Bug 1140951 - Implement start/stopNotifications for GATT client API. r=shuang, r=mrbkap

dom/bluetooth2/BluetoothGattCharacteristic.cpp

@@ -4,6 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "BluetoothReplyRunnable.h"
 #include "BluetoothService.h"
 #include "BluetoothUtils.h"
 #include "mozilla/dom/BluetoothGattCharacteristicBinding.h"
@@ -12,6 +13,7 @@
 #include "mozilla/dom/bluetooth/BluetoothGattDescriptor.h"
 #include "mozilla/dom/bluetooth/BluetoothGattService.h"
 #include "mozilla/dom/bluetooth/BluetoothTypes.h"
+#include "mozilla/dom/Promise.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -58,6 +60,64 @@ BluetoothGattCharacteristic::~BluetoothGattCharacteristic()
   bs->UnregisterBluetoothSignalHandler(path, this);
 }
 
+already_AddRefed<Promise>
+BluetoothGattCharacteristic::StartNotifications(ErrorResult& aRv)
+{
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  if (!global) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  nsRefPtr<Promise> promise = Promise::Create(global, aRv);
+  NS_ENSURE_TRUE(!aRv.Failed(), nullptr);
+
+  BluetoothService* bs = BluetoothService::Get();
+  BT_ENSURE_TRUE_REJECT(bs, NS_ERROR_NOT_AVAILABLE);
+  BT_ENSURE_TRUE_REJECT(mService, NS_ERROR_NOT_AVAILABLE);
+
+  nsRefPtr<BluetoothReplyRunnable> result =
+    new BluetoothVoidReplyRunnable(
+      nullptr /* DOMRequest */,
+      promise,
+      NS_LITERAL_STRING("GattClientStartNotifications"));
+  bs->GattClientStartNotificationsInternal(mService->GetAppUuid(),
+                                           mService->GetServiceId(),
+                                           mCharId,
+                                           result);
+
+  return promise.forget();
+}
+
+already_AddRefed<Promise>
+BluetoothGattCharacteristic::StopNotifications(ErrorResult& aRv)
+{
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  if (!global) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  nsRefPtr<Promise> promise = Promise::Create(global, aRv);
+  NS_ENSURE_TRUE(!aRv.Failed(), nullptr);
+
+  BluetoothService* bs = BluetoothService::Get();
+  BT_ENSURE_TRUE_REJECT(bs, NS_ERROR_NOT_AVAILABLE);
+  BT_ENSURE_TRUE_REJECT(mService, NS_ERROR_NOT_AVAILABLE);
+
+  nsRefPtr<BluetoothReplyRunnable> result =
+    new BluetoothVoidReplyRunnable(
+      nullptr /* DOMRequest */,
+      promise,
+      NS_LITERAL_STRING("GattClientStopNotifications"));
+  bs->GattClientStopNotificationsInternal(mService->GetAppUuid(),
+                                          mService->GetServiceId(),
+                                          mCharId,
+                                          result);
+
+  return promise.forget();
+}
+
 void
 BluetoothGattCharacteristic::HandleDescriptorsDiscovered(
   const BluetoothValue& aValue)

dom/bluetooth2/BluetoothGattCharacteristic.h

@@ -15,6 +15,12 @@
 #include "nsWrapperCache.h"
 #include "nsPIDOMWindow.h"
 
+namespace mozilla {
+namespace dom {
+class Promise;
+}
+}
+
 BEGIN_BLUETOOTH_NAMESPACE
 
 class BluetoothGattService;
@@ -53,6 +59,12 @@ public:
     return mCharId.mInstanceId;
   }
 
+  /****************************************************************************
+   * Methods (Web API Implementation)
+   ***************************************************************************/
+  already_AddRefed<Promise> StartNotifications(ErrorResult& aRv);
+  already_AddRefed<Promise> StopNotifications(ErrorResult& aRv);
+
   /****************************************************************************
    * Others
    ***************************************************************************/

dom/bluetooth2/BluetoothService.h

@@ -372,6 +372,26 @@ public:
   DiscoverGattServicesInternal(const nsAString& aAppUuid,
                                BluetoothReplyRunnable* aRunnable) = 0;
 
