bluetooth: Create base class BluetoothDevice::CreateGattConnection impl.

device/bluetooth/bluetooth_gatt_connection.cc

 // Copyright 2014 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 "device/bluetooth/bluetooth_gatt_connection.h"
 
+#include "device/bluetooth/bluetooth_adapter.h"
+
 namespace device {
 
-BluetoothGattConnection::BluetoothGattConnection() {
+BluetoothGattConnection::BluetoothGattConnection(
+    BluetoothAdapter* adapter,
+    const std::string& device_address)
+    : adapter_(adapter), device_address_(device_address) {
+  DCHECK(adapter_.get());
+  DCHECK(!device_address_.empty());
+
+  BluetoothDevice* device = adapter_->GetDevice(device_address_);
+  if (device)

[Jeffrey Yasskin, 2015/08/19 22:49:45]

If !device, IsConnected() should probably return false, even if the device is
later paired and connected, since this object doesn't own a connection
reference.

[scheib, 2015/09/13 02:40:28]

Done.

+    device->IncrementGattConnectionReferenceCount();
 }
 
 BluetoothGattConnection::~BluetoothGattConnection() {
+  Disconnect();
+}
+
+std::string BluetoothGattConnection::GetDeviceAddress() const {

[Jeffrey Yasskin, 2015/08/19 22:49:46]

Return a const std::string&?

[scheib, 2015/09/13 02:40:28]

Done.

+  return device_address_;
+}
+
+bool BluetoothGattConnection::IsConnected() {
+  return !already_decremented_connection_reference_on_device_ &&
+         adapter_->GetDevice(device_address_)->IsGattConnected();

[Jeffrey Yasskin, 2015/08/19 22:49:46]

This leads to an interesting situation where:
1) we have a Connection object
2) the device moves out of range leading to a disconnection
3) the device moves back into range
4) a *different webpage* reconnects.

I think at this point, our original Connection object now returns true from
IsConnected(), which doesn't seem correct. It should record that it's
disconnected until its owner reconnects it.

[Jeffrey Yasskin, 2015/08/19 22:49:46]

Do you need to check for adapter_->GetDevice() returning null? If not, comment
why.

[scheib, 2015/09/13 02:40:28]

Done - refactored reference counting to have pointers to BluetoothGattConnection
objects and to ensure they are set to be disconnected.

[scheib, 2015/09/13 02:40:28]

Done.

+}
+
+void BluetoothGattConnection::Disconnect() {
+  if (already_decremented_connection_reference_on_device_)
+    return;
+
+  already_decremented_connection_reference_on_device_ = true;
+  BluetoothDevice* device = adapter_->GetDevice(device_address_);
+  if (device)
+    device->DecrementGattConnectionReferenceCount();
 }
 
 }  // namespace device