Remove window mask and shadow during window dragging.

It can improve the fps of overview window dragging about 4~5fps.

Bug: 925131, 925122
Change-Id: Ia76d1baf2e8a35f5dd53e1ec7bb325ab4f6c45eb
Reviewed-on: https://chromium-review.googlesource.com/c/1439930
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626906}

ash/wm/overview/overview_controller.cc

@@ -521,6 +521,10 @@ void OverviewController::OnOverviewButtonTrayLongPressed(
       base::UserMetricsAction("Tablet_LongPressOverviewButtonEnterSplitView"));
 }
 
+bool OverviewController::IsInStartAnimation() {
+  return !start_animations_.empty();
+}
+
 std::vector<aura::Window*>
 OverviewController::GetWindowsListInOverviewGridsForTesting() {
   std::vector<aura::Window*> windows;
@@ -551,9 +555,10 @@ void OverviewController::OnSelectionEnded() {
     OnStartingAnimationComplete(/*canceled=*/true);
   start_animations_.clear();
 
-  overview_session_->UpdateMaskAndShadow(/*show=*/false);
-
   auto* overview_session = overview_session_.release();
+  // Do not show mask and show during overview shutdown.
+  overview_session->UpdateMaskAndShadow();
+
   Shell::Get()->NotifyOverviewModeEnding(overview_session);
   overview_session->Shutdown();
   // Don't delete |overview_session_| yet since the stack is still using it.

ash/wm/overview/overview_controller.h

@@ -61,6 +61,9 @@ class ASH_EXPORT OverviewController : public OverviewDelegate,
   // if device is not currently in overview mode.
   void OnOverviewButtonTrayLongPressed(const gfx::Point& event_location);
 
+  // Returns true if we're in start-overview animation.
+  bool IsInStartAnimation();
+
   // Gets the windows list that are shown in the overview windows grids if the
   // overview mode is active for testing.
   std::vector<aura::Window*> GetWindowsListInOverviewGridsForTesting();

ash/wm/overview/overview_item.cc

@@ -270,12 +270,8 @@ void OverviewItem::SetBounds(const gfx::Rect& target_bounds,
   // animations, manually set the shadow. Shadow relies on both the window
   // transform and |item_widget_|'s new bounds so set it after SetItemBounds
   // and UpdateHeaderLayout. Do not apply the shadow for drop target.
-  if (new_animation_type == OVERVIEW_ANIMATION_NONE) {
-    SetShadowBounds(
-        overview_grid_->IsDropTargetWindow(GetWindow())
-            ? base::nullopt
-            : base::make_optional(transform_window_.GetTransformedBounds()));
-  }
+  if (new_animation_type == OVERVIEW_ANIMATION_NONE)
+    UpdateMaskAndShadow();
 
   UpdateBackdropBounds();
 }
@@ -348,15 +344,19 @@ void OverviewItem::UpdateCannotSnapWarningVisibility() {
 }
 
 void OverviewItem::OnSelectorItemDragStarted(OverviewItem* item) {
+  is_being_dragged_ = (item == this);
   caption_container_view_->SetHeaderVisibility(
-      item == this
+      is_being_dragged_
           ? CaptionContainerView::HeaderVisibility::kInvisible
           : CaptionContainerView::HeaderVisibility::kCloseButtonInvisibleOnly);
+  UpdateMaskAndShadow();
 }
 
 void OverviewItem::OnSelectorItemDragEnded() {
+  is_being_dragged_ = false;
   caption_container_view_->SetHeaderVisibility(
       CaptionContainerView::HeaderVisibility::kVisible);
+  UpdateMaskAndShadow();
 }
 
 ScopedOverviewTransformWindow::GridWindowFillMode
@@ -557,16 +557,38 @@ void OverviewItem::SetShadowBounds(base::Optional<gfx::Rect> bounds_in_screen) {
   shadow_->SetContentBounds(bounds_in_item);
 }
 
