overview: Hide close button and title bar on overview item dragged.

Hide both for the item currently dragged. Only hide the close button for
the rest of the items.
Spec: https://mccanny.users.x20web.corp.google.com/www/splitscreen-motion/index.html
Window selection and deselection

Test: ash_unittests WindowSelectorTest.WindowItemTitleCloseVisibilityOnDrag
Bug: 782320, 775655
Change-Id: I7e06a0154a9afdb391966109517b1aed419083e4
Reviewed-on: https://chromium-review.googlesource.com/893212Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534764}

ash/wm/overview/window_grid.cc

@@ -685,6 +685,16 @@ void WindowGrid::UpdateCannotSnapWarningVisibility() {
     window_selector_item->UpdateCannotSnapWarningVisibility();
 }
 
+void WindowGrid::OnSelectorItemDragStarted(WindowSelectorItem* item) {
+  for (auto& window_selector_item : window_list_)
+    window_selector_item->OnSelectorItemDragStarted(item);
+}
+
+void WindowGrid::OnSelectorItemDragEnded(WindowSelectorItem* item) {
+  for (auto& window_selector_item : window_list_)
+    window_selector_item->OnSelectorItemDragEnded(item);
+}
+
 void WindowGrid::OnWindowDestroying(aura::Window* window) {
   window_observer_.Remove(window);
   window_state_observer_.Remove(wm::GetWindowState(window));

ash/wm/overview/window_grid.h

@@ -123,6 +123,11 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver,
 
   void UpdateCannotSnapWarningVisibility();
 
+  // Called when any WindowSelectorItem on any WindowGrid has started/ended
+  // being dragged.
+  void OnSelectorItemDragStarted(WindowSelectorItem* item);
+  void OnSelectorItemDragEnded(WindowSelectorItem* item);
+
   // Returns true if the grid has no more windows.
   bool empty() const { return window_list_.empty(); }
 

ash/wm/overview/window_selector.cc

@@ -545,6 +545,12 @@ void WindowSelector::InitiateDrag(WindowSelectorItem* item,
                                   const gfx::Point& location_in_screen) {
   window_drag_controller_.reset(new OverviewWindowDragController(this));
   window_drag_controller_->InitiateDrag(item, location_in_screen);
+
+  if (!IsNewOverviewUi())
+    return;
+
+  for (std::unique_ptr<WindowGrid>& grid : grid_list_)
+    grid->OnSelectorItemDragStarted(item);
 }
 
 void WindowSelector::Drag(WindowSelectorItem* item,
@@ -559,6 +565,12 @@ void WindowSelector::CompleteDrag(WindowSelectorItem* item,
   DCHECK(window_drag_controller_.get());
   DCHECK_EQ(item, window_drag_controller_->item());
   window_drag_controller_->CompleteDrag(location_in_screen);
+
+  if (!IsNewOverviewUi())
+    return;
+
+  for (std::unique_ptr<WindowGrid>& grid : grid_list_)
+    grid->OnSelectorItemDragEnded(item);
 }
 
 void WindowSelector::ActivateDraggedWindow() {

ash/wm/overview/window_selector_item.cc

@@ -106,6 +106,10 @@ constexpr int kSelectorFadeInMilliseconds = 350;
 // Duration of background opacity transition when exiting overview mode.
 constexpr int kExitFadeInMilliseconds = 30;
 
+// Duration of the header and close button fade in/out when a drag is
+// started/finished on a window selector item;
+constexpr int kDragAnimationMs = 167;
+
 // Before closing a window animate both the window and the caption to shrink by
 // this fraction of size.
 constexpr float kPreCloseScale = 0.02f;
@@ -495,6 +499,14 @@ class WindowSelectorItem::CaptionContainerView : public views::View {
 
   ShieldButton* listener_button() { return listener_button_; }
 
+  void SetCloseButtonVisibility(bool visible) {
+    AnimateLayerOpacity(close_button_->layer(), visible);
+  }
+
+  void SetTitleLabelVisibility(bool visible) {
+    AnimateLayerOpacity(background_->layer(), visible);
+  }
+
   void SetCannotSnapLabelVisibility(bool visible) {
     AnimateSplitviewLabelOpacity(cannot_snap_container_->layer(), visible);
   }
@@ -560,6 +572,34 @@ class WindowSelectorItem::CaptionContainerView : public views::View {
   const char* GetClassName() const override { return "CaptionContainerView"; }
 
  private:
+  // Animates |layer| from 0 -> 1 opacity if |visible| and 1 -> 0 opacity
+  // otherwise. The tween type differs for |visible| and if |visible| is true
+  // there is a slight delay before the animation begins. Does not animate if
+  // opacity matches |visible|.
+  void AnimateLayerOpacity(ui::Layer* layer, bool visible) {
+    float target_opacity = visible ? 1.f : 0.f;
+    if (layer->GetTargetOpacity() == target_opacity)
+      return;
+
+    layer->SetOpacity(1.f - target_opacity);
+    {
+      ui::LayerAnimator* animator = layer->GetAnimator();
+      ui::ScopedLayerAnimationSettings settings(animator);
+      settings.SetPreemptionStrategy(
+          ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
+      if (visible) {
+        animator->SchedulePauseForProperties(
+            base::TimeDelta::FromMilliseconds(kDragAnimationMs),
+            ui::LayerAnimationElement::OPACITY);
+      }
+      settings.SetTransitionDuration(
+          base::TimeDelta::FromMilliseconds(kDragAnimationMs));
+      settings.SetTweenType(visible ? gfx::Tween::LINEAR_OUT_SLOW_IN
+                                    : gfx::Tween::FAST_OUT_LINEAR_IN);
+      layer->SetOpacity(target_opacity);
+    }
+  }
+
   ShieldButton* listener_button_;
   WindowSelectorItem::RoundedContainerView* background_;
   views::ImageView* image_view_;
@@ -710,6 +750,17 @@ void WindowSelectorItem::UpdateCannotSnapWarningVisibility() {
   caption_container_view_->SetCannotSnapLabelVisibility(visible);
 }
 
