applist: Remove dead code from home_laucher_gesture_handler.cc.

The logic to check if we should handle certain scrolls was moved to
shelf_layout_manager.cc in [1]. The logic remaining in
home_laucher_gesture_handler.cc is no longer needed.

[1] https://chromium-review.googlesource.com/c/1307233

Test: manual
Bug: 896790
Change-Id: Ic4b8a65ff8b4f6f3b5ed39147c09a68506bb1181
Reviewed-on: https://chromium-review.googlesource.com/c/1334648
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608205}

ash/app_list/app_list_controller_impl.cc

@@ -809,8 +809,7 @@ bool AppListControllerImpl::ProcessHomeLauncherGesture(
       return home_launcher_gesture_handler_->OnScrollEvent(
           screen_location, event->details().scroll_y());
     case ui::ET_GESTURE_END:
-      return home_launcher_gesture_handler_->OnReleaseEvent(
-          screen_location, /*out_dragged_down=*/nullptr);
+      return home_launcher_gesture_handler_->OnReleaseEvent(screen_location);
     default:
       break;
   }

ash/app_list/home_launcher_gesture_handler.cc

@@ -74,6 +74,7 @@ bool CanProcessWindow(aura::Window* window,
   if (window->type() == aura::client::WINDOW_TYPE_POPUP)
     return false;
 
+  // Do not process if |window| is not the root of a transient tree.
   if (::wm::GetTransientParent(window))
     return false;
 
@@ -181,7 +182,6 @@ bool HomeLauncherGestureHandler::OnPressEvent(Mode mode,
     return false;
 
   mode_ = mode;
-  initial_event_location_ = location;
   last_event_location_ = base::make_optional(location);
 
   UpdateWindows(0.0, /*animate=*/false);
@@ -198,11 +198,6 @@ bool HomeLauncherGestureHandler::OnScrollEvent(const gfx::Point& location,
 
   last_event_location_ = base::make_optional(location);
   last_scroll_y_ = scroll_y;
-  if (mode_ == Mode::kSlideUpToShow &&
-      (*last_event_location_ - initial_event_location_).y() > 0) {
-    UpdateWindows(0.0, /*animate=*/false);
-    return true;
-  }
 
   DCHECK(display_.is_valid());
   UpdateWindows(GetHeightInWorkAreaAsRatio(location, display_.work_area()),
@@ -210,8 +205,7 @@ bool HomeLauncherGestureHandler::OnScrollEvent(const gfx::Point& location,
   return true;
 }
 
-bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location,
-                                                bool* out_dragged_down) {
+bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location) {
   if (IsAnimating())
     return false;
 
@@ -228,11 +222,6 @@ bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location,
   }
 
   last_event_location_ = base::make_optional(location);
-  if (out_dragged_down) {
-    DCHECK_EQ(mode_, Mode::kSlideUpToShow);
-    *out_dragged_down =
-        (*last_event_location_ - initial_event_location_).y() > 0;
-  }
   AnimateToFinalState();
   return true;
 }

ash/app_list/home_launcher_gesture_handler.h

@@ -53,7 +53,7 @@ class ASH_EXPORT HomeLauncherGestureHandler : aura::WindowObserver,
   // was not processed.
   bool OnPressEvent(Mode mode, const gfx::Point& location);
   bool OnScrollEvent(const gfx::Point& location, float scroll_y);
-  bool OnReleaseEvent(const gfx::Point& location, bool* out_dragged_down);
+  bool OnReleaseEvent(const gfx::Point& location);
 
   // Cancel a current drag and animates the items to their final state based on
   // |last_event_location_|.
@@ -158,8 +158,6 @@ class ASH_EXPORT HomeLauncherGestureHandler : aura::WindowObserver,
   // hidden so the home launcher is visible when swiping up.
   std::vector<aura::Window*> hidden_windows_;
 
