Add PresentationTimeRecorder For Tablet Mode

Add PresentationTimeRecorder to record all tablet mode launcher
gesture interactions, which include:
(1) Swiping from bottom of screen to show launcher
(2) Swiping from top of screen to hide launcher

Test: ash_unittests
Bug: 947105
Change-Id: Ib1d014b1b7141883d9e78035a26cbeeea689c651
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1564880
Commit-Queue: Andrew Xu <andrewxu@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652410}

ash/app_list/app_list_controller_impl.cc

@@ -1113,6 +1113,24 @@ void AppListControllerImpl::NotifyAppListTargetVisibilityChanged(bool visible) {
 ////////////////////////////////////////////////////////////////////////////////
 // Private used only:
 
+void AppListControllerImpl::OnHomeLauncherDragStart() {
+  app_list::AppListView* app_list_view = presenter_.GetView();
+  DCHECK(app_list_view);
+  app_list_view->OnHomeLauncherDragStart();
+}
+
+void AppListControllerImpl::OnHomeLauncherDragInProgress() {
+  app_list::AppListView* app_list_view = presenter_.GetView();
+  DCHECK(app_list_view);
+  app_list_view->OnHomeLauncherDragInProgress();
+}
+
+void AppListControllerImpl::OnHomeLauncherDragEnd() {
+  app_list::AppListView* app_list_view = presenter_.GetView();
+  DCHECK(app_list_view);
+  app_list_view->OnHomeLauncherDragEnd();
+}
+
 syncer::StringOrdinal AppListControllerImpl::GetOemFolderPos() {
   // Place the OEM folder just after the web store, which should always be
   // followed by a pre-installed app (e.g. Search), so the poosition should be

ash/app_list/app_list_controller_impl.h

@@ -304,6 +304,11 @@ class ASH_EXPORT AppListControllerImpl
       base::Optional<mojom::AppListViewState> recorded_app_list_view_state);
 
  private:
+  // HomeScreenDelegate:
+  void OnHomeLauncherDragStart() override;
+  void OnHomeLauncherDragInProgress() override;
+  void OnHomeLauncherDragEnd() override;
+
   syncer::StringOrdinal GetOemFolderPos();
   std::unique_ptr<app_list::AppListItem> CreateAppListItem(
       AppListItemMetadataPtr metadata);

ash/app_list/app_list_controller_impl_unittest.cc

@@ -13,6 +13,9 @@
 #include "ash/home_screen/home_launcher_gesture_handler.h"
 #include "ash/home_screen/home_screen_controller.h"
 #include "ash/keyboard/ash_keyboard_controller.h"
+#include "ash/public/cpp/presentation_time_recorder.h"
+#include "ash/shelf/shelf.h"
+#include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
@@ -21,6 +24,7 @@
 #include "base/strings/string16.cc"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/metrics/histogram_tester.h"
+#include "ui/events/test/event_generator.h"
 
 namespace ash {
 
@@ -247,6 +251,14 @@ class AppListControllerImplMetricsTest : public AshTestBase {
   void SetUp() override {
     AshTestBase::SetUp();
     controller_ = ash::Shell::Get()->app_list_controller();
+    ash::PresentationTimeRecorder::SetReportPresentationTimeImmediatelyForTest(
+        true);
+  }
+
+  void TearDown() override {
+    ash::PresentationTimeRecorder::SetReportPresentationTimeImmediatelyForTest(
+        false);
+    AshTestBase::TearDown();
   }
 
   AppListControllerImpl* controller_;
@@ -309,4 +321,159 @@ TEST_F(AppListControllerImplMetricsTest, LogManyClicksInOneBucket) {
                                        32, 50);
 }
 
