[Proximity Auth] Port the UnlockManager class.

components/proximity_auth/unlock_manager.h

+// Copyright 2015 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 COMPONENTS_PROXIMITY_AUTH_UNLOCK_MANAGER_H
+#define COMPONENTS_PROXIMITY_AUTH_UNLOCK_MANAGER_H
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "components/proximity_auth/client_observer.h"
+#include "components/proximity_auth/controller.h"
+#include "components/proximity_auth/remote_status_update.h"
+#include "components/proximity_auth/screenlock_bridge.h"
+#include "components/proximity_auth/screenlock_state.h"
+#include "device/bluetooth/bluetooth_adapter.h"
+
+#if defined(OS_CHROMEOS)
+#include "chromeos/dbus/power_manager_client.h"
+#endif
+
+namespace proximity_auth {
+
+class Client;
+class ProximityAuthClient;
+class ProximityMonitor;
+
+// The unlock manager is responsible for controlling the lock screen UI based on
+// the authentication status of the registered remote devices.
+class UnlockManager : public ClientObserver,
+                      public ScreenlockBridge::Observer,
+                      public device::BluetoothAdapter::Observer {
+ public:
+  enum class ScreenlockType {
+    SESSION_LOCK,
+    SIGN_IN,
+  };
+
+  // The |proximity_auth_client| is not owned and should outlive the constructed
+  // unlock manager.
+  // TODO(isherman): Rather than passing a single ProximityMonitor instance, we
+  // should pass a factory, as the UnlockManager should create and destroy
+  // ProximityMonitors as needed.  Currently, the expectations are misaligned
+  // between the ProximityMonitor and the UnlockManager classes.
+  UnlockManager(ScreenlockType screenlock_type,
+                scoped_ptr<ProximityMonitor> proximity_monitor,
+                ProximityAuthClient* proximity_auth_client);
+  ~UnlockManager() override;
+
+  // Whether proximity-based unlocking is currently allowed. True if any one of
+  // the remote devices is authenticated.

[Tim Song, 2015/07/23 21:32:15]

nit: and in range.

[Ilya Sherman, 2015/08/11 23:37:15]

Done.

+  bool IsUnlockAllowed();
+
+  // Sets the |controller| to which local events are dispatched. A null
+  // controller indicates that proximity-based authentication is inactive.
+  void SetController(Controller* controller);
+
+  // Called when the controller's state changes to |state|.

[Tim Song, 2015/07/23 21:32:15]

nit: there is no |state| argument.

[Ilya Sherman, 2015/08/11 23:37:15]

Done.

