Pause occlusion when the overview is closed by activation

I also added a unit test for occlusion tracker pause during
overview transition.

Bug: None
Test: covered by unittests.

Change-Id: I5e8441e176eaa0dc9793d22059edb22e357d899e
Reviewed-on: https://chromium-review.googlesource.com/c/1344888
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611323}

ash/wm/overview/window_selector_controller.cc

@@ -252,7 +252,8 @@ class WindowSelectorController::OverviewBlurController
 };
 
 WindowSelectorController::WindowSelectorController()
-    : overview_blur_controller_(std::make_unique<OverviewBlurController>()),
+    : occlusion_pause_duration_for_end_ms_(kOcclusionPauseDurationForEndMs),
+      overview_blur_controller_(std::make_unique<OverviewBlurController>()),
       weak_ptr_factory_(this) {
   Shell::Get()->activation_client()->AddObserver(this);
 }
@@ -396,7 +397,7 @@ void WindowSelectorController::OnEndingAnimationComplete(bool canceled) {
       &WindowSelectorController::ResetPauser, weak_ptr_factory_.GetWeakPtr()));
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, reset_pauser_task_.callback(),
-      base::TimeDelta::FromMilliseconds(kOcclusionPauseDurationForEndMs));
+      base::TimeDelta::FromMilliseconds(occlusion_pause_duration_for_end_ms_));
 }
 
 void WindowSelectorController::ResetPauser() {
@@ -540,6 +541,13 @@ void WindowSelectorController::OnSelectionEnded() {
   if (is_shutting_down_)
     return;
 
+  if (!occlusion_tracker_pauser_) {
+    reset_pauser_task_.Cancel();
+    occlusion_tracker_pauser_ =
+        std::make_unique<aura::WindowOcclusionTracker::ScopedPause>(
+            Shell::Get()->aura_env());
+  }
+
   if (!start_animations_.empty())
     OnStartingAnimationComplete(/*canceled=*/true);
   start_animations_.clear();

ash/wm/overview/window_selector_controller.h

@@ -98,6 +98,10 @@ class ASH_EXPORT WindowSelectorController
 
   WindowSelector* window_selector() { return window_selector_.get(); }
 
+  void set_occlusion_pause_duration_for_end_ms_for_test(int duration) {
+    occlusion_pause_duration_for_end_ms_ = duration;
+  }
+
  private:
   class OverviewBlurController;
   friend class WindowSelectorTest;
@@ -133,6 +137,8 @@ class ASH_EXPORT WindowSelectorController
   // If we are in middle of ending overview mode.
   bool is_shutting_down_ = false;
 
+  int occlusion_pause_duration_for_end_ms_;
+
   // Handles blurring of the wallpaper when entering or exiting overview mode.
   // Animates the blurring if necessary.
   std::unique_ptr<OverviewBlurController> overview_blur_controller_;

ash/wm/overview/window_selector_controller_unittest.cc

@@ -69,6 +69,16 @@ class TestShellObserver : public ShellObserver {
     ending_animation_state_ = UNKNOWN;
   }
 
+  void WaitForStartingAnimationComplete() {
+    while (starting_animation_state_ != COMPLETED)
+      base::RunLoop().RunUntilIdle();
+  }
+
+  void WaitForEndingAnimationComplete() {
+    while (ending_animation_state_ != COMPLETED)
+      base::RunLoop().RunUntilIdle();
+  }
+
   bool is_ended() const { return ending_animation_state_ != UNKNOWN; }
   bool is_started() const { return starting_animation_state_ != UNKNOWN; }
   AnimationState starting_animation_state() const {
@@ -99,6 +109,12 @@ class TestShellObserver : public ShellObserver {
   DISALLOW_COPY_AND_ASSIGN(TestShellObserver);
 };
 
+void WaitForOcclusionStateChange(aura::Window* window) {
+  auto current_state = window->occlusion_state();
+  while (window->occlusion_state() == current_state)
+    base::RunLoop().RunUntilIdle();
+}
+
 }  // namespace
 
 using WindowSelectorControllerTest = AshTestBase;
@@ -133,8 +149,7 @@ TEST_F(WindowSelectorControllerTest, AnimationCallbacks) {
   EXPECT_FALSE(Shell::Get()->window_selector_controller()->IsSelecting());
   EXPECT_EQ(TestShellObserver::UNKNOWN, observer.ending_animation_state());
 
