Overview: Animation refactoring.

No functionality is changed in this CL.

Bug: None
Change-Id: Ib9a935b7a2b15254f21e79f996c28c5ff5e17895
Reviewed-on: https://chromium-review.googlesource.com/1149611
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577981}

ash/wm/overview/scoped_transform_overview_window.cc

@@ -254,7 +254,7 @@ void ScopedTransformOverviewWindow::BeginScopedAnimation(
     // ScopedOverviewAnimationSettings in order to monitor the complete of its
     // exiting animation.
     if (window == GetOverviewWindow() &&
-        selector_item_->ShouldBeObservedWhenExiting()) {
+        selector_item_->should_be_observed_when_exiting()) {
       auto window_animation_observer_weak_ptr =
           selector_item_->window_grid()->window_animation_observer();
       if (window_animation_observer_weak_ptr)
@@ -405,7 +405,7 @@ void ScopedTransformOverviewWindow::SetTransform(
     // If current |window_| should not animate during exiting process, we defer
     // set transfrom on the window by adding the layer and transform information
     // to the |window_animation_observer|.
-    if (!selector_item_->ShouldAnimateWhenExiting() &&
+    if (!selector_item_->should_animate_when_exiting() &&
         window_animation_observer_weak_ptr) {
       window_animation_observer_weak_ptr->AddLayerTransformPair(window->layer(),
                                                                 new_transform);

ash/wm/overview/window_grid.cc

@@ -345,10 +345,13 @@ void WindowGrid::PrepareForOverview() {
   prepared_for_overview_ = true;
 }
 
-void WindowGrid::PositionWindows(bool animate,
-                                 WindowSelectorItem* ignored_item) {
+void WindowGrid::PositionWindows(
+    bool animate,
+    WindowSelectorItem* ignored_item,
+    WindowSelector::OverviewTransition transition) {
   if (window_selector_->IsShuttingDown())
     return;
+  DCHECK_NE(transition, WindowSelector::OverviewTransition::kExit);
 
   DCHECK(shield_widget_.get());
   // Keep the background shield widget covering the whole screen. A grid without
@@ -368,15 +371,26 @@ void WindowGrid::PositionWindows(bool animate,
   // position |ignored_item| if it is not nullptr and matches a item in
   // |window_list_|.
   for (size_t i = 0; i < window_list_.size(); ++i) {
-    if (window_list_[i]->animating_to_close() ||
-        (ignored_item != nullptr && window_list_[i].get() == ignored_item)) {
+    WindowSelectorItem* window_item = window_list_[i].get();
+    if (window_item->animating_to_close() ||
+        (ignored_item != nullptr && window_item == ignored_item)) {
       continue;
     }
 
-    const bool should_animate = window_list_[i]->ShouldAnimateWhenEntering();
-    window_list_[i]->SetBounds(
+    // Calculate if each window item needs animation.
+    bool should_animate_item = animate;
+    // If we're in entering overview process, not all window items in the grid
+    // might need animation even if the grid needs animation.
+    if (animate && transition == WindowSelector::OverviewTransition::kEnter)
+      should_animate_item = window_item->should_animate_when_entering();
+    // Do not do the bounds animation for the new selector item. We'll do the
+    // opacity animation by ourselves.
+    if (IsNewSelectorItemWindow(window_item->GetWindow()))
+      should_animate_item = false;
+
+    window_item->SetBounds(
         rects[i],
-        animate && should_animate
+        should_animate_item
             ? OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS
             : OverviewAnimationType::OVERVIEW_ANIMATION_NONE);
   }
@@ -471,13 +485,6 @@ void WindowGrid::AddItem(aura::Window* window, bool reposition) {
       std::make_unique<WindowSelectorItem>(window, window_selector_, this));
   window_list_.back()->PrepareForOverview();
 
-  if (IsNewSelectorItemWindow(window)) {
-    // If we're adding the new selector item, don't do the layout animation.
-    // We'll do opacity animation by ourselves.
-    window_list_.back()->set_should_animate_when_entering(false);
-    window_list_.back()->set_should_animate_when_exiting(false);
-  }
-
   if (reposition)
     PositionWindows(/*animate=*/true);
 }
@@ -835,11 +842,6 @@ void WindowGrid::SetWindowListNotAnimatedWhenExiting() {
   }
 }
 
-void WindowGrid::ResetWindowListAnimationStates() {
-  for (const auto& selector_item : window_list_)
-    selector_item->ResetAnimationStates();
-}
-
 void WindowGrid::StartNudge(WindowSelectorItem* item) {
   // When there is one window left, there is no need to nudge.
   if (window_list_.size() <= 1) {

ash/wm/overview/window_grid.h

@@ -70,8 +70,11 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver,
   // fit that height. Optionally animates the windows to their targets when
   // |animate| is true. If |ignored_item| is not null and is an item in
   // |window_list_|, that item is not positioned. This is for split screen.
+  // |transition| specifies the overview state when this function is called.
   void PositionWindows(bool animate,
-                       WindowSelectorItem* ignored_item = nullptr);
+                       WindowSelectorItem* ignored_item = nullptr,
+                       WindowSelector::OverviewTransition transition =
+                           WindowSelector::OverviewTransition::kInOverview);
 
