1 /* 2 * Copyright (C) 2013 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 android.bluetooth; 18 19 import android.os.Parcel; 20 import android.os.Parcelable; 21 import android.os.ParcelUuid; 22 import java.util.UUID; 23 24 /** 25 * Represents a Bluetooth GATT Descriptor 26 * 27 * <p> GATT Descriptors contain additional information and attributes of a GATT 28 * characteristic, {@link BluetoothGattCharacteristic}. They can be used to describe 29 * the characteristic's features or to control certain behaviours of the characteristic. 30 */ 31 public class BluetoothGattDescriptor implements Parcelable { 32 33 /** 34 * Value used to enable notification for a client configuration descriptor 35 */ 36 public static final byte[] ENABLE_NOTIFICATION_VALUE = {0x01, 0x00}; 37 38 /** 39 * Value used to enable indication for a client configuration descriptor 40 */ 41 public static final byte[] ENABLE_INDICATION_VALUE = {0x02, 0x00}; 42 43 /** 44 * Value used to disable notifications or indicatinos 45 */ 46 public static final byte[] DISABLE_NOTIFICATION_VALUE = {0x00, 0x00}; 47 48 /** 49 * Descriptor read permission 50 */ 51 public static final int PERMISSION_READ = 0x01; 52 53 /** 54 * Descriptor permission: Allow encrypted read operations 55 */ 56 public static final int PERMISSION_READ_ENCRYPTED = 0x02; 57 58 /** 59 * Descriptor permission: Allow reading with man-in-the-middle protection 60 */ 61 public static final int PERMISSION_READ_ENCRYPTED_MITM = 0x04; 62 63 /** 64 * Descriptor write permission 65 */ 66 public static final int PERMISSION_WRITE = 0x10; 67 68 /** 69 * Descriptor permission: Allow encrypted writes 70 */ 71 public static final int PERMISSION_WRITE_ENCRYPTED = 0x20; 72 73 /** 74 * Descriptor permission: Allow encrypted writes with man-in-the-middle 75 * protection 76 */ 77 public static final int PERMISSION_WRITE_ENCRYPTED_MITM = 0x40; 78 79 /** 80 * Descriptor permission: Allow signed write operations 81 */ 82 public static final int PERMISSION_WRITE_SIGNED = 0x80; 83 84 /** 85 * Descriptor permission: Allow signed write operations with 86 * man-in-the-middle protection 87 */ 88 public static final int PERMISSION_WRITE_SIGNED_MITM = 0x100; 89 90 /** 91 * The UUID of this descriptor. 92 * @hide 93 */ 94 protected UUID mUuid; 95 96 /** 97 * Instance ID for this descriptor. 98 * @hide 99 */ 100 protected int mInstance; 101 102 /** 103 * Permissions for this descriptor 104 * @hide 105 */ 106 protected int mPermissions; 107 108 /** 109 * Back-reference to the characteristic this descriptor belongs to. 110 * @hide 111 */ 112 protected BluetoothGattCharacteristic mCharacteristic; 113 114 /** 115 * The value for this descriptor. 116 * @hide 117 */ 118 protected byte[] mValue; 119 120 /** 121 * Create a new BluetoothGattDescriptor. 122 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission. 123 * 124 * @param uuid The UUID for this descriptor 125 * @param permissions Permissions for this descriptor 126 */ 127 public BluetoothGattDescriptor(UUID uuid, int permissions) { 128 initDescriptor(null, uuid, 0, permissions); 129 } 130 131 /** 132 * Create a new BluetoothGattDescriptor. 133 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission. 134 * 135 * @param characteristic The characteristic this descriptor belongs to 136 * @param uuid The UUID for this descriptor 137 * @param permissions Permissions for this descriptor 138 */ 139 /*package*/ BluetoothGattDescriptor(BluetoothGattCharacteristic characteristic, UUID uuid, 140 int instance, int permissions) { 141 initDescriptor(characteristic, uuid, instance, permissions); 142 } 143 144 /** 145 * @hide 146 */ 147 public BluetoothGattDescriptor(UUID uuid, int instance, int permissions) { 148 initDescriptor(null, uuid, instance, permissions); 149 } 150 151 private void initDescriptor(BluetoothGattCharacteristic characteristic, UUID uuid, 152 int instance, int permissions) { 153 mCharacteristic = characteristic; 154 mUuid = uuid; 155 mInstance = instance; 156 mPermissions = permissions; 157 } 158 159 /** 160 * @hide 161 */ 162 public int describeContents() { 163 return 0; 164 } 165 166 public void writeToParcel(Parcel out, int flags) { 167 out.writeParcelable(new ParcelUuid(mUuid), 0); 168 out.writeInt(mInstance); 169 out.writeInt(mPermissions); 170 } 171 172 public static final Parcelable.Creator<BluetoothGattDescriptor> CREATOR 173 = new Parcelable.Creator<BluetoothGattDescriptor>() { 174 public BluetoothGattDescriptor createFromParcel(Parcel in) { 175 return new BluetoothGattDescriptor(in); 176 } 177 178 public BluetoothGattDescriptor[] newArray(int size) { 179 return new BluetoothGattDescriptor[size]; 180 } 181 }; 182 183 private BluetoothGattDescriptor(Parcel in) { 184 mUuid = ((ParcelUuid)in.readParcelable(null)).getUuid(); 185 mInstance = in.readInt(); 186 mPermissions = in.readInt(); 187 } 188 189 /** 190 * Returns the characteristic this descriptor belongs to. 191 * @return The characteristic. 192 */ 193 public BluetoothGattCharacteristic getCharacteristic() { 194 return mCharacteristic; 195 } 196 197 /** 198 * Set the back-reference to the associated characteristic 199 * @hide 200 */ 201 /*package*/ void setCharacteristic(BluetoothGattCharacteristic characteristic) { 202 mCharacteristic = characteristic; 203 } 204 205 /** 206 * Returns the UUID of this descriptor. 207 * 208 * @return UUID of this descriptor 209 */ 210 public UUID getUuid() { 211 return mUuid; 212 } 213 214 /** 215 * Returns the instance ID for this descriptor. 216 * 217 * <p>If a remote device offers multiple descriptors with the same UUID, 218 * the instance ID is used to distuinguish between descriptors. 219 * 220 * <p>Requires {@link android.Manifest.permission#BLUETOOTH} permission. 221 * 222 * @return Instance ID of this descriptor 223 * @hide 224 */ 225 public int getInstanceId() { 226 return mInstance; 227 } 228 229 /** 230 * Returns the permissions for this descriptor. 231 * 232 * @return Permissions of this descriptor 233 */ 234 public int getPermissions() { 235 return mPermissions; 236 } 237 238 /** 239 * Returns the stored value for this descriptor 240 * 241 * <p>This function returns the stored value for this descriptor as 242 * retrieved by calling {@link BluetoothGatt#readDescriptor}. The cached 243 * value of the descriptor is updated as a result of a descriptor read 244 * operation. 245 * 246 * @return Cached value of the descriptor 247 */ 248 public byte[] getValue() { 249 return mValue; 250 } 251 252 /** 253 * Updates the locally stored value of this descriptor. 254 * 255 * <p>This function modifies the locally stored cached value of this 256 * descriptor. To send the value to the remote device, call 257 * {@link BluetoothGatt#writeDescriptor} to send the value to the 258 * remote device. 259 * 260 * @param value New value for this descriptor 261 * @return true if the locally stored value has been set, false if the 262 * requested value could not be stored locally. 263 */ 264 public boolean setValue(byte[] value) { 265 mValue = value; 266 return true; 267 } 268 } 269
