components/proximity_auth/remote_device_life_cycle.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_PROXIMITY_AUTH_REMOTE_DEVICE_LIFE_CYCLE_H
   6 #define COMPONENTS_PROXIMITY_AUTH_REMOTE_DEVICE_LIFE_CYCLE_H
   7
   8 #include "base/macros.h"
   9
  10 namespace proximity_auth {
  11
  12 class Authenticator;
  13 class Client;
  14 class ConnectionFinder;
  15
  16 // Controls the life cycle of connecting and authenticating to a remote device.
  17 // After the life cycle is started, it can be in the following states:
  18 //   FINDING_CONNECTION:
  19 //       Continuiously attempts to create a connection to the remote device.
  20 //       After connecting, transitions to the AUTHENTICATING state.
  21 //   AUTHENTICATING:
  22 //       Verifies that the connected device has the correct credentials. On
  23 //       success, transitions to SECURE_CHANNEL_ESTABLISHED; otherwise,
  24 //       transitions to AUTHENTICATION_FAILED.
  25 //   SECURE_CHANNEL_ESTABLISHED:
  26 //       Can send and receive messages securely from the remote device. Upon
  27 //       disconnection, transitions to FINDING_CONNECTION.
  28 //   AUTHENTICATION_FAILED:
  29 //       Recovery state after authentication fails. After a brief wait,
  30 //       transition to FINDING_CONNECTION.
  31 // To stop the life cycle and clean up the connection, simply destroying this
  32 // object.
  33 class RemoteDeviceLifeCycle {
  34  public:
  35   // The possible states in the life cycle.
  36   enum class State {
  37     STOPPED,
  38     FINDING_CONNECTION,
  39     AUTHENTICATING,
  40     SECURE_CHANNEL_ESTABLISHED,
  41     AUTHENTICATION_FAILED,
  42   };
  43
  44   // Interface for observing changes to the life cycle.
  45   class Observer {
  46    public:
  47     virtual ~Observer() {}
  48
  49     // Called when the state in the life cycle changes.
  50     virtual void OnLifeCycleStateChanged(State old_state, State new_state) = 0;
  51   };
  52
  53   virtual ~RemoteDeviceLifeCycle() {}
  54
  55   // Starts the life cycle.
  56   virtual void Start() = 0;
  57
  58   // Returns the current state of in the life cycle.
  59   virtual State GetState() const = 0;
  60
  61   // Returns the client for sending and receiving messages. This function will
  62   // only return an instance if the state is SECURE_CHANNEL_ESTABLISHED;
  63   // otherwise, it will return nullptr.
  64   virtual Client* GetClient() = 0;
  65
  66   // Adds an observer.
  67   virtual void AddObserver(Observer* observer) = 0;
  68
  69   // Removes an observer.
  70   virtual void RemoveObserver(Observer* observer) = 0;
  71 };
  72
  73 }  // namespace proximity_auth
  74
  75 #endif  // COMPONENTS_PROXIMITY_AUTH_REMOTE_DEVICE_LIFE_CYCLE_H