   // Updates |selected_index_| according to the specified |direction| and calls
   // MoveSelectionWidget(). Returns |true| if the new selection index is out of
@@ -206,10 +209,6 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver,
   // directly when the animation is completed.
   void SetWindowListNotAnimatedWhenExiting();
 
-  // Reset |selector_item|'s |should_animate_when_entering_|,
-  // |should_animate_when_exiting_| and |should_be_observed_when_exiting_|.
-  void ResetWindowListAnimationStates();
-
   // Starts a nudge, with |item| being the item that may be deleted. This method
   // calculates which items in |window_list_| are to be updated, and their
   // destination bounds and fills |nudge_data_| accordingly.

ash/wm/overview/window_selector.cc

@@ -290,13 +290,11 @@ void WindowSelector::Init(const WindowList& windows,
     // as we don't want to cause any window updates until all windows in
     // overview are observed. See http://crbug.com/384495.
     for (std::unique_ptr<WindowGrid>& window_grid : grid_list_) {
-        window_grid->SetWindowListAnimationStates(/*selected_item=*/nullptr,
-                                                  OverviewTransition::kEnter);
+      window_grid->SetWindowListAnimationStates(/*selected_item=*/nullptr,
+                                                OverviewTransition::kEnter);
       window_grid->PrepareForOverview();
-      window_grid->PositionWindows(/*animate=*/true);
-      // Reset |should_animate_when_entering_| in order to animate during
-      // overview mode, such as dragging animations.
-      window_grid->ResetWindowListAnimationStates();
+      window_grid->PositionWindows(/*animate=*/true, /*ignore_item=*/nullptr,
+                                   OverviewTransition::kEnter);
     }
 
     // Image used for text filter textfield.

ash/wm/overview/window_selector.h

@@ -57,8 +57,9 @@ class ASH_EXPORT WindowSelector : public display::DisplayObserver,
   enum Direction { LEFT, UP, RIGHT, DOWN };
 
   enum class OverviewTransition {
-    kEnter,  // In the entering process of overview.
-    kExit    // In the exiting process of overview.
+    kEnter,       // In the entering process of overview.
+    kInOverview,  // Already in overview.
+    kExit         // In the exiting process of overview.
   };
 
   using WindowList = std::vector<aura::Window*>;

ash/wm/overview/window_selector_item.cc

@@ -1139,32 +1139,14 @@ float WindowSelectorItem::GetOpacity() {
   return item_widget_->GetNativeWindow()->layer()->opacity();
 }
 
-bool WindowSelectorItem::ShouldAnimateWhenEntering() const {
-  return should_animate_when_entering_;
-}
-
-bool WindowSelectorItem::ShouldAnimateWhenExiting() const {
-  return should_animate_when_exiting_;
-}
-
-bool WindowSelectorItem::ShouldBeObservedWhenExiting() const {
-  return should_be_observed_when_exiting_;
-}
-
-void WindowSelectorItem::ResetAnimationStates() {
-  should_animate_when_entering_ = true;
-  should_animate_when_exiting_ = true;
-  should_be_observed_when_exiting_ = false;
-}
-
 OverviewAnimationType WindowSelectorItem::GetExitOverviewAnimationType() {
-  return ShouldAnimateWhenExiting()
+  return should_animate_when_exiting_
              ? OverviewAnimationType::OVERVIEW_ANIMATION_LAY_OUT_SELECTOR_ITEMS
              : OverviewAnimationType::OVERVIEW_ANIMATION_NONE;
 }
 
 OverviewAnimationType WindowSelectorItem::GetExitTransformAnimationType() {
-  return ShouldAnimateWhenExiting()
+  return should_animate_when_exiting_
              ? OverviewAnimationType::OVERVIEW_ANIMATION_RESTORE_WINDOW
              : OverviewAnimationType::OVERVIEW_ANIMATION_NONE;
 }

ash/wm/overview/window_selector_item.h

@@ -223,19 +223,23 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   void set_should_animate_when_entering(bool should_animate) {
     should_animate_when_entering_ = should_animate;
   }
-  bool ShouldAnimateWhenEntering() const;
+  bool should_animate_when_entering() const {
+    return should_animate_when_entering_;
+  }
 
   void set_should_animate_when_exiting(bool should_animate) {
     should_animate_when_exiting_ = should_animate;
   }
-  bool ShouldAnimateWhenExiting() const;
+  bool should_animate_when_exiting() const {
+    return should_animate_when_exiting_;
+  }
 
   void set_should_be_observed_when_exiting(bool should_be_observed) {
     should_be_observed_when_exiting_ = should_be_observed;
   }
-  bool ShouldBeObservedWhenExiting() const;
-
-  void ResetAnimationStates();
+  bool should_be_observed_when_exiting() const {
+    return should_be_observed_when_exiting_;
+  }
 
   OverviewAnimationType GetExitOverviewAnimationType();
   OverviewAnimationType GetExitTransformAnimationType();