overview: Drop target background not showing correctly.

Prior to this patch, the drop target would:
  - show an extra background for windows with backdrop or maximized
    windows with top insets
  - shift when dragging a maximized window with top insets

Test: manual
Bug: 1035526
Change-Id: Iac2ae0ec35268417d8cf369c76d9890b49583587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1976312Reviewed-by: Avery Musbach <amusbach@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726474}

ash/wm/overview/overview_grid.cc

@@ -194,6 +194,7 @@ std::unique_ptr<views::Widget> CreateDropTargetWidget(
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.activatable = views::Widget::InitParams::Activatable::ACTIVATABLE_NO;
   params.opacity = views::Widget::InitParams::WindowOpacity::kTranslucent;
+  params.name = "OverviewDropTarget";
   params.accept_events = false;
   params.parent = desks_util::GetActiveDeskContainerForRoot(root_window);
   params.init_properties_container.SetProperty(kHideInDeskMiniViewKey, true);
@@ -201,15 +202,7 @@ std::unique_ptr<views::Widget> CreateDropTargetWidget(
   widget->set_focus_on_creation(false);
   widget->Init(std::move(params));
   widget->SetVisibilityAnimationTransition(views::Widget::ANIMATE_NONE);
-  // |OverviewGrid::PositionWindows| will set the bounds of the drop target,
-  // overwriting the size that we set here. However, the drop target bounds
-  // computation will use the aspect ratio from the size that we set here.
-  gfx::Size size_for_aspect_ratio = dragged_window->bounds().size();
-  DCHECK_GT(size_for_aspect_ratio.height(),
-            dragged_window->GetProperty(aura::client::kTopViewInset));
-  size_for_aspect_ratio.Enlarge(
-      0, -dragged_window->GetProperty(aura::client::kTopViewInset));
-  widget->SetSize(size_for_aspect_ratio);
+
   // Show plus icon if drag a tab from a multi-tab window.
   widget->SetContentsView(new DropTargetView(
       dragged_window->GetProperty(ash::kTabDraggingSourceWindowKey)));
@@ -1515,20 +1508,26 @@ int OverviewGrid::CalculateWidthAndMaybeSetUnclippedBounds(OverviewItem* item,
   const gfx::Size item_size(0, height);
   gfx::RectF target_bounds = item->GetTargetBoundsInScreen();
   float scale = item->GetItemScale(item_size);
+  ScopedOverviewTransformWindow::GridWindowFillMode grid_fill_mode =
+      item->GetWindowDimensionsType();
 
   // The drop target, unlike the other windows has its bounds set directly, so
   // |GetTargetBoundsInScreen()| won't return the value we want. Instead, get
   // the scale from the window it was meant to be a placeholder for.
   if (IsDropTargetWindow(item->GetWindow())) {
     aura::Window* dragged_window = nullptr;
-    OverviewItem* item =
+    OverviewItem* grid_dragged_item =
         overview_session_->window_drag_controller()
             ? overview_session_->window_drag_controller()->item()
             : nullptr;
-    if (item)
-      dragged_window = item->GetWindow();
-    else if (dragged_window_)
+    if (grid_dragged_item) {
+      dragged_window = grid_dragged_item->GetWindow();
+      grid_fill_mode = grid_dragged_item->GetWindowDimensionsType();
+    } else if (dragged_window_) {
       dragged_window = dragged_window_;
+      grid_fill_mode = ScopedOverviewTransformWindow::GetWindowDimensionsType(
+          dragged_window);
+    }
 
     if (dragged_window && dragged_window->parent()) {
       target_bounds = ::ash::GetTargetBoundsInScreen(dragged_window);
@@ -1542,7 +1541,7 @@ int OverviewGrid::CalculateWidthAndMaybeSetUnclippedBounds(OverviewItem* item,
 
   int width = std::max(
       1, gfx::ToFlooredInt(target_bounds.width() * scale) + 2 * kWindowMargin);
-  switch (item->GetWindowDimensionsType()) {
+  switch (grid_fill_mode) {
     case ScopedOverviewTransformWindow::GridWindowFillMode::kLetterBoxed:
       width =
           ScopedOverviewTransformWindow::kExtremeWindowRatioThreshold * height;

ash/wm/overview/overview_item.cc

@@ -150,7 +150,8 @@ void SetWidgetBoundsAndMaybeAnimateTransform(
       new_bounds_in_screen,
       display::Screen::GetScreen()->GetDisplayNearestWindow(window));
   if (animation_type == OVERVIEW_ANIMATION_NONE ||
-      animation_type == OVERVIEW_ANIMATION_ENTER_FROM_HOME_LAUNCHER) {
+      animation_type == OVERVIEW_ANIMATION_ENTER_FROM_HOME_LAUNCHER ||
+      previous_bounds.IsEmpty()) {
     window->SetTransform(gfx::Transform());
 
     // Make sure that |observer|, which could be a self-deleting object, will

ash/wm/overview/scoped_overview_transform_window.cc

@@ -54,23 +54,6 @@ bool immediate_close_for_tests = false;
 // Delay closing window to allow it to shrink and fade out.
 constexpr int kCloseWindowDelayInMilliseconds = 150;
 
-ScopedOverviewTransformWindow::GridWindowFillMode GetWindowDimensionsType(
-    aura::Window* window) {
-  if (window->bounds().width() >
-      window->bounds().height() *
-          ScopedOverviewTransformWindow::kExtremeWindowRatioThreshold) {
-    return ScopedOverviewTransformWindow::GridWindowFillMode::kLetterBoxed;
-  }
-
-  if (window->bounds().height() >
-      window->bounds().width() *
-          ScopedOverviewTransformWindow::kExtremeWindowRatioThreshold) {
-    return ScopedOverviewTransformWindow::GridWindowFillMode::kPillarBoxed;
-  }
-
-  return ScopedOverviewTransformWindow::GridWindowFillMode::kNormal;
-}
-
 }  // namespace
 
 class ScopedOverviewTransformWindow::LayerCachingAndFilteringObserver
@@ -184,6 +167,19 @@ float ScopedOverviewTransformWindow::GetItemScale(const gfx::SizeF& source,
                             (source.height() - top_view_inset));
 }
 
+// static
+ScopedOverviewTransformWindow::GridWindowFillMode
+ScopedOverviewTransformWindow::GetWindowDimensionsType(aura::Window* window) {
+  const gfx::Size size = window->bounds().size();
+  if (size.width() > size.height() * kExtremeWindowRatioThreshold)
+    return ScopedOverviewTransformWindow::GridWindowFillMode::kLetterBoxed;
+
+  if (size.height() > size.width() * kExtremeWindowRatioThreshold)
+    return ScopedOverviewTransformWindow::GridWindowFillMode::kPillarBoxed;
+
+  return ScopedOverviewTransformWindow::GridWindowFillMode::kNormal;
+}
+
 void ScopedOverviewTransformWindow::RestoreWindow(bool reset_transform) {
   // Shadow controller may be null on shutdown.
   if (Shell::Get()->shadow_controller())

ash/wm/overview/scoped_overview_transform_window.h

@@ -67,6 +67,9 @@ class ASH_EXPORT ScopedOverviewTransformWindow
                             int top_view_inset,
                             int title_height);
 
+  static ScopedOverviewTransformWindow::GridWindowFillMode
+  GetWindowDimensionsType(aura::Window* window);
+
   ScopedOverviewTransformWindow(OverviewItem* overview_item,
                                 aura::Window* window);
   ~ScopedOverviewTransformWindow() override;