arc: bluetooth: Implement Gatt notify

components/arc/bluetooth/arc_bluetooth_bridge.cc

 // Copyright 2016 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/arc/bluetooth/arc_bluetooth_bridge.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 
 #include <iomanip>
@@ skipping 27 matching lines @@
 using device::BluetoothGattNotifySession;
 using device::BluetoothGattCharacteristic;
 using device::BluetoothGattDescriptor;
 using device::BluetoothGattService;
 using device::BluetoothRemoteGattCharacteristic;
 using device::BluetoothRemoteGattDescriptor;
 using device::BluetoothRemoteGattService;
 using device::BluetoothUUID;
 
 namespace {
-const int kMinBtleVersion = 1;
+enum { kMinBtleVersion = 1 };
+enum { kMinBtleNotifyVersion = 2 };
 const uint32_t kGattReadPermission =
     BluetoothGattCharacteristic::Permission::PERMISSION_READ |
     BluetoothGattCharacteristic::Permission::PERMISSION_READ_ENCRYPTED |
     BluetoothGattCharacteristic::Permission::
         PERMISSION_READ_ENCRYPTED_AUTHENTICATED;
 const uint32_t kGattWritePermission =
     BluetoothGattCharacteristic::Permission::PERMISSION_WRITE |
     BluetoothGattCharacteristic::Permission::PERMISSION_WRITE_ENCRYPTED |
     BluetoothGattCharacteristic::Permission::
         PERMISSION_WRITE_ENCRYPTED_AUTHENTICATED;
@@ skipping 191 matching lines @@
 void ArcBluetoothBridge::GattDescriptorRemoved(
     BluetoothAdapter* adapter,
     BluetoothRemoteGattDescriptor* descriptor) {
   // Placeholder for GATT client functionality
 }
 
 void ArcBluetoothBridge::GattCharacteristicValueChanged(
     BluetoothAdapter* adapter,
     BluetoothRemoteGattCharacteristic* characteristic,
     const std::vector<uint8_t>& value) {
-  // Placeholder for GATT client functionality
+  if (!HasBluetoothInstance())
+    return;
+
+  if (arc_bridge_service()->bluetooth_version() < kMinBtleNotifyVersion) {
+    LOG(WARNING) << "Bluetooth instance is too old and does not support notify";
+    return;
+  }
+  BluetoothRemoteGattService* service = characteristic->GetService();
+  BluetoothDevice* device = service->GetDevice();
+  mojom::BluetoothAddressPtr address =
+      mojom::BluetoothAddress::From(device->GetAddress());
+  mojom::BluetoothGattServiceIDPtr service_id =
+      mojom::BluetoothGattServiceID::New();
+  service_id->is_primary = service->IsPrimary();
+  service_id->id = mojom::BluetoothGattID::New();
+  service_id->id->inst_id = ConvertGattIdentifierToId(service->GetIdentifier());
+  service_id->id->uuid = mojom::BluetoothUUID::From(service->GetUUID());
+
+  mojom::BluetoothGattIDPtr char_id = mojom::BluetoothGattID::New();
+  char_id->inst_id = ConvertGattIdentifierToId(characteristic->GetIdentifier());
+  char_id->uuid = mojom::BluetoothUUID::From(characteristic->GetUUID());
+
+  arc_bridge_service()->bluetooth_instance()->OnGattNotify(
+      std::move(address), std::move(service_id), std::move(char_id),
+      true /* is_notify */, mojo::Array<uint8_t>::From(value));
 }
 
 void ArcBluetoothBridge::GattDescriptorValueChanged(
     BluetoothAdapter* adapter,
     BluetoothRemoteGattDescriptor* descriptor,
     const std::vector<uint8_t>& value) {
   // Placeholder for GATT client functionality
 }
 
 void ArcBluetoothBridge::EnableAdapter(const EnableAdapterCallback& callback) {
@@ skipping 624 matching lines @@
     mojom::BluetoothGattIDPtr char_id,
     mojom::BluetoothGattIDPtr desc_id,
     mojom::BluetoothGattValuePtr value,
     const WriteGattDescriptorCallback& callback) {
   BluetoothRemoteGattDescriptor* descriptor =
       FindGattDescriptor(std::move(remote_addr), std::move(service_id),
                          std::move(char_id), std::move(desc_id));
   DCHECK(descriptor);
   DCHECK(descriptor->GetPermissions() & kGattWritePermission);
 
+  // Chrome does not support writing to CCC Descriptor
+  // Always return success when encounter this.

[palmer, 2016/06/27 19:25:42]

These 2 comment lines don't seem to agree — it's unsupported, so report success.
Can you please explain in the comment why we want to do that?

[puthik_chromium, 2016/06/27 19:55:07]

Done.

+  // TODO(http://crbug.com/622832)
+  if (descriptor->GetUUID() ==
+      BluetoothGattDescriptor::ClientCharacteristicConfigurationUuid()) {
+    OnGattWriteDone(callback);
+    return;
+  }
+
   descriptor->WriteRemoteDescriptor(
       value->value.To<std::vector<uint8_t>>(),
       base::Bind(&ArcBluetoothBridge::OnGattWriteDone,
                  weak_factory_.GetWeakPtr(), callback),
       base::Bind(&ArcBluetoothBridge::OnGattWriteError,
                  weak_factory_.GetWeakPtr(), callback));
 }
 
 void ArcBluetoothBridge::OnGattNotifyStartDone(
     const RegisterForGattNotificationCallback& callback,
@@ skipping 397 matching lines @@
     // to
     // make sure the bond state machine on Android is ready to take the
     // pair-done event. Otherwise the pair-done event will be dropped as an
     // invalid change of paired status.
     OnPairing(addr->Clone());
     OnPairedDone(std::move(addr));
   }
 }
 
 }  // namespace arc