Introduce lock screen app manager interface

chrome/browser/chromeos/lock_screen_apps/state_controller.h

 // Copyright 2017 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 CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_STATE_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_STATE_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/public/interfaces/tray_action.mojom.h"
 #include "base/observer_list.h"
+#include "base/scoped_observer.h"
+#include "chrome/browser/chromeos/lock_screen_apps/app_manager.h"
 #include "chrome/browser/chromeos/lock_screen_apps/state_observer.h"
+#include "components/session_manager/core/session_manager_observer.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
+class Profile;
+
+namespace session_manager {
+class SessionManager;
+}
+
 namespace lock_screen_apps {
 
 class StateObserver;
 
 // Manages state of lock screen action handler apps, and notifies
 // interested parties as the state changes.
 // Currently assumes single supported action - NEW_NOTE.
-class StateController : public ash::mojom::TrayActionClient {
+class StateController : public ash::mojom::TrayActionClient,
+                        public session_manager::SessionManagerObserver {
  public:
   // Returns whether the StateController is enabled - it is currently guarded by
   // a feature flag. If not enabled, |StateController| instance is not allowed
   // to be created. |Get| will still work, but it will return nullptr.
   static bool IsEnabled();
 
   // Returns the global StateController instance. Note that this can return
   // nullptr when lock screen apps are not enabled (see |IsEnabled|).
   static StateController* Get();
 
   // Note that only one StateController is allowed per process. Creating a
   // StateController will set global instance ptr that can be accessed using
   // |Get|. This pointer will be reset when the StateController is destroyed.
   StateController();
   ~StateController() override;
 
   // Sets the tray action that should be used by |StateController|.
   // Has to be called before |Initialize|.
   void SetTrayActionPtrForTesting(ash::mojom::TrayActionPtr tray_action_ptr);
   void FlushTrayActionForTesting();
+  // Sets test AppManager implementation. Should be called before
+  // |SetPrimaryProfile|
+  void SetAppManagerForTesting(std::unique_ptr<AppManager> app_manager);
 
   // Initializes mojo bindings for the StateController - it creates binding to
   // ash's tray action interface and sets this object as the interface's client.
   void Initialize();
+  void SetPrimaryProfile(Profile* profile);
 
   void AddObserver(StateObserver* observer);
   void RemoveObserver(StateObserver* observer);
 
   // Gets current state assiciated with the lock screen note action.
   ash::mojom::TrayActionState GetLockScreenNoteState() const;
 
   // ash::mojom::TrayActionClient:
   void RequestNewLockScreenNote() override;
 
+  // session_manager::SessionManagerObserver:
+  void OnSessionStateChanged() override;
+
   // If there are any active lock screen action handlers, moved their windows
   // to background, to ensure lock screen UI is visible.
   void MoveToBackground();
 
   // If there are any lock screen action handler in background, moves their
   // windows back to foreground (i.e. visible over lock screen UI).
   void MoveToForeground();
 
   // Sets the current state - to be used in tests. Hopefully, when this class
   // has more logic implemented, this will not be needed.
   void SetLockScreenNoteStateForTesting(ash::mojom::TrayActionState state);
 
  private:
+  // Called when app manager reports that note taking availability has changed.
+  void OnNoteTakingAvailabilityChanged();
+
   // Requests lock screen note action state change to |state|.
   // Returns whether the action state has changed.
   bool UpdateLockScreenNoteState(ash::mojom::TrayActionState state);
 
   // Notifies observers that the lock screen note action state changed.
   void NotifyLockScreenNoteStateChanged();
 
   // Lock screen note action state.
   ash::mojom::TrayActionState lock_screen_note_state_ =
       ash::mojom::TrayActionState::kNotAvailable;
 
   base::ObserverList<StateObserver> observers_;
 
   mojo::Binding<ash::mojom::TrayActionClient> binding_;
   ash::mojom::TrayActionPtr tray_action_ptr_;
 
+  std::unique_ptr<AppManager> app_manager_;
+
+  ScopedObserver<session_manager::SessionManager,
+                 session_manager::SessionManagerObserver>
+      session_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(StateController);
 };
 
 }  // namespace lock_screen_apps
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOCK_SCREEN_APPS_STATE_CONTROLLER_H_