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 {

[msarda, 2015/04/22 08:55:14]

This function is internal. Use an anonymous namespace for it:
namespace {
....

[sacomoto, 2015/04/22 09:44:19]

Done.

+

[msarda, 2015/04/22 08:55:14]

Kill empty line.

[sacomoto, 2015/04/22 09:44:19]

Done.

+void DoNothingErrorCallback(BluetoothDevice::ConnectErrorCode error_code) {
+}
+
+BluetoothLowEnergyConnectionFinder::BluetoothLowEnergyConnectionFinder(
+    const std::string& remote_service_uuid)
+    : remote_service_uuid_(device::BluetoothUUID(remote_service_uuid)),
+      weak_ptr_factory_(this) {
+}
+
+BluetoothLowEnergyConnectionFinder::~BluetoothLowEnergyConnectionFinder() {
+  if (adapter_.get()) {

[msarda, 2015/04/22 08:55:14]

You are starting discovery after the adapter is set. I think we should destroy
them in the opposite order - first stop discovery settings ans then stop the
observer.

I also think you do not need the .get() in this if (I think if (adapater_) {
should work).

[sacomoto, 2015/04/22 09:44:19]

Done.

[sacomoto, 2015/04/22 09:44:19]

Done.

+    adapter_->RemoveObserver(this);
+    adapter_ = NULL;
+  }
+  if (discovery_session_.get()) {
+    StopDiscoverySession();
+    discovery_session_.reset();
+  }
+}
+
+void BluetoothLowEnergyConnectionFinder::Find(
+    const BluetoothDevice::GattConnectionCallback& connection_callback) {
+  DVLOG(1) << "Finding connection";

[msarda, 2015/04/22 08:55:14]

Move this below the IsBluetoothAvailable line.

[sacomoto, 2015/04/22 09:44:19]

Done.

+
+  if (!device::BluetoothAdapterFactory::IsBluetoothAdapterAvailable()) {
+    VLOG(1) << "[BCF] Bluetooth is unsupported on this platform. Aborting.";

[msarda, 2015/04/22 08:55:14]

LOG(WARNING)

[sacomoto, 2015/04/22 09:44:19]

I'm being consistent with the current proximity/bluetooth_connection_finder
implementation. I think we should keep like this for now. Later we can change
everything to LOG(WARNING). 

+    return;
+  }
+
+  connection_callback_ = connection_callback;
+
+  device::BluetoothAdapterFactory::GetAdapter(
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnAdapterInitialized,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void BluetoothLowEnergyConnectionFinder::Find(
+    const ConnectionCallback& connection_callback) {

[msarda, 2015/04/22 08:55:14]

I would expect this would be the method that we should call. Why do we have a
different method than the ConnectionFinder?

[sacomoto, 2015/04/22 09:44:19]

I agree. The problem is that the current callback types don't match. The
callback required for BluetoothDevice::CreateGattConnection is not the same as
ConnectionCallback.

I'm planing to change this once the BluetoothLowEnergyConnection is implemented.
  

+}
+
+void BluetoothLowEnergyConnectionFinder::DeviceAdded(BluetoothAdapter* adapter,
+                                                     BluetoothDevice* device) {
+  if (device) {
+    DVLOG(1) << "New device found: " << device->GetName();
+    if (HasService(device)) {
+      CreateConnection(device);
+    }
+  }
+}
+
+void BluetoothLowEnergyConnectionFinder::OnAdapterInitialized(
+    scoped_refptr<BluetoothAdapter> adapter) {
+  DVLOG(1) << "Adapter ready";
+
+  adapter_ = adapter;
+  adapter_->AddObserver(this);
+
+  std::vector<BluetoothDevice*> devices = adapter_->GetDevices();
+  for (auto iter = devices.begin(); iter != devices.end(); iter++) {
+    if (HasService(*iter)) {
+      CreateConnection(*iter);
+    }
+  }
+
+  StartDiscoverySession();
+}
+
+void BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted(
+    scoped_ptr<device::BluetoothDiscoverySession> discovery_session) {
+  DVLOG(1) << "Discovery session started";
+  discovery_session_.reset(discovery_session.release());

[msarda, 2015/04/22 08:55:14]

discovery_session_ = discovery_session.Pass();

[sacomoto, 2015/04/22 09:44:19]

Done.

+}
+
+void BluetoothLowEnergyConnectionFinder::StartDiscoverySession() {
+  if (!adapter_.get()) {
+    DVLOG(1) << "Adapter not initialized";
+    return;
+  }
+  if (discovery_session_.get() && discovery_session_->IsActive()) {
+    DVLOG(1) << "Discovery session already active";
+    return;
+  }
+  adapter_->StartDiscoverySession(
+      base::Bind(&BluetoothLowEnergyConnectionFinder::OnDiscoverySessionStarted,
+                 weak_ptr_factory_.GetWeakPtr()),
+      base::Bind(base::DoNothing));
+}
+
+void BluetoothLowEnergyConnectionFinder::StopDiscoverySession() {
+  DVLOG(1) << "Stopping discovery sesison";
+
+  if (!adapter_.get()) {
+    DVLOG(1) << "Adapter not initialized";
+    return;
+  }
+  if (!discovery_session_.get() || !discovery_session_->IsActive()) {
+    DVLOG(1) << "No Active discovery session";
+  }
+
+  discovery_session_->Stop(base::Bind(base::DoNothing),

[msarda, 2015/04/22 08:55:14]

Should you reset the discovery_session_ object when the Stop function is over?

[sacomoto, 2015/04/22 09:44:19]

Done.

+                           base::Bind(base::DoNothing));
+}
+
+bool BluetoothLowEnergyConnectionFinder::HasService(
+    BluetoothDevice* remote_device) {
+  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::CreateConnection(
+    device::BluetoothDevice* remote_device) {
+  DVLOG(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(&DoNothingErrorCallback));
+}
+
+}  // namespace proximity_auth