+// Verifies that the PresentationTimeRecorder works correctly for the home
+// launcher gesture drag in tablet mode (https://crbug.com/947105).
+TEST_F(AppListControllerImplMetricsTest,
+       PresentationTimeRecordedForDragInTabletMode) {
+  // Wait until the construction of TabletModeController finishes.
+  base::RunLoop().RunUntilIdle();
+
+  // Turn on the tablet mode.
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+  EXPECT_TRUE(IsTabletMode());
+
+  // Create a window then press the home launcher button. Expect that |w| is
+  // hidden.
+  std::unique_ptr<aura::Window> w(
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400)));
+  Shell::Get()
+      ->home_screen_controller()
+      ->home_launcher_gesture_handler()
+      ->ShowHomeLauncher(display::Screen::GetScreen()->GetPrimaryDisplay());
+  EXPECT_FALSE(w->IsVisible());
+  EXPECT_EQ(mojom::AppListViewState::kFullscreenAllApps,
+            GetAppListView()->app_list_state());
+
+  int delta_y = 1;
+  gfx::Point start = GetAppListView()
+                         ->get_fullscreen_widget_for_test()
+                         ->GetWindowBoundsInScreen()
+                         .top_right();
+  base::TimeTicks timestamp = base::TimeTicks::Now();
+
+  // Emulate to drag the launcher downward.
+  // Send SCROLL_START event. Check the presentation metrics values.
+  ui::GestureEvent start_event = ui::GestureEvent(
+      start.x(), start.y(), ui::EF_NONE, timestamp,
+      ui::GestureEventDetails(ui::ET_GESTURE_SCROLL_BEGIN, 0, delta_y));
+  GetAppListView()->OnGestureEvent(&start_event);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.TabletMode", 0);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode", 0);
+
+  // Send SCROLL_UPDATE event. Check the presentation metrics values.
+  timestamp += base::TimeDelta::FromMilliseconds(25);
+  delta_y += 20;
+  start.Offset(0, 1);
+  ui::GestureEvent update_event = ui::GestureEvent(
+      start.x(), start.y(), ui::EF_NONE, timestamp,
+      ui::GestureEventDetails(ui::ET_GESTURE_SCROLL_UPDATE, 0, delta_y));
+  GetAppListView()->OnGestureEvent(&update_event);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.TabletMode", 1);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode", 0);
+
+  // Send SCROLL_END event. Check the presentation metrics values.
+  timestamp += base::TimeDelta::FromMilliseconds(25);
+  start.Offset(0, 1);
+  ui::GestureEvent end_event =
+      ui::GestureEvent(start.x(), start.y() + delta_y, ui::EF_NONE, timestamp,
+                       ui::GestureEventDetails(ui::ET_GESTURE_END));
+  GetAppListView()->OnGestureEvent(&end_event);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.TabletMode", 1);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode", 1);
+
+  // After the gesture scroll event ends, the window shows.
+  EXPECT_TRUE(w->IsVisible());
+  ASSERT_TRUE(IsTabletMode());
+}
+
+// One edge case may do harm to the presentation metrics reporter for tablet
+// mode: the user may keep pressing on launcher while exiting the tablet mode by
+// rotating the lid. In this situation, OnHomeLauncherDragEnd is not triggered.
+// It is handled correctly now because the AppListView is always closed after
+// exiting the tablet mode. But it still has potential risk to break in future.
+// Write this test case for precaution (https://crbug.com/947105).
+TEST_F(AppListControllerImplMetricsTest,
+       PresentationMetricsForTabletNotRecordedInClamshell) {
+  // Wait until the construction of TabletModeController finishes.
+  base::RunLoop().RunUntilIdle();
+
+  // Turn on the tablet mode.
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+  EXPECT_TRUE(IsTabletMode());
+
+  // Create a window then press the home launcher button. Expect that |w| is
+  // hidden.
+  std::unique_ptr<aura::Window> w(
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400)));
+  Shell::Get()
+      ->home_screen_controller()
+      ->home_launcher_gesture_handler()
+      ->ShowHomeLauncher(display::Screen::GetScreen()->GetPrimaryDisplay());
+  EXPECT_FALSE(w->IsVisible());
+  EXPECT_EQ(mojom::AppListViewState::kFullscreenAllApps,
+            GetAppListView()->app_list_state());
+
+  gfx::Point start = GetAppListView()
+                         ->get_fullscreen_widget_for_test()
+                         ->GetWindowBoundsInScreen()
+                         .top_right();
+  base::TimeTicks timestamp = base::TimeTicks::Now();
+
+  // Emulate to drag the launcher downward.
+  // Send SCROLL_START event. Check the presentation metrics values.
+  ui::GestureEvent start_event = ui::GestureEvent(
+      start.x(), start.y(), ui::EF_NONE, timestamp,
+      ui::GestureEventDetails(ui::ET_GESTURE_SCROLL_BEGIN, 0, 1));
+  GetAppListView()->OnGestureEvent(&start_event);
+
+  // Turn off the tablet mode before scrolling is finished.
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(false);
+  EXPECT_FALSE(IsTabletMode());
+  base::RunLoop().RunUntilIdle();
+  EXPECT_FALSE(GetAppListView());
+
+  // Check metrics initial values.
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.TabletMode", 0);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode", 0);
+
+  // Emulate to drag launcher from shelf. Then verifies the following things:
+  // (1) Metrics values for tablet mode are not recorded.
+  // (2) Metrics values for clamshell mode are recorded correctly.
+  gfx::Rect shelf_bounds =
+      GetPrimaryShelf()->shelf_widget()->GetWindowBoundsInScreen();
+  shelf_bounds.Intersect(
+      display::Screen::GetScreen()->GetPrimaryDisplay().bounds());
+  gfx::Point shelf_center = shelf_bounds.CenterPoint();
+  gfx::Point target_point =
+      display::Screen::GetScreen()->GetPrimaryDisplay().bounds().CenterPoint();
+  ui::test::EventGenerator* generator = GetEventGenerator();
+  generator->GestureScrollSequence(shelf_center, target_point,
+                                   base::TimeDelta::FromMicroseconds(500), 1);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(mojom::AppListViewState::kFullscreenAllApps,
+            GetAppListView()->app_list_state());
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.TabletMode", 0);
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode", 0);
+
+  // AppListView::UpdateYPositionAndOpacity is triggered by
+  // ShelfLayoutManager::StartGestureDrag and
+  // ShelfLayoutManager::UpdateGestureDrag. Note that scrolling step of event
+  // generator is 1. So the expected value is 2.
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.ClamshellMode", 2);
+
+  histogram_tester_.ExpectTotalCount(
+      "Apps.StateTransition.Drag.PresentationTime.MaxLatency.ClamshellMode", 1);
+}
+
 }  // namespace ash

