cros: WallpaperController reparent based on session state

ash/wallpaper/wallpaper_controller.h

 // Copyright (c) 2012 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_WALLPAPER_WALLPAPER_CONTROLLER_H_
 #define ASH_WALLPAPER_WALLPAPER_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/public/interfaces/wallpaper.mojom.h"
 #include "ash/session/session_observer.h"
 #include "ash/shell_observer.h"
 #include "ash/wm_display_observer.h"
 #include "base/compiler_specific.h"

[James Cook, 2017/04/21 17:30:55]

nit: still needed?

[xiyuan, 2017/04/21 18:09:35]

Done.

 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/timer/timer.h"
 #include "components/wallpaper/wallpaper_color_calculator_observer.h"
 #include "components/wallpaper/wallpaper_layout.h"
 #include "components/wallpaper/wallpaper_resizer_observer.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "ui/gfx/color_analysis.h"
 #include "ui/gfx/image/image_skia.h"
 
 namespace base {
 class TaskRunner;
 }
 
 namespace wallpaper {
 class WallpaperColorCalculator;
 class WallpaperResizer;
 }
 
 namespace ash {
 
 class WallpaperControllerObserver;
 
 // Controls the desktop background wallpaper.

[James Cook, 2017/04/21 17:30:55]

totally optional: Maybe add some docs about how wallpaper works with screen
locking? I presume it changes containers to hide open windows on the desktop,
but it would be nice to say that somewhere. I wish this directory had a README,
but class-level docs would be nice.

[xiyuan, 2017/04/21 18:09:35]

Done.

 class ASH_EXPORT WallpaperController
     : public NON_EXPORTED_BASE(mojom::WallpaperController),
       public WmDisplayObserver,
       public ShellObserver,
       public wallpaper::WallpaperResizerObserver,
       public wallpaper::WallpaperColorCalculatorObserver,
       public SessionObserver {
  public:
   enum WallpaperMode { WALLPAPER_NONE, WALLPAPER_IMAGE };
 
@@ skipping 26 matching lines @@
                          wallpaper::WallpaperLayout layout);
 
   // Creates an empty wallpaper. Some tests require a wallpaper widget is ready
   // when running. However, the wallpaper widgets are now created
   // asynchronously. If loading a real wallpaper, there are cases that these
   // tests crash because the required widget is not ready. This function
   // synchronously creates an empty widget for those tests to prevent
   // crashes. An example test is SystemGestureEventFilterTest.ThreeFingerSwipe.
   void CreateEmptyWallpaper();
 
-  // Move all wallpaper widgets to the locked container.
-  // Returns true if the wallpaper moved.
-  bool MoveToLockedContainer();
-
-  // Move all wallpaper widgets to unlocked container.
-  // Returns true if the wallpaper moved.
-  bool MoveToUnlockedContainer();
-
   // WmDisplayObserver:
   void OnDisplayConfigurationChanged() override;
 
   // ShellObserver:
   void OnRootWindowAdded(WmWindow* root_window) override;
 
   // SessionObserver:
   void OnSessionStateChanged(session_manager::SessionState state) override;
 
   // Returns the maximum size of all displays combined in native
@@ skipping 21 matching lines @@
   void SetWallpaper(const SkBitmap& wallpaper,
                     wallpaper::WallpaperLayout layout) override;
 
   // WallpaperResizerObserver:
   void OnWallpaperResized() override;
 
   // WallpaperColorCalculatorObserver:
   void OnColorCalculationComplete() override;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(WallpaperControllerTest, BasicReparenting);
+  FRIEND_TEST_ALL_PREFIXES(WallpaperControllerTest,
+                           WallpaperMovementDuringUnlock);
   friend class WallpaperControllerTest;
 
   // Creates a WallpaperWidgetController for |root_window|.
   void InstallDesktopController(WmWindow* root_window);
 
   // Creates a WallpaperWidgetController for all root windows.
   void InstallDesktopControllerForAllWindows();
 
   // Moves the wallpaper to the specified container across all root windows.
   // Returns true if a wallpaper moved.
@@ skipping 13 matching lines @@
   // |observers_| of the value, either synchronously or asynchronously. In some
   // cases the wallpaper image will not actually be processed (e.g. user isn't
   // logged in, feature isn't enabled).
   // If an existing calculation is in progress it is destroyed.
   void CalculateWallpaperColors();
 
   // Returns false when the color extraction algorithm shouldn't be run based on
   // system state (e.g. wallpaper image, SessionState, etc.).
   bool ShouldCalculateColors() const;
 
+  // Move all wallpaper widgets to the locked container.
+  // Returns true if the wallpaper moved.
+  bool MoveToLockedContainer();
+
+  // Move all wallpaper widgets to unlocked container.
+  // Returns true if the wallpaper moved.
+  bool MoveToUnlockedContainer();
+
   bool locked_;
 
   WallpaperMode wallpaper_mode_;
 
   // Wallpaper picker interface in chrome browser, used to open the picker.
   mojom::WallpaperPickerPtr wallpaper_picker_;
 
   // Bindings for the WallpaperController interface.
   mojo::BindingSet<mojom::WallpaperController> bindings_;
 
@@ skipping 17 matching lines @@
   scoped_refptr<base::TaskRunner> task_runner_;
 
   ScopedSessionObserver scoped_session_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(WallpaperController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WALLPAPER_WALLPAPER_CONTROLLER_H_