-  gfx::Point initial_event_location_;
-
   // Tracks the location of the last received event in screen coordinates. Empty
   // if there is currently no window being processed.
   base::Optional<gfx::Point> last_event_location_;

ash/app_list/home_launcher_gesture_handler_unittest.cc

@@ -141,14 +141,14 @@ TEST_F(HomeLauncherGestureHandlerTest, FlingingSlideUp) {
   // Tests that flinging down in this mode will keep the window visible.
   DoPress(Mode::kSlideUpToShow);
   GetGestureHandler()->OnScrollEvent(gfx::Point(0, 300), 10.f);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   ASSERT_TRUE(window->IsVisible());
 
   // Tests that flinging up in this mode will hide the window and show the
   // home launcher.
   DoPress(Mode::kSlideUpToShow);
   GetGestureHandler()->OnScrollEvent(gfx::Point(0, 300), -10.f);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_FALSE(window->IsVisible());
 }
 
@@ -164,13 +164,13 @@ TEST_F(HomeLauncherGestureHandlerTest, FlingingSlideDown) {
   // Tests that flinging up in this mode will not show the mru window.
   DoPress(Mode::kSlideDownToHide);
   GetGestureHandler()->OnScrollEvent(gfx::Point(0, 100), -10.f);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   ASSERT_FALSE(window->IsVisible());
 
   // Tests that flinging down in this mode will show the mru window.
   DoPress(Mode::kSlideDownToHide);
   GetGestureHandler()->OnScrollEvent(gfx::Point(0, 100), 10.f);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   EXPECT_TRUE(window->IsVisible());
 }
 
@@ -185,12 +185,6 @@ TEST_F(HomeLauncherGestureHandlerTest, SlidingBelowPressPoint) {
   GetGestureHandler()->OnPressEvent(Mode::kSlideUpToShow, gfx::Point(0, 400));
   GetGestureHandler()->OnScrollEvent(gfx::Point(0, 420), 1.f);
   EXPECT_EQ(gfx::Transform(), window->transform());
-
-  // Tests that OnReleaseEvent returns true when checking if the release point
-  // is below the press point.
-  bool released_below;
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 420), &released_below);
-  EXPECT_TRUE(released_below);
 }
 
 // Tests that the home launcher gestures work with overview mode as expected.
@@ -221,7 +215,7 @@ TEST_F(HomeLauncherGestureHandlerTest, OverviewMode) {
 
   // Tests that after releasing at below the halfway point, we remain in
   // overview mode.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_TRUE(controller->IsSelecting());
   EXPECT_EQ(window1_initial_translation,
             window1->transform().To2dTranslation().y());
@@ -231,7 +225,7 @@ TEST_F(HomeLauncherGestureHandlerTest, OverviewMode) {
   // Tests that after releasing on the bottom half, overview mode has been
   // exited, and the two windows have been minimized to show the home launcher.
   DoPress(Mode::kSlideUpToShow);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   EXPECT_FALSE(controller->IsSelecting());
   EXPECT_TRUE(wm::GetWindowState(window1.get())->IsMinimized());
   EXPECT_TRUE(wm::GetWindowState(window2.get())->IsMinimized());
@@ -268,7 +262,7 @@ TEST_F(HomeLauncherGestureHandlerTest, SplitviewOneSnappedWindow) {
 
   // Tests that after releasing at below the halfway point, we remain in
   // both splitview and overview mode.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_EQ(window1->transform(), gfx::Transform());
   EXPECT_EQ(window2_initial_translation,
             window2->transform().To2dTranslation().y());
@@ -278,7 +272,7 @@ TEST_F(HomeLauncherGestureHandlerTest, SplitviewOneSnappedWindow) {
   // Tests that after releasing on the bottom half, overivew and splitview have
   // both been exited, and both windows are minimized to show the home launcher.
   DoPress(Mode::kSlideUpToShow);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   EXPECT_FALSE(window_selector_controller->IsSelecting());
   EXPECT_FALSE(split_view_controller->IsSplitViewModeActive());
   EXPECT_TRUE(wm::GetWindowState(window1.get())->IsMinimized());
@@ -314,7 +308,7 @@ TEST_F(HomeLauncherGestureHandlerTest, SplitviewTwoSnappedWindows) {
 
