/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package uk.co.alt236.btlescan.services;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import java.util.List;
/**
* Service for managing connection and data communication with a GATT server hosted on a
* given Bluetooth LE device.
*/
public class BluetoothLeService extends Service {
public final static String ACTION_GATT_CONNECTED = BluetoothLeService.class.getName() + ".ACTION_GATT_CONNECTED";
public final static String ACTION_GATT_CONNECTING = BluetoothLeService.class.getName() + ".ACTION_GATT_CONNECTING";
public final static String ACTION_GATT_DISCONNECTED = BluetoothLeService.class.getName() + ".ACTION_GATT_DISCONNECTED";
public final static String ACTION_GATT_SERVICES_DISCOVERED = BluetoothLeService.class.getName() + ".ACTION_GATT_SERVICES_DISCOVERED";
public final static String ACTION_DATA_AVAILABLE = BluetoothLeService.class.getName() + ".ACTION_DATA_AVAILABLE";
public final static String EXTRA_DATA_RAW = BluetoothLeService.class.getName() + ".EXTRA_DATA_RAW";
public final static String EXTRA_UUID_CHAR = BluetoothLeService.class.getName() + ".EXTRA_UUID_CHAR";
private final static String TAG = BluetoothLeService.class.getSimpleName();
private final IBinder mBinder = new LocalBinder();
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private String mBluetoothDeviceAddress;
private BluetoothGatt mBluetoothGatt;
private State mConnectionState = State.DISCONNECTED;
// Implements callback methods for GATT events that the app cares about. For example,
// connection change and services discovered.
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onCharacteristicChanged(final BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
@Override
public void onCharacteristicRead(final BluetoothGatt gatt,
final BluetoothGattCharacteristic characteristic,
final int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
}
@Override
public void onConnectionStateChange(final BluetoothGatt gatt,
final int status,
final int newState) {
Log.d(TAG, "onConnectionStateChange: status=" + status + ", newState=" + newState);
if (newState == BluetoothProfile.STATE_CONNECTED) {
setConnectionState(State.CONNECTED, true);
Log.i(TAG, "Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:" + mBluetoothGatt.discoverServices());
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
// Make sure we tidy up. On certain devices reusing a Gatt after a disconnection
// can cause problems.
disconnect();
setConnectionState(State.DISCONNECTED, true);
Log.i(TAG, "Disconnected from GATT server.");
}
}
@Override
public void onServicesDiscovered(final BluetoothGatt gatt, final int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
};
private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}
private void broadcastUpdate(final String action, final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
intent.putExtra(EXTRA_UUID_CHAR, characteristic.getUuid().toString());
// Always try to add the RAW value
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
intent.putExtra(EXTRA_DATA_RAW, data);
}
sendBroadcast(intent);
}
/**
* After using a given BLE device, the app must call this method to ensure resources are
* released properly.
*/
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
}
/**
* Connects to the GATT server hosted on the Bluetooth LE device.
*
* @param address The device address of the destination device.
* @return Return true if the connection is initiated successfully. The connection result
* is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public boolean connect(final String address) {
final boolean retVal;
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
retVal = false;
// Previously connected device. Try to reconnect.
} else if (mBluetoothDeviceAddress != null
&& address.equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
Log.d(TAG, "Connection attempt OK.");
setConnectionState(State.CONNECTING, true);
retVal = true;
} else {
Log.w(TAG, "Connection attempt failed.");
setConnectionState(State.DISCONNECTED, true);
retVal = false;
}
} else {
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
retVal = false;
} else {
// We want to directly connect to the device, so we are setting the autoConnect
// parameter to false.
Log.d(TAG, "Trying to create a new connection.");
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
mBluetoothDeviceAddress = address;
setConnectionState(State.CONNECTING, true);
retVal = true;
}
}
return retVal;
}
private synchronized void setConnectionState(final State newState, final boolean broadCast) {
Log.i(TAG, "Setting internal state to " + newState);
mConnectionState = newState;
final String broadcastAction;
switch (newState) {
case CONNECTED:
broadcastAction = ACTION_GATT_CONNECTED;
break;
case CONNECTING:
broadcastAction = ACTION_GATT_CONNECTING;
break;
case DISCONNECTED:
broadcastAction = ACTION_GATT_DISCONNECTED;
break;
default:
throw new IllegalArgumentException("Unknown state: " + newState);
}
if (broadCast) {
Log.i(TAG, "Broadcasting " + broadcastAction);
broadcastUpdate(broadcastAction);
}
}
/**
* Disconnects an existing connection or cancel a pending connection. The disconnection result
* is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.disconnect();
// Reusing a Gatt after disconnecting can cause problems
mBluetoothGatt = null;
}
/**
* Retrieves a list of supported GATT services on the connected device. This should be
* invoked only after {@code BluetoothGatt#discoverServices()} completes successfully.
*
* @return A {@code List} of supported services.
*/
public List<BluetoothGattService> getSupportedGattServices() {
if (mBluetoothGatt == null) return null;
return mBluetoothGatt.getServices();
}
/**
* Initializes a reference to the local Bluetooth adapter.
*
* @return Return true if the initialization is successful.
*/
public boolean initialize() {
// For API level 18 and above, get a reference to BluetoothAdapter through
// BluetoothManager.
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
Log.e(TAG, "Unable to initialize BluetoothManager.");
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
return false;
}
return true;
}
@Override
public IBinder onBind(final Intent intent) {
return mBinder;
}
@Override
public boolean onUnbind(final Intent intent) {
// After using a given device, you should make sure that BluetoothGatt.close() is called
// such that resources are cleaned up properly. In this particular example, close() is
// invoked when the UI is disconnected from the Service.
close();
return super.onUnbind(intent);
}
/**
* Request a read on a given {@code BluetoothGattCharacteristic}. The read result is reported
* asynchronously through the {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*
* @param characteristic The characteristic to read from.
*/
public void readCharacteristic(final BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.readCharacteristic(characteristic);
}
/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic Characteristic to act on.
* @param enabled If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(final BluetoothGattCharacteristic characteristic, final boolean enabled) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
}
public class LocalBinder extends Binder {
public BluetoothLeService getService() {
return BluetoothLeService.this;
}
}
private enum State {
DISCONNECTED,
CONNECTING,
CONNECTED
}
}