Decoupling visibility states from webcontent, adding visibility management in ResourceManager

athena/content/app_activity_proxy.h

 // Copyright 2014 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 ATHENA_CONTENT_APP_ACTIVITY_PROXY_H_
 #define ATHENA_CONTENT_APP_ACTIVITY_PROXY_H_
 
 #include <vector>
 
 #include "athena/activity/public/activity.h"
 #include "athena/activity/public/activity_view_model.h"
 #include "ui/gfx/image/image_skia.h"
 
 namespace athena {
 
 class AppActivityRegistry;
 
 // This activity object is a proxy placeholder for the application while it is
 // unloaded. When selected it will launch the applciation again and destroy
 // itself indirectly.
 class AppActivityProxy : public Activity,
                          public ActivityViewModel {
  public:
-  AppActivityProxy(ActivityViewModel* view_model, AppActivityRegistry* creator);
+  // The |replaced_activity| is the activity which this proxy replaces. Note
+  // that after the Init() call got called, this object will become invalid.
+  // The |creator| should be informed when the object goes away.
+  AppActivityProxy(Activity* replaced_activity, AppActivityRegistry* creator);
+
+ protected:
   virtual ~AppActivityProxy();
 
-  // Activity overrides:
+ // Activity overrides:
   virtual ActivityViewModel* GetActivityViewModel() OVERRIDE;
   virtual void SetCurrentState(ActivityState state) OVERRIDE;
   virtual ActivityState GetCurrentState() OVERRIDE;
   virtual bool IsVisible() OVERRIDE;
   virtual ActivityMediaState GetMediaState() OVERRIDE;
   virtual aura::Window* GetWindow() OVERRIDE;
 
   // ActivityViewModel overrides:
   virtual void Init() OVERRIDE;
   virtual SkColor GetRepresentativeColor() const OVERRIDE;
   virtual base::string16 GetTitle() const OVERRIDE;
   virtual bool UsesFrame() const OVERRIDE;
   virtual views::View* GetContentsView() OVERRIDE;
   virtual void CreateOverviewModeImage() OVERRIDE;
   virtual gfx::ImageSkia GetOverviewModeImage() OVERRIDE;
 
  private:
   // The creator of this object which needs to be informed if the object gets
   // destroyed or the application should get restarted.
   AppActivityRegistry* app_activity_registry_;
 
   // The presentation values.
   const base::string16 title_;
   const gfx::ImageSkia image_;
   const SkColor color_;
 
+  // The activity which gets replaced. It is used to sort the activity against
+  // upon initialization. Once moved, this value gets reset since the object
+  // can go away at any time.
+  Activity* replaced_activity_;
+
   // The associated view.
   views::View* view_;
 
   DISALLOW_COPY_AND_ASSIGN(AppActivityProxy);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_CONTENT_APP_ACTIVITY_PROXY_H_