Athena: Adding basic resource management framework (un-/re-loading) of V2 applications

athena/content/app_activity_registry.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_REGISTRY_H_
+#define ATHENA_CONTENT_APP_ACTIVITY_REGISTRY_H_
+
+#include <vector>
+
+#include "athena/activity/public/activity_view_model.h"
+#include "athena/content/app_activity_proxy.h"
+
+namespace aura {
+class Window;
+}
+
+namespace content {
+class BrowserContext;
+}
+
+namespace athena {
+
+class AppActivity;
+
+// This class keeps track of all existing |AppActivity|s and shuts down all of
+// them when the application gets unloaded to save memory. It will then replace
+// the |AppActivity| in the Activity list as proxy to allow restarting of the
+// application.
+class AppActivityRegistry {

[oshima, 2014/08/15 15:15:59]

Isn't it possible to generalize this for both app and web?

[Mr4D (OOO till 08-26), 2014/08/18 16:09:32]

Well... Maybe. As stated earlier in our chats, the current TabDiscarder exists
since years and never produced trouble. As such we can postpone this problem
till later and first address the problems at hand (high and low level stuff)
before generalizing this.

Furthermore, apps are detected on app_id's whereas for content we need to keep
reference on who called whom - which is slightly different, but can be - of
course - done.

+ public:
+  AppActivityRegistry(const std::string& app_id,
+                      content::BrowserContext* browser_context);
+  virtual ~AppActivityRegistry();
+
+  // Register an |AppActivity| with this application.
+  void RegisterAppActivity(AppActivity* app_activity);
+
+  // Unregister a previously attached |AppActivity|.
+  // Note that detaching the last |AppActivity| will delete this object - unless
+  // the resource manager was trying to unload the application.
+  // Note furthermore that Detach can be called without ever being registered.
+  void UnregisterAppActivity(AppActivity* app_activity);
+
+  // Returns the number of activities/windows with this application.
+  int NumberOfActivities() const { return activity_list_.size(); }
+
+  // Unload all application associated activities to save resources.
+  void Unload();
+
+  // Returns true if the application is in the unloaded state.
+  bool IsUnloaded() { return unloaded_activity_proxy_ != NULL; }
+
+  content::BrowserContext* browser_context() { return browser_context_; }
+  const std::string& app_id() { return app_id_; }

[oshima, 2014/08/15 15:15:59]

const

[Mr4D (OOO till 08-26), 2014/08/18 16:09:32]

Done.

+
+ protected:
+  friend AppActivityProxy;
+
+  void ProxyDestroyed(AppActivityProxy* proxy);
+
+  // Called by the |AppActivityProxy| to restart the application upon user
+  // request.
+  void RestartApplication(AppActivityProxy* proxy);
+
+ private:
+  // Find the most recently used window of the application.
+  aura::Window* FindMruApplicationWindow();
+
+  // A list of all activities associated with this application.
+  std::vector<AppActivity*> activity_list_;
+
+  // The application id for this proxy.
+  std::string app_id_;
+
+  // The browser context of the user.
+  content::BrowserContext* browser_context_;
+
+  // When the activity is unloaded this is the AppActivityProxy. The object is
+  // owned the the ActivityManager.
+  AppActivityProxy* unloaded_activity_proxy_;
+
+  // The presentation values.
+  SkColor color_;
+  base::string16 title_;
+  gfx::ImageSkia image_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppActivityRegistry);
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_CONTENT_APP_ACTIVITY_REGISTRY_H_