/*
* Copyright (C) 2014 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 android.bluetooth.le;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallbackWrapper;
import android.bluetooth.BluetoothUuid;
import android.bluetooth.IBluetoothGatt;
import android.bluetooth.IBluetoothManager;
import android.os.Handler;
import android.os.Looper;
import android.os.ParcelUuid;
import android.os.RemoteException;
import android.util.Log;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
/**
* This class provides a way to perform Bluetooth LE advertise operations, such as starting and
* stopping advertising. An advertiser can broadcast up to 31 bytes of advertisement data
* represented by {@link AdvertiseData}.
* <p>
* To get an instance of {@link BluetoothLeAdvertiser}, call the
* {@link BluetoothAdapter#getBluetoothLeAdvertiser()} method.
* <p>
* <b>Note:</b> Most of the methods here require {@link android.Manifest.permission#BLUETOOTH_ADMIN}
* permission.
*
* @see AdvertiseData
*/
public final class BluetoothLeAdvertiser {
private static final String TAG = "BluetoothLeAdvertiser";
private static final int MAX_ADVERTISING_DATA_BYTES = 31;
// Each fields need one byte for field length and another byte for field type.
private static final int OVERHEAD_BYTES_PER_FIELD = 2;
// Flags field will be set by system.
private static final int FLAGS_FIELD_BYTES = 3;
private static final int MANUFACTURER_SPECIFIC_DATA_LENGTH = 2;
private static final int SERVICE_DATA_UUID_LENGTH = 2;
private final IBluetoothManager mBluetoothManager;
private final Handler mHandler;
private BluetoothAdapter mBluetoothAdapter;
private final Map<AdvertiseCallback, AdvertiseCallbackWrapper>
mLeAdvertisers = new HashMap<AdvertiseCallback, AdvertiseCallbackWrapper>();
/**
* Use BluetoothAdapter.getLeAdvertiser() instead.
*
* @param bluetoothManager BluetoothManager that conducts overall Bluetooth Management
* @hide
*/
public BluetoothLeAdvertiser(IBluetoothManager bluetoothManager) {
mBluetoothManager = bluetoothManager;
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mHandler = new Handler(Looper.getMainLooper());
}
/**
* Start Bluetooth LE Advertising. On success, the {@code advertiseData} will be broadcasted.
* Returns immediately, the operation status is delivered through {@code callback}.
* <p>
* Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} permission.
*
* @param settings Settings for Bluetooth LE advertising.
* @param advertiseData Advertisement data to be broadcasted.
* @param callback Callback for advertising status.
*/
public void startAdvertising(AdvertiseSettings settings,
AdvertiseData advertiseData, final AdvertiseCallback callback) {
startAdvertising(settings, advertiseData, null, callback);
}
/**
* Start Bluetooth LE Advertising. The {@code advertiseData} will be broadcasted if the
* operation succeeds. The {@code scanResponse} is returned when a scanning device sends an
* active scan request. This method returns immediately, the operation status is delivered
* through {@code callback}.
* <p>
* Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN}
*
* @param settings Settings for Bluetooth LE advertising.
* @param advertiseData Advertisement data to be advertised in advertisement packet.
* @param scanResponse Scan response associated with the advertisement data.
* @param callback Callback for advertising status.
*/
public void startAdvertising(AdvertiseSettings settings,
AdvertiseData advertiseData, AdvertiseData scanResponse,
final AdvertiseCallback callback) {
synchronized (mLeAdvertisers) {
BluetoothLeUtils.checkAdapterStateOn(mBluetoothAdapter);
if (callback == null) {
throw new IllegalArgumentException("callback cannot be null");
}
if (!mBluetoothAdapter.isMultipleAdvertisementSupported() &&
!mBluetoothAdapter.isPeripheralModeSupported()) {
postStartFailure(callback,
AdvertiseCallback.ADVERTISE_FAILED_FEATURE_UNSUPPORTED);
return;
}
boolean isConnectable = settings.isConnectable();
if (totalBytes(advertiseData, isConnectable) > MAX_ADVERTISING_DATA_BYTES ||
totalBytes(scanResponse, false) > MAX_ADVERTISING_DATA_BYTES) {
postStartFailure(callback, AdvertiseCallback.ADVERTISE_FAILED_DATA_TOO_LARGE);
return;
}
if (mLeAdvertisers.containsKey(callback)) {
postStartFailure(callback, AdvertiseCallback.ADVERTISE_FAILED_ALREADY_STARTED);
return;
}
IBluetoothGatt gatt;
try {
gatt = mBluetoothManager.getBluetoothGatt();
} catch (RemoteException e) {
Log.e(TAG, "Failed to get Bluetooth gatt - ", e);
postStartFailure(callback, AdvertiseCallback.ADVERTISE_FAILED_INTERNAL_ERROR);
return;
}
AdvertiseCallbackWrapper wrapper = new AdvertiseCallbackWrapper(callback, advertiseData,
scanResponse, settings, gatt);
wrapper.startRegisteration();
}
}
/**
* Stop Bluetooth LE advertising. The {@code callback} must be the same one use in
* {@link BluetoothLeAdvertiser#startAdvertising}.
