[ash] Don't remove an item when associated window is dragged

ash/shelf/shelf_window_watcher.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_SHELF_SHELF_WINDOW_WATCHER_H_
 #define ASH_SHELF_SHELF_WINDOW_WATCHER_H_
 
 #include "ash/shelf/scoped_observer_with_duplicated_sources.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 38 matching lines @@
    private:
     // aura::WindowObserver overrides:
     virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
 
     // Owned by Shell.
     ShelfWindowWatcher* window_watcher_;
 
     DISALLOW_COPY_AND_ASSIGN(RootWindowObserver);
   };
 
+  // Observer of removed Window that has an item.

[sky, 2014/01/08 15:01:49]

Change comments to:
Used to track windows that are removed. See description of ... for more details.

[simonhong, 2014/01/09 01:00:09]

Done.

+  // See the comments of ShelfWindowWatcher::StartObserveRemovedWindow() why
+  // removed window needs this observer.
+  class RemovedWindowObserver : public aura::WindowObserver {
+   public:
+    explicit RemovedWindowObserver(ShelfWindowWatcher* window_watcher);
+    virtual ~RemovedWindowObserver();
+
+   private:
+    // aura::WindowObserver overrides:
+    virtual void OnWindowParentChanged(aura::Window* window,
+                                       aura::Window* parent) OVERRIDE;
+    virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
+
+    // Owned by Shell.
+    ShelfWindowWatcher* window_watcher_;
+
+    DISALLOW_COPY_AND_ASSIGN(RemovedWindowObserver);
+  };
+
   // Creates a LauncherItem for |window| that has LauncherItemDetails.
   void AddLauncherItem(aura::Window* window);
 
   // Removes a LauncherItem for |window|.
   void RemoveLauncherItem(aura::Window* window);
 
   // Adds observer to default container and ActivationClient of |root_window|.
   void OnRootWindowAdded(aura::Window* root_window);
 
   // Removes observer from ActivationClient of |root_window|.
   void OnRootWindowRemoved(aura::Window* root_window);
 
   // Updates the status of LauncherItem for |window|.
   void UpdateLauncherItemStatus(aura::Window* window, bool is_active);
 
   // Returns the index of LauncherItem associated with |window|.
   int GetLauncherItemIndexForWindow(aura::Window* window) const;
 
+  // Start observing removed |window| from ShelfWindowWatcher by
+  // RemovedWindowObserver. In some situations like dragging, it re-parents
+  // |window| to other container. But the item of |window| should not be
+  // removed immediately because |window| is not destroyed at that situation.
+  // We should observe to check whether |window| is destroyed or not.
+  void StartObserveRemovedWindow(aura::Window* window);

[sky, 2014/01/08 15:01:49]

StartObservingRemovedWindow

Used when a window is removed. During dragging a window may be removed and when
the drag completes added back. When this happens we don't want to remove the
launcher item. StartObservingRemovedWindow, if necessary, attaches and observer.
When done FinishObservingRemovedWindow() is invoked.

[simonhong, 2014/01/09 01:00:09]

Done.

+
+  // Stop observing |window| by RemovedWindowObserver and remove an item
+  // associated with |window|.
+  void FinishObserveRemovedWindow(aura::Window* window);

[simonhong, 2014/01/09 01:00:09]

Changed to FinishObservingRemovedWindow().

+
   // aura::client::ActivationChangeObserver overrides:
   virtual void OnWindowActivated(aura::Window* gained_active,
                                  aura::Window* lost_active) OVERRIDE;
 
   // aura::WindowObserver overrides:
   virtual void OnWindowAdded(aura::Window* window) OVERRIDE;
   virtual void OnWillRemoveWindow(aura::Window* window) OVERRIDE;
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
   virtual void OnWindowPropertyChanged(aura::Window* window,
                                        const void* key,
                                        intptr_t old) OVERRIDE;
 
   // gfx::DisplayObserver overrides:
   virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE;
   virtual void OnDisplayAdded(const gfx::Display& display) OVERRIDE;
   virtual void OnDisplayRemoved(const gfx::Display& old_display) OVERRIDE;
 
   // Owned by Shell.
   ShelfModel* model_;
   ShelfItemDelegateManager* item_delegate_manager_;
 
   RootWindowObserver root_window_observer_;
 
+  RemovedWindowObserver removed_window_observer_;
+
   // Holds all observed windows.
   ScopedObserver<aura::Window, aura::WindowObserver> observed_windows_;
 
   // Holds all observed root windows.
   ScopedObserver<aura::Window, aura::WindowObserver> observed_root_windows_;
 
+  // Holds removed windows that has an item from default container.
+  ScopedObserver<aura::Window, aura::WindowObserver> observed_removed_windows_;
+
   // Holds all observed activation clients.
   ScopedObserverWithDuplicatedSources<aura::client::ActivationClient,
       aura::client::ActivationChangeObserver> observed_activation_clients_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfWindowWatcher);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_WINDOW_WATCHER_H_