &animation_settings);
-  // Rounded corners are achieved by using a mask layer on the original window
-  // before the transform. Dividing by scale factor obtains the corner radius
-  // which when scaled will yield |kLabelBackgroundRadius|.
-  transform_window_.SetTransform(
-      root_window_, transform, use_mask_, use_shape_,
-      (kLabelBackgroundRadius / GetItemScale(target_bounds.size())));
+  transform_window_.SetTransform(root_window_, transform, use_mask_);
   transform_window_.set_overview_transform(transform);
 }
 
 void WindowSelectorItem::SetOpacity(float opacity) {
   window_label_->SetOpacity(opacity);
+  if (background_view_) {
+    background_view_->AnimateBackgroundOpacity(
+        selected_ ? 0.f : kHeaderOpacity * opacity);
+  }
+
   if (!ash::MaterialDesignController::IsOverviewMaterial())
     close_button_widget_->SetOpacity(opacity);
 
@@ -514,23 +680,47 @@ void WindowSelectorItem::UpdateWindowLabel(
 
 void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
   const bool material = ash::MaterialDesignController::IsOverviewMaterial();
-  window_label_.reset(new views::Widget);
-  views::Widget::InitParams params;
-  params.type = views::Widget::InitParams::TYPE_POPUP;
-  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
-  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
-  params.visible_on_all_workspaces = true;
-  params.name = "OverviewModeLabel";
-  window_label_->set_focus_on_creation(false);
+  if (material) {
+    background_view_ = new RoundedContainerView(
+        this, transform_window_.window(), kLabelBackgroundRadius,
+        transform_window_.GetTopColor());
+    // |background_view_| will get added as a child to CaptionContainerView.
+  }
+  views::Widget::InitParams params_label;
+  params_label.type = views::Widget::InitParams::TYPE_POPUP;
+  params_label.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  params_label.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
+  params_label.visible_on_all_workspaces = true;
+  params_label.name = "OverviewModeLabel";
+  params_label.activatable =
+      views::Widget::InitParams::Activatable::ACTIVATABLE_DEFAULT;
+  params_label.accept_events = true;
   root_window_->GetRootWindowController()
       ->ConfigureWidgetInitParamsForContainer(
-          window_label_.get(), kShellWindowId_StatusContainer, &params);
-  window_label_->Init(params);
+          window_label_.get(),
+          transform_window_.window()->GetParent()->GetShellWindowId(),
+          &params_label);
+  window_label_.reset(new views::Widget);
+  window_label_->set_focus_on_creation(false);
+  window_label_->Init(params_label);
   window_label_button_view_ = new OverviewLabelButton(this, title);
   window_label_button_view_->SetBorder(views::Border::NullBorder());
   window_label_button_view_->SetEnabledTextColors(kLabelColor);
   window_label_button_view_->set_animate_on_state_change(false);
   if (material) {
+    WmWindow* label_window =
+        WmLookup::Get()->GetWindowForWidget(window_label_.get());
+    if (transform_window_.GetTopInset()) {
+      // For windows with headers the overview header fades in above the
+      // original window header.
+      label_window->GetParent()->StackChildAbove(label_window,
+                                                 transform_window_.window());
+    } else {
+      // For tabbed windows the overview header slides from behind. The stacking
+      // is then corrected when the animation completes.
+      label_window->GetParent()->StackChildBelow(label_window,
+                                                 transform_window_.window());
+    }
     window_label_button_view_->SetHorizontalAlignment(gfx::ALIGN_LEFT);
   } else {
     window_label_button_view_->SetHorizontalAlignment(gfx::ALIGN_CENTER);
@@ -545,28 +735,27 @@ void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
     // Hint at the background color that the label will be drawn onto (for
     // subpixel antialiasing). Does not actually set the background color.
     window_label_button_view_->SetBackgroundColorHint(kLabelBackgroundColor);
-    caption_container_view_ =
-        new CaptionContainerView(window_label_button_view_, close_button_);
+    caption_container_view_ = new CaptionContainerView(
+        window_label_button_view_, close_button_, background_view_);
     window_label_->SetContentsView(caption_container_view_);
     window_label_button_view_->SetVisible(false);
+    window_label_->SetOpacity(0);
     window_label_->Show();
 