   // Tests that after releasing at below the halfway point, we remain in
   // splitview.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_EQ(window1->transform(), gfx::Transform());
   EXPECT_EQ(window2->transform(), gfx::Transform());
   EXPECT_TRUE(split_view_controller->IsSplitViewModeActive());
@@ -322,7 +316,7 @@ TEST_F(HomeLauncherGestureHandlerTest, SplitviewTwoSnappedWindows) {
   // Tests that after releasing on the bottom half, splitview has been ended,
   // and the two windows have been minimized to show the home launcher.
   DoPress(Mode::kSlideUpToShow);
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   EXPECT_FALSE(split_view_controller->IsSplitViewModeActive());
   EXPECT_TRUE(wm::GetWindowState(window1.get())->IsMinimized());
   EXPECT_TRUE(wm::GetWindowState(window2.get())->IsMinimized());
@@ -399,7 +393,7 @@ TEST_P(HomeLauncherModeGestureHandlerTest, BelowHalfShowsWindow) {
   EXPECT_NE(1.f, window1->layer()->opacity());
 
   // Tests the transform and opacity have returned to the identity and 1.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_EQ(gfx::Transform(), window1->transform());
   EXPECT_EQ(1.f, window1->layer()->opacity());
 
@@ -426,7 +420,7 @@ TEST_P(HomeLauncherModeGestureHandlerTest, AboveHalfReleaseMinimizesWindow) {
   ASSERT_FALSE(window3->IsVisible());
 
   // Test that |window1| is minimized on release.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 100));
   EXPECT_TRUE(wm::GetWindowState(window1.get())->IsMinimized());
 
   // The rest of the windows remain invisible, to show the home launcher.
@@ -460,7 +454,7 @@ TEST_P(HomeLauncherModeGestureHandlerTest, WindowWithTransientChild) {
 
   // Tests that after releasing on the bottom half, the transient child reverts
   // to its original values.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(0, 300));
   EXPECT_EQ(1.0f, child->layer()->opacity());
   EXPECT_EQ(gfx::Transform(), child->transform());
 }
@@ -514,7 +508,7 @@ TEST_P(HomeLauncherModeGestureHandlerTest, AnimatingToEndResetsState) {
   EXPECT_FALSE(GetGestureHandler()->transient_descendants_values_.empty());
 
   // Tests that after a drag, the variables are either null or empty.
-  GetGestureHandler()->OnReleaseEvent(gfx::Point(10, 10), nullptr);
+  GetGestureHandler()->OnReleaseEvent(gfx::Point(10, 10));
   EXPECT_FALSE(GetGestureHandler()->window());
   EXPECT_FALSE(GetGestureHandler()->last_event_location_);
   EXPECT_EQ(Mode::kNone, GetGestureHandler()->mode_);

ash/shelf/shelf_layout_manager.cc

@@ -1318,16 +1318,8 @@ void ShelfLayoutManager::CompleteAppListDrag(
 
   HomeLauncherGestureHandler* home_launcher_handler =
       Shell::Get()->app_list_controller()->home_launcher_gesture_handler();
-  bool dragged_down;
   if (home_launcher_handler &&
-      home_launcher_handler->OnReleaseEvent(gesture_in_screen.location(),
-                                            &dragged_down)) {
-    if (dragged_down && visibility_state() == SHELF_AUTO_HIDE) {
-      DCHECK_EQ(SHELF_AUTO_HIDE_SHOWN, gesture_drag_auto_hide_state_);
-      gesture_drag_auto_hide_state_ = SHELF_AUTO_HIDE_HIDDEN;
-      gesture_drag_status_ = GESTURE_DRAG_COMPLETE_IN_PROGRESS;
-      UpdateVisibilityState();
-    }
+      home_launcher_handler->OnReleaseEvent(gesture_in_screen.location())) {
     gesture_drag_status_ = GESTURE_DRAG_NONE;
     return;
   }