* <p>
* Requires {@link android.Manifest.permission#BLUETOOTH_ADMIN} permission.
*
* @param callback {@link AdvertiseCallback} identifies the advertising instance to stop.
*/
public void stopAdvertising(final AdvertiseCallback callback) {
synchronized (mLeAdvertisers) {
BluetoothLeUtils.checkAdapterStateOn(mBluetoothAdapter);
if (callback == null) {
throw new IllegalArgumentException("callback cannot be null");
}
AdvertiseCallbackWrapper wrapper = mLeAdvertisers.get(callback);
if (wrapper == null) return;
wrapper.stopAdvertising();
}
}
/**
* Cleans up advertise clients. Should be called when bluetooth is down.
*
* @hide
*/
public void cleanup() {
mLeAdvertisers.clear();
}
// Compute the size of advertisement data or scan resp
private int totalBytes(AdvertiseData data, boolean isFlagsIncluded) {
if (data == null) return 0;
// Flags field is omitted if the advertising is not connectable.
int size = (isFlagsIncluded) ? FLAGS_FIELD_BYTES : 0;
if (data.getServiceUuids() != null) {
int num16BitUuids = 0;
int num32BitUuids = 0;
int num128BitUuids = 0;
for (ParcelUuid uuid : data.getServiceUuids()) {
if (BluetoothUuid.is16BitUuid(uuid)) {
++num16BitUuids;
} else if (BluetoothUuid.is32BitUuid(uuid)) {
++num32BitUuids;
} else {
++num128BitUuids;
}
}
// 16 bit service uuids are grouped into one field when doing advertising.
if (num16BitUuids != 0) {
size += OVERHEAD_BYTES_PER_FIELD +
num16BitUuids * BluetoothUuid.UUID_BYTES_16_BIT;
}
// 32 bit service uuids are grouped into one field when doing advertising.
if (num32BitUuids != 0) {
size += OVERHEAD_BYTES_PER_FIELD +
num32BitUuids * BluetoothUuid.UUID_BYTES_32_BIT;
}
// 128 bit service uuids are grouped into one field when doing advertising.
if (num128BitUuids != 0) {
size += OVERHEAD_BYTES_PER_FIELD +
num128BitUuids * BluetoothUuid.UUID_BYTES_128_BIT;
}
}
for (ParcelUuid uuid : data.getServiceData().keySet()) {
size += OVERHEAD_BYTES_PER_FIELD + SERVICE_DATA_UUID_LENGTH
+ byteLength(data.getServiceData().get(uuid));
}
for (int i = 0; i < data.getManufacturerSpecificData().size(); ++i) {
size += OVERHEAD_BYTES_PER_FIELD + MANUFACTURER_SPECIFIC_DATA_LENGTH +
byteLength(data.getManufacturerSpecificData().valueAt(i));
}
if (data.getIncludeTxPowerLevel()) {
size += OVERHEAD_BYTES_PER_FIELD + 1; // tx power level value is one byte.
}
if (data.getIncludeDeviceName() && mBluetoothAdapter.getName() != null) {
size += OVERHEAD_BYTES_PER_FIELD + mBluetoothAdapter.getName().length();
}
return size;
}
private int byteLength(byte[] array) {
return array == null ? 0 : array.length;
}
/**
* Bluetooth GATT interface callbacks for advertising.
