overview gesture: Remove kDragWindowToHomeOrOverview mode and migrate tests.

Remove kDragWindowToHomeOrOverview mode from HomeLauncherGestureHandler
and migrate tests.

No functional change.

Bug: 997885
Change-Id: I727e1c6bbc11d88416eb3e92a8f113c7d4c8e4ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1879818
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709291}

ash/BUILD.gn

@@ -1734,6 +1734,7 @@ test("ash_unittests") {
     "frame/non_client_frame_view_ash_unittest.cc",
     "highlighter/highlighter_controller_unittest.cc",
     "highlighter/highlighter_gesture_util_unittest.cc",
+    "home_screen/drag_window_from_shelf_controller_unittest.cc",
     "home_screen/home_launcher_gesture_handler_unittest.cc",
     "home_screen/home_screen_controller_unittest.cc",
     "ime/ime_controller_unittest.cc",

ash/home_screen/drag_window_from_shelf_controller.h

@@ -7,6 +7,7 @@
 
 #include <vector>
 
+#include "ash/ash_export.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/splitview/split_view_drag_indicators.h"
@@ -24,7 +25,7 @@ namespace ash {
 
 // The window drag controller that will be used when a window is dragged up by
 // swiping up from the shelf to homescreen, overview or splitview.
-class DragWindowFromShelfController : public aura::WindowObserver {
+class ASH_EXPORT DragWindowFromShelfController : public aura::WindowObserver {
  public:
   // The distance for the dragged window to pass over shelf so that it can be
   // dragged into home launcher or overview. If not pass this value, the window
@@ -61,6 +62,9 @@ class DragWindowFromShelfController : public aura::WindowObserver {
   // aura::WindowObserver:
   void OnWindowDestroying(aura::Window* window) override;
 
+  aura::Window* dragged_window() const { return window_; }
+  bool drag_started() const { return drag_started_; }
+
  private:
   class WindowsHider;
 

ash/home_screen/home_launcher_gesture_handler.h

@@ -26,7 +26,6 @@ namespace ash {
 
 class HomeLauncherGestureHandlerObserver;
 class SwipeHomeToOverviewController;
-class DragWindowFromShelfController;
 
 // HomeLauncherGestureHandler makes modifications to a window's transform and
 // opacity when gesture drag events are received and forwarded to it.
@@ -45,13 +44,6 @@ class ASH_EXPORT HomeLauncherGestureHandler
     // Sliding up the MRU window to display launcher. If in overview mode,
     // slides up overview mode as well.
     kSlideUpToShow,
-    // Sliding up from the shelf to drag the MRU window (or one of the snapped
-    // window in splitview) around to enter either home launcher screen or to
-    // overview screen. If in overview mode, this mode is a no-op. Note: This
-    // mode is behind the feature flag kDragFromShelfToHomeOrOverview.
-    // TODO(crbug.com/997885): Remove this mode. The window dragging logic has
-    // been moved into shelf dragging.
-    kDragWindowToHomeOrOverview,
     // Sliding down the MRU window to hide launcher.
     kSlideDownToHide,
     // Sliding up from the shelf in home launcher screen to the overview screen.
@@ -154,10 +146,8 @@ class ASH_EXPORT HomeLauncherGestureHandler
 
   // Sets up windows that will be used in dragging and animation. If |window| is
   // not null for kSlideDownToHide mode, it will be set as the window to run
-  // slide down animation. |window| is not used for kSlideUpToShow or
-  // kDragWindowToHomeOrOverview mode. |location_in_screen| is only used for
-  // kDragWindowToHomeOrOverview mode to find the eligible widnow to drag.
-  // Returns true if windows are successfully set up.
+  // slide down animation. |window| is not used for kSlideUpToShow mode. Returns
+  // true if windows are successfully set up.
   bool SetUpWindows(Mode mode,
                     aura::Window* window,
                     base::Optional<gfx::Point> location_in_screen);
@@ -218,10 +208,6 @@ class ASH_EXPORT HomeLauncherGestureHandler
   // The display where the windows are being processed.
   display::Display display_;
 
-  // The window drag controller that will be used in kDragWindowToHomeOrOverview
-  // mode. Will not be created in other modes.
-  std::unique_ptr<DragWindowFromShelfController> window_drag_controller_;
-
   // The gesture controller that switches from home screen to overview when it
   // detects a swipe from the shelf area.
   std::unique_ptr<SwipeHomeToOverviewController>

ash/shelf/shelf_layout_manager.cc

@@ -128,9 +128,6 @@ GetHomeLauncherGestureHandlerModeForDrag() {
     return HomeLauncherGestureHandler::Mode::kSwipeHomeToOverview;
   }
 
-  if (features::IsDragFromShelfToHomeOrOverviewEnabled())
-    return HomeLauncherGestureHandler::Mode::kDragWindowToHomeOrOverview;
-
   return HomeLauncherGestureHandler::Mode::kSlideUpToShow;
 }
 

ash/shelf/shelf_layout_manager.h

@@ -237,6 +237,10 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   ShelfAutoHideState auto_hide_state() const { return state_.auto_hide_state; }
   HotseatState hotseat_state() const { return state_.hotseat_state; }
 
+  DragWindowFromShelfController* window_drag_controller_for_testing() {
+    return window_drag_controller_.get();
+  }
+
   // TODO(harrym|oshima): These templates will be moved to a new Shelf class.
   // A helper function for choosing values specific to a shelf alignment.
   template <typename T>

ash/shelf/shelf_layout_manager_unittest.cc

@@ -14,6 +14,7 @@
 #include "ash/app_list/test/app_list_test_helper.h"
 #include "ash/app_list/views/app_list_view.h"
 #include "ash/focus_cycler.h"
+#include "ash/home_screen/drag_window_from_shelf_controller.h"
 #include "ash/home_screen/home_launcher_gesture_handler.h"
 #include "ash/home_screen/home_screen_controller.h"
 #include "ash/keyboard/ui/keyboard_ui.h"
@@ -3738,6 +3739,121 @@ TEST_F(HotseatShelfLayoutManagerTest, HotseatHidesWhenSwipedToBezel) {
   EXPECT_EQ(HotseatState::kHidden, GetShelfLayoutManager()->hotseat_state());
 }
 
