Merge pull request #76 from beaufortfrancois/addDescriptors

Add Characteristic User Description GATT descriptor

.travis.yml

@@ -7,7 +7,7 @@ android:
     - tools
 
     # The BuildTools version
-    - build-tools-23.0.2
+    - build-tools-24.0.1
 
     # The SDK version used to compile
     - android-22

app/build.gradle

@@ -2,14 +2,13 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 22
-    buildToolsVersion "23.0.2"
-
+    buildToolsVersion '24.0.1'
     defaultConfig {
         applicationId "io.github.webbluetoothcg.bletestperipheral"
         minSdkVersion 21
         targetSdkVersion 22
-        versionCode 8
-        versionName "8.0"
+        versionCode 9
+        versionName '9.0'
     }
     buildTypes {
         release {
@@ -26,5 +25,5 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
+    compile fileTree(include: ['*.jar'], dir: 'libs')
 }

app/src/main/java/io/github/webbluetoothcg/bletestperipheral/BatteryServiceFragment.java

@@ -48,6 +48,8 @@ public class BatteryServiceFragment extends ServiceFragment {
       .fromString("00002A19-0000-1000-8000-00805f9b34fb");
   private static final int INITIAL_BATTERY_LEVEL = 50;
   private static final int BATTERY_LEVEL_MAX = 100;
+  private static final String BATTERY_LEVEL_DESCRIPTION = "The current charge level of a " +
+      "battery. 100% represents fully charged while 0% represents fully discharged.";
 
   private ServiceFragmentDelegate mDelegate;
   // UI
@@ -116,6 +118,9 @@ public BatteryServiceFragment() {
     mBatteryLevelCharacteristic.addDescriptor(
         Peripheral.getClientCharacteristicConfigurationDescriptor());
 
+    mBatteryLevelCharacteristic.addDescriptor(
+        Peripheral.getCharacteristicUserDescriptionDescriptor(BATTERY_LEVEL_DESCRIPTION));
+
     mBatteryService = new BluetoothGattService(BATTERY_SERVICE_UUID,
         BluetoothGattService.SERVICE_TYPE_PRIMARY);
     mBatteryService.addCharacteristic(mBatteryLevelCharacteristic);

app/src/main/java/io/github/webbluetoothcg/bletestperipheral/HeartRateServiceFragment.java

@@ -64,6 +64,8 @@ public class HeartRateServiceFragment extends ServiceFragment {
   private static final int INITIAL_HEART_RATE_MEASUREMENT_VALUE = 60;
   private static final int EXPENDED_ENERGY_FORMAT = BluetoothGattCharacteristic.FORMAT_UINT16;
   private static final int INITIAL_EXPENDED_ENERGY = 0;
+  private static final String HEART_RATE_MEASUREMENT_DESCRIPTION = "Used to send a heart rate " +
+      "measurement";
 
   /**
    * See <a href="https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.body_sensor_location.xml">
@@ -158,6 +160,9 @@ public HeartRateServiceFragment() {
     mHeartRateMeasurementCharacteristic.addDescriptor(
         Peripheral.getClientCharacteristicConfigurationDescriptor());
 
+    mHeartRateMeasurementCharacteristic.addDescriptor(
+        Peripheral.getCharacteristicUserDescriptionDescriptor(HEART_RATE_MEASUREMENT_DESCRIPTION));
+
     mBodySensorLocationCharacteristic =
         new BluetoothGattCharacteristic(BODY_SENSOR_LOCATION_UUID,
             BluetoothGattCharacteristic.PROPERTY_READ,

app/src/main/java/io/github/webbluetoothcg/bletestperipheral/Peripheral.java

@@ -53,6 +53,8 @@ public class Peripheral extends Activity implements ServiceFragmentDelegate {
   private static final String TAG = Peripheral.class.getCanonicalName();
   private static final String CURRENT_FRAGMENT_TAG = "CURRENT_FRAGMENT";
 
+  private static final UUID CHARACTERISTIC_USER_DESCRIPTION_UUID = UUID
+      .fromString("00002901-0000-1000-8000-00805f9b34fb");
   private static final UUID CLIENT_CHARACTERISTIC_CONFIGURATION_UUID = UUID
       .fromString("00002902-0000-1000-8000-00805f9b34fb");
 
@@ -172,6 +174,21 @@ public void onCharacteristicWriteRequest(BluetoothDevice device, int requestId,
       }
     }
 
+    @Override
+    public void onDescriptorReadRequest(BluetoothDevice device, int requestId,
+        int offset, BluetoothGattDescriptor descriptor) {
+      Log.d(TAG, "Device tried to read descriptor: " + descriptor.getUuid());
+      Log.d(TAG, "Value: " + Arrays.toString(descriptor.getValue()));
+      super.onDescriptorReadRequest(device, requestId, offset, descriptor);
+      if (offset != 0) {
+        mGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_INVALID_OFFSET, offset,
+            /* value (optional) */ null);
+        return;
+      }
+      mGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset,
+          descriptor.getValue());
+    }
+
     @Override
     public void onDescriptorWriteRequest(BluetoothDevice device, int requestId,
         BluetoothGattDescriptor descriptor, boolean preparedWrite, boolean responseNeeded,
@@ -180,7 +197,8 @@ public void onDescriptorWriteRequest(BluetoothDevice device, int requestId,
       Log.v(TAG, "Descriptor Write Request " + descriptor.getUuid() + " " + Arrays.toString(value));
       super.onDescriptorWriteRequest(device, requestId, descriptor, preparedWrite, responseNeeded,
           offset, value);
-      if(responseNeeded) {
+      descriptor.setValue(value);
+      if (responseNeeded) {
         mGattServer.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS,
             /* No need to respond with offset */ 0,
             /* No need to respond with a value */ null);
@@ -346,8 +364,21 @@ public void run() {
   ////// Bluetooth //////
   ///////////////////////
   public static BluetoothGattDescriptor getClientCharacteristicConfigurationDescriptor() {
-    return new BluetoothGattDescriptor(CLIENT_CHARACTERISTIC_CONFIGURATION_UUID,
-            (BluetoothGattDescriptor.PERMISSION_READ | BluetoothGattDescriptor.PERMISSION_WRITE));
+    BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(
+        CLIENT_CHARACTERISTIC_CONFIGURATION_UUID,
+        (BluetoothGattDescriptor.PERMISSION_READ | BluetoothGattDescriptor.PERMISSION_WRITE));
+    descriptor.setValue(new byte[]{0, 0});
+    return descriptor;
+  }
+
+  public static BluetoothGattDescriptor getCharacteristicUserDescriptionDescriptor(String defaultValue) {
+    BluetoothGattDescriptor descriptor = new BluetoothGattDescriptor(
+        CHARACTERISTIC_USER_DESCRIPTION_UUID, (BluetoothGattDescriptor.PERMISSION_READ));
+    try {
+      descriptor.setValue(defaultValue.getBytes("UTF-8"));
+    } finally {
+      return descriptor;
+    }
   }
 
   private void ensureBleFeaturesAvailable() {

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.1'
+        classpath 'com.android.tools.build:gradle:2.2.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files