+  void OnControllerStateChanged();
+
+ protected:
+  // Called when the user pod is clicked for an authentication attempt of type
+  // |auth_type|.
+  // Exposed for testing.
+  void OnAuthAttempted(ScreenlockBridge::LockHandler::AuthType auth_type);
+
+ private:
+  // The possible lock screen states for the remote device.
+  enum class RemoteScreenlockState {
+    UNKNOWN,
+    UNLOCKED,
+    DISABLED,
+    LOCKED,
+  };
+
+  // ClientObserver:
+  void OnUnlockEventSent(bool success) override;
+  void OnRemoteStatusUpdate(const RemoteStatusUpdate& status_update) override;
+  void OnDecryptResponse(scoped_ptr<std::string> decrypted_bytes) override;
+  void OnUnlockResponse(bool success) override;
+  void OnDisconnected() override;
+
+  // ScreenlockBridge::Observer
+  void OnScreenDidLock(
+      ScreenlockBridge::LockHandler::ScreenType screen_type) override;
+  void OnScreenDidUnlock(
+      ScreenlockBridge::LockHandler::ScreenType screen_type) override;
+  void OnFocusedUserChanged(const std::string& user_id) override;
+
+  // Called when the screenlock state changes.
+  void OnScreenLockStateChanged(bool is_locked);
+
+  // Called when the Bluetooth adapter is initialized.
+  void OnBluetoothAdapterInitialized(
+      scoped_refptr<device::BluetoothAdapter> adapter);
+
+  // device::BluetoothAdapter::Observer:
+  void AdapterPresentChanged(device::BluetoothAdapter* adapter,
+                             bool present) override;
+  void AdapterPoweredChanged(device::BluetoothAdapter* adapter,
+                             bool powered) override;
+
+#if defined(OS_CHROMEOS)
+  // PowerManagerClient::Observer:
+  void SuspendDone(const base::TimeDelta& sleep_duration) override;
+#endif  // defined(OS_CHROMEOS)
+
+  // Called when auth is attempted to send the sign-in challenge to the remote
+  // device for decryption.
+  void SendSignInChallenge();
+
+  // Returns the current state for the screen lock UI.
+  ScreenlockState GetScreenlockState();
+
+  // Updates the lock screen based on the manager's current state.
+  void UpdateLockScreen();
+
+  // Activates or deactivates the proximity monitor, as appropriate given the
+  // current state of |this| unlock manager.
+  void UpdateProximityMonitorState();
+
+  // Sets waking up state.
+  void SetWakingUpState(bool is_waking_up);
+
+  // Accepts or rejects the current auth attempt according to |should_accept|.
+  // If the auth attempt is accepted, unlocks the screen.
+  void AcceptAuthAttempt(bool should_accept);
+
+  // Returns the screen lock state corresponding to the given remote |status|
+  // update.
+  RemoteScreenlockState GetScreenlockStateFromRemoteUpdate(
+      RemoteStatusUpdate update);
+
+  // Whether |this| manager is being used for sign-in or session unlock.
+  const ScreenlockType screenlock_type_;
+
+  // Whether the user is present at the remote device. Unset if no remote status
+  // update has yet been received.
+  scoped_ptr<RemoteScreenlockState> remote_screenlock_state_;
+
+  // Controls the proximity auth flow logic. Not owned, and expcted to outlive
+  // |this| instance.
+  Controller* controller_;
+
+  // The client used to communicate with the remote device once a secure channel
+  // is established. Null if no secure channel has been established yet. Not
+  // owned, and expected to outlive |this| instance.
+  Client* client_;
+
+  // Tracks whether the remote device is currently in close enough proximity to
+  // the local device to allow unlocking.
+  scoped_ptr<ProximityMonitor> proximity_monitor_;
+
+  // Used to call into the embedder. Stored as a weak reference, and expected to

[Tim Song, 2015/07/23 21:32:15]

nit: this is not stored as a weak reference.

[Ilya Sherman, 2015/08/11 23:37:15]

Done.

+  // outlive |this| instance.
+  ProximityAuthClient* proximity_auth_client_;
+
+  // Whether the screen is currently locked.
+  bool is_locked_;
+
+  // True if the manager is currently processing a user-initiated authentication
+  // attempt, which is initiated when the user pod is clicked.
+  bool is_attempting_auth_;
+
+  // Whether the system is waking up from sleep.
+  bool is_waking_up_;
+
+  // The Bluetooth adapter. Null if there is no adapter present on the local
+  // device.
+  scoped_refptr<device::BluetoothAdapter> bluetooth_adapter_;
+
+  // The sign-in secret received from the remote device by decrypting the
+  // sign-in challenge.
+  scoped_ptr<std::string> sign_in_secret_;
+
+  // The state of the current screen lock UI.
+  ScreenlockState screenlock_state_;
+
+  // Used to clear the waking up state after a timeout.
+  base::WeakPtrFactory<UnlockManager> clear_waking_up_state_weak_ptr_factory_;

[Tim Song, 2015/07/23 21:32:15]

Wouldn't it be clearer to use timers instead to better express intent?

[Ilya Sherman, 2015/08/11 23:37:15]

I tend to prefer directly posting tasks to message loops, for ease of testing. 
I can switch to a timer if it's important to you, though.

+
+  // Used to reject auth attempts after a timeout. An in-progress auth attempt
+  // blocks the sign-in screen UI, so it's important to prevent the auth attempt
+  // from blocking the UI in case a step in the code path hangs.
+  base::WeakPtrFactory<UnlockManager> reject_auth_attempt_weak_ptr_factory_;
+
+  // Used to vend all other weak pointers.
+  base::WeakPtrFactory<UnlockManager> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(UnlockManager);
+};
+
+}  // namespace proximity_auth
+
+#endif  // COMPONENTS_PROXIMITY_AUTH_UNLOCK_MANAGER_H