wip: Refactoring Ash's AppListController, moving the bulk of the logic to chrome/browser/ui/ash/app…

ash/wm/app_list_layout_delegate.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/wm/app_list_controller.h"
+#include "ash/wm/app_list_layout_delegate.h"
 
 #include "ash/ash_switches.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
 #include "base/command_line.h"
+#include "base/memory/singleton.h"
 #include "ui/app_list/app_list_constants.h"
+#include "ui/app_list/app_list_controller.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/events/event.h"
 #include "ui/gfx/transform_util.h"
 #include "ui/keyboard/keyboard_controller.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
 namespace {
 
-// Duration for show/hide animation in milliseconds.
-const int kAnimationDurationMs = 200;
-
 // Offset in pixels to animation away/towards the shelf.
 const int kAnimationOffset = 8;
 
-// The maximum shift in pixels when over-scroll happens.
-const int kMaxOverScrollShift = 48;
-
 // The minimal anchor position offset to make sure that the bubble is still on
 // the screen with 8 pixels spacing on the left / right. This constant is a
 // result of minimal bubble arrow sizes and offsets.
 const int kMinimalAnchorPositionOffset = 57;
 
 // The minimal margin (in pixels) around the app list when in centered mode.
 const int kMinimalCenteredAppListMargin = 10;
 
-ui::Layer* GetLayer(views::Widget* widget) {
-  return widget->GetNativeView()->layer();
-}
-
 // Gets arrow location based on shelf alignment.
 views::BubbleBorder::Arrow GetBubbleArrow(aura::Window* window) {
   DCHECK(Shell::HasInstance());
-  return ShelfLayoutManager::ForShelf(window)->
-      SelectValueForShelfAlignment(
-          views::BubbleBorder::BOTTOM_CENTER,
-          views::BubbleBorder::LEFT_CENTER,
-          views::BubbleBorder::RIGHT_CENTER,
-          views::BubbleBorder::TOP_CENTER);
-}
-
-// Offset given |rect| towards shelf.
-gfx::Rect OffsetTowardsShelf(const gfx::Rect& rect, views::Widget* widget) {
-  DCHECK(Shell::HasInstance());
-  ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
-      widget->GetNativeView()->GetRootWindow());
-  gfx::Rect offseted(rect);
-  switch (shelf_alignment) {
-    case SHELF_ALIGNMENT_BOTTOM:
-      offseted.Offset(0, kAnimationOffset);
-      break;
-    case SHELF_ALIGNMENT_LEFT:
-      offseted.Offset(-kAnimationOffset, 0);
-      break;
-    case SHELF_ALIGNMENT_RIGHT:
-      offseted.Offset(kAnimationOffset, 0);
-      break;
-    case SHELF_ALIGNMENT_TOP:
-      offseted.Offset(0, -kAnimationOffset);
-      break;
-  }
-
-  return offseted;
+  return ShelfLayoutManager::ForShelf(window)->SelectValueForShelfAlignment(
+      views::BubbleBorder::BOTTOM_CENTER, views::BubbleBorder::LEFT_CENTER,
+      views::BubbleBorder::RIGHT_CENTER, views::BubbleBorder::TOP_CENTER);
 }
 
 // Using |button_bounds|, determine the anchor offset so that the bubble gets
 // shown above the shelf (used for the alternate shelf theme).
 gfx::Vector2d GetAnchorPositionOffsetToShelf(
     const gfx::Rect& button_bounds, views::Widget* widget) {
   DCHECK(Shell::HasInstance());
   ShelfAlignment shelf_alignment = Shell::GetInstance()->GetShelfAlignment(
       widget->GetNativeView()->GetRootWindow());
   gfx::Point anchor(button_bounds.CenterPoint());
@@ skipping 57 matching lines @@
              switches::kAshEnableFullscreenAppList) &&
          app_list::switches::IsExperimentalAppListEnabled();
 #else
   return false;
 #endif
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, public:
+// AppListLayoutDelegate, public:
 