-  while (!observer.is_ended())
-    base::RunLoop().RunUntilIdle();
+  observer.WaitForEndingAnimationComplete();
   EXPECT_EQ(TestShellObserver::COMPLETED, observer.ending_animation_state());
 
   gfx::Rect bounds(0, 0, 100, 100);
@@ -152,7 +167,7 @@ TEST_F(WindowSelectorControllerTest, AnimationCallbacks) {
   EXPECT_TRUE(Shell::Get()->window_selector_controller()->IsSelecting());
   EXPECT_EQ(TestShellObserver::UNKNOWN, observer.starting_animation_state());
 
-  // Exit with windows.
+  // Exit with windows before starting animation ends.
   Shell::Get()->window_selector_controller()->ToggleOverview();
   EXPECT_FALSE(Shell::Get()->window_selector_controller()->IsSelecting());
   EXPECT_EQ(TestShellObserver::CANCELED, observer.starting_animation_state());
@@ -160,7 +175,7 @@ TEST_F(WindowSelectorControllerTest, AnimationCallbacks) {
 
   observer.Reset();
 
-  // Enter again.
+  // Enter again before exit animation ends.
   Shell::Get()->window_selector_controller()->ToggleOverview();
   EXPECT_TRUE(Shell::Get()->window_selector_controller()->IsSelecting());
   EXPECT_EQ(TestShellObserver::CANCELED, observer.ending_animation_state());
@@ -224,6 +239,77 @@ TEST_F(WindowSelectorControllerTest, OverviewEnterExitAnimationTablet) {
   EXPECT_TRUE(observer.last_animation_was_slide());
 }
 
+TEST_F(WindowSelectorControllerTest, OcclusionTest) {
+  using OcclusionState = aura::Window::OcclusionState;
+
+  Shell::Get()
+      ->window_selector_controller()
+      ->set_occlusion_pause_duration_for_end_ms_for_test(50);
+  TestShellObserver observer(/*should_monitor_animation_state = */ true);
+  ui::ScopedAnimationDurationScaleMode non_zero(
+      ui::ScopedAnimationDurationScaleMode::NON_ZERO_DURATION);
+  gfx::Rect bounds(0, 0, 100, 100);
+  std::unique_ptr<aura::Window> window1(
+      CreateTestWindowInShellWithBounds(bounds));
+  std::unique_ptr<aura::Window> window2(
+      CreateTestWindowInShellWithBounds(bounds));
+  window1->TrackOcclusionState();
+  window2->TrackOcclusionState();
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+
+  // Enter with windows.
+  Shell::Get()->window_selector_controller()->ToggleOverview();
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+
+  observer.WaitForStartingAnimationComplete();
+  // Occlusion tracking is paused.
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+  WaitForOcclusionStateChange(window1.get());
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+
+  // Exit with windows.
+  Shell::Get()->window_selector_controller()->ToggleOverview();
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+  observer.WaitForEndingAnimationComplete();
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+  WaitForOcclusionStateChange(window1.get());
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+
+  observer.Reset();
+
+  // Enter again.
+  Shell::Get()->window_selector_controller()->ToggleOverview();
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+  auto* active = wm::GetActiveWindow();
+  EXPECT_EQ(window2.get(), active);
+
+  observer.WaitForStartingAnimationComplete();
+
+  // Window 1 is still occluded because tracker is paused.
+  EXPECT_EQ(OcclusionState::OCCLUDED, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+
+  WaitForOcclusionStateChange(window1.get());
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+
+  wm::ActivateWindow(window1.get());
+  observer.WaitForEndingAnimationComplete();
+
+  // Windows are visible because tracker is paused.
+  EXPECT_FALSE(Shell::Get()->window_selector_controller()->IsSelecting());
+  EXPECT_EQ(OcclusionState::VISIBLE, window2->occlusion_state());
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+  WaitForOcclusionStateChange(window2.get());
+  EXPECT_EQ(OcclusionState::VISIBLE, window1->occlusion_state());
+  EXPECT_EQ(OcclusionState::OCCLUDED, window2->occlusion_state());
+}
+
 class OverviewVirtualKeyboardTest : public WindowSelectorControllerTest {
  protected:
   void SetUp() override {