+  /**
+   * Enable notifications of a given GATT characteristic.
+   * (platform specific implementation)
+   */
+  virtual void
+  GattClientStartNotificationsInternal(const nsAString& aAppUuid,
+                                       const BluetoothGattServiceId& aServId,
+                                       const BluetoothGattId& aCharId,
+                                       BluetoothReplyRunnable* aRunnable) = 0;
+
+  /**
+   * Disable notifications of a given GATT characteristic.
+   * (platform specific implementation)
+   */
+  virtual void
+  GattClientStopNotificationsInternal(const nsAString& aAppUuid,
+                                      const BluetoothGattServiceId& aServId,
+                                      const BluetoothGattId& aCharId,
+                                      BluetoothReplyRunnable* aRunnable) = 0;
+
   /**
    * Unregister a GATT client. (platform specific implementation)
    */

dom/bluetooth2/bluedroid/BluetoothGattManager.cpp

@@ -58,6 +58,8 @@ public:
     mDiscoverRunnable = nullptr;
     mUnregisterClientRunnable = nullptr;
     mReadRemoteRssiRunnable = nullptr;
+    mRegisterNotificationsRunnable = nullptr;
+    mDeregisterNotificationsRunnable = nullptr;
   }
 
   void NotifyDiscoverCompleted(bool aSuccess)
@@ -98,6 +100,8 @@ public:
   nsRefPtr<BluetoothReplyRunnable> mDisconnectRunnable;
   nsRefPtr<BluetoothReplyRunnable> mDiscoverRunnable;
   nsRefPtr<BluetoothReplyRunnable> mReadRemoteRssiRunnable;
+  nsRefPtr<BluetoothReplyRunnable> mRegisterNotificationsRunnable;
+  nsRefPtr<BluetoothReplyRunnable> mDeregisterNotificationsRunnable;
   nsRefPtr<BluetoothReplyRunnable> mUnregisterClientRunnable;
 
   /**
@@ -636,6 +640,151 @@ BluetoothGattManager::ReadRemoteRssi(int aClientIf,
     new ReadRemoteRssiResultHandler(client));
 }
 