*/
private class AdvertiseCallbackWrapper extends BluetoothGattCallbackWrapper {
private static final int LE_CALLBACK_TIMEOUT_MILLIS = 2000;
private final AdvertiseCallback mAdvertiseCallback;
private final AdvertiseData mAdvertisement;
private final AdvertiseData mScanResponse;
private final AdvertiseSettings mSettings;
private final IBluetoothGatt mBluetoothGatt;
// mClientIf 0: not registered
// -1: scan stopped
// >0: registered and scan started
private int mClientIf;
private boolean mIsAdvertising = false;
public AdvertiseCallbackWrapper(AdvertiseCallback advertiseCallback,
AdvertiseData advertiseData, AdvertiseData scanResponse,
AdvertiseSettings settings,
IBluetoothGatt bluetoothGatt) {
mAdvertiseCallback = advertiseCallback;
mAdvertisement = advertiseData;
mScanResponse = scanResponse;
mSettings = settings;
mBluetoothGatt = bluetoothGatt;
mClientIf = 0;
}
public void startRegisteration() {
synchronized (this) {
if (mClientIf == -1) return;
try {
UUID uuid = UUID.randomUUID();
mBluetoothGatt.registerClient(new ParcelUuid(uuid), this);
wait(LE_CALLBACK_TIMEOUT_MILLIS);
} catch (InterruptedException | RemoteException e) {
Log.e(TAG, "Failed to start registeration", e);
}
if (mClientIf > 0 && mIsAdvertising) {
mLeAdvertisers.put(mAdvertiseCallback, this);
} else if (mClientIf <= 0) {
// Post internal error if registration failed.
postStartFailure(mAdvertiseCallback,
AdvertiseCallback.ADVERTISE_FAILED_INTERNAL_ERROR);
} else {
// Unregister application if it's already registered but advertise failed.
try {
mBluetoothGatt.unregisterClient(mClientIf);
mClientIf = -1;
} catch (RemoteException e) {
Log.e(TAG, "remote exception when unregistering", e);
}
}
}
}
public void stopAdvertising() {
synchronized (this) {
try {
mBluetoothGatt.stopMultiAdvertising(mClientIf);
wait(LE_CALLBACK_TIMEOUT_MILLIS);
} catch (InterruptedException | RemoteException e) {
Log.e(TAG, "Failed to stop advertising", e);
}
// Advertise callback should have been removed from LeAdvertisers when
// onMultiAdvertiseCallback was called. In case onMultiAdvertiseCallback is never
// invoked and wait timeout expires, remove callback here.
if (mLeAdvertisers.containsKey(mAdvertiseCallback)) {
mLeAdvertisers.remove(mAdvertiseCallback);
}
}
}
/**
* Application interface registered - app is ready to go
*/
@Override
public void onClientRegistered(int status, int clientIf) {
Log.d(TAG, "onClientRegistered() - status=" + status + " clientIf=" + clientIf);
synchronized (this) {
if (status == BluetoothGatt.GATT_SUCCESS) {
mClientIf = clientIf;
try {
mBluetoothGatt.startMultiAdvertising(mClientIf, mAdvertisement,
mScanResponse, mSettings);
return;
} catch (RemoteException e) {
Log.e(TAG, "failed to start advertising", e);
}
}
// Registration failed.
mClientIf = -1;
notifyAll();
}
}
@Override
public void onMultiAdvertiseCallback(int status, boolean isStart,
AdvertiseSettings settings) {
synchronized (this) {
if (isStart) {
if (status == AdvertiseCallback.ADVERTISE_SUCCESS) {
// Start success
mIsAdvertising = true;
postStartSuccess(mAdvertiseCallback, settings);
} else {
// Start failure.
postStartFailure(mAdvertiseCallback, status);
}
} else {
// unregister client for stop.
try {
mBluetoothGatt.unregisterClient(mClientIf);
mClientIf = -1;
mIsAdvertising = false;
mLeAdvertisers.remove(mAdvertiseCallback);
} catch (RemoteException e) {
Log.e(TAG, "remote exception when unregistering", e);
}
}
notifyAll();
}
}
}
private void postStartFailure(final AdvertiseCallback callback, final int error) {
mHandler.post(new Runnable() {
@Override
public void run() {
callback.onStartFailure(error);
}
});
}
private void postStartSuccess(final AdvertiseCallback callback,
final AdvertiseSettings settings) {
mHandler.post(new Runnable() {
@Override
public void run() {
callback.onStartSuccess(settings);
}
});
}
}
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