Dan Harms | 2713943 | 2020-01-06 16:21:11 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.car.connecteddevice.ble; |
| 18 | |
| 19 | import static com.android.car.connecteddevice.util.SafeLog.logd; |
| 20 | import static com.android.car.connecteddevice.util.SafeLog.logw; |
| 21 | |
| 22 | import android.annotation.NonNull; |
| 23 | import android.annotation.Nullable; |
| 24 | import android.bluetooth.BluetoothDevice; |
| 25 | import android.bluetooth.BluetoothGatt; |
| 26 | |
| 27 | import com.android.car.connecteddevice.storage.ConnectedDeviceStorage; |
| 28 | import com.android.car.connecteddevice.util.ThreadSafeCallbacks; |
| 29 | |
| 30 | import java.util.concurrent.CopyOnWriteArraySet; |
| 31 | import java.util.concurrent.Executor; |
| 32 | |
| 33 | /** |
| 34 | * Generic BLE manager for a car that keeps track of connected devices and their associated |
| 35 | * callbacks. |
| 36 | */ |
| 37 | public abstract class CarBleManager { |
| 38 | |
| 39 | private static final String TAG = "CarBleManager"; |
| 40 | |
| 41 | final ConnectedDeviceStorage mStorage; |
| 42 | |
| 43 | final CopyOnWriteArraySet<BleDevice> mConnectedDevices = new CopyOnWriteArraySet<>(); |
| 44 | |
| 45 | final ThreadSafeCallbacks<Callback> mCallbacks = new ThreadSafeCallbacks<>(); |
| 46 | |
| 47 | protected CarBleManager(@NonNull ConnectedDeviceStorage connectedDeviceStorage) { |
| 48 | mStorage = connectedDeviceStorage; |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * Initialize and start the manager. |
| 53 | */ |
| 54 | public void start() { |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * Stop the manager and clean up. |
| 59 | */ |
| 60 | public void stop() { |
| 61 | for (BleDevice device : mConnectedDevices) { |
| 62 | if (device.mGatt != null) { |
| 63 | device.mGatt.close(); |
| 64 | } |
| 65 | } |
| 66 | mConnectedDevices.clear(); |
| 67 | mCallbacks.clear(); |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Register a {@link Callback} to be notified on the {@link Executor}. |
| 72 | */ |
| 73 | public void registerCallback(@NonNull Callback callback, @NonNull Executor executor) { |
| 74 | mCallbacks.add(callback, executor); |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * Unregister a callback. |
| 79 | * |
| 80 | * @param callback The {@link Callback} to unregister. |
| 81 | */ |
| 82 | public void unregisterCallback(@NonNull Callback callback) { |
| 83 | mCallbacks.remove(callback); |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Send a message to a connected device. |
| 88 | * |
| 89 | * @param deviceId Id of connected device. |
| 90 | * @param message {@link DeviceMessage} to send. |
| 91 | */ |
| 92 | public void sendMessage(@NonNull String deviceId, @NonNull DeviceMessage message) { |
| 93 | BleDevice device = getConnectedDevice(deviceId); |
| 94 | if (device == null) { |
| 95 | logw(TAG, "Attempted to send message to unknown device $deviceId. Ignored."); |
| 96 | return; |
| 97 | } |
| 98 | |
| 99 | sendMessage(device, message); |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * Send a message to a connected device. |
| 104 | * |
| 105 | * @param device The connected {@link BleDevice}. |
| 106 | * @param message {@link DeviceMessage} to send. |
| 107 | */ |
| 108 | public void sendMessage(@NonNull BleDevice device, @NonNull DeviceMessage message) { |
| 109 | String deviceId = device.mDeviceId; |
| 110 | if (deviceId == null) { |
| 111 | deviceId = "Unidentified device"; |
| 112 | } |
| 113 | |
| 114 | logd(TAG, "Writing " + message.getMessage().length + " bytes to " + deviceId + "."); |
| 115 | |
| 116 | |
| 117 | if (message.isMessageEncrypted()) { |
| 118 | device.mSecureChannel.sendEncryptedMessage(message); |
| 119 | } else { |
| 120 | device.mSecureChannel.getStream().writeMessage(message); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * Get the {@link BleDevice} with matching {@link BluetoothGatt} if available. Returns |
| 126 | * {@code null} if no matches are found. |
| 127 | */ |
| 128 | @Nullable |
| 129 | BleDevice getConnectedDevice(@NonNull BluetoothGatt gatt) { |
