cros: Add blur to hotseat and shelf widgets in tablet mode

The added blur will only be visible when the "shelf-hotseat" flag
is enabled.

Bug: 1006965
Change-Id: I58d27a7701b22de83590fdc7ce27f402c95baf71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1834762
Commit-Queue: Matthew Mourgos <mmourgos@chromium.org>
Reviewed-by: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703885}

ash/public/cpp/shelf_config.h

@@ -137,6 +137,7 @@ class ASH_EXPORT ShelfConfig : public TabletModeObserver,
   float shelf_tooltip_preview_min_ratio() const {
     return shelf_tooltip_preview_min_ratio_;
   }
+  int shelf_blur_radius() const { return shelf_blur_radius_; }
 
   // Gets the current color for the shelf control buttons.
   SkColor GetShelfControlButtonColor() const;
@@ -151,6 +152,9 @@ class ASH_EXPORT ShelfConfig : public TabletModeObserver,
   // available.
   SkColor GetDefaultShelfColor() const;
 
+  // Returns the current blur radius to use for the control buttons.
+  int GetShelfControlButtonBlurRadius() const;
+
  private:
   friend class ShelfConfigTest;
 
@@ -220,6 +224,9 @@ class ASH_EXPORT ShelfConfig : public TabletModeObserver,
   const float shelf_tooltip_preview_max_ratio_;
   const float shelf_tooltip_preview_min_ratio_;
 
+  // The blur radius used for the shelf.
+  const int shelf_blur_radius_;
+
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfConfig);

ash/shelf/hotseat_widget.cc

@@ -117,6 +117,8 @@ void HotseatWidget::DelegateView::UpdateOpaqueBackground() {
       scrollable_shelf_view_->GetHotseatBackgroundBounds();
   if (opaque_background_.bounds() != background_bounds)
     opaque_background_.SetBounds(background_bounds);
+
+  opaque_background_.SetBackgroundBlur(ShelfConfig::Get()->shelf_blur_radius());
 }
 
 void HotseatWidget::DelegateView::OnTabletModeChanged() {

ash/shelf/shelf_config.cc

@@ -55,8 +55,9 @@ ShelfConfig::ShelfConfig()
       status_indicator_offset_from_shelf_edge_(1),
       shelf_tooltip_preview_height_(128),
       shelf_tooltip_preview_max_width_(192),
-      shelf_tooltip_preview_max_ratio_(1.5),     // = 3/2
-      shelf_tooltip_preview_min_ratio_(0.666) {  // = 2/3
+      shelf_tooltip_preview_max_ratio_(1.5),    // = 3/2
+      shelf_tooltip_preview_min_ratio_(0.666),  // = 2/3
+      shelf_blur_radius_(30) {
   UpdateIsDense();
 }
 
@@ -250,8 +251,7 @@ SkColor ShelfConfig::GetMaximizedShelfColor() const {
 }
 
 SkColor ShelfConfig::GetDefaultShelfColor() const {
-  if (!features::IsBackgroundBlurEnabled() ||
-      chromeos::switches::ShouldShowShelfHotseat()) {
+  if (!features::IsBackgroundBlurEnabled()) {
     return AshColorProvider::Get()->GetBaseLayerColor(
         AshColorProvider::BaseLayerType::kTransparentWithoutBlur,
         AshColorProvider::AshColorMode::kDark);
@@ -279,6 +279,15 @@ SkColor ShelfConfig::GetDefaultShelfColor() const {
   return SkColorSetA(final_color, 189);  // 74% opacity
 }
 
+int ShelfConfig::GetShelfControlButtonBlurRadius() const {
+  if (features::IsBackgroundBlurEnabled() &&
+      chromeos::switches::ShouldShowShelfHotseat() && IsTabletMode() &&
+      !is_in_app()) {
+    return shelf_blur_radius_;
+  }
+  return 0;
+}
+
 void ShelfConfig::OnShelfConfigUpdated() {
   for (auto& observer : observers_)
     observer.OnShelfConfigUpdated();

ash/shelf/shelf_navigation_widget.cc

@@ -14,6 +14,7 @@
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "chromeos/constants/chromeos_switches.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/views/animation/bounds_animator.h"
@@ -57,9 +58,16 @@ class ShelfNavigationWidget::Delegate : public views::AccessiblePaneView,
   Delegate(Shelf* shelf, ShelfView* shelf_view);
   ~Delegate() override;
 
+  // Initializes the view.
+  void Init(ui::Layer* parent_layer);
+
+  void UpdateOpaqueBackground();
+
   // views::View:
   FocusTraversable* GetPaneFocusTraversable() override;
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
+  void ReorderChildLayers(ui::Layer* parent_layer) override;
+  void OnBoundsChanged(const gfx::Rect& old_bounds) override;
 
