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

ash/shelf/shelf_window_watcher.cc

 // 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.
 
 #include "ash/shelf/shelf_window_watcher.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/shelf/shelf_item_delegate_manager.h"
 #include "ash/shelf/shelf_model.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shelf/shelf_window_watcher_item_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/window.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/screen.h"
 
 namespace {
 
 // Sets LauncherItem property by using the value of |details|.
 void SetLauncherItemDetailsForLauncherItem(
     ash::LauncherItem* item,
     const ash::LauncherItemDetails& details) {
   item->type = details.type;
   if (details.image_resource_id != ash::kInvalidImageResourceID) {
     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     item->image = *rb.GetImageSkiaNamed(details.image_resource_id);
   }
 }
 
 // Returns true if |window| has a LauncherItem added by ShelfWindowWatcher.
 bool HasLauncherItemForWindow(aura::Window* window) {
   if (ash::GetLauncherItemDetailsForWindow(window) != NULL &&
       ash::GetLauncherIDForWindow(window) != ash::kInvalidLauncherID)
     return true;
   return false;
 }
 
+// Returns true if |window| is in the process of being dragged.
+bool IsDragging(aura::Window* window) {
+  return ash::wm::GetWindowState(window)->is_dragged();
+}
+
 }  // namespace
 
 namespace ash {
 namespace internal {
 
 ShelfWindowWatcher::RootWindowObserver::RootWindowObserver(
     ShelfWindowWatcher* window_watcher)
     : window_watcher_(window_watcher) {
 }
 
@@ skipping 96 matching lines @@
   observed_windows_.Add(window);
   // Add LauncherItem if |window| already has a LauncherItemDetails when it is
   // created. Don't make a new LauncherItem for the re-parented |window| that
   // already has a LauncherItem.
   if (GetLauncherIDForWindow(window) == ash::kInvalidLauncherID &&
       GetLauncherItemDetailsForWindow(window))
     AddLauncherItem(window);
 }
 
 void ShelfWindowWatcher::OnWillRemoveWindow(aura::Window* window) {
-  // Remove a child window of default container and its item if it has.
+  // Remove a child window of default container.
   if (observed_windows_.IsObserving(window))
     observed_windows_.Remove(window);
 
-  if (HasLauncherItemForWindow(window))
+  // When |window| is dragged, its item should not be removed.
+  if (HasLauncherItemForWindow(window) && !IsDragging(window))

[sky, 2013/12/14 00:17:20]

If the window is deleted while dragging how does this cleanup? You remove the
observer on 167, right? Please add test coverage for this.

[simonhong, 2013/12/16 02:24:16]

When a |window| is dragging its observer and item is not removed.
Instead, deleted |window| during the dragging is handled by
OnWindowDestroying().
For the test case, I found that WindowResizer can't handle deleted |window|
during the dragging. WindowResizer uses weak pointer of |window|. So I can't
simulate deleting a |window| before WindowResizer is destroyed for now. I think
it needs some refactoring for this.

     RemoveLauncherItem(window);
 }
 
 void ShelfWindowWatcher::OnWindowDestroying(aura::Window* window) {
   // Remove the default container.
   if (observed_windows_.IsObserving(window))
     observed_windows_.Remove(window);
 }
 
 void ShelfWindowWatcher::OnWindowPropertyChanged(aura::Window* window,
@@ skipping 41 matching lines @@
 
 void ShelfWindowWatcher::OnDisplayRemoved(const gfx::Display& old_display) {
   // When this is called, RootWindow of |old_display| is already removed.
   // Instead, we remove an observer from RootWindow and ActivationClient in the
   // OnRootWindowDestroyed().
   // Do nothing here.
 }
 
 }  // namespace internal
 }  // namespace ash