Cros splitscreen - Make the shelf fully opaque when splitscreen is active.

Bug: 807106
Change-Id: I8ff4939634f919f7566b499985af89960fd6ab09
Reviewed-on: https://chromium-review.googlesource.com/954346
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542861}

ash/public/cpp/shelf_types.h

@@ -61,6 +61,9 @@ enum ShelfBackgroundType {
 
   // The background when fullscreen app list is visible.
   SHELF_BACKGROUND_APP_LIST,
+
+  // The background when split view mode is active.
+  SHELF_BACKGROUND_SPLIT_VIEW,
 };
 
 // Source of the launch or activation request, for tracking.

ash/shelf/shelf_background_animator.cc

@@ -75,6 +75,10 @@ std::pair<int, int> GetTargetColorAlphaValues(
       target_shelf_color_alpha = 0;
       target_item_color_alpha = 0;
       break;
+    case SHELF_BACKGROUND_SPLIT_VIEW:
+      target_shelf_color_alpha = ShelfBackgroundAnimator::kMaxAlpha;
+      target_item_color_alpha = 0;
+      break;
     default:
       NOTREACHED();
   }
@@ -250,6 +254,7 @@ void ShelfBackgroundAnimator::CreateAnimator(
       duration_ms = 500;
       break;
     case SHELF_BACKGROUND_MAXIMIZED:
+    case SHELF_BACKGROUND_SPLIT_VIEW:
       duration_ms = 250;
       break;
   }
@@ -304,6 +309,9 @@ void ShelfBackgroundAnimator::GetTargetValues(
       case SHELF_BACKGROUND_MAXIMIZED:
         darkening_alpha = kShelfOpaqueColorDarkenAlpha;
         break;
+      case SHELF_BACKGROUND_SPLIT_VIEW:
+        darkening_alpha = ShelfBackgroundAnimator::kMaxAlpha;
+        break;
     }
     target_color = color_utils::GetResultingPaintColor(
         SkColorSetA(kShelfDefaultBaseColor, darkening_alpha), target_color);

ash/shelf/shelf_background_animator_unittest.cc

@@ -246,6 +246,15 @@ TEST_F(ShelfBackgroundAnimatorTest, MaximizedBackground) {
   EXPECT_EQ(0, observer_.GetItemBackgroundAlpha());
 }
 
+// Verify the alpha values for the SHELF_BACKGROUND_SPLIT_VIEW state.
+TEST_F(ShelfBackgroundAnimatorTest, SplitViewBackground) {
+  PaintBackground(SHELF_BACKGROUND_SPLIT_VIEW);
+
+  EXPECT_EQ(SHELF_BACKGROUND_SPLIT_VIEW, animator_->target_background_type());
+  EXPECT_EQ(kMaxAlpha, observer_.GetBackgroundAlpha());
+  EXPECT_EQ(0, observer_.GetItemBackgroundAlpha());
+}
+
 // Verify the alpha values for the SHELF_BACKGROUND_APP_LIST state.
 TEST_F(ShelfBackgroundAnimatorTest, FullscreenAppListBackground) {
   PaintBackground(SHELF_BACKGROUND_APP_LIST);

ash/shelf/shelf_layout_manager.cc

@@ -462,6 +462,14 @@ void ShelfLayoutManager::OnAppListVisibilityChanged(bool shown,
   MaybeUpdateShelfBackground(AnimationChangeType::IMMEDIATE);
 }
 
+void ShelfLayoutManager::OnSplitViewModeStarted() {
+  MaybeUpdateShelfBackground(AnimationChangeType::ANIMATE);
+}
+
+void ShelfLayoutManager::OnSplitViewModeEnded() {
+  MaybeUpdateShelfBackground(AnimationChangeType::ANIMATE);
+}
+
 void ShelfLayoutManager::OnWindowActivated(ActivationReason reason,
                                            aura::Window* gained_active,
                                            aura::Window* lost_active) {
@@ -514,6 +522,10 @@ ShelfBackgroundType ShelfLayoutManager::GetShelfBackgroundType() const {
     return SHELF_BACKGROUND_OVERLAP;
   }
 
+  // If split view mode is active, make the shelf fully opapue.
+  if (Shell::Get()->IsSplitViewModeActive())
+    return SHELF_BACKGROUND_SPLIT_VIEW;
+
   return SHELF_BACKGROUND_DEFAULT;
 }
 

ash/shelf/shelf_layout_manager.h

@@ -154,6 +154,8 @@ class ASH_EXPORT ShelfLayoutManager
                                      aura::Window* root_window) override;
   void OnAppListVisibilityChanged(bool shown,
                                   aura::Window* root_window) override;
+  void OnSplitViewModeStarted() override;
+  void OnSplitViewModeEnded() override;
 