+class ShelfLayoutManagerWindowDraggingTest : public ShelfLayoutManagerTestBase {
+ public:
+  ShelfLayoutManagerWindowDraggingTest() = default;
+  ~ShelfLayoutManagerWindowDraggingTest() override = default;
+
+  // AshTestBase:
+  void SetUp() override {
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
+        chromeos::switches::kShelfHotseat);
+    scoped_feature_list_.InitAndEnableFeature(
+        features::kDragFromShelfToHomeOrOverview);
+    AshTestBase::SetUp();
+
+    TabletModeControllerTestApi().EnterTabletMode();
+    base::RunLoop().RunUntilIdle();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+  DISALLOW_COPY_AND_ASSIGN(ShelfLayoutManagerWindowDraggingTest);
+};
+
+// Test that when swiping up on the shelf, we may or may not drag up the MRU
+// window.
+TEST_F(ShelfLayoutManagerWindowDraggingTest, DraggedMRUWindow) {
+  const gfx::Rect shelf_widget_bounds =
+      GetShelfWidget()->GetWindowBoundsInScreen();
+  const int hotseat_size = ShelfConfig::Get()->hotseat_size();
+
+  // Starts the drag from the center of the shelf's bottom.
+  gfx::Point start = shelf_widget_bounds.bottom_center();
+  StartScroll(start);
+  // We need at least one window to work with.
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+  UpdateScroll(-shelf_widget_bounds.height() - hotseat_size);
+  EndScroll(/*is_fling=*/false, 0.f);
+
+  std::unique_ptr<aura::Window> window =
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400));
+  wm::ActivateWindow(window.get());
+
+  StartScroll(start);
+  DragWindowFromShelfController* window_drag_controller =
+      GetShelfLayoutManager()->window_drag_controller_for_testing();
+  EXPECT_TRUE(window_drag_controller);
+  EXPECT_EQ(window_drag_controller->dragged_window(), window.get());
+  UpdateScroll(-shelf_widget_bounds.height() - hotseat_size);
+  EndScroll(/*is_fling=*/false, 0.f);
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+
+  // The window needs to be visible to drag up.
+  window->Hide();
+  StartScroll(start);
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+  UpdateScroll(-shelf_widget_bounds.height() - hotseat_size);
+  EndScroll(/*is_fling=*/false, 0.f);
+
+  // In splitview, depends on the drag position, the active dragged window might
+  // be different.
+  window->Show();
+  auto window2 = AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400));
+  SplitViewController* split_view_controller =
+      SplitViewController::Get(Shell::GetPrimaryRootWindow());
+  split_view_controller->SnapWindow(window.get(), SplitViewController::LEFT);
+  split_view_controller->SnapWindow(window2.get(), SplitViewController::RIGHT);
+  StartScroll(shelf_widget_bounds.bottom_left());
+  window_drag_controller =
+      GetShelfLayoutManager()->window_drag_controller_for_testing();
+  EXPECT_TRUE(window_drag_controller);
+  EXPECT_EQ(window_drag_controller->dragged_window(), window.get());
+  EndScroll(/*is_fling=*/false, 0.f);
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+
+  StartScroll(shelf_widget_bounds.bottom_right());
+  window_drag_controller =
+      GetShelfLayoutManager()->window_drag_controller_for_testing();
+  EXPECT_TRUE(window_drag_controller);
+  EXPECT_EQ(window_drag_controller->dragged_window(), window2.get());
+  EndScroll(/*is_fling=*/false, 0.f);
+  split_view_controller->EndSplitView();
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+}
+
+// Test that drag from shelf when overview is active is a no-op.
+TEST_F(ShelfLayoutManagerWindowDraggingTest, NoOpInOverview) {
+  const gfx::Rect shelf_widget_bounds =
+      GetShelfWidget()->GetWindowBoundsInScreen();
+  std::unique_ptr<aura::Window> window1 =
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400));
+  std::unique_ptr<aura::Window> window2 =
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400));
+  wm::ActivateWindow(window1.get());
+
+  // Starts the drag from the center of the shelf's bottom.
+  OverviewController* overview_controller = Shell::Get()->overview_controller();
+  overview_controller->StartOverview();
+  gfx::Point start = shelf_widget_bounds.bottom_center();
+  StartScroll(start);
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+  EndScroll(/*is_fling=*/false, 0.f);
+
+  // In splitview + overview case, drag from shelf in the overview side of the
+  // screen also does nothing.
+  SplitViewController* split_view_controller =
+      SplitViewController::Get(Shell::GetPrimaryRootWindow());
+  split_view_controller->SnapWindow(window1.get(), SplitViewController::LEFT);
+  split_view_controller->SnapWindow(window2.get(), SplitViewController::RIGHT);
+  overview_controller->StartOverview();
+  EXPECT_TRUE(split_view_controller->InSplitViewMode());
+  EXPECT_TRUE(overview_controller->InOverviewSession());
+  StartScroll(shelf_widget_bounds.bottom_right());
+  EXPECT_FALSE(GetShelfLayoutManager()->window_drag_controller_for_testing());
+  EndScroll(/*is_fling=*/false, 0.f);
+}
+
 class ShelfLayoutManagerKeyboardTest : public AshTestBase {
  public:
   ShelfLayoutManagerKeyboardTest() = default;