   // views::AccessiblePaneView:
   View* GetDefaultFocusableChild() override;
@@ -77,16 +85,22 @@ class ShelfNavigationWidget::Delegate : public views::AccessiblePaneView,
   }
 
  private:
+  void SetParentLayer(ui::Layer* layer);
+
   BackButton* back_button_ = nullptr;
   HomeButton* home_button_ = nullptr;
   // When true, the default focus of the navigation widget is the last
   // focusable child.
   bool default_last_focusable_child_ = false;
 
+  // A background layer that may be visible depending on shelf state.
+  ui::Layer opaque_background_;
+
   DISALLOW_COPY_AND_ASSIGN(Delegate);
 };
 
-ShelfNavigationWidget::Delegate::Delegate(Shelf* shelf, ShelfView* shelf_view) {
+ShelfNavigationWidget::Delegate::Delegate(Shelf* shelf, ShelfView* shelf_view)
+    : opaque_background_(ui::LAYER_SOLID_COLOR) {
   set_allow_deactivate_on_esc(true);
 
   const int control_size = ShelfConfig::Get()->control_size();
@@ -108,6 +122,31 @@ ShelfNavigationWidget::Delegate::Delegate(Shelf* shelf, ShelfView* shelf_view) {
 
 ShelfNavigationWidget::Delegate::~Delegate() = default;
 
+void ShelfNavigationWidget::Delegate::Init(ui::Layer* parent_layer) {
+  SetParentLayer(parent_layer);
+  UpdateOpaqueBackground();
+}
+
+void ShelfNavigationWidget::Delegate::UpdateOpaqueBackground() {
+  opaque_background_.SetColor(ShelfConfig::Get()->GetShelfControlButtonColor());
+
+  if (chromeos::switches::ShouldShowShelfHotseat() && IsTabletMode() &&
+      ShelfConfig::Get()->is_in_app()) {
+    opaque_background_.SetVisible(false);
+    return;
+  }
+  opaque_background_.SetVisible(true);
+
+  int radius = ShelfConfig::Get()->control_border_radius();
+  gfx::RoundedCornersF rounded_corners = {radius, radius, radius, radius};
+  if (opaque_background_.rounded_corner_radii() != rounded_corners)
+    opaque_background_.SetRoundedCornerRadius(rounded_corners);
+
+  opaque_background_.SetBounds(GetLocalBounds());
+  opaque_background_.SetBackgroundBlur(
+      ShelfConfig::Get()->GetShelfControlButtonBlurRadius());
+}
+
 bool ShelfNavigationWidget::Delegate::CanActivate() const {
   // We don't want mouse clicks to activate us, but we need to allow
   // activation when the user is using the keyboard (FocusCycler).
@@ -125,11 +164,27 @@ void ShelfNavigationWidget::Delegate::GetAccessibleNodeData(
   node_data->SetName(l10n_util::GetStringUTF8(IDS_ASH_SHELF_ACCESSIBLE_NAME));
 }
 
+void ShelfNavigationWidget::Delegate::ReorderChildLayers(
+    ui::Layer* parent_layer) {
+  views::View::ReorderChildLayers(parent_layer);
+  parent_layer->StackAtBottom(&opaque_background_);
+}
+
+void ShelfNavigationWidget::Delegate::OnBoundsChanged(
+    const gfx::Rect& old_bounds) {
+  UpdateOpaqueBackground();
+}
+
 views::View* ShelfNavigationWidget::Delegate::GetDefaultFocusableChild() {
   return default_last_focusable_child_ ? GetLastFocusableChild()
                                        : GetFirstFocusableChild();
 }
 
+void ShelfNavigationWidget::Delegate::SetParentLayer(ui::Layer* layer) {
+  layer->Add(&opaque_background_);
+  ReorderLayers();
+}
+
 ShelfNavigationWidget::ShelfNavigationWidget(Shelf* shelf,
                                              ShelfView* shelf_view)
     : shelf_(shelf),
@@ -160,6 +215,7 @@ void ShelfNavigationWidget::Initialize(aura::Window* container) {
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.parent = container;
   Init(std::move(params));
+  delegate_->Init(GetLayer());
   set_focus_on_creation(false);
   GetFocusManager()->set_arrow_key_traversal_enabled_for_widget(true);
   SetContentsView(delegate_);
@@ -247,9 +303,7 @@ void ShelfNavigationWidget::UpdateLayout() {
       tablet_mode ? GetSecondButtonBounds() : GetFirstButtonBounds());
   GetBackButton()->SetBoundsRect(GetFirstButtonBounds());
 
-  delegate_->SetBackground(views::CreateRoundedRectBackground(
-      ShelfConfig::Get()->GetShelfControlButtonColor(),
-      ShelfConfig::Get()->control_border_radius()));
+  delegate_->UpdateOpaqueBackground();
 }
 
 }  // namespace ash

ash/system/tray/tray_background_view.cc

@@ -115,34 +115,6 @@ class TrayBackgroundView::TrayWidgetObserver : public views::WidgetObserver {
   DISALLOW_COPY_AND_ASSIGN(TrayWidgetObserver);
 };
 