   // Overridden from wm::ActivationChangeObserver:
   void OnWindowActivated(ActivationReason reason,

ash/shelf/shelf_layout_manager_unittest.cc

@@ -28,6 +28,7 @@
 #include "ash/system/tray/test_system_tray_item.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/lock_state_controller.h"
+#include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
@@ -1981,6 +1982,35 @@ TEST_F(ShelfLayoutManagerTest, ShelfBackgroundColor) {
   EXPECT_EQ(SHELF_BACKGROUND_DEFAULT, GetShelfWidget()->GetBackgroundType());
 }
 
+// Test the background color for split view mode.
+TEST_F(ShelfLayoutManagerTest, ShelfBackgroundColorInSplitView) {
+  // Split view is only enabled in tablet mode.
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+
+  std::unique_ptr<aura::Window> window1(CreateTestWindow());
+  window1->SetProperty(aura::client::kResizeBehaviorKey,
+                       ui::mojom::kResizeBehaviorCanResize |
+                           ui::mojom::kResizeBehaviorCanMaximize);
+  window1->Show();
+
+  SplitViewController* split_view_controller =
+      Shell::Get()->split_view_controller();
+  split_view_controller->SnapWindow(window1.get(), SplitViewController::LEFT);
+  EXPECT_EQ(SHELF_BACKGROUND_SPLIT_VIEW, GetShelfWidget()->GetBackgroundType());
+
+  std::unique_ptr<aura::Window> window2(CreateTestWindow());
+  window2->SetProperty(aura::client::kResizeBehaviorKey,
+                       ui::mojom::kResizeBehaviorCanResize |
+                           ui::mojom::kResizeBehaviorCanMaximize);
+  window2->Show();
+  split_view_controller->SnapWindow(window2.get(), SplitViewController::RIGHT);
+  EXPECT_EQ(SHELF_BACKGROUND_SPLIT_VIEW, GetShelfWidget()->GetBackgroundType());
+
+  // Ending split view mode will maximize the two windows.
+  split_view_controller->EndSplitView();
+  EXPECT_EQ(SHELF_BACKGROUND_MAXIMIZED, GetShelfWidget()->GetBackgroundType());
+}
+
 // Verify that the shelf doesn't have the opaque background if it's auto-hide
 // status.
 TEST_F(ShelfLayoutManagerTest, ShelfBackgroundColorAutoHide) {

ash/shell.cc

@@ -535,7 +535,8 @@ void Shell::DoInitialWorkspaceAnimation() {
 }
 
 bool Shell::IsSplitViewModeActive() const {
-  return split_view_controller_->IsSplitViewModeActive();
+  return split_view_controller_.get() &&
+         split_view_controller_->IsSplitViewModeActive();
 }
 
 void Shell::AddShellObserver(ShellObserver* observer) {
@@ -571,6 +572,11 @@ void Shell::NotifySplitViewModeStarting() {
     observer.OnSplitViewModeStarting();
 }
 
+void Shell::NotifySplitViewModeStarted() {
+  for (auto& observer : shell_observers_)
+    observer.OnSplitViewModeStarted();
+}
+
 void Shell::NotifySplitViewModeEnded() {
   for (auto& observer : shell_observers_)
     observer.OnSplitViewModeEnded();

ash/shell.h

@@ -557,6 +557,9 @@ class ASH_EXPORT Shell : public SessionObserver,
   // window gets snapped and activated).
   void NotifySplitViewModeStarting();
 
+  // Notifies observers that split view mode has been started.
+  void NotifySplitViewModeStarted();
+
   // Notifies observers that split view mode has ended.
   void NotifySplitViewModeEnded();
 

ash/shell_observer.h

@@ -59,6 +59,9 @@ class ASH_EXPORT ShellObserver {
   // gets snapped and activated).
   virtual void OnSplitViewModeStarting() {}
 
+  // Called when the split view mode has been started.
+  virtual void OnSplitViewModeStarted() {}
+
   // Called after split view mode has ended.
   virtual void OnSplitViewModeEnded() {}
 

ash/wm/splitview/split_view_controller.cc

@@ -274,6 +274,8 @@ void SplitViewController::SnapWindow(aura::Window* window,
     wm::GetWindowState(window)->OnWMEvent(&event);
   }
 
+  if (previous_state == NO_SNAP && previous_state != state_)
+    Shell::Get()->NotifySplitViewModeStarted();
   NotifySplitViewStateChanged(previous_state, state_);
   base::RecordAction(base::UserMetricsAction("SplitView_SnapWindow"));
 }