ash/shelf/shelf_layout_manager_unittest.cc

@@ -9,6 +9,8 @@
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_table.h"
+#include "ash/app_list/app_list_controller_impl.h"
+#include "ash/app_list/home_launcher_gesture_handler.h"
 #include "ash/app_list/test/app_list_test_helper.h"
 #include "ash/focus_cycler.h"
 #include "ash/public/cpp/app_list/app_list_features.h"
@@ -2481,6 +2483,70 @@ TEST_F(ShelfLayoutManagerTest, ShelfLayoutInUnifiedDesktop) {
   EXPECT_EQ(gfx::Point(500, 400), status_area_bounds.bottom_right());
 }
 
+// Tests that the shelf forwards the appropriate events to the home launcher
+// gesture handler to handle.
+TEST_F(ShelfLayoutManagerTest, HomeLauncherGestureHandler) {
+  // Home launcher is only available in tablet mode.
+  Shell::Get()->tablet_mode_controller()->EnableTabletModeWindowManager(true);
+
+  // Home launcher gesture handler needs at least one window.
+  std::unique_ptr<aura::Window> window =
+      AshTestBase::CreateTestWindow(gfx::Rect(0, 0, 400, 400));
+  wm::ActivateWindow(window.get());
+
+  const gfx::Point shelf_center =
+      GetVisibleShelfWidgetBoundsInScreen().CenterPoint();
+
+  // Helper to create a scroll event for this test.
+  auto create_scroll_event = [&shelf_center](ui::EventType type,
+                                             float scroll_y) {
+    ui::GestureEventDetails details =
+        type == ui::ET_GESTURE_SCROLL_END
+            ? ui::GestureEventDetails(type)
+            : ui::GestureEventDetails(type, 0, scroll_y);
+    return ui::GestureEvent(shelf_center.x(), shelf_center.y(), 0,
+                            base::TimeTicks(), details);
+  };
+
+  // The home launcher gesture handler should not be handling any window
+  // initially.
+  ShelfLayoutManager* manager = GetShelfLayoutManager();
+  HomeLauncherGestureHandler* gesture_handler =
+      Shell::Get()->app_list_controller()->home_launcher_gesture_handler();
+  ASSERT_TRUE(gesture_handler);
+  ASSERT_FALSE(gesture_handler->window());
+
+  // Tests that after scrolling up on the shelf, the home launcher gesture
+  // handler will be acting on |window|.
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_BEGIN, -1.f));
+  EXPECT_EQ(window.get(), gesture_handler->window());
+
+  // Tests that since the initial scroll event was scrolled up, the home
+  // launcher gesture handler will continue to act on |window| regardless of
+  // direction of scroll updates.
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_UPDATE, -1.f));
+  EXPECT_EQ(window.get(), gesture_handler->window());
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_UPDATE, 1.f));
+  EXPECT_EQ(window.get(), gesture_handler->window());
+
+  // End the scroll.
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_END, 1.f));
+  ASSERT_FALSE(gesture_handler->window());
+
+  // Tests that if the initial scroll event is directed downwards, the home
+  // launcher gesture handler will not act on |window|.
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_BEGIN, 1.f));
+  EXPECT_FALSE(gesture_handler->window());
+  manager->ProcessGestureEvent(
+      create_scroll_event(ui::ET_GESTURE_SCROLL_UPDATE, -1.f));
+  EXPECT_FALSE(gesture_handler->window());
+}
+
 class ShelfLayoutManagerKeyboardTest : public AshTestBase {
  public:
   ShelfLayoutManagerKeyboardTest() = default;