ash/app_list/views/app_list_view.cc

@@ -99,13 +99,18 @@ constexpr float kAppListBlurQuality = 0.33f;
 // TODO(oshima): Use ui::ScopedAnimationDurationScaleMode instead.
 bool short_animations_for_testing;
 
-// Histogram for the app list dragging. The suffix ClamshellMode is added
-// in case a similar UI is added to TabletMode in the future.
+// Histogram for the app list dragging in clamshell mode.
 constexpr char kAppListDragInClamshellHistogram[] =
     "Apps.StateTransition.Drag.PresentationTime.ClamshellMode";
 constexpr char kAppListDragInClamshellMaxLatencyHistogram[] =
     "Apps.StateTransition.Drag.PresentationTime.MaxLatency.ClamshellMode";
 
+// Histogram for the app list dragging in tablet mode.
+constexpr char kAppListDragInTabletHistogram[] =
+    "Apps.StateTransition.Drag.PresentationTime.TabletMode";
+constexpr char kAppListDragInTabletMaxLatencyHistogram[] =
+    "Apps.StateTransition.Drag.PresentationTime.MaxLatency.TabletMode";
+
 // This view forwards the focus to the search box widget by providing it as a
 // FocusTraversable when a focus search is provided.
 class SearchBoxFocusHost : public views::View {
@@ -1527,7 +1532,9 @@ gfx::Rect AppListView::GetAppInfoDialogBounds() const {
 }
 
 void AppListView::SetIsInDrag(bool is_in_drag) {
-  if (!is_in_drag)
+  // In tablet mode, |presentation_time_recorder_| is constructed/reset by
+  // HomeLauncherGestureHandler.
+  if (!is_in_drag && !is_tablet_mode_)
     presentation_time_recorder_.reset();
 
   if (app_list_state_ == ash::mojom::AppListViewState::kClosed)
@@ -1536,14 +1543,11 @@ void AppListView::SetIsInDrag(bool is_in_drag) {
   if (is_in_drag == is_in_drag_)
     return;
 