+class BluetoothGattManager::RegisterNotificationsResultHandler final
+  : public BluetoothGattClientResultHandler
+{
+public:
+  RegisterNotificationsResultHandler(BluetoothGattClient* aClient)
+  : mClient(aClient)
+  {
+    MOZ_ASSERT(mClient);
+  }
+
+  void RegisterNotification() override
+  {
+    MOZ_ASSERT(mClient->mRegisterNotificationsRunnable);
+
+    /**
+     * Resolve the promise directly if we successfully issued this request to
+     * stack.
+     *
+     * We resolve the promise here since bluedroid stack always returns
+     * incorrect connId in |RegisterNotificationNotification| and we cannot map
+     * back to the target client because of it.
+     * Please see Bug 1149043 for more information.
+     */
+    DispatchReplySuccess(mClient->mRegisterNotificationsRunnable);
+    mClient->mRegisterNotificationsRunnable = nullptr;
+  }
+
+  void OnError(BluetoothStatus aStatus) override
+  {
+    BT_WARNING(
+      "BluetoothGattClientInterface::RegisterNotifications failed: %d",
+      (int)aStatus);
+    MOZ_ASSERT(mClient->mRegisterNotificationsRunnable);
+
+    DispatchReplyError(mClient->mRegisterNotificationsRunnable,
+                       NS_LITERAL_STRING("RegisterNotifications failed"));
+    mClient->mRegisterNotificationsRunnable = nullptr;
+  }
+
+private:
+  nsRefPtr<BluetoothGattClient> mClient;
+};
+
+void
+BluetoothGattManager::RegisterNotifications(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aRunnable);
+
+  ENSURE_GATT_CLIENT_INTF_IS_READY_VOID(aRunnable);
+
+  size_t index = sClients->IndexOf(aAppUuid, 0 /* Start */, UuidComparator());
+  MOZ_ASSERT(index != sClients->NoIndex);
+
+  nsRefPtr<BluetoothGattClient> client = sClients->ElementAt(index);
+
+  // Reject the request if there is an ongoing request or client is already
+  // disconnected
+  if (client->mRegisterNotificationsRunnable || client->mConnId <= 0) {
+    DispatchReplyError(aRunnable,
+                       NS_LITERAL_STRING("RegisterNotifications failed"));
+    return;
+  }
+
+  client->mRegisterNotificationsRunnable = aRunnable;
+
+  sBluetoothGattClientInterface->RegisterNotification(
+    client->mClientIf, client->mDeviceAddr, aServId, aCharId,
+    new RegisterNotificationsResultHandler(client));
+}
+
+class BluetoothGattManager::DeregisterNotificationsResultHandler final
+  : public BluetoothGattClientResultHandler
+{
+public:
+  DeregisterNotificationsResultHandler(BluetoothGattClient* aClient)
+  : mClient(aClient)
+  {
+    MOZ_ASSERT(mClient);
+  }
+
+  void DeregisterNotification() override
+  {
+    MOZ_ASSERT(mClient->mDeregisterNotificationsRunnable);
+
+    /**
+     * Resolve the promise directly if we successfully issued this request to
+     * stack.
+     *
+     * We resolve the promise here since bluedroid stack always returns
+     * incorrect connId in |RegisterNotificationNotification| and we cannot map
+     * back to the target client because of it.
+     * Please see Bug 1149043 for more information.
+     */
+    DispatchReplySuccess(mClient->mDeregisterNotificationsRunnable);
+    mClient->mDeregisterNotificationsRunnable = nullptr;
+  }
+
+  void OnError(BluetoothStatus aStatus) override
+  {
+    BT_WARNING(
+      "BluetoothGattClientInterface::DeregisterNotifications failed: %d",
+      (int)aStatus);
+    MOZ_ASSERT(mClient->mDeregisterNotificationsRunnable);
+
+    DispatchReplyError(mClient->mDeregisterNotificationsRunnable,
+                       NS_LITERAL_STRING("DeregisterNotifications failed"));
+    mClient->mDeregisterNotificationsRunnable = nullptr;
+  }
+
+private:
+  nsRefPtr<BluetoothGattClient> mClient;
+};
+
+void
+BluetoothGattManager::DeregisterNotifications(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aRunnable);
+
+  ENSURE_GATT_CLIENT_INTF_IS_READY_VOID(aRunnable);
+
+  size_t index = sClients->IndexOf(aAppUuid, 0 /* Start */, UuidComparator());
+  MOZ_ASSERT(index != sClients->NoIndex);
+
+  nsRefPtr<BluetoothGattClient> client = sClients->ElementAt(index);
+
+  // Reject the request if there is an ongoing request
+  if (client->mDeregisterNotificationsRunnable) {
+    DispatchReplyError(aRunnable,
+                       NS_LITERAL_STRING("DeregisterNotifications failed"));
+    return;
+  }
+
+  client->mDeregisterNotificationsRunnable = aRunnable;
+
+  sBluetoothGattClientInterface->DeregisterNotification(
+    client->mClientIf, client->mDeviceAddr, aServId, aCharId,
+    new DeregisterNotificationsResultHandler(client));
+}
+
 //
 // Notification Handlers
 //
@@ -999,7 +1148,25 @@ BluetoothGattManager::RegisterNotificationNotification(
   int aConnId, int aIsRegister, BluetoothGattStatus aStatus,
   const BluetoothGattServiceId& aServiceId,
   const BluetoothGattId& aCharId)
-{ }
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  BT_LOGD("aStatus = %d, aConnId = %d, aIsRegister = %d",
+          aStatus, aConnId, aIsRegister);
+
+  /**
+   * FIXME: Bug 1149043
+   *
+   * aConnId reported by bluedroid stack is wrong, with these limited
+   * information we have, we currently cannot map back to the client from this
+   * callback. Therefore, we resolve/reject the Promise for registering or
+   * deregistering notifications in their result handlers instead of this
+   * callback.
+   * We should resolve/reject the Promise for registering or deregistering
+   * notifications here if this bluedroid stack bug is fixed.
+   *
+   * Please see Bug 1149043 for more information.
+   */
+}
 
 void
 BluetoothGattManager::NotifyNotification(

dom/bluetooth2/bluedroid/BluetoothGattManager.h

@@ -46,6 +46,16 @@ public:
                       const nsAString& aDeviceAddr,
                       BluetoothReplyRunnable* aRunnable);
 
+  void RegisterNotifications(const nsAString& aAppUuid,
+                             const BluetoothGattServiceId& aServId,
+                             const BluetoothGattId& aCharId,
+                             BluetoothReplyRunnable* aRunnable);
+
+  void DeregisterNotifications(const nsAString& aAppUuid,
+                               const BluetoothGattServiceId& aServId,
+                               const BluetoothGattId& aCharId,
+                               BluetoothReplyRunnable* aRunnable);
+
 private:
   class CleanupResultHandler;
   class CleanupResultHandlerRunnable;
@@ -56,6 +66,8 @@ private:
   class DisconnectResultHandler;
   class DiscoverResultHandler;
   class ReadRemoteRssiResultHandler;
+  class RegisterNotificationsResultHandler;
+  class DeregisterNotificationsResultHandler;
 