-AppListController::AppListController()
+AppListLayoutDelegate::AppListLayoutDelegate(
+    app_list::AppListController* controller)
     : is_visible_(false),
       is_centered_(false),
-      view_(NULL),
-      current_apps_page_(-1),
-      should_snap_back_(false) {
+      controller_(controller),
+      view_(NULL) {
   Shell::GetInstance()->AddShellObserver(this);
 }
 
-AppListController::~AppListController() {
-  // Ensures app list view goes before the controller since pagination model
-  // lives in the controller and app list view would access it on destruction.
-  if (view_) {
-    view_->GetAppsPaginationModel()->RemoveObserver(this);
-    if (view_->GetWidget())
-      view_->GetWidget()->CloseNow();
-  }
-
+AppListLayoutDelegate::~AppListLayoutDelegate() {
+  views::Widget* widget = view_->GetWidget();
+  Shell::GetInstance()->RemovePreTargetHandler(this);
+  Shelf::ForWindow(widget->GetNativeWindow())->RemoveIconObserver(this);
   Shell::GetInstance()->RemoveShellObserver(this);
 }
 
-void AppListController::Show(aura::Window* window) {
-  if (is_visible_)
-    return;
-
-  is_visible_ = true;
-
+void AppListLayoutDelegate::Init(app_list::AppListView* view,
+                                 aura::Window* root_window,
+                                 int current_apps_page) {
   // App list needs to know the new shelf layout in order to calculate its
   // UI layout when AppListView visibility changes.
-  Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager()->
-      UpdateAutoHideState();
+  ash::Shell::GetPrimaryRootWindowController()
+      ->GetShelfLayoutManager()
+      ->UpdateAutoHideState();
+  view_ = view;
+  aura::Window* container = GetRootWindowController(root_window)
+                                ->GetContainer(kShellWindowId_AppListContainer);
+  views::View* applist_button =
+      Shelf::ForWindow(container)->GetAppListButtonView();
+  is_centered_ = view->ShouldCenterWindow();
+  bool is_fullscreen = IsFullscreenAppListEnabled() &&
+                       Shell::GetInstance()
+                           ->maximize_mode_controller()
+                           ->IsMaximizeModeWindowManagerEnabled();
+  if (is_fullscreen) {
+    view->InitAsFramelessWindow(
+        container, current_apps_page,
+        ScreenUtil::GetDisplayWorkAreaBoundsInParent(container));
+  } else if (is_centered_) {
+    // Note: We can't center the app list until we have its dimensions, so we
+    // init at (0, 0) and then reset its anchor point.
+    view->InitAsBubbleAtFixedLocation(container,
+                                      current_apps_page,
+                                      gfx::Point(),
+                                      views::BubbleBorder::FLOAT,
+                                      true /* border_accepts_events */);
+    // The experimental app list is centered over the display of the app list
+    // button that was pressed (if triggered via keyboard, this is the display
+    // with the currently focused window).
+    view->SetAnchorPoint(GetCenterOfDisplayForView(
+        applist_button, GetMinimumBoundsHeightForAppList(view)));
+  } else {
+    gfx::Rect applist_button_bounds = applist_button->GetBoundsInScreen();
+    // We need the location of the button within the local screen.
+    applist_button_bounds = ScreenUtil::ConvertRectFromScreen(
+        root_window,
+        applist_button_bounds);
+    view->InitAsBubbleAttachedToAnchor(
+        container,
+        current_apps_page,
+        Shelf::ForWindow(container)->GetAppListButtonView(),
+        GetAnchorPositionOffsetToShelf(
+            applist_button_bounds,
+            Shelf::ForWindow(container)->GetAppListButtonView()->GetWidget()),
+        GetBubbleArrow(container),
+        true /* border_accepts_events */);
+    view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);
+  }
 
