Add GattServer#NotifyCharacteristicChanged to ble_v2

PiperOrigin-RevId: 512124578

internal/platform/ble_v2.h

@@ -148,6 +148,7 @@ class BleV2ServerSocket final {
 //
 // Note that some of the methods return absl::optional instead
 // of std::optional, because iOS platform is still in C++14.
+// LINT.IfChange
 class GattServer final {
  public:
   explicit GattServer(std::unique_ptr<api::ble_v2::GattServer> gatt_server)
@@ -171,6 +172,13 @@ class GattServer final {
     return impl_->UpdateCharacteristic(characteristic, value);
   }
 
+  absl::Status NotifyCharacteristicChanged(
+      const api::ble_v2::GattCharacteristic& characteristic, bool confirm,
+      const ByteArray& new_value) {
+    return impl_->NotifyCharacteristicChanged(characteristic, confirm,
+                                              new_value);
+  }
+
   void Stop() {
     if (impl_) return impl_->Stop();
   }
@@ -187,6 +195,7 @@ class GattServer final {
  private:
   std::unique_ptr<api::ble_v2::GattServer> impl_;
 };
+// LINT.ThenChange(//depot/google3/third_party/nearby/internal/platform/implementation/ble_v2.h)
 
 // Opaque wrapper for a GattClient.
 //

internal/platform/ble_v2_test.cc

@@ -532,5 +532,32 @@ TEST_F(BleV2MediumTest, GattClientConnectToGattServerWorks) {
   env_.Stop();
 }
 
+TEST_F(BleV2MediumTest, GattServerCanNotifyChange) {
+  env_.Start();
+  BluetoothAdapter adapter_a;
+  BleV2Medium ble_a(adapter_a);
+  Uuid service_uuid(1234, 5678);
+  Uuid characteristic_uuid(5678, 1234);
+  std::vector<GattCharacteristic::Permission> permissions = {
+      GattCharacteristic::Permission::kRead};
+  std::vector<GattCharacteristic::Property> properties = {
+      GattCharacteristic::Property::kRead};
+
+  // Start GattServer
+  std::unique_ptr<GattServer> gatt_server =
+      ble_a.StartGattServer(/*ServerGattConnectionCallback=*/{});
+
+  ASSERT_NE(gatt_server, nullptr);
+  // Add characteristic and its value.
+  // NOLINTNEXTLINE(google3-legacy-absl-backports)
+  absl::optional<GattCharacteristic> server_characteristic =
+      gatt_server->CreateCharacteristic(service_uuid, characteristic_uuid,
+                                        permissions, properties);
+
+  EXPECT_THAT(gatt_server->NotifyCharacteristicChanged(
+                  server_characteristic.value(), false, ByteArray("hello")),
+              testing::status::StatusIs(absl::StatusCode::kUnimplemented));
+}
+
 }  // namespace
 }  // namespace nearby

internal/platform/implementation/apple/ble.h

@@ -157,6 +157,8 @@ class BleMedium : public api::ble_v2::BleMedium {
 
     bool UpdateCharacteristic(const api::ble_v2::GattCharacteristic &characteristic,
                               const nearby::ByteArray &value) override;
+    absl::Status NotifyCharacteristicChanged(const api::ble_v2::GattCharacteristic &characteristic,
+                                             bool confirm, const ByteArray &new_value) override;
     void Stop() override;
 
    private:

internal/platform/implementation/apple/ble.mm

@@ -511,6 +511,13 @@ bool BleMedium::GattServer::UpdateCharacteristic(
   return true;
 }
 
+absl::Status BleMedium::GattServer::NotifyCharacteristicChanged(
+    const api::ble_v2::GattCharacteristic& characteristic, bool confirm,
+    const ByteArray& new_value) {
+  // no-op because client cannot request notifications.
+  return absl::UnimplementedError("Unimplemented!");
+}
+
 void BleMedium::GattServer::Stop() { [peripheral_ stopGATTService]; }
 
 bool BleMedium::GattClient::DiscoverServiceAndCharacteristics(

internal/platform/implementation/ble_v2.h

@@ -194,6 +194,7 @@ class GattClient {
 // https://developer.android.com/reference/android/bluetooth/BluetoothGattServer
 //
 // Representation of a BLE GATT server.
+// LINT.IfChange
 class GattServer {
  public:
   virtual ~GattServer() = default;
@@ -223,9 +224,18 @@ class GattServer {
   virtual bool UpdateCharacteristic(const GattCharacteristic& characteristic,
                                     const nearby::ByteArray& value) = 0;
 
+  // https://developer.android.com/reference/android/bluetooth/BluetoothGattServer#notifyCharacteristicChanged(android.bluetooth.BluetoothDevice,%20android.bluetooth.BluetoothGattCharacteristic,%20boolean,%20byte[])
+  //
+  // Send a notification or indication that a local characteristic has been
+  // updated and returns an absl::Status indicating success or what went wrong.
+  virtual absl::Status NotifyCharacteristicChanged(
+      const GattCharacteristic& characteristic, bool confirm,
+      const ByteArray& new_value) = 0;
+
   // Stops a GATT server.
   virtual void Stop() = 0;
 };
+// LINT.ThenChange(//depot/google3/third_party/nearby/internal/platform/ble_v2.h)
 
 // Callback for asynchronous events on the client side of a GATT connection.
 struct ClientGattConnectionCallback {

internal/platform/implementation/g3/ble_v2.cc

@@ -375,6 +375,14 @@ bool BleV2Medium::GattServer::UpdateCharacteristic(
   return true;
 }
 
+absl::Status BleV2Medium::GattServer::NotifyCharacteristicChanged(
+    const api::ble_v2::GattCharacteristic& characteristic, bool confirm,
+    const ByteArray& new_value) {
+  // check if client has requested notifications.
+  // no-op for now because client cannot request notifications.
+  return absl::UnimplementedError("Unimplemented!");
+}
+
 void BleV2Medium::GattServer::Stop() {
   NEARBY_LOGS(INFO) << "G3 Ble GattServer Stop";
   MediumEnvironment::Instance().ClearBleV2MediumGattCharacteristics();

internal/platform/implementation/g3/ble_v2.h

@@ -220,6 +220,10 @@ class BleV2Medium : public api::ble_v2::BleMedium {
         const api::ble_v2::GattCharacteristic& characteristic,
         const nearby::ByteArray& value) override;
 
+    absl::Status NotifyCharacteristicChanged(
+        const api::ble_v2::GattCharacteristic& characteristic, bool confirm,
+        const ByteArray& new_value) override;
+
     void Stop() override;
   };