applist: Allow swiping up on shelf to show applist when autohide.

Test: manual
Bug: 881483, 891366
Change-Id: I88c5d7a5d41f7ef4013c84debf5c4e963f891d21
Reviewed-on: https://chromium-review.googlesource.com/c/1279356
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599778}

ash/app_list/app_list_controller_impl.cc

@@ -729,7 +729,8 @@ 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);
+      return home_launcher_gesture_handler_->OnReleaseEvent(
+          screen_location, /*out_dragged_down=*/nullptr);
     default:
       break;
   }

ash/app_list/home_launcher_gesture_handler.cc

@@ -58,10 +58,6 @@ bool CanProcessWindow(aura::Window* window,
   if (!window)
     return false;
 
-  // Window should not be fullscreen as we do not allow swiping up when auto
-  // hide for shelf.
-  DCHECK(!wm::GetWindowState(window)->IsFullscreen());
-
   if (!window->IsVisible() &&
       mode == HomeLauncherGestureHandler::Mode::kSlideUpToShow) {
     return false;
@@ -208,6 +204,7 @@ 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);
@@ -221,17 +218,29 @@ 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()),
                 /*animate=*/false);
   return true;
 }
 
-bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location) {
+bool HomeLauncherGestureHandler::OnReleaseEvent(const gfx::Point& location,
+                                                bool* out_dragged_down) {
   if (!IsDragInProgress())
     return false;
 
   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 OnReleaseEvent(const gfx::Point& location, bool* out_dragged_down);
 
   // Cancel a current drag and animates the items to their final state based on
   // |last_event_location_|.
@@ -155,6 +155,8 @@ 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/shelf/shelf_layout_manager.cc

@@ -1212,7 +1212,7 @@ void ShelfLayoutManager::StartGestureDrag(
   } else {
     HomeLauncherGestureHandler* home_launcher_handler =
         Shell::Get()->app_list_controller()->home_launcher_gesture_handler();
-    if (home_launcher_handler && visibility_state() == SHELF_VISIBLE &&
+    if (home_launcher_handler && IsVisible() &&
         home_launcher_handler->OnPressEvent(
             HomeLauncherGestureHandler::Mode::kSlideUpToShow,
             gesture_in_screen.location())) {
@@ -1237,7 +1237,7 @@ void ShelfLayoutManager::UpdateGestureDrag(
     const ui::GestureEvent& gesture_in_screen) {
   HomeLauncherGestureHandler* home_launcher_handler =
       Shell::Get()->app_list_controller()->home_launcher_gesture_handler();
-  if (home_launcher_handler && visibility_state() == SHELF_VISIBLE &&
+  if (home_launcher_handler && IsVisible() &&
       home_launcher_handler->OnScrollEvent(
           gesture_in_screen.location(),
           gesture_in_screen.details().scroll_y())) {
@@ -1301,8 +1301,16 @@ void ShelfLayoutManager::CompleteAppListDrag(
 
   HomeLauncherGestureHandler* home_launcher_handler =
       Shell::Get()->app_list_controller()->home_launcher_gesture_handler();
-  if (home_launcher_handler && visibility_state() == SHELF_VISIBLE &&
-      home_launcher_handler->OnReleaseEvent(gesture_in_screen.location())) {
+  bool dragged_down;
+  if (home_launcher_handler && IsVisible() &&
+      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();
+    }
     gesture_drag_status_ = GESTURE_DRAG_NONE;
     return;
   }