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 ATHENA_EXPORT AppActivityRegistry {
+ 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(); }
+
+  // Returns the |AppActivity| at |index|. It will return NULL if an invalid
+  // index was specified.
+  AppActivity* GetAppActivityAt(size_t index);
+
+  // 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() const { return browser_context_; }
+  const std::string& app_id() const { return app_id_; }
+
+  AppActivityProxy* unloaded_activity_proxy_for_test() {
+    return unloaded_activity_proxy_;
+  }
+
+ protected:
+  friend AppActivityProxy;
+
+  // When the |AppActivityProxy| gets destroyed it should call this function
+  // to disconnect from this object. This call might destroy |this|.
+  void ProxyDestroyed(AppActivityProxy* proxy);
+
+  // When called by the |AppActivityProxy| to restart the application, it can
+  // cause the application to restart. When that happens the proxy will get
+  // destroyed. After this call |this| might be destroyed.
+  void RestartApplication(AppActivityProxy* proxy);
+
+ private:
+  // Move the window before the most recently used application window.
+  void MoveBeforeMruApplicationWindow(aura::Window* window);
+
+  // 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_