-  if (view_) {
-    ScheduleAnimation();
-  } else {
-    // Note the AppListViewDelegate outlives the AppListView. For Ash, the view
-    // is destroyed when dismissed.
-    app_list::AppListView* view = new app_list::AppListView(
-        Shell::GetInstance()->delegate()->GetAppListViewDelegate());
-    aura::Window* root_window = window->GetRootWindow();
-    aura::Window* container = GetRootWindowController(root_window)->
-        GetContainer(kShellWindowId_AppListContainer);
-    views::View* applist_button =
-        Shelf::ForWindow(container)->GetAppListButtonView();
-    is_centered_ = view->ShouldCenterWindow();
-    bool is_fullscreen = IsFullscreenAppListEnabled() &&
-                         Shell::GetInstance()
-                             ->maximize_mode_controller()
-                             ->IsMaximizeModeWindowManagerEnabled();
-    if (is_fullscreen) {
-      view->InitAsFramelessWindow(
-          container, current_apps_page_,
-          ScreenUtil::GetDisplayWorkAreaBoundsInParent(container));
-    } else if (is_centered_) {
-      // Note: We can't center the app list until we have its dimensions, so we
-      // init at (0, 0) and then reset its anchor point.
-      view->InitAsBubbleAtFixedLocation(container,
-                                        current_apps_page_,
-                                        gfx::Point(),
-                                        views::BubbleBorder::FLOAT,
-                                        true /* border_accepts_events */);
-      // The experimental app list is centered over the display of the app list
-      // button that was pressed (if triggered via keyboard, this is the display
-      // with the currently focused window).
-      view->SetAnchorPoint(GetCenterOfDisplayForView(
-          applist_button, GetMinimumBoundsHeightForAppList(view)));
-    } else {
-      gfx::Rect applist_button_bounds = applist_button->GetBoundsInScreen();
-      // We need the location of the button within the local screen.
-      applist_button_bounds = ScreenUtil::ConvertRectFromScreen(
-          root_window,
-          applist_button_bounds);
-      view->InitAsBubbleAttachedToAnchor(
-          container,
-          current_apps_page_,
-          Shelf::ForWindow(container)->GetAppListButtonView(),
-          GetAnchorPositionOffsetToShelf(
-              applist_button_bounds,
-              Shelf::ForWindow(container)->GetAppListButtonView()->GetWidget()),
-          GetBubbleArrow(container),
-          true /* border_accepts_events */);
-      view->SetArrowPaintType(views::BubbleBorder::PAINT_NONE);
-    }
-    SetView(view);
-    // By setting us as DnD recipient, the app list knows that we can
-    // handle items.
-    SetDragAndDropHostOfCurrentAppList(
-        Shelf::ForWindow(window)->GetDragAndDropHostForAppList());
-  }
-  // Update applist button status when app list visibility is changed.
-  Shelf::ForWindow(window)->GetAppListButtonView()->SchedulePaint();
+  Shell::GetInstance()->AddPreTargetHandler(this);
+  views::Widget* widget = view->GetWidget();
+  Shelf::ForWindow(widget->GetNativeWindow())->AddIconObserver(this);
+
+  // By setting us as DnD recipient, the app list knows that we can
+  // handle items.
+  view->SetDragAndDropHostOfCurrentAppList(
+      Shelf::ForWindow(root_window)->GetDragAndDropHostForAppList());
 }
 
-void AppListController::Dismiss() {
-  if (!is_visible_)
-    return;
+void AppListLayoutDelegate::OnShown(aura::Window* root_window) {
+  is_visible_ = true;
+  // Update applist button status when app list visibility is changed.
+  Shelf::ForWindow(root_window)->GetAppListButtonView()->SchedulePaint();
+}
 
-  // If the app list is currently visible, there should be an existing view.
+void AppListLayoutDelegate::OnDismissed() {
+  DCHECK(is_visible_);
   DCHECK(view_);
 
   is_visible_ = false;
 
   // App list needs to know the new shelf layout in order to calculate its
   // UI layout when AppListView visibility changes.
   Shell::GetPrimaryRootWindowController()
       ->GetShelfLayoutManager()
       ->UpdateAutoHideState();
 
-  // Our widget is currently active. When the animation completes we'll hide
-  // the widget, changing activation. If a menu is shown before the animation
-  // completes then the activation change triggers the menu to close. By
-  // deactivating now we ensure there is no activation change when the
-  // animation completes and any menus stay open.
-  view_->GetWidget()->Deactivate();
-  ScheduleAnimation();
-
   // Update applist button status when app list visibility is changed.
   Shelf::ForWindow(view_->GetWidget()->GetNativeView())
       ->GetAppListButtonView()
       ->SchedulePaint();
 }
 