   BluetoothGattManager();
 

dom/bluetooth2/bluedroid/BluetoothServiceBluedroid.cpp

@@ -1148,6 +1148,36 @@ BluetoothServiceBluedroid::DiscoverGattServicesInternal(
   gatt->Discover(aAppUuid, aRunnable);
 }
 
+void
+BluetoothServiceBluedroid::GattClientStartNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  ENSURE_BLUETOOTH_IS_READY_VOID(aRunnable);
+
+  BluetoothGattManager* gatt = BluetoothGattManager::Get();
+  ENSURE_GATT_MGR_IS_READY_VOID(gatt, aRunnable);
+
+  gatt->RegisterNotifications(aAppUuid, aServId, aCharId, aRunnable);
+}
+
+void
+BluetoothServiceBluedroid::GattClientStopNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  ENSURE_BLUETOOTH_IS_READY_VOID(aRunnable);
+
+  BluetoothGattManager* gatt = BluetoothGattManager::Get();
+  ENSURE_GATT_MGR_IS_READY_VOID(gatt, aRunnable);
+
+  gatt->DeregisterNotifications(aAppUuid, aServId, aCharId, aRunnable);
+}
+
 void
 BluetoothServiceBluedroid::UnregisterGattClientInternal(
   int aClientIf, BluetoothReplyRunnable* aRunnable)

dom/bluetooth2/bluedroid/BluetoothServiceBluedroid.h

@@ -203,6 +203,20 @@ public:
   DiscoverGattServicesInternal(const nsAString& aAppUuid,
                                BluetoothReplyRunnable* aRunnable) override;
 
+  virtual void
+  GattClientStartNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
+  virtual void
+  GattClientStopNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
   virtual void
   UnregisterGattClientInternal(int aClientIf,
                                BluetoothReplyRunnable* aRunnable) override;

dom/bluetooth2/bluez/BluetoothDBusService.cpp

@@ -4301,6 +4301,20 @@ BluetoothDBusService::DiscoverGattServicesInternal(
 {
 }
 
+void
+BluetoothDBusService::GattClientStartNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+}
+
+void
+BluetoothDBusService::GattClientStopNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+}
+
 void
 BluetoothDBusService::UnregisterGattClientInternal(
   int aClientIf, BluetoothReplyRunnable* aRunnable)

dom/bluetooth2/bluez/BluetoothDBusService.h

@@ -213,6 +213,20 @@ public:
   DiscoverGattServicesInternal(const nsAString& aAppUuid,
                                BluetoothReplyRunnable* aRunnable) override;
 
+  virtual void
+  GattClientStartNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
+  virtual void
+  GattClientStopNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
   virtual void
   UnregisterGattClientInternal(int aClientIf,
                                BluetoothReplyRunnable* aRunnable) override;

dom/bluetooth2/ipc/BluetoothParent.cpp

@@ -260,6 +260,12 @@ BluetoothParent::RecvPBluetoothRequestConstructor(
       return actor->DoRequest(aRequest.get_DisconnectGattClientRequest());
     case Request::TDiscoverGattServicesRequest:
       return actor->DoRequest(aRequest.get_DiscoverGattServicesRequest());
+    case Request::TGattClientStartNotificationsRequest:
+      return actor->DoRequest(
+        aRequest.get_GattClientStartNotificationsRequest());
+    case Request::TGattClientStopNotificationsRequest:
+      return actor->DoRequest(
+        aRequest.get_GattClientStopNotificationsRequest());
     case Request::TUnregisterGattClientRequest:
       return actor->DoRequest(aRequest.get_UnregisterGattClientRequest());
     case Request::TGattClientReadRemoteRssiRequest:
@@ -765,6 +771,36 @@ BluetoothRequestParent::DoRequest(const DiscoverGattServicesRequest& aRequest)
   return true;
 }
 
