Add server-side callback for change in MTU (4/4)

When a client requests to update the LE transport MTU, the server
currently does not get notified and can therefor not properly size
notifications appropriate to the current MTU.

Bug: 18388114
Change-Id: I515bfc2cc9846490d57de71860f41ea9a61fa243

3 files changed, 31 insertions, 0 deletions

diff --git a/framework/java/android/bluetooth/BluetoothGattServer.java b/framework/java/android/bluetooth/BluetoothGattServer.java
index e94a8cea21..f4513405b1 100644
--- a/framework/java/android/bluetooth/BluetoothGattServer.java
+++ b/framework/java/android/bluetooth/BluetoothGattServer.java
@@ -284,6 +284,24 @@ public final class BluetoothGattServer implements BluetoothProfile {
                     Log.w(TAG, "Unhandled exception: " + ex);
                 }
             }
+
+            /**
+             * The MTU for a connection has changed
+             * @hide
+             */
+            public void onMtuChanged(String address, int mtu) {
+                if (DBG) Log.d(TAG, "onMtuChanged() - "
+                    + "device=" + address + ", mtu=" + mtu);
+
+                BluetoothDevice device = mAdapter.getRemoteDevice(address);
+                if (device == null) return;
+
+                try {
+                    mCallback.onMtuChanged(device, mtu);
+                } catch (Exception ex) {
+                    Log.w(TAG, "Unhandled exception: " + ex);
+                }
+            }
         };
 
     /**
diff --git a/framework/java/android/bluetooth/BluetoothGattServerCallback.java b/framework/java/android/bluetooth/BluetoothGattServerCallback.java
index 1dd06f2ce1..2afcf9a322 100644
--- a/framework/java/android/bluetooth/BluetoothGattServerCallback.java
+++ b/framework/java/android/bluetooth/BluetoothGattServerCallback.java
@@ -145,4 +145,16 @@ public abstract class BluetoothGattServerCallback {
      */
     public void onNotificationSent(BluetoothDevice device, int status) {
     }
+
+    /**
+     * Callback indicating the MTU for a given device connection has changed.
+     *
+     * <p>This callback will be invoked if a remote client has requested to change
+     * the MTU for a given connection.
+     *
+     * @param device The remote device that requested the MTU change
+     * @param mtu The new MTU size
+     */
+    public void onMtuChanged(BluetoothDevice device, int mtu) {
+    }
 }
diff --git a/framework/java/android/bluetooth/IBluetoothGattServerCallback.aidl b/framework/java/android/bluetooth/IBluetoothGattServerCallback.aidl
index 5d4d6c63ef..8b202b23cc 100644
--- a/framework/java/android/bluetooth/IBluetoothGattServerCallback.aidl
+++ b/framework/java/android/bluetooth/IBluetoothGattServerCallback.aidl
@@ -59,4 +59,5 @@ oneway interface IBluetoothGattServerCallback {
                                      in byte[] value);
     void onExecuteWrite(in String address, in int transId, in boolean execWrite);
     void onNotificationSent(in String address, in int status);
+    void onMtuChanged(in String address, in int mtu);
 }