Virtual Desks 2.3: Extract DesksBarView into its own widget

In preparation for removing the overview's shield widget,
this CL extracts the DesksBarView into its own widget.

BUG=866622, 942759
TEST=Manual, DesksTests still pass.

Change-Id: Ic378e113dae4b7abdc1ce856655b74cfcd3337d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1542664
Commit-Queue: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645351}

ash/wm/desks/desks_bar_view.cc

@@ -8,14 +8,18 @@
 #include <iterator>
 #include <utility>
 
+#include "ash/public/cpp/shell_window_ids.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/wm/desks/desk_mini_view.h"
 #include "ash/wm/desks/desk_mini_view_animations.h"
 #include "ash/wm/desks/new_desk_button.h"
 #include "base/stl_util.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/aura/window.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/geometry/insets.h"
+#include "ui/views/widget/widget.h"
+#include "ui/wm/core/window_animations.h"
 
 namespace ash {
 
@@ -61,6 +65,32 @@ int DesksBarView::GetBarHeight() {
   return kBarHeight;
 }
 
+// static
+std::unique_ptr<views::Widget> DesksBarView::CreateDesksWidget(
+    aura::Window* root,
+    const gfx::Rect& bounds) {
+  DCHECK(root);
+  DCHECK(root->IsRootWindow());
+
+  auto widget = std::make_unique<views::Widget>();
+  views::Widget::InitParams params(
+      views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
+  params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
+  params.accept_events = true;
+  params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
+  // Use the wallpaper container similar to all background widgets created in
+  // overview mode.
+  params.parent = root->GetChildById(kShellWindowId_WallpaperContainer);
+  params.bounds = bounds;
+  params.name = "VirtualDesksWidget";
+  widget->Init(params);
+  ::wm::SetWindowVisibilityAnimationTransition(widget->GetNativeWindow(),
+                                               ::wm::ANIMATE_NONE);
+
+  return widget;
+}
+
 void DesksBarView::Init() {
   UpdateNewMiniViews(/*animate=*/false);
 }

ash/wm/desks/desks_bar_view.h

@@ -30,6 +30,13 @@ class ASH_EXPORT DesksBarView : public views::View,
   // The height of the desk bar view.
   static int GetBarHeight();
 
+  // Creates and returns the widget that contains the DeskBarView in overview
+  // mode. The returned widget has no content view yet, and hasn't been shown
+  // yet.
+  static std::unique_ptr<views::Widget> CreateDesksWidget(
+      aura::Window* root,
+      const gfx::Rect& bounds);
+
   views::View* backgroud_view() const { return backgroud_view_; }
 
   NewDeskButton* new_desk_button() const { return new_desk_button_; }

ash/wm/overview/overview_grid.cc

@@ -263,6 +263,11 @@ gfx::Rect GetGridBoundsInScreenDuringDragging(aura::Window* dragged_window,
   }
 }
 
+gfx::Rect GetDesksWidgetBounds(aura::Window* root, int overview_grid_width) {
+  return screen_util::SnapBoundsToDisplayEdge(
+      gfx::Rect(overview_grid_width, DesksBarView::GetBarHeight()), root);
+}
+
 }  // namespace
 
 // ShieldView contains the background for overview mode. It also contains text
@@ -299,20 +304,6 @@ class OverviewGrid::ShieldView : public views::View {
 
   ~ShieldView() override = default;
 
-  const DesksBarView* desks_bar_view() const { return desks_bar_view_; }
-
-  // Call this only after this view has been added to a widget. This is needed
-  // because the desks mini views need to access the widget to get the
-  // root window in order to know how to layout themselves.
-  void MaybeInitVirtualDesksBar() {
-    if (!features::IsVirtualDesksEnabled())
-      return;
-
-    desks_bar_view_ = new DesksBarView;
-    AddChildView(desks_bar_view_);
-    desks_bar_view_->Init();
-  }
-
   void SetLabelVisibility(bool visible) {
     label_container_->SetVisible(visible);
   }
@@ -331,18 +322,10 @@ class OverviewGrid::ShieldView : public views::View {
     label_container_bounds.ClampToCenteredSize(
         gfx::Size(label_width, kNoItemsIndicatorHeightDp));
     label_container_->SetBoundsRect(label_container_bounds);
-
-    UpdateDesksBarBounds();
   }
 
   bool IsLabelVisible() const { return label_container_->visible(); }
 
- protected:
-  // views::View:
-  void Layout() override {
-    UpdateDesksBarBounds();
-  }
-
  private:
   // ui::EventHandler:
   void OnMouseEvent(ui::MouseEvent* event) override {
@@ -378,21 +361,9 @@ class OverviewGrid::ShieldView : public views::View {
     event->StopPropagation();
   }
 