-bool AppListController::IsVisible() const {
-  return view_ && view_->GetWidget()->IsVisible();
+void AppListLayoutDelegate::UpdateBounds() {
+  if (!view_ || !is_visible_)
+    return;
+
+  view_->UpdateBounds();
+
+  if (is_centered_)
+    view_->SetAnchorPoint(GetCenterOfDisplayForView(
+        view_, GetMinimumBoundsHeightForAppList(view_)));
 }
 
-aura::Window* AppListController::GetWindow() {
-  return is_visible_ && view_ ? view_->GetWidget()->GetNativeWindow() : NULL;
+gfx::Vector2d AppListLayoutDelegate::GetVisibilityAnimationOffset(
+    aura::Window* root_window) {
+  DCHECK(Shell::HasInstance());
+
+  // App list needs to know the new shelf layout in order to calculate its
+  // UI layout when AppListView visibility changes.
+  Shell::GetPrimaryRootWindowController()
+      ->GetShelfLayoutManager()
+      ->UpdateAutoHideState();
+
+  ShelfAlignment shelf_alignment =
+      Shell::GetInstance()->GetShelfAlignment(root_window);
+  switch (shelf_alignment) {
+    case SHELF_ALIGNMENT_BOTTOM:
+      return gfx::Vector2d(0, kAnimationOffset);
+    case SHELF_ALIGNMENT_LEFT:
+      return gfx::Vector2d(-kAnimationOffset, 0);
+    case SHELF_ALIGNMENT_RIGHT:
+      return gfx::Vector2d(kAnimationOffset, 0);
+    case SHELF_ALIGNMENT_TOP:
+      return gfx::Vector2d(0, -kAnimationOffset);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, private:
+// AppListLayoutDelegate, private:
 
-void AppListController::SetDragAndDropHostOfCurrentAppList(
-    app_list::ApplicationDragAndDropHost* drag_and_drop_host) {
-  if (view_ && is_visible_)
-    view_->SetDragAndDropHostOfCurrentAppList(drag_and_drop_host);
-}
-
-void AppListController::SetView(app_list::AppListView* view) {
-  DCHECK(view_ == NULL);
-  DCHECK(is_visible_);
-
-  view_ = view;
-  views::Widget* widget = view_->GetWidget();
-  widget->AddObserver(this);
-  keyboard::KeyboardController* keyboard_controller =
-      keyboard::KeyboardController::GetInstance();
-  if (keyboard_controller)
-    keyboard_controller->AddObserver(this);
-  Shell::GetInstance()->AddPreTargetHandler(this);
-  Shelf::ForWindow(widget->GetNativeWindow())->AddIconObserver(this);
-  widget->GetNativeView()->GetRootWindow()->AddObserver(this);
-  aura::client::GetFocusClient(widget->GetNativeView())->AddObserver(this);
-
-  view_->GetAppsPaginationModel()->AddObserver(this);
-
-  view_->ShowWhenReady();
-}
-
-void AppListController::ResetView() {
-  if (!view_)
-    return;
-
-  views::Widget* widget = view_->GetWidget();
-  widget->RemoveObserver(this);
-  GetLayer(widget)->GetAnimator()->RemoveObserver(this);
-  keyboard::KeyboardController* keyboard_controller =
-      keyboard::KeyboardController::GetInstance();
-  if (keyboard_controller)
-    keyboard_controller->RemoveObserver(this);
-  Shell::GetInstance()->RemovePreTargetHandler(this);
-  Shelf::ForWindow(widget->GetNativeWindow())->RemoveIconObserver(this);
-  widget->GetNativeView()->GetRootWindow()->RemoveObserver(this);
-  aura::client::GetFocusClient(widget->GetNativeView())->RemoveObserver(this);
-
-  view_->GetAppsPaginationModel()->RemoveObserver(this);
-
-  view_ = NULL;
-}
-
-void AppListController::ScheduleAnimation() {
-  // Stop observing previous animation.
-  StopObservingImplicitAnimations();
-
-  views::Widget* widget = view_->GetWidget();
-  ui::Layer* layer = GetLayer(widget);
-  layer->GetAnimator()->StopAnimating();
-
-  gfx::Rect target_bounds;
-  if (is_visible_) {
-    target_bounds = widget->GetWindowBoundsInScreen();
-    widget->SetBounds(OffsetTowardsShelf(target_bounds, widget));
-  } else {
-    target_bounds = OffsetTowardsShelf(widget->GetWindowBoundsInScreen(),
-                                       widget);
-  }
-
-  ui::ScopedLayerAnimationSettings animation(layer->GetAnimator());
-  animation.SetTransitionDuration(
-      base::TimeDelta::FromMilliseconds(
-          is_visible_ ? 0 : kAnimationDurationMs));
-  animation.AddObserver(this);
-
-  layer->SetOpacity(is_visible_ ? 1.0 : 0.0);
-  widget->SetBounds(target_bounds);
-}
-
-void AppListController::ProcessLocatedEvent(ui::LocatedEvent* event) {
+void AppListLayoutDelegate::ProcessLocatedEvent(ui::LocatedEvent* event) {
   if (!view_ || !is_visible_)
     return;
 