+void WindowSelectorItem::OnSelectorItemDragStarted(WindowSelectorItem* item) {
+  caption_container_view_->SetCloseButtonVisibility(false);
+  if (item == this)
+    caption_container_view_->SetTitleLabelVisibility(false);
+}
+
+void WindowSelectorItem::OnSelectorItemDragEnded(WindowSelectorItem* item) {
+  caption_container_view_->SetCloseButtonVisibility(true);
+  caption_container_view_->SetTitleLabelVisibility(true);
+}
+
 ScopedTransformOverviewWindow::GridWindowFillMode
 WindowSelectorItem::GetWindowDimensionsType() const {
   return transform_window_.type();
@@ -791,6 +842,14 @@ void WindowSelectorItem::ResetDraggedWindowGesture() {
   window_selector_->ResetDraggedWindowGesture();
 }
 
+float WindowSelectorItem::GetCloseButtonOpacityForTesting() {
+  return close_button_->layer()->opacity();
+}
+
+float WindowSelectorItem::GetTitlebarOpacityForTesting() {
+  return background_view_->layer()->opacity();
+}
+
 gfx::Rect WindowSelectorItem::GetTargetBoundsInScreen() const {
   return transform_window_.GetTargetBoundsInScreen();
 }

ash/wm/overview/window_selector_item.h

@@ -122,6 +122,12 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // window cannot be snapped.
   void UpdateCannotSnapWarningVisibility();
 
+  // Called when a WindowSelectorItem on any grid is dragged. Hides the close
+  // button when a drag is started, and reshows it when a drag is finished.
+  // Additional hides the title and window icon if |item| is this.
+  void OnSelectorItemDragStarted(WindowSelectorItem* item);
+  void OnSelectorItemDragEnded(WindowSelectorItem* item);
+
   ScopedTransformOverviewWindow::GridWindowFillMode GetWindowDimensionsType()
       const;
 
@@ -150,6 +156,9 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   void ActivateDraggedWindow();
   void ResetDraggedWindowGesture();
 
+  float GetCloseButtonOpacityForTesting();
+  float GetTitlebarOpacityForTesting();
+
  private:
   class CaptionContainerView;
   class RoundedContainerView;

ash/wm/overview/window_selector_unittest.cc

@@ -2121,6 +2121,48 @@ TEST_F(WindowSelectorTest, ExtremeWindowBounds) {
             normal_item->GetWindowDimensionsType());
 }
 
+// Verify that the window selector items titlebar and close button change
+// visibility when a item is being dragged.
+TEST_F(WindowSelectorTest, WindowItemTitleCloseVisibilityOnDrag) {
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kAshEnableNewOverviewUi);
+
+  UpdateDisplay("400x400");
+  const gfx::Rect bounds(10, 10, 200, 200);
+  std::unique_ptr<aura::Window> window1(CreateWindow(bounds));
+  std::unique_ptr<aura::Window> window2(CreateWindow(bounds));
+
+  // Dragging is only allowed in tablet mode.
+  RunAllPendingInMessageLoop();
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+
+  ToggleOverview();
+  WindowSelectorItem* item1 = GetWindowItemForWindow(0, window1.get());
+  WindowSelectorItem* item2 = GetWindowItemForWindow(0, window2.get());
+
+  // Start the drag on |item1|. Verify the dragged item, |item1| has both the
+  // close button and titlebar hidden. All other items, |item2| should only have
+  // the close button hidden.
+  GetEventGenerator().MoveMouseTo(item1->target_bounds().CenterPoint());
+  GetEventGenerator().PressLeftButton();
+  RunAllPendingInMessageLoop();
+  EXPECT_EQ(0.f, item1->GetTitlebarOpacityForTesting());
+  EXPECT_EQ(0.f, item1->GetCloseButtonOpacityForTesting());
+  EXPECT_EQ(1.f, item2->GetTitlebarOpacityForTesting());
+  EXPECT_EQ(0.f, item2->GetCloseButtonOpacityForTesting());
+
+  // Drag |item1| in a way so that |window1| does not get activated (drags
+  // within a certain threshold count as clicks). Verify the close button and
+  // titlebar is visible for all items.
+  GetEventGenerator().MoveMouseTo(gfx::Point(200, 200));
+  GetEventGenerator().ReleaseLeftButton();
+  RunAllPendingInMessageLoop();
+  EXPECT_EQ(1.f, item1->GetTitlebarOpacityForTesting());
+  EXPECT_EQ(1.f, item1->GetCloseButtonOpacityForTesting());
+  EXPECT_EQ(1.f, item2->GetTitlebarOpacityForTesting());
+  EXPECT_EQ(1.f, item2->GetCloseButtonOpacityForTesting());
+}
+
 class SplitViewWindowSelectorTest : public WindowSelectorTest {
  public:
   SplitViewWindowSelectorTest() = default;