-  void UpdateDesksBarBounds() {
-    if (!desks_bar_view_)
-      return;
-
-    // TODO: Make the ShieldView's bounds match the overview grid bounds rather
-    // than the entire screen?
-    const auto bar_bounds =
-        gfx::Rect{bounds().width(), DesksBarView::GetBarHeight()};
-    desks_bar_view_->SetBoundsRect(bar_bounds);
-  }
-
   // Owned by views heirarchy.
   RoundedRectView* label_container_ = nullptr;
   views::Label* label_ = nullptr;
-  DesksBarView* desks_bar_view_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(ShieldView);
 };
@@ -547,8 +518,10 @@ void OverviewGrid::Shutdown() {
 }
 
 void OverviewGrid::PrepareForOverview() {
-  if (!ShouldAnimateWallpaper())
+  if (!ShouldAnimateWallpaper()) {
     InitShieldWidget(/*animate=*/false);
+    MaybeInitDesksWidget();
+  }
 
   for (const auto& window : window_list_)
     window->PrepareForOverview();
@@ -774,6 +747,10 @@ void OverviewGrid::SetBoundsAndUpdatePositionsIgnoringWindow(
   bounds_ = bounds;
   if (shield_view_)
     shield_view_->SetGridBounds(bounds_);
+  if (desks_widget_) {
+    desks_widget_->SetBounds(
+        GetDesksWidgetBounds(root_window_, bounds_.width()));
+  }
   PositionWindows(/*animate=*/true, ignored_item);
 }
 
@@ -1108,6 +1085,8 @@ void OverviewGrid::OnStartingAnimationComplete(bool canceled) {
     ShowNoRecentsWindowMessage(window_list_.empty());
   }
 
+  MaybeInitDesksWidget();
+
   for (auto& window : window_list())
     window->OnStartingAnimationComplete();
 }
@@ -1408,10 +1387,6 @@ aura::Window* OverviewGrid::GetTargetWindowOnLocation(
   return (iter != window_list_.end()) ? (*iter)->GetWindow() : nullptr;
 }
 
-const DesksBarView* OverviewGrid::GetDesksBarViewForTesting() const {
-  return shield_view_->desks_bar_view();
-}
-
 bool OverviewGrid::IsDesksBarViewActive() const {
   DCHECK(features::IsVirtualDesksEnabled());
 
@@ -1419,8 +1394,7 @@ bool OverviewGrid::IsDesksBarViewActive() const {
   // overview is started. Once there are more than one desk, it should stay
   // active even if the 2nd to last desk is deleted.
   return DesksController::Get()->desks().size() > 1 ||
-         (shield_view_ &&
-          !shield_view_->desks_bar_view()->mini_views().empty());
+         (desks_bar_view_ && !desks_bar_view_->mini_views().empty());
 }
 
 void OverviewGrid::InitShieldWidget(bool animate) {
@@ -1446,7 +1420,6 @@ void OverviewGrid::InitShieldWidget(bool animate) {
   // Create |shield_view_| and animate its background and label if needed.
   shield_view_ = new ShieldView();
   shield_widget_->SetContentsView(shield_view_);
-  shield_view_->MaybeInitVirtualDesksBar();
   shield_view_->SetGridBounds(bounds_);
 
   // TODO(sammiequon): The shield widget is not anymore in most cases. Remove
@@ -1462,6 +1435,24 @@ void OverviewGrid::InitShieldWidget(bool animate) {
   }
 }
 
+void OverviewGrid::MaybeInitDesksWidget() {
+  if (!features::IsVirtualDesksEnabled() || desks_widget_)
+    return;
+
+  desks_widget_ = DesksBarView::CreateDesksWidget(
+      root_window_, GetDesksWidgetBounds(root_window_, bounds_.width()));
+  desks_bar_view_ = new DesksBarView;
+
+  // The following order of function calls is significant: SetContentsView()
+  // must be called before DesksBarView:: Init(). This is needed because the
+  // desks mini views need to access the widget to get the root window in order
+  // to know how to layout themselves.
+  desks_widget_->SetContentsView(desks_bar_view_);
+  desks_bar_view_->Init();
+
+  desks_widget_->Show();
+}
+
 void OverviewGrid::InitSelectionWidget(OverviewSession::Direction direction) {
   selection_widget_ = CreateBackgroundWidget(
       root_window_, ui::LAYER_TEXTURED, kWindowSelectionColor, 0,

ash/wm/overview/overview_grid.h

@@ -252,7 +252,9 @@ class ASH_EXPORT OverviewGrid : public aura::WindowObserver,
 
   void set_suspend_reposition(bool value) { suspend_reposition_ = value; }
 
-  const DesksBarView* GetDesksBarViewForTesting() const;
+  const DesksBarView* GetDesksBarViewForTesting() const {
+    return desks_bar_view_;
+  }
 
  private:
   class ShieldView;
@@ -269,6 +271,10 @@ class ASH_EXPORT OverviewGrid : public aura::WindowObserver,
   // Initializes the screen shield widget.
   void InitShieldWidget(bool animate);
 
+  // If the Virtual Desks feature is enabled, it initializes the widget that
+  // contains the DeskBarView contents.
+  void MaybeInitDesksWidget();
+
   // Internal function to initialize the selection widget.
   void InitSelectionWidget(OverviewSession::Direction direction);
 
@@ -346,6 +352,12 @@ class ASH_EXPORT OverviewGrid : public aura::WindowObserver,
   // A pointer to |shield_widget_|'s content view.
   ShieldView* shield_view_ = nullptr;
 
+  // Widget that contains the DeskBarView contents when the Virtual Desks
+  // feature is enabled.
+  std::unique_ptr<views::Widget> desks_widget_;
+  // The contents view of the above |desks_widget_| if created.
+  DesksBarView* desks_bar_view_ = nullptr;
+
   // Widget that indicates to the user which is the selected window.
   std::unique_ptr<views::Widget> selection_widget_;