-  if (is_in_drag) {
+  if (is_in_drag && !is_tablet_mode_) {
     DCHECK(!presentation_time_recorder_);
-    if (!is_tablet_mode_) {
-      presentation_time_recorder_ =
-          ash::CreatePresentationTimeHistogramRecorder(
-              GetWidget()->GetCompositor(), kAppListDragInClamshellHistogram,
-              kAppListDragInClamshellMaxLatencyHistogram);
-    }
+    presentation_time_recorder_ = ash::CreatePresentationTimeHistogramRecorder(
+        GetWidget()->GetCompositor(), kAppListDragInClamshellHistogram,
+        kAppListDragInClamshellMaxLatencyHistogram);
   }
 
   is_in_drag_ = is_in_drag;
@@ -1642,6 +1646,22 @@ ui::AnimationMetricsReporter* AppListView::GetStateTransitionMetricsReporter() {
   return state_animation_metrics_reporter_.get();
 }
 
+void AppListView::OnHomeLauncherDragStart() {
+  DCHECK(!presentation_time_recorder_);
+  presentation_time_recorder_ = ash::CreatePresentationTimeHistogramRecorder(
+      GetWidget()->GetCompositor(), kAppListDragInTabletHistogram,
+      kAppListDragInTabletMaxLatencyHistogram);
+}
+
+void AppListView::OnHomeLauncherDragInProgress() {
+  DCHECK(presentation_time_recorder_);
+  presentation_time_recorder_->RequestNext();
+}
+
+void AppListView::OnHomeLauncherDragEnd() {
+  presentation_time_recorder_.reset();
+}
+
 void AppListView::OnWindowDestroying(aura::Window* window) {
   DCHECK_EQ(fullscreen_widget_->GetNativeView(), window);
   window->RemoveObserver(this);

ash/app_list/views/app_list_view.h

@@ -38,6 +38,8 @@ FORWARD_DECLARE_TEST(AppListControllerImplTest,
                      CheckAppListViewBoundsWhenVKeyboardEnabled);
 FORWARD_DECLARE_TEST(AppListControllerImplTest,
                      CheckAppListViewBoundsWhenDismissVKeyboard);
+FORWARD_DECLARE_TEST(AppListControllerImplMetricsTest,
+                     PresentationTimeRecordedForDragInTabletMode);
 }
 
 namespace app_list {
@@ -254,6 +256,11 @@ class APP_LIST_EXPORT AppListView : public views::WidgetDelegateView,
   // Returns a animation metrics reportre for state transition.
   ui::AnimationMetricsReporter* GetStateTransitionMetricsReporter();
 
+  // Called when drag in tablet mode starts/proceeds/ends.
+  void OnHomeLauncherDragStart();
+  void OnHomeLauncherDragInProgress();
+  void OnHomeLauncherDragEnd();
+
   // WindowObserver overrides:
   void OnWindowDestroying(aura::Window* window) override;
   void OnWindowBoundsChanged(aura::Window* window,
@@ -311,6 +318,8 @@ class APP_LIST_EXPORT AppListView : public views::WidgetDelegateView,
                            CheckAppListViewBoundsWhenVKeyboardEnabled);
   FRIEND_TEST_ALL_PREFIXES(ash::AppListControllerImplTest,
                            CheckAppListViewBoundsWhenDismissVKeyboard);
+  FRIEND_TEST_ALL_PREFIXES(ash::AppListControllerImplMetricsTest,
+                           PresentationTimeRecordedForDragInTabletMode);
 
   // A widget observer that is responsible for keeping the AppListView state up
   // to date on closing.

ash/home_screen/home_launcher_gesture_handler.cc

@@ -173,6 +173,10 @@ aura::Window* GetDividerWindow() {
       ->GetNativeWindow();
 }
 