-class TrayBackground : public views::Background {
- public:
-  explicit TrayBackground(TrayBackgroundView* tray_background_view)
-      : tray_background_view_(tray_background_view) {}
-
-  ~TrayBackground() override = default;
-
- private:
-  // Overridden from views::Background.
-  void Paint(gfx::Canvas* canvas, views::View* view) const override {
-    gfx::ScopedCanvas scoped_canvas(canvas);
-    cc::PaintFlags background_flags;
-    background_flags.setAntiAlias(true);
-    background_flags.setColor(ShelfConfig::Get()->GetShelfControlButtonColor());
-
-    gfx::Rect bounds = tray_background_view_->GetBackgroundBounds();
-    const float dsf = canvas->UndoDeviceScaleFactor();
-    canvas->DrawRoundRect(gfx::ScaleToRoundedRect(bounds, dsf),
-                          ShelfConfig::Get()->control_border_radius() * dsf,
-                          background_flags);
-  }
-
-  // Reference to the TrayBackgroundView for which this is a background.
-  TrayBackgroundView* tray_background_view_;
-
-  DISALLOW_COPY_AND_ASSIGN(TrayBackground);
-};
-
 ////////////////////////////////////////////////////////////////////////////////
 // TrayBackgroundView
 
@@ -151,7 +123,6 @@ TrayBackgroundView::TrayBackgroundView(Shelf* shelf)
     : ActionableView(TrayPopupInkDropStyle::FILL_BOUNDS),
       shelf_(shelf),
       tray_container_(new TrayContainer(shelf)),
-      background_(new TrayBackground(this)),
       is_active_(false),
       separator_visible_(true),
       visible_preferred_(false),
@@ -164,7 +135,6 @@ TrayBackgroundView::TrayBackgroundView(Shelf* shelf)
       ShelfConfig::Get()->shelf_ink_drop_visible_opacity());
 
   SetLayoutManager(std::make_unique<views::FillLayout>());
-  SetBackground(std::unique_ptr<views::Background>(background_));
   SetInstallFocusRingOnFocus(true);
   focus_ring()->SetColor(ShelfConfig::Get()->shelf_focus_border_color());
   SetFocusPainter(nullptr);
@@ -173,8 +143,13 @@ TrayBackgroundView::TrayBackgroundView(Shelf* shelf)
 
   tray_event_filter_.reset(new TrayEventFilter);
 
-  SetPaintToLayer();
+  // Use layer color to provide background color. Note that children views
+  // need to have their own layers to be visible.
+  SetPaintToLayer(ui::LAYER_SOLID_COLOR);
   layer()->SetFillsBoundsOpaquely(false);
+
+  UpdateBackground();
+
   // Start the tray items not visible, because visibility changes are animated.
   views::View::SetVisible(false);
 }
@@ -444,6 +419,9 @@ void TrayBackgroundView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   path->addRoundRect(gfx::RectToSkRect(GetBackgroundBounds()), border_radius,
                      border_radius);
   SetProperty(views::kHighlightPathKey, path.release());
+
+  UpdateBackground();
+
   // Bypass ActionableView::OnBoundsChanged which sets its own highlight path.
   Button::OnBoundsChanged(previous_bounds);
 }
@@ -485,4 +463,14 @@ gfx::Insets TrayBackgroundView::GetBackgroundInsets() const {
   return insets;
 }
 
+void TrayBackgroundView::UpdateBackground() {
+  const int radius = ShelfConfig::Get()->control_border_radius();
+  gfx::RoundedCornersF rounded_corners = {radius, radius, radius, radius};
+  layer()->SetRoundedCornerRadius(rounded_corners);
+  layer()->SetBackgroundBlur(
+      ShelfConfig::Get()->GetShelfControlButtonBlurRadius());
+  layer()->SetColor(ShelfConfig::Get()->GetShelfControlButtonColor());
+  layer()->SetClipRect(GetBackgroundBounds());
+}
+
 }  // namespace ash

ash/system/tray/tray_background_view.h

@@ -18,7 +18,6 @@
 
 namespace ash {
 class Shelf;
-class TrayBackground;
 class TrayContainer;
 class TrayEventFilter;
 
@@ -148,6 +147,8 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // Helper function that calculates background insets relative to local bounds.
   gfx::Insets GetBackgroundInsets() const;
 
+  // Updates the background layer.
+  void UpdateBackground();
 
   // The shelf containing the system tray for this view.
   Shelf* shelf_;
@@ -155,9 +156,6 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // Convenience pointer to the contents view.
   TrayContainer* tray_container_;
 
-  // Owned by the view passed to SetContents().
-  TrayBackground* background_;
-
   // Determines if the view is active. This changes how  the ink drop ripples
   // behave.
   bool is_active_;

ash/system/tray/tray_container.cc

@@ -20,6 +20,8 @@ TrayContainer::TrayContainer(Shelf* shelf) : shelf_(shelf) {
 
   ShelfConfig::Get()->AddObserver(this);
 
+  SetPaintToLayer();
+  layer()->SetFillsBoundsOpaquely(false);
   UpdateLayout();
 }