components/proximity_auth/bluetooth_connection_finder.cc

   1 // Copyright 2014 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 #include "components/proximity_auth/bluetooth_connection_finder.h"
   6
   7 #include "base/bind.h"
   8 #include "base/location.h"
   9 #include "base/logging.h"
  10 #include "base/message_loop/message_loop_proxy.h"
  11 #include "components/proximity_auth/bluetooth_connection.h"
  12 #include "device/bluetooth/bluetooth_adapter_factory.h"
  13
  14 using device::BluetoothAdapter;
  15
  16 namespace proximity_auth {
  17
  18 BluetoothConnectionFinder::BluetoothConnectionFinder(
  19     const RemoteDevice& remote_device,
  20     const device::BluetoothUUID& uuid,
  21     const base::TimeDelta& polling_interval)
  22     : remote_device_(remote_device),
  23       uuid_(uuid),
  24       polling_interval_(polling_interval),
  25       has_delayed_poll_scheduled_(false),
  26       weak_ptr_factory_(this) {
  27 }
  28
  29 BluetoothConnectionFinder::~BluetoothConnectionFinder() {
  30   UnregisterAsObserver();
  31 }
  32
  33 void BluetoothConnectionFinder::Find(
  34     const ConnectionCallback& connection_callback) {
  35   if (!device::BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
  36     VLOG(1) << "[BCF] Bluetooth is unsupported on this platform. Aborting.";
  37     return;
  38   }
  39
  40   DCHECK(start_time_.is_null());
  41   VLOG(1) << "[BCF] Finding Bluetooth connection...";
  42
  43   start_time_ = base::TimeTicks::Now();
  44   connection_callback_ = connection_callback;
  45
  46   device::BluetoothAdapterFactory::GetAdapter(
  47       base::Bind(&BluetoothConnectionFinder::OnAdapterInitialized,
  48                  weak_ptr_factory_.GetWeakPtr()));
  49 }
  50
  51 scoped_ptr<Connection> BluetoothConnectionFinder::CreateConnection() {
  52   return scoped_ptr<Connection>(new BluetoothConnection(remote_device_, uuid_));
  53 }
  54
  55 bool BluetoothConnectionFinder::IsReadyToPoll() {
  56   bool is_adapter_available =
  57       adapter_.get() && adapter_->IsPresent() && adapter_->IsPowered();
  58   VLOG(1) << "[BCF] Readiness: adapter="
  59           << (is_adapter_available ? "available" : "unavailable");
  60   return is_adapter_available;
  61 }
  62
  63 void BluetoothConnectionFinder::PollIfReady() {
  64   if (!IsReadyToPoll())
  65     return;
  66
  67   // If there is a pending task to poll at a later time, the time requisite
  68   // timeout has not yet elapsed since the previous polling attempt. In that
  69   // case, keep waiting until the delayed task comes in.
  70   if (has_delayed_poll_scheduled_)
  71     return;
  72
  73   // If the |connection_| exists, wait for it to connect or fail prior to
  74   // polling again.
  75   if (connection_)
  76     return;
  77
  78   VLOG(1) << "[BCF] Polling for connection...";
  79   connection_ = CreateConnection();
  80   connection_->AddObserver(this);
  81   connection_->Connect();
  82 }
  83
  84 void BluetoothConnectionFinder::DelayedPollIfReady() {
  85   // Note that there is no longer a pending task, and therefore polling is
  86   // permitted.
  87   has_delayed_poll_scheduled_ = false;
  88   PollIfReady();
  89 }
  90
  91 void BluetoothConnectionFinder::UnregisterAsObserver() {
  92   if (connection_) {
  93     connection_->RemoveObserver(this);
  94     // The connection is about to be released or destroyed, so no need to clear
  95     // it explicitly here.
  96   }
  97
  98   if (adapter_.get()) {
  99     adapter_->RemoveObserver(this);
 100     adapter_ = NULL;
 101   }
 102 }
 103
 104 void BluetoothConnectionFinder::OnAdapterInitialized(
 105     scoped_refptr<BluetoothAdapter> adapter) {
 106   adapter_ = adapter;
 107   adapter_->AddObserver(this);
 108   PollIfReady();
 109 }
 110
 111 void BluetoothConnectionFinder::AdapterPresentChanged(BluetoothAdapter* adapter,
 112                                                       bool present) {
 113   PollIfReady();
 114 }
 115
 116 void BluetoothConnectionFinder::AdapterPoweredChanged(BluetoothAdapter* adapter,
 117                                                       bool powered) {
 118   PollIfReady();
 119 }
 120
 121 void BluetoothConnectionFinder::OnConnectionStatusChanged(
 122     const Connection& connection,
 123     Connection::Status old_status,
 124     Connection::Status new_status) {
 125   DCHECK_EQ(&connection, connection_.get());
 126
 127   if (connection_->IsConnected()) {
 128     base::TimeDelta elapsed = base::TimeTicks::Now() - start_time_;
 129     VLOG(1) << "[BCF] Connection found! Elapsed Time: "
 130             << elapsed.InMilliseconds() << "ms.";
 131     UnregisterAsObserver();
 132     connection_callback_.Run(connection_.Pass());
 133   } else if (old_status == Connection::IN_PROGRESS) {
 134     VLOG(1) << "[BCF] Connection failed! Scheduling another polling iteration.";
 135     connection_.reset();
 136     has_delayed_poll_scheduled_ = true;
 137     base::MessageLoopProxy::current()->PostDelayedTask(
 138         FROM_HERE,
 139         base::Bind(&BluetoothConnectionFinder::DelayedPollIfReady,
 140                    weak_ptr_factory_.GetWeakPtr()),
 141         polling_interval_);
 142   }
 143 }
 144
 145 }  // namespace proximity_auth