   // If the event happened on a menu, then the event should not close the app
   // list.
   aura::Window* target = static_cast<aura::Window*>(event->target());
   if (target) {
     RootWindowController* root_controller =
         GetRootWindowController(target->GetRootWindow());
     if (root_controller) {
       aura::Window* menu_container =
           root_controller->GetContainer(kShellWindowId_MenuContainer);
       if (menu_container->Contains(target))
         return;
       aura::Window* keyboard_container = root_controller->GetContainer(
           kShellWindowId_VirtualKeyboardContainer);
       if (keyboard_container->Contains(target))
         return;
     }
   }
 
   aura::Window* window = view_->GetWidget()->GetNativeView()->parent();
   if (!window->Contains(target) &&
       !app_list::switches::ShouldNotDismissOnBlur()) {
-    Dismiss();
+    controller_->Dismiss();
   }
 }
 
-void AppListController::UpdateBounds() {
-  if (!view_ || !is_visible_)
-    return;
+////////////////////////////////////////////////////////////////////////////////
+// AppListLayoutDelegate, aura::EventFilter implementation:
 
-  view_->UpdateBounds();
-
-  if (is_centered_)
-    view_->SetAnchorPoint(GetCenterOfDisplayForView(
-        view_, GetMinimumBoundsHeightForAppList(view_)));
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, aura::EventFilter implementation:
-
-void AppListController::OnMouseEvent(ui::MouseEvent* event) {
+void AppListLayoutDelegate::OnMouseEvent(ui::MouseEvent* event) {
   if (event->type() == ui::ET_MOUSE_PRESSED)
     ProcessLocatedEvent(event);
 }
 
-void AppListController::OnGestureEvent(ui::GestureEvent* event) {
+void AppListLayoutDelegate::OnGestureEvent(ui::GestureEvent* event) {
   if (event->type() == ui::ET_GESTURE_TAP_DOWN)
     ProcessLocatedEvent(event);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController,  aura::FocusObserver implementation:
-
-void AppListController::OnWindowFocused(aura::Window* gained_focus,
-                                        aura::Window* lost_focus) {
-  if (view_ && is_visible_) {
-    aura::Window* applist_window = view_->GetWidget()->GetNativeView();
-    aura::Window* applist_container = applist_window->parent();
-
-    if (applist_container->Contains(lost_focus) &&
-        (!gained_focus || !applist_container->Contains(gained_focus)) &&
-        !app_list::switches::ShouldNotDismissOnBlur()) {
-      Dismiss();
-    }
-  }
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController,  aura::WindowObserver implementation:
-void AppListController::OnWindowBoundsChanged(aura::Window* root,
-                                              const gfx::Rect& old_bounds,
-                                              const gfx::Rect& new_bounds) {
-  UpdateBounds();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, ui::ImplicitAnimationObserver implementation:
-
-void AppListController::OnImplicitAnimationsCompleted() {
-  if (is_visible_ )
-    view_->GetWidget()->Activate();
-  else
-    view_->GetWidget()->Close();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, views::WidgetObserver implementation:
-
-void AppListController::OnWidgetDestroying(views::Widget* widget) {
-  DCHECK(view_->GetWidget() == widget);
-  if (is_visible_)
-    Dismiss();
-  ResetView();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, keyboard::KeyboardControllerObserver implementation:
-
-void AppListController::OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) {
-  UpdateBounds();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, ShellObserver implementation:
-void AppListController::OnShelfAlignmentChanged(aura::Window* root_window) {
+// AppListLayoutDelegate, ShellObserver implementation:
+void AppListLayoutDelegate::OnShelfAlignmentChanged(aura::Window* root_window) {
   if (view_)
     view_->SetBubbleArrow(GetBubbleArrow(view_->GetWidget()->GetNativeView()));
 }
 
