Implementing a BLE connection finder.

components/proximity_auth/ble/bluetooth_low_energy_connection_finder.cc

+// 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.
+
+#include "components/proximity_auth/ble/bluetooth_low_energy_connection_finder.h"
+
+#include <string>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "device/bluetooth/bluetooth_adapter_factory.h"
+#include "device/bluetooth/bluetooth_device.h"
+#include "device/bluetooth/bluetooth_discovery_session.h"
+#include "device/bluetooth/bluetooth_uuid.h"
+
+using device::BluetoothAdapter;
+using device::BluetoothDevice;
+
+namespace proximity_auth {
+
+BluetoothLowEnergyConnectionFinder::BluetoothLowEnergyConnectionFinder(
+    const std::string& remote_service_uuid)
+    : remote_service_uuid_(device::BluetoothUUID(remote_service_uuid)),
+      weak_ptr_factory_(this) {
+}
+
+BluetoothLowEnergyConnectionFinder::~BluetoothLowEnergyConnectionFinder() {
+  if (discovery_session_.get()) {
+    StopDiscoverySession();
+  }
+  if (adapter_) {
+    adapter_->RemoveObserver(this);
+    adapter_ = NULL;
+  }
+}
+
+void BluetoothLowEnergyConnectionFinder::Find(
+    const BluetoothDevice::GattConnectionCallback& connection_callback) {
+  if (!device::BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
+    VLOG(1) << "[BCF] Bluetooth is unsupported on this platform. Aborting.";
+    return;
+  }
+  VLOG(1) << "Finding connection";
+
+  connection_callback_ = connection_callback;
+
+  device::BluetoothAdapterFactory::GetAdapter(
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnAdapterInitialized,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void BluetoothLowEnergyConnectionFinder::Find(
+    const ConnectionCallback& connection_callback) {
+  NOTREACHED();
+}
+
+void BluetoothLowEnergyConnectionFinder::DeviceAdded(BluetoothAdapter* adapter,
+                                                     BluetoothDevice* device) {
+  if (device) {
+    VLOG(1) << "New device found: " << device->GetName();
+    HandleDeviceAdded(device);
+  }
+}
+
+void BluetoothLowEnergyConnectionFinder::OnAdapterInitialized(
+    scoped_refptr<BluetoothAdapter> adapter) {
+  VLOG(1) << "Adapter ready";
+
+  adapter_ = adapter;
+  adapter_->AddObserver(this);
+
+  std::vector<BluetoothDevice*> devices = adapter_->GetDevices();
+  for (auto iter = devices.begin(); iter != devices.end(); iter++) {
+    HandleDeviceAdded((*iter));
+  }
+
+  StartDiscoverySession();
+}
+
+void BluetoothLowEnergyConnectionFinder::HandleDeviceAdded(
+    BluetoothDevice* remote_device) {
+  if (HasService(remote_device)) {
+    CreateConnection(remote_device);

[msarda, 2015/04/24 14:12:16]

This seems to potentially create multiple concurrent connections. Is that
something you want?

[sacomoto, 2015/04/24 14:56:22]

You are right. Modified.

+  }
+}
+
+void BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted(
+    scoped_ptr<device::BluetoothDiscoverySession> discovery_session) {
+  VLOG(1) << "Discovery session started";
+  discovery_session_ = discovery_session.Pass();
+}
+
+void BluetoothLowEnergyConnectionFinder::OnStartDiscoverySessionError() {
+  VLOG(1) << "Error starting discovery session";
+}
+
+void BluetoothLowEnergyConnectionFinder::StartDiscoverySession() {
+  DCHECK(adapter_);
+  if (discovery_session_.get() && discovery_session_->IsActive()) {
+    VLOG(1) << "Discovery session already active";
+    return;
+  }
+  adapter_->StartDiscoverySession(
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(
+          &BluetoothLowEnergyConnectionFinder::OnStartDiscoverySessionError,
+          weak_ptr_factory_.GetWeakPtr()));
+}
+
+void BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStopped() {
+  VLOG(1) << "Discovery session stopped";
+  discovery_session_.reset();
+}
+
+void BluetoothLowEnergyConnectionFinder::OnStopDiscoverySessionError() {
+  VLOG(1) << "Error stopping discovery session";
+}
+
+void BluetoothLowEnergyConnectionFinder::StopDiscoverySession() {
+  VLOG(1) << "Stopping discovery sesison";
+
+  if (!adapter_.get()) {
+    VLOG(1) << "Adapter not initialized";
+    return;
+  }
+  if (!discovery_session_.get() || !discovery_session_->IsActive()) {
+    VLOG(1) << "No Active discovery session";
+  }
+
+  discovery_session_->Stop(
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStopped,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(
+          &BluetoothLowEnergyConnectionFinder::OnStopDiscoverySessionError,
+          weak_ptr_factory_.GetWeakPtr()));
+}
+
+bool BluetoothLowEnergyConnectionFinder::HasService(
+    BluetoothDevice* remote_device) {
+  if (remote_device) {

[msarda, 2015/04/24 14:12:16]

Can this actually be nullptr? If not, then I think it would be better to use
DCHECK(remote_device) here.

[sacomoto, 2015/04/24 14:56:22]

I think it can. When the observer interface method DeviceAdded is called there
is no guarantee that the device is non-NULL.

+    std::vector<device::BluetoothUUID> uuids = remote_device->GetUUIDs();
+    for (auto iter = uuids.begin(); iter != uuids.end(); iter++) {
+      if (remote_service_uuid_ == *iter) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+void BluetoothLowEnergyConnectionFinder::OnCreateConnectionError(
+    BluetoothDevice::ConnectErrorCode error_code) {
+  VLOG(1) << "Error creating connection";
+}
+
+void BluetoothLowEnergyConnectionFinder::CreateConnection(
+    device::BluetoothDevice* remote_device) {
+  VLOG(1) << "SmartLock service found ("
+          << remote_service_uuid_.canonical_value() << ")\n"
+          << "device = " << remote_device->GetAddress()
+          << ", name = " << remote_device->GetName();
+  remote_device->CreateGattConnection(
+      connection_callback_,
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnCreateConnectionError,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+}  // namespace proximity_auth