| 130 | for (BleDevice device : mConnectedDevices) { |
| 131 | if (device.mGatt == gatt) { |
| 132 | return device; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | return null; |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Get the {@link BleDevice} with matching {@link BluetoothDevice} if available. Returns |
| 141 | * {@code null} if no matches are found. |
| 142 | */ |
| 143 | @Nullable |
| 144 | BleDevice getConnectedDevice(@NonNull BluetoothDevice device) { |
| 145 | for (BleDevice connectedDevice : mConnectedDevices) { |
| 146 | if (device.equals(connectedDevice.mDevice)) { |
| 147 | return connectedDevice; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | return null; |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Get the {@link BleDevice} with matching device id if available. Returns {@code null} if |
| 156 | * no matches are found. |
| 157 | */ |
| 158 | @Nullable |
| 159 | BleDevice getConnectedDevice(@NonNull String deviceId) { |
| 160 | for (BleDevice device : mConnectedDevices) { |
| 161 | if (deviceId.equals(device.mDeviceId)) { |
| 162 | return device; |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | return null; |
| 167 | } |
| 168 | |
| 169 | /** Add the {@link BleDevice} that has connected. */ |
| 170 | void addConnectedDevice(@NonNull BleDevice device) { |
| 171 | mConnectedDevices.add(device); |
| 172 | } |
| 173 | |
| 174 | /** Return the number of devices currently connected. */ |
| 175 | int getConnectedDevicesCount() { |
| 176 | return mConnectedDevices.size(); |
| 177 | } |
| 178 | |
| 179 | /** Remove [@link BleDevice} that has been disconnected. */ |
| 180 | void removeConnectedDevice(@NonNull BleDevice device) { |
| 181 | mConnectedDevices.remove(device); |
| 182 | } |
| 183 | |
| 184 | /** State for a connected device. */ |
| 185 | enum BleDeviceState { |
| 186 | CONNECTING, |
| 187 | PENDING_VERIFICATION, |
| 188 | CONNECTED, |
| 189 | UNKNOWN |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * Container class to hold information about a connected device. |
| 194 | */ |
| 195 | static class BleDevice { |
| 196 | |
| 197 | BluetoothDevice mDevice; |
| 198 | BluetoothGatt mGatt; |
| 199 | BleDeviceState mState; |
| 200 | String mDeviceId; |
| 201 | SecureBleChannel mSecureChannel; |
| 202 | |
| 203 | BleDevice(@NonNull BluetoothDevice device, @Nullable BluetoothGatt gatt) { |
| 204 | mDevice = device; |
| 205 | mGatt = gatt; |
| 206 | mState = BleDeviceState.UNKNOWN; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * Callback for triggered events from {@link CarBleManager}. |
| 212 | */ |
| 213 | public interface Callback { |
| 214 | /** |
| 215 | * Triggered when device is connected and device id retrieved. Device is now ready to |
| 216 | * receive messages. |
| 217 | * |
| 218 | * @param deviceId Id of device that has connected. |
| 219 | */ |
| 220 | void onDeviceConnected(@NonNull String deviceId); |
| 221 | |
| 222 | /** |
| 223 | * Triggered when device is disconnected. |
| 224 | * |
| 225 | * @param deviceId Id of device that has disconnected. |
| 226 | */ |
| 227 | void onDeviceDisconnected(@NonNull String deviceId); |
| 228 | |
| 229 | /** |
| 230 | * Triggered when device has established encryption for secure communication. |
| 231 | * |
| 232 | * @param deviceId Id of device that has established encryption. |
| 233 | */ |
| 234 | void onSecureChannelEstablished(@NonNull String deviceId); |
| 235 | |
| 236 | /** |
| 237 | * Triggered when a new message is received. |
| 238 | * |
| 239 | * @param deviceId Id of the device that sent the message. |
| 240 | * @param message {@link DeviceMessage} received. |
| 241 | */ |
| 242 | void onMessageReceived(@NonNull String deviceId, @NonNull DeviceMessage message); |
| 243 | |
| 244 | /** |
| 245 | * Triggered when an error when establishing the secure channel. |
| 246 | * |
| 247 | * @param deviceId Id of the device that experienced the error. |
| 248 | */ |
| 249 | void onSecureChannelError(@NonNull String deviceId); |
| 250 | } |
| 251 | } |