-    shadow_.reset(new ::wm::Shadow());
-    shadow_->Init(::wm::Shadow::STYLE_INACTIVE);
-    shadow_->layer()->SetVisible(true);
-    window_label_->GetLayer()->Add(shadow_->layer());
+    // TODO(varkha): Restore shadows when programmatic shadows exist.
+    // Note: current shadow implementation does not allow proper animation when
+    // the parent layer bounds change during the animation since
+    // Shadow::UpdateLayerBounds() only happens before the animation starts.
+    if (ash::MaterialDesignController::GetMode() ==
+        ash::MaterialDesignController::Mode::MATERIAL_EXPERIMENTAL) {
+      shadow_.reset(new ::wm::Shadow());
+      shadow_->Init(::wm::Shadow::STYLE_INACTIVE);
+      shadow_->layer()->SetVisible(true);
+      window_label_->GetLayer()->Add(shadow_->layer());
+    }
     window_label_->GetLayer()->SetMasksToBounds(false);
-
-    views::View* background_view =
-        new RoundedContainerView(kLabelBackgroundRadius, kLabelBackgroundColor);
-    window_label_selector_.reset(new views::Widget);
-    params.activatable = views::Widget::InitParams::Activatable::ACTIVATABLE_NO;
-    params.accept_events = false;
-    params.name = "OverviewModeLabelSelector";
-    window_label_selector_->Init(params);
-    window_label_selector_->set_focus_on_creation(false);
-    window_label_selector_->SetContentsView(background_view);
-    window_label_selector_->Show();
+    UpdateHeaderLayout(HeaderFadeInMode::ENTER,
+                       OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
   } else {
     // Indicate that the label will be drawn onto a transparent background
     // (disables subpixel antialiasing).
@@ -576,50 +765,65 @@ void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
 }
 
 void WindowSelectorItem::UpdateHeaderLayout(
+    HeaderFadeInMode mode,
     OverviewAnimationType animation_type) {
   gfx::Rect transformed_window_bounds = root_window_->ConvertRectFromScreen(
       transform_window_.GetTransformedBounds(hide_header()));
 
   if (ash::MaterialDesignController::IsOverviewMaterial()) {
     gfx::Rect label_rect(close_button_->GetPreferredSize());
-    label_rect.set_y(-label_rect.height());
     label_rect.set_width(transformed_window_bounds.width());
-
+    // For tabbed windows the initial bounds of the caption are set such that it
+    // appears to be "growing" up from the window content area.
+    label_rect.set_y(
+        (mode != HeaderFadeInMode::ENTER || transform_window_.GetTopInset())
+            ? -label_rect.height()
+            : 0);
+    if (background_view_) {
+      if (mode == HeaderFadeInMode::ENTER) {
+        background_view_->ObserveLayerAnimations(window_label_->GetLayer());
+        background_view_->set_color(kLabelBackgroundColor);
+        // The color will be animated only once the label widget is faded in.
+      } else if (mode == HeaderFadeInMode::EXIT) {
+        // Normally the observer is disconnected when the fade-in animations
+        // complete but some tests invoke animations with |NON_ZERO_DURATION|
+        // without waiting for completion so do it here.
+        background_view_->StopObservingLayerAnimations();
+        // Make the header visible above the window. It will be faded out when
+        // the Shutdown() is called.
+        background_view_->AnimateColor(gfx::Tween::EASE_OUT,
+                                       kExitFadeInMilliseconds);
+        background_view_->set_color(kLabelExitColor);
+      }
+    }
     if (!window_label_button_view_->visible()) {
       window_label_button_view_->SetVisible(true);
       SetupFadeInAfterLayout(window_label_.get());
-      SetupFadeInAfterLayout(window_label_selector_.get());
     }
     WmWindow* window_label_window =
         WmLookup::Get()->GetWindowForWidget(window_label_.get());
-    WmWindow* window_label_selector_window =
-        WmLookup::Get()->GetWindowForWidget(window_label_selector_.get());
     std::unique_ptr<ScopedOverviewAnimationSettings> animation_settings =
         ScopedOverviewAnimationSettingsFactory::Get()
             ->CreateOverviewAnimationSettings(animation_type,
                                               window_label_window);
-    std::unique_ptr<ScopedOverviewAnimationSettings>
-        animation_settings_selector =
-            ScopedOverviewAnimationSettingsFactory::Get()
-                ->CreateOverviewAnimationSettings(animation_type,
-                                                  window_label_selector_window);
-    window_label_selector_window->SetBounds(label_rect);
     // |window_label_window| covers both the transformed window and the header
     // as well as the gap between the windows to prevent events from reaching
     // the window including its sizing borders.
-    label_rect.set_height(label_rect.height() +
-                          transformed_window_bounds.height());
-    gfx::Rect shadow_bounds(label_rect.size());
+    if (mode != HeaderFadeInMode::ENTER) {
+      label_rect.set_height(close_button_->GetPreferredSize().height() +
+                            transformed_window_bounds.height());
+    }
     label_rect.Inset(-kWindowSelectorMargin, -kWindowSelectorMargin);
     window_label_window->SetBounds(label_rect);
     gfx::Transform label_transform;
     label_transform.Translate(transformed_window_bounds.x(),
                               transformed_window_bounds.y());
     window_label_window->SetTransform(label_transform);
-    window_label_selector_window->SetTransform(label_transform);
 
