CrOS Shelf: Relax constraints on what can happen during overview anim

Separate suspension of shelf visibility updates and work area
updates (the former is needed for desk transitions, the latter is
needed for overview transitions).

Bug: 1021691, 1017435, 1019531
Change-Id: Ie0bb64d931a06b2157a58afc2b1c8604ccf2d71c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1898718
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714290}

ash/app_list/app_list_controller_impl.cc

@@ -613,12 +613,8 @@ void AppListControllerImpl::OnShellDestroying() {
   Shutdown();
 }
 
-void AppListControllerImpl::OnOverviewModeWillStart() {
+void AppListControllerImpl::OnOverviewModeStarting() {
   if (IsTabletMode()) {
-    scoped_suspend_visibility_update_ =
-        std::make_unique<ShelfLayoutManager::ScopedSuspendVisibilityUpdate>(
-            RootWindowController::ForWindow(presenter_.GetWindow())
-                ->GetShelfLayoutManager());
     const int64_t display_id = last_visible_display_id_;
     OnHomeLauncherTargetPositionChanged(false /* showing */, display_id);
     OnVisibilityWillChange(false /* visible */, display_id);
@@ -631,8 +627,6 @@ void AppListControllerImpl::OnOverviewModeStartingAnimationComplete(
     bool canceled) {
   if (!IsTabletMode())
     return;
-  if (scoped_suspend_visibility_update_)
-    scoped_suspend_visibility_update_.reset();
   OnHomeLauncherAnimationComplete(false /* shown */, last_visible_display_id_);
 }
 

ash/app_list/app_list_controller_impl.h

@@ -232,7 +232,7 @@ class ASH_EXPORT AppListControllerImpl
   void OnShellDestroying() override;
 
   // OverviewObserver:
-  void OnOverviewModeWillStart() override;
+  void OnOverviewModeStarting() override;
   void OnOverviewModeStartingAnimationComplete(bool canceled) override;
   void OnOverviewModeEnding(OverviewSession* session) override;
   void OnOverviewModeEnded() override;
@@ -433,11 +433,6 @@ class ASH_EXPORT AppListControllerImpl
   // visibility animation to finish. Should only be used in tablet mode.
   HomeLauncherAnimationCallback home_launcher_animation_callback_;
 
-  // Used to prevent ShelfLayoutManager updating visibility state when overview
-  // is showing over the AppList.
-  std::unique_ptr<ShelfLayoutManager::ScopedSuspendVisibilityUpdate>
-      scoped_suspend_visibility_update_;
-
   base::ObserverList<AppListControllerObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(AppListControllerImpl);

ash/root_window_controller.cc

@@ -663,7 +663,7 @@ void RootWindowController::MoveWindowsTo(aura::Window* dst) {
   // Suspend unnecessary updates of the shelf visibility indefinitely since it
   // is going away.
   if (GetShelfLayoutManager())
-    GetShelfLayoutManager()->SuspendVisibilityUpdate();
+    GetShelfLayoutManager()->SuspendVisibilityUpdateForShutdown();
 
   // Clear the workspace controller to avoid a lot of unnecessary operations
   // when window are removed.

ash/shelf/shelf_layout_manager.h

@@ -75,17 +75,17 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
                                       public LocaleChangeObserver,
                                       public DesksController::Observer {
  public:
-  // Suspend shelf visibility update within its scope. Note that relevant
+  // Suspend work area updates within its scope. Note that relevant
   // ShelfLayoutManager must outlive this class.
-  class ScopedSuspendVisibilityUpdate {
+  class ScopedSuspendWorkAreaUpdate {
    public:
     // |manager| is the ShelfLayoutManager whose visibility update is suspended.
-    explicit ScopedSuspendVisibilityUpdate(ShelfLayoutManager* manager);
-    ~ScopedSuspendVisibilityUpdate();
+    explicit ScopedSuspendWorkAreaUpdate(ShelfLayoutManager* manager);
+    ~ScopedSuspendWorkAreaUpdate();
 
    private:
     ShelfLayoutManager* const manager_;
-    DISALLOW_COPY_AND_ASSIGN(ScopedSuspendVisibilityUpdate);
+    DISALLOW_COPY_AND_ASSIGN(ScopedSuspendWorkAreaUpdate);
   };
 
   ShelfLayoutManager(ShelfWidget* shelf_widget, Shelf* shelf);
@@ -163,10 +163,9 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   // Cancel the drag if the shelf is in drag progress.
   void CancelDragOnShelfIfInProgress();
 
-  // Suspends/resumes visibility update. Use ScopedSuspendVisibilityUpdate when
-  // possible to ensure there are balanced calls.
-  void SuspendVisibilityUpdate();
-  void ResumeVisiblityUpdate();
+  // Suspends shelf visibility updates, to be used during shutdown. Since there
+  // is no balanced "resume" public API, the suspension will be indefinite.
+  void SuspendVisibilityUpdateForShutdown();
 
   // Called when ShelfItems are interacted with in the shelf.
   void OnShelfItemSelected(ShelfAction action);
@@ -186,6 +185,7 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
                                SplitViewController::State state) override;
 
   // OverviewObserver:
+  void OnOverviewModeWillStart() override;
   void OnOverviewModeStarting() override;
   void OnOverviewModeStartingAnimationComplete(bool canceled) override;
   void OnOverviewModeEnding(OverviewSession* overview_session) override;
@@ -366,6 +366,10 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
     session_manager::SessionState session_state;
   };
 
+  // Suspends/resumes work area updates.
+  void SuspendWorkAreaUpdate();
+  void ResumeWorkAreaUpdate();
+
   // Sets the visibility of the shelf to |state|.
   void SetState(ShelfVisibilityState visibility_state);
 
@@ -530,10 +534,14 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   ShelfWidget* shelf_widget_;
   Shelf* shelf_;
 
-  // Count of pending visibility update suspensions. Skip updating shelf
+  // Count of pending visibility update suspensions. Skip updating the shelf
   // visibility state if it is greater than 0.
   int suspend_visibility_update_ = 0;
 
+  // Count of pending work area update suspensions. Skip updating the work
+  // area if it is greater than 0.
+  int suspend_work_area_update_ = 0;
+
   base::OneShotTimer auto_hide_timer_;
 
   // Whether the mouse was over the shelf when the auto hide timer started.
@@ -571,6 +579,10 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   // detects that the background has been interacted with.
   bool should_hide_hotseat_ = false;
 
+  // Whether the overview mode is about to start. This becomes false again
+  // once the overview mode has actually started.
+  bool overview_mode_will_start_ = false;
+
   // Tracks the amount of the drag. The value is only valid when
   // |drag_status_| is set to kDragInProgress.
   float drag_amount_ = 0.f;
@@ -630,12 +642,12 @@ class ASH_EXPORT ShelfLayoutManager : public AppListControllerObserver,
   // state.
   bool is_auto_hide_state_locked_ = false;
 
-  // An optional ScopedSuspendVisibilityUpdate that gets created when suspend
+  // An optional ScopedSuspendWorkAreaUpdate that gets created when suspend
   // visibility update is requested for overview and resets when overview no
   // longer needs it. It is used because OnOverviewModeStarting() and
   // OnOverviewModeStartingAnimationComplete() calls are not balanced.
-  base::Optional<ScopedSuspendVisibilityUpdate>
-      overview_suspend_visibility_update_;
+  base::Optional<ScopedSuspendWorkAreaUpdate>
+      overview_suspend_work_area_update_;
 
   // The window drag controller that will be used when a window can be dragged
   // up from shelf to homescreen, overview or splitview.