From dc60e8db7549d44b668cb6487ee912b98d9c8336 Mon Sep 17 00:00:00 2001
From: Matthias Granberry <matthias.granberry@tabbedout.com>
Date: Mon, 18 Apr 2016 10:25:03 -0500
Subject: [PATCH] Character indications on connection as well.

---
 .../polidea/rxandroidble/RxBleConnection.java | 15 ++++++++
 .../connection/RxBleConnectionImpl.java       | 38 +++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/rxandroidble/src/main/java/com/polidea/rxandroidble/RxBleConnection.java b/rxandroidble/src/main/java/com/polidea/rxandroidble/RxBleConnection.java
index 440050830..211fea70e 100644
--- a/rxandroidble/src/main/java/com/polidea/rxandroidble/RxBleConnection.java
+++ b/rxandroidble/src/main/java/com/polidea/rxandroidble/RxBleConnection.java
@@ -72,6 +72,21 @@ public String toString() {
      */
     Observable<Observable<byte[]>> setupNotification(@NonNull UUID characteristicUuid);
 
+    /**
+     * Setup characteristic indication in order to receive callbacks when given characteristic has been changed. Returned observable will
+     * emit Observable<byte[]> once the indication setup has been completed. It is possible to setup more observables for the same
+     * characteristic and the lifecycle of the indication will be shared among them.
+     * <p>
+     * Indication is automatically unregistered once this observable is unsubscribed.
+     *
+     * @param characteristicUuid Characteristic UUID for indication setup.
+     * @return Observable emitting another observable when the indication setup is complete.
+     * @throws BleCharacteristicNotFoundException              if characteristic with given UUID hasn't been found.
+     * @throws BleCannotSetCharacteristicNotificationException if setup process indication setup process fail. This may be an internal
+     *                                                         reason or lack of permissions.
+     */
+    Observable<Observable<byte[]>> setupIndication(@NonNull UUID characteristicUuid);
+
     /**
      * Convenience method for characteristic retrieval. First step is service discovery which is followed by service/characteristic
      * traversal. This is an alias to:
diff --git a/rxandroidble/src/main/java/com/polidea/rxandroidble/internal/connection/RxBleConnectionImpl.java b/rxandroidble/src/main/java/com/polidea/rxandroidble/internal/connection/RxBleConnectionImpl.java
index 1fc4fa88c..20057eca5 100644
--- a/rxandroidble/src/main/java/com/polidea/rxandroidble/internal/connection/RxBleConnectionImpl.java
+++ b/rxandroidble/src/main/java/com/polidea/rxandroidble/internal/connection/RxBleConnectionImpl.java
@@ -27,6 +27,7 @@
 import rx.Observable;
 
 import static android.bluetooth.BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE;
+import static android.bluetooth.BluetoothGattDescriptor.ENABLE_INDICATION_VALUE;
 import static android.bluetooth.BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE;
 import static rx.Observable.create;
 import static rx.Observable.error;
@@ -94,12 +95,37 @@ public Observable<Observable<byte[]>> setupNotification(@NonNull UUID characteri
         }
     }
 
+    @Override
+    public Observable<Observable<byte[]>> setupIndication(@NonNull UUID characteristicUuid) {
+        synchronized (notificationObservableMap) {
+            final Observable<Observable<byte[]>> availableObservable = notificationObservableMap.get(characteristicUuid);
+
+            if (availableObservable != null) {
+                return availableObservable;
+            }
+
+            final Observable<Observable<byte[]>> newObservable = createCharacteristicIndicationObservable(characteristicUuid)
+                    .doOnUnsubscribe(() -> dismissCharacteristicNotification(characteristicUuid))
+                    .map(notificationDescriptorData -> observeOnCharacteristicChangeCallbacks(characteristicUuid))
+                    .replay(1)
+                    .refCount();
+            notificationObservableMap.put(characteristicUuid, newObservable);
+            return newObservable;
+        }
+    }
+
     private Observable<byte[]> createCharacteristicNotificationObservable(UUID characteristicUuid) {
         return getClientConfigurationDescriptor(characteristicUuid)
                 .flatMap(descriptor -> setupCharacteristicNotification(descriptor, true))
                 .flatMap(ObservableUtil::justOnNext);
     }
 
+    private Observable<byte[]> createCharacteristicIndicationObservable(UUID characteristicUuid) {
+        return getClientConfigurationDescriptor(characteristicUuid)
+                .flatMap(descriptor -> setupCharacteristicIndication(descriptor, true))
+                .flatMap(ObservableUtil::justOnNext);
+    }
+
     private void dismissCharacteristicNotification(UUID characteristicUuid) {
 
         synchronized (notificationObservableMap) {
@@ -134,6 +160,18 @@ private Observable<byte[]> setupCharacteristicNotification(BluetoothGattDescript
         }
     }
 
+    @NonNull
+    private Observable<byte[]> setupCharacteristicIndication(BluetoothGattDescriptor bluetoothGattDescriptor, boolean enabled) {
+        final BluetoothGattCharacteristic characteristic = bluetoothGattDescriptor.getCharacteristic();
+
+        if (bluetoothGatt.setCharacteristicNotification(characteristic, enabled)) {
+            return writeDescriptor(bluetoothGattDescriptor, enabled ? ENABLE_INDICATION_VALUE : DISABLE_NOTIFICATION_VALUE)
+                    .onErrorResumeNext(throwable -> error(new BleCannotSetCharacteristicNotificationException(characteristic)));
+        } else {
+            return error(new BleCannotSetCharacteristicNotificationException(characteristic));
+        }
+    }
+
     @NonNull
     private Observable<BluetoothGattDescriptor> getClientConfigurationDescriptor(UUID characteristicUuid) {
         return getCharacteristic(characteristicUuid)