-    shadow_bounds.Offset(kWindowSelectorMargin, kWindowSelectorMargin);
-    shadow_->SetContentBounds(shadow_bounds);
+    gfx::Rect shadow_bounds(label_rect.size());
+    shadow_bounds.Inset(kWindowSelectorMargin, kWindowSelectorMargin);
+    if (shadow_)
+      shadow_->SetContentBounds(shadow_bounds);
   } else {
     if (!close_button_->visible()) {
       close_button_->SetVisible(true);
@@ -647,21 +851,14 @@ void WindowSelectorItem::AnimateOpacity(float opacity,
   transform_window_.BeginScopedAnimation(animation_type, &animation_settings);
   transform_window_.SetOpacity(opacity);
 
+  const float header_opacity = selected_ ? 0.f : kHeaderOpacity * opacity;
   WmWindow* window_label_window =
       WmLookup::Get()->GetWindowForWidget(window_label_.get());
   std::unique_ptr<ScopedOverviewAnimationSettings> animation_settings_label =
       ScopedOverviewAnimationSettingsFactory::Get()
           ->CreateOverviewAnimationSettings(animation_type,
                                             window_label_window);
-  window_label_window->SetOpacity(opacity);
-
-  WmWindow* window_label_selector_window =
-      WmLookup::Get()->GetWindowForWidget(window_label_selector_.get());
-  std::unique_ptr<ScopedOverviewAnimationSettings> animation_settings_selector =
-      ScopedOverviewAnimationSettingsFactory::Get()
-          ->CreateOverviewAnimationSettings(animation_type,
-                                            window_label_selector_window);
-  window_label_selector_window->SetOpacity(opacity);
+  window_label_window->SetOpacity(header_opacity);
 }
 
 void WindowSelectorItem::UpdateCloseButtonAccessibilityName() {
@@ -670,4 +867,29 @@ void WindowSelectorItem::UpdateCloseButtonAccessibilityName() {
       GetWindow()->GetTitle()));
 }
 
+void WindowSelectorItem::FadeOut(std::unique_ptr<views::Widget> widget) {
+  widget->SetOpacity(1.f);
+
+  // Fade out the widget. This animation continues past the lifetime of |this|.
+  WmWindow* widget_window = WmLookup::Get()->GetWindowForWidget(widget.get());
+  std::unique_ptr<ScopedOverviewAnimationSettings> animation_settings =
+      ScopedOverviewAnimationSettingsFactory::Get()
+          ->CreateOverviewAnimationSettings(
+              OverviewAnimationType::
+                  OVERVIEW_ANIMATION_EXIT_OVERVIEW_MODE_FADE_OUT,
+              widget_window);
+  // CleanupAnimationObserver will delete itself (and the widget) when the
+  // opacity animation is complete.
+  // Ownership over the observer is passed to the window_selector_->delegate()
+  // which has longer lifetime so that animations can continue even after the
+  // overview mode is shut down.
+  views::Widget* widget_ptr = widget.get();
+  std::unique_ptr<CleanupAnimationObserver> observer(
+      new CleanupAnimationObserver(std::move(widget)));
+  animation_settings->AddObserver(observer.get());
+  window_selector_->delegate()->AddDelayedAnimationObserver(
+      std::move(observer));
+  widget_ptr->SetOpacity(0.f);
+}
+
 }  // namespace ash