-void AppListController::OnMaximizeModeStarted() {
+void AppListLayoutDelegate::OnMaximizeModeStarted() {
   // The "fullscreen" app-list is initialized as in a different type of window,
   // therefore we can't switch between the fullscreen status and the normal
   // app-list bubble. App-list should be dismissed for the transition between
   // maximize mode (touch-view mode) and non-maximize mode, otherwise the app
   // list tries to behave as a bubble which leads to a crash. crbug.com/510062
   if (IsFullscreenAppListEnabled() && is_visible_)
-    Dismiss();
+    controller_->Dismiss();
 }
 
-void AppListController::OnMaximizeModeEnded() {
+void AppListLayoutDelegate::OnMaximizeModeEnded() {
   // See the comments of OnMaximizeModeStarted().
   if (IsFullscreenAppListEnabled() && is_visible_)
-    Dismiss();
+    controller_->Dismiss();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// AppListController, ShelfIconObserver implementation:
+// AppListLayoutDelegate, ShelfIconObserver implementation:
 
-void AppListController::OnShelfIconPositionsChanged() {
+void AppListLayoutDelegate::OnShelfIconPositionsChanged() {
   UpdateBounds();
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// AppListController, PaginationModelObserver implementation:
-
-void AppListController::TotalPagesChanged() {
-}
-
-void AppListController::SelectedPageChanged(int old_selected,
-                                            int new_selected) {
-  current_apps_page_ = new_selected;
-}
-
-void AppListController::TransitionStarted() {
-}
-
-void AppListController::TransitionChanged() {
-  // |view_| could be NULL when app list is closed with a running transition.
-  if (!view_)
-    return;
-
-  app_list::PaginationModel* pagination_model = view_->GetAppsPaginationModel();
-
-  const app_list::PaginationModel::Transition& transition =
-      pagination_model->transition();
-  if (pagination_model->is_valid_page(transition.target_page))
-    return;
-
-  views::Widget* widget = view_->GetWidget();
-  ui::LayerAnimator* widget_animator = GetLayer(widget)->GetAnimator();
-  if (!pagination_model->IsRevertingCurrentTransition()) {
-    // Update cached |view_bounds_| if it is the first over-scroll move and
-    // widget does not have running animations.
-    if (!should_snap_back_ && !widget_animator->is_animating())
-      view_bounds_ = widget->GetWindowBoundsInScreen();
-
-    const int current_page = pagination_model->selected_page();
-    const int dir = transition.target_page > current_page ? -1 : 1;
-
-    const double progress = 1.0 - pow(1.0 - transition.progress, 4);
-    const int shift = kMaxOverScrollShift * progress * dir;
-
-    gfx::Rect shifted(view_bounds_);
-    shifted.set_x(shifted.x() + shift);
-
-    widget->SetBounds(shifted);
-
-    should_snap_back_ = true;
-  } else if (should_snap_back_) {
-    should_snap_back_ = false;
-    ui::ScopedLayerAnimationSettings animation(widget_animator);
-    animation.SetTransitionDuration(base::TimeDelta::FromMilliseconds(
-        app_list::kOverscrollPageTransitionDurationMs));
-    widget->SetBounds(view_bounds_);
-  }
-}
-
 }  // namespace ash