-void OverviewItem::UpdateMaskAndShadow(bool show) {
-  transform_window_.UpdateMask(show);
+void OverviewItem::UpdateMaskAndShadow() {
+  // Do not show mask and shadow if:
+  // 1) overview is shutting down or
+  // 2) this overview item is in an overview grid that contains more than 10
+  //    windows. In this case don't apply rounded corner mask because it can
+  //    push the compositor memory usage to the limit. TODO(oshima): Remove
+  //    this once new rounded corner impl is available. (crbug.com/903486)
+  // 3) we're currently in entering overview animation or
+  // 4) this overview item is being dragged or
+  // 5) this overview item is the drop target window or
+  // 6) this overview item is in animation.
+  bool should_show = true;
+  OverviewController* overview_controller = Shell::Get()->overview_controller();
+  if (!overview_controller->IsSelecting() ||
+      overview_grid_->window_list().size() > 10 ||
+      overview_controller->IsInStartAnimation() || is_being_dragged_ ||
+      overview_grid_->IsDropTargetWindow(GetWindow()) ||
+      transform_window_.GetOverviewWindow()
+          ->layer()
+          ->GetAnimator()
+          ->is_animating()) {
+    should_show = false;
+  }
 
-  // Do not apply the shadow for the drop target in overview.
-  if (!show || overview_grid_->IsDropTargetWindow(GetWindow())) {
+  if (!should_show) {
+    transform_window_.UpdateMask(false);
     SetShadowBounds(base::nullopt);
     DisableBackdrop();
     return;
   }
 
+  transform_window_.UpdateMask(true);
   SetShadowBounds(transform_window_.GetTransformedBounds());
   EnableBackdropIfNeeded();
 }

ash/wm/overview/overview_item.h

@@ -191,8 +191,8 @@ class ASH_EXPORT OverviewItem : public views::ButtonListener,
   // the shadow is hidden.
   void SetShadowBounds(base::Optional<gfx::Rect> bounds_in_screen);
 
-  // Show or hide the mask and shadow on this window item.
-  void UpdateMaskAndShadow(bool show);
+  // Updates the mask and shadow on this overview window item.
+  void UpdateMaskAndShadow();
 
   // Called when the starting animation is completed, or called immediately
   // if there was no starting animation.
@@ -336,6 +336,9 @@ class ASH_EXPORT OverviewItem : public views::ButtonListener,
   // OverviewGrid::PositionWindows.
   bool animating_to_close_ = false;
 
+  // True if this overview item is currently being dragged around.
+  bool is_being_dragged_ = false;
+
   // The shadow around the overview window. Shadows the original window, not
   // |item_widget_|. Done here instead of on the original window because of the
   // rounded edges mask applied on entering overview window.

ash/wm/overview/overview_session.cc

@@ -566,22 +566,15 @@ void OverviewSession::UpdateGridAtLocationYPositionAndOpacity(
     grid->UpdateYPositionAndOpacity(new_y, opacity, work_area, callback);
 }
 
-void OverviewSession::UpdateMaskAndShadow(bool show) {
-  for (auto& grid : grid_list_) {
-    // Don't apply rounded corner mask if the grid has move than 10 windows
-    // because it can push the compositor memory usage to the limit.
-    // TODO(osima): Remove this once new rounded corner impl is available.
-    // (crbug.com/903486)
-    if (show && grid->window_list().size() > 10)
-      continue;
+void OverviewSession::UpdateMaskAndShadow() {
+  for (auto& grid : grid_list_)
     for (auto& window : grid->window_list())
-      window->UpdateMaskAndShadow(show);
-  }
+      window->UpdateMaskAndShadow();
 }
 
 void OverviewSession::OnStartingAnimationComplete(bool canceled) {
   if (!canceled) {
-    UpdateMaskAndShadow(!canceled);
+    UpdateMaskAndShadow();
     if (overview_focus_widget_)
       overview_focus_widget_->Show();
     for (auto& grid : grid_list_)

ash/wm/overview/overview_session.h

@@ -201,8 +201,8 @@ class ASH_EXPORT OverviewSession : public display::DisplayObserver,
       const gfx::Rect& work_area,
       UpdateAnimationSettingsCallback callback);
 
-  // Shows or hides all the window selector items' mask and shadow.
-  void UpdateMaskAndShadow(bool show);
+  // Updates all the window selector items' mask and shadow.
+  void UpdateMaskAndShadow();
 