+bool
+BluetoothRequestParent::DoRequest(
+  const GattClientStartNotificationsRequest& aRequest)
+{
+  MOZ_ASSERT(mService);
+  MOZ_ASSERT(mRequestType == Request::TGattClientStartNotificationsRequest);
+
+  mService->GattClientStartNotificationsInternal(aRequest.appUuid(),
+                                                 aRequest.servId(),
+                                                 aRequest.charId(),
+                                                 mReplyRunnable.get());
+
+  return true;
+}
+
+bool
+BluetoothRequestParent::DoRequest(
+  const GattClientStopNotificationsRequest& aRequest)
+{
+  MOZ_ASSERT(mService);
+  MOZ_ASSERT(mRequestType == Request::TGattClientStopNotificationsRequest);
+
+  mService->GattClientStopNotificationsInternal(aRequest.appUuid(),
+                                                aRequest.servId(),
+                                                aRequest.charId(),
+                                                mReplyRunnable.get());
+
+  return true;
+}
+
 bool
 BluetoothRequestParent::DoRequest(const UnregisterGattClientRequest& aRequest)
 {

dom/bluetooth2/ipc/BluetoothParent.h

@@ -232,6 +232,12 @@ protected:
   bool
   DoRequest(const DiscoverGattServicesRequest& aRequest);
 
+  bool
+  DoRequest(const GattClientStartNotificationsRequest& aRequest);
+
+  bool
+  DoRequest(const GattClientStopNotificationsRequest& aRequest);
+
   bool
   DoRequest(const UnregisterGattClientRequest& aRequest);
 

dom/bluetooth2/ipc/BluetoothServiceChildProcess.cpp

@@ -427,6 +427,24 @@ BluetoothServiceChildProcess::DiscoverGattServicesInternal(
     DiscoverGattServicesRequest(nsString(aAppUuid)));
 }
 
+void
+BluetoothServiceChildProcess::GattClientStartNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  SendRequest(aRunnable,
+    GattClientStartNotificationsRequest(nsString(aAppUuid), aServId, aCharId));
+}
+
+void
+BluetoothServiceChildProcess::GattClientStopNotificationsInternal(
+  const nsAString& aAppUuid, const BluetoothGattServiceId& aServId,
+  const BluetoothGattId& aCharId, BluetoothReplyRunnable* aRunnable)
+{
+  SendRequest(aRunnable,
+    GattClientStopNotificationsRequest(nsString(aAppUuid), aServId, aCharId));
+}
+
 void
 BluetoothServiceChildProcess::UnregisterGattClientInternal(
   int aClientIf, BluetoothReplyRunnable* aRunnable)

dom/bluetooth2/ipc/BluetoothServiceChildProcess.h

@@ -218,6 +218,20 @@ public:
   DiscoverGattServicesInternal(const nsAString& aAppUuid,
                                BluetoothReplyRunnable* aRunnable) override;
 
+  virtual void
+  GattClientStartNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
+  virtual void
+  GattClientStopNotificationsInternal(
+    const nsAString& aAppUuid,
+    const BluetoothGattServiceId& aServId,
+    const BluetoothGattId& aCharId,
+    BluetoothReplyRunnable* aRunnable) override;
+
   virtual void
   UnregisterGattClientInternal(int aClientIf,
                                BluetoothReplyRunnable* aRunnable) override;

dom/bluetooth2/ipc/BluetoothTypes.ipdlh

@@ -30,7 +30,9 @@ union BluetoothValue
   nsString[];
   uint8_t[];
   BluetoothNamedValue[];
+  BluetoothGattId;
   BluetoothGattId[];
+  BluetoothGattServiceId;
   BluetoothGattServiceId[];
 };
 

dom/bluetooth2/ipc/PBluetooth.ipdl

@@ -207,6 +207,20 @@ struct DiscoverGattServicesRequest
   nsString appUuid;
 };
 
+struct GattClientStartNotificationsRequest
+{
+  nsString appUuid;
+  BluetoothGattServiceId servId;
+  BluetoothGattId charId;
+};
+
+struct GattClientStopNotificationsRequest
+{
+  nsString appUuid;
+  BluetoothGattServiceId servId;
+  BluetoothGattId charId;
+};
+
 struct UnregisterGattClientRequest
 {
   int clientIf;
@@ -255,6 +269,8 @@ union Request
   ConnectGattClientRequest;
   DisconnectGattClientRequest;
   DiscoverGattServicesRequest;
+  GattClientStartNotificationsRequest;
+  GattClientStopNotificationsRequest;
   UnregisterGattClientRequest;
   GattClientReadRemoteRssiRequest;
 };

dom/webidl/BluetoothGattCharacteristic.webidl

@@ -13,4 +13,13 @@ interface BluetoothGattCharacteristic
 
   readonly attribute DOMString                              uuid;
   readonly attribute unsigned short                         instanceId;
+
+  /**
+   * Start or stop subscribing notifications of this characteristic from the
+   * remote GATT server.
+   */
+  [NewObject]
+  Promise<void> startNotifications();
+  [NewObject]
+  Promise<void> stopNotifications();
 };