+HomeScreenDelegate* GetHomeScreenDelegate() {
+  return Shell::Get()->home_screen_controller()->delegate();
+}
+
 }  // namespace
 
 // Class which allows us to make modifications to a window, and removes those
@@ -307,6 +311,10 @@ bool HomeLauncherGestureHandler::OnPressEvent(Mode mode,
         mode == Mode::kSlideUpToShow /*showing*/, display_.id());
   }
 
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
+  DCHECK(home_screen_delegate);
+  home_screen_delegate->OnHomeLauncherDragStart();
+
   UpdateWindows(0.0, /*animate=*/false);
   return true;
 }
@@ -323,6 +331,11 @@ bool HomeLauncherGestureHandler::OnScrollEvent(const gfx::Point& location,
   last_scroll_y_ = scroll_y;
 
   DCHECK(display_.is_valid());
+
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
+  DCHECK(home_screen_delegate);
+  home_screen_delegate->OnHomeLauncherDragInProgress();
+
   UpdateWindows(GetHeightInWorkAreaAsRatio(location, display_.work_area()),
                 /*animate=*/false);
   return true;
@@ -332,6 +345,14 @@ bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location) {
   if (IsAnimating())
     return false;
 
+  // In clamshell mode, AppListView::SetIsInDrag is called explicitly so it
+  // does not need the notification from HomeLauncherGestureHandler.
+  if (IsTabletMode()) {
+    HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
+    DCHECK(home_screen_delegate);
+    home_screen_delegate->OnHomeLauncherDragEnd();
+  }
+
   if (!IsDragInProgress()) {
     if (GetActiveWindow()) {
       // |active_window_| may not be nullptr when this release event is
@@ -354,6 +375,10 @@ void HomeLauncherGestureHandler::Cancel() {
   if (!IsDragInProgress())
     return;
 
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
+  DCHECK(home_screen_delegate);
+  home_screen_delegate->OnHomeLauncherDragEnd();
+
   AnimateToFinalState();
   return;
 }
@@ -487,8 +512,7 @@ void HomeLauncherGestureHandler::OnImplicitAnimationsCompleted() {
     }
   }
 
-  HomeScreenDelegate* home_screen_delegate =
-      Shell::Get()->home_screen_controller()->delegate();
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
   DCHECK(home_screen_delegate);
 
   // Return the app list to its original opacity and transform without
@@ -569,8 +593,7 @@ void HomeLauncherGestureHandler::UpdateSettings(
   if (IsDragInProgress())
     duration_ms = kAnimationDurationMs;
 
-  HomeScreenDelegate* home_screen_delegate =
-      Shell::Get()->home_screen_controller()->delegate();
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
   duration_ms = home_screen_delegate->GetOptionalAnimationDuration().value_or(
       duration_ms);
 
@@ -588,8 +611,7 @@ void HomeLauncherGestureHandler::UpdateWindows(double progress, bool animate) {
   const int y_position =
       gfx::Tween::IntValueBetween(progress, work_area.bottom(), work_area.y());
   const float opacity = gfx::Tween::FloatValueBetween(progress, 0.f, 1.f);
-  HomeScreenDelegate* home_screen_delegate =
-      Shell::Get()->home_screen_controller()->delegate();
+  HomeScreenDelegate* home_screen_delegate = GetHomeScreenDelegate();
   DCHECK(home_screen_delegate);
   home_screen_delegate->UpdateYPositionAndOpacityForHomeLauncher(
       y_position, opacity,

ash/home_screen/home_screen_delegate.h

@@ -56,6 +56,12 @@ class HomeScreenDelegate {
   // Note: Visibility of the shelf and status area are independent, but the
   // variant with shelf visible and status area hidden is currently unsupported.
   virtual bool ShouldShowStatusAreaOnHomeScreen() const = 0;
+
+  // Triggered when dragging launcher in tablet mode starts/proceeds/ends. They
+  // cover both dragging launcher to show and hide.
+  virtual void OnHomeLauncherDragStart() {}
+  virtual void OnHomeLauncherDragInProgress() {}
+  virtual void OnHomeLauncherDragEnd() {}
 };
 
 }  // namespace ash