   // Called when the overview mode starting animation completes.
   void OnStartingAnimationComplete(bool canceled);

ash/wm/overview/overview_session_unittest.cc

@@ -2234,8 +2234,9 @@ TEST_F(OverviewSessionTest, RoundedEdgeMaskVisibility) {
   ui::ScopedAnimationDurationScaleMode test_duration_mode(
       ui::ScopedAnimationDurationScaleMode::NON_ZERO_DURATION);
 
-  // Drag the first window. Verify that the mask still exists for both items as
-  // we do not apply any animation to the window items at this point.
+  // Drag the first window. Verify that the mask was removed for the first
+  // window but still exists for the second window as we do not apply mask
+  // for a dragged window.
   const gfx::Point start_drag = item1->target_bounds().CenterPoint();
   ui::test::EventGenerator* generator = GetEventGenerator();
   generator->MoveMouseTo(start_drag);
@@ -2243,7 +2244,7 @@ TEST_F(OverviewSessionTest, RoundedEdgeMaskVisibility) {
   EXPECT_FALSE(window1->layer()->GetAnimator()->is_animating());
   EXPECT_FALSE(window2->layer()->GetAnimator()->is_animating());
   base::RunLoop().RunUntilIdle();
-  EXPECT_TRUE(HasMaskForItem(item1));
+  EXPECT_FALSE(HasMaskForItem(item1));
   EXPECT_TRUE(HasMaskForItem(item2));
 
   // Drag to horizontally and then back to the start to avoid activating the

ash/wm/overview/scoped_overview_transform_window.cc

@@ -188,6 +188,7 @@ ScopedOverviewTransformWindow::~ScopedOverviewTransformWindow() {
   if (null_targeter_ == window_->targeter())
     window_->SetEventTargeter(std::move(original_targeter_));
 
+  UpdateMask(/*show=*/false);
   StopObservingImplicitAnimations();
 }
 
@@ -258,11 +259,6 @@ void ScopedOverviewTransformWindow::BeginScopedAnimation(
   if (animation_type == OVERVIEW_ANIMATION_NONE)
     return;
 
-  // Remove the mask before animating because masks affect animation
-  // performance. Observe the animation and add the mask after animating if the
-  // animation type is layouting selector items during overview.
-  selector_item_->UpdateMaskAndShadow(/*show=*/false);
-
   for (auto* window : wm::GetTransientTreeIterator(GetOverviewWindow())) {
     auto settings = std::make_unique<ScopedOverviewAnimationSettings>(
         animation_type, window);
@@ -512,8 +508,15 @@ void ScopedOverviewTransformWindow::UpdateMinimizedWidget() {
   minimized_widget_->SetContentsView(preview_view);
 }
 
+void ScopedOverviewTransformWindow::OnLayerAnimationStarted(
+    ui::LayerAnimationSequence* sequence) {
+  // Remove the mask before animating because masks affect animation
+  // performance. The mask will be added back once the animation is completed.
+  selector_item_->UpdateMaskAndShadow();
+}
+
 void ScopedOverviewTransformWindow::OnImplicitAnimationsCompleted() {
-  selector_item_->UpdateMaskAndShadow(/*show=*/true);
+  selector_item_->UpdateMaskAndShadow();
   selector_item_->OnDragAnimationCompleted();
 }
 
@@ -551,6 +554,8 @@ void ScopedOverviewTransformWindow::CreateMirrorWindowForMinimizedState() {
     bounds.Inset(0, 0, 0, inset);
   }
   minimized_widget_->SetBounds(bounds);
+  minimized_widget_->SetVisibilityAnimationTransition(
+      views::Widget::ANIMATE_NONE);
   minimized_widget_->Show();
 
   // Stack the minimized window at the bottom since it is never transformed in

ash/wm/overview/scoped_overview_transform_window.h

@@ -178,6 +178,7 @@ class ASH_EXPORT ScopedOverviewTransformWindow
   views::Widget* minimized_widget() { return minimized_widget_.get(); }
 
   // ui::ImplicitAnimationObserver:
+  void OnLayerAnimationStarted(ui::LayerAnimationSequence* sequence) override;
   void OnImplicitAnimationsCompleted() override;
 
   gfx::Rect GetMaskBoundsForTesting() const;