Creating UI binding platform as dart interface.

PiperOrigin-RevId: 543851724

fastpair/dart/binding/BUILD

@@ -0,0 +1,34 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+load("//dart:build_defs.bzl", "dart_library", "dart_package")
+
+dart_package(sound_null_safety = True)
+
+dart_library(
+    name = "fast_pair_mapping",
+    srcs = glob(["lib/**/*.dart"]),
+    required_libs = [
+        "isolate",
+        "ffi",
+    ],
+    visibility = [
+        "//fastpair/dart:__subpackages__",
+        "//location/nearby/apps/better_together/app/fast_pair:__subpackages__",
+    ],
+    deps = [
+        "//fastpair/dart/proto:fastpair_dart_proto",
+        "//third_party/dart/auto_disposable",
+    ],
+)

fastpair/dart/binding/lib/fast_pair_mapping.dart

@@ -0,0 +1,104 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'dart:ffi';
+import 'device_metadata.dart';
+import 'dart:typed_data';
+
+import 'package:auto_disposable/auto_disposable.dart';
+
+import 'listener.dart';
+import 'bindings.dart';
+import 'ffi_types.dart';
+
+import 'package:third_party.nearby.fastpair.dart.proto/callbacks.pb.dart'
+    as proto;
+import 'package:third_party.nearby.fastpair.dart.proto/enum.pb.dart'
+    as enumproto;
+
+class FastPairMapping with AutoDisposerMixin {
+  final binding = FastpairBinding();
+  late final Pointer<Uint64> _fastpairPointer;
+
+  FastPairMapping._internal() {
+    final result = binding.initializeApi(NativeApi.initializeApiDLData);
+    if (result != 0) {
+      throw 'failed to init API.';
+    }
+    _fastpairPointer = binding.initMediator();
+    if (_fastpairPointer == nullptr) {
+      throw 'initMediator failed: _fastpairPointer is null.';
+    }
+    autoDisposeCustom(() => binding.closeMediator(_fastpairPointer));
+  }
+  static final _instance = FastPairMapping._internal();
+
+  factory FastPairMapping() => _instance;
+
+  void startScan() {
+    binding.startFastPairScanning(_fastpairPointer);
+  }
+
+  Listener addNotificationControllerObserver(
+      OnMetadataChanged onMetadataChanged) {
+    final listener = Listener();
+
+    listener.onData((data) {
+      if (data is Uint8List) {
+        final params = proto.DeviceDownloadedCallbackData.fromBuffer(data);
+        onMetadataChanged(
+          deviceMetadata: List<DeviceMetadata>.from(
+            params.devices.map(
+              (device) => DeviceMetadata(
+                  id: device.id.toString(),
+                  name: device.name,
+                  imageUrl: device.imageUrl),
+            ),
+          ),
+        );
+      }
+    });
+
+    binding.addNotificationControllerObserver(_fastpairPointer, listener.port);
+
+    return listener;
+  }
+
+  void removeNotificationControllerObserver(dynamic listener) {
+    binding.removeNotificationControllerObserver(
+      _fastpairPointer,
+      listener.port,
+    );
+  }
+
+  void connectClicked() {
+    binding.discoveryClicked(_fastpairPointer,
+        enumproto.DiscoveryAction.DISCOVERY_ACTION_PAIR_TO_DEVICE.value);
+  }
+
+  void learnMoreClicked() {
+    binding.discoveryClicked(_fastpairPointer,
+        enumproto.DiscoveryAction.DISCOVERY_ACTION_LEARN_MORE.value);
+  }
+
+  void dismissedByUserClicked() {
+    binding.discoveryClicked(_fastpairPointer,
+        enumproto.DiscoveryAction.DISCOVERY_ACTION_DISMISSED_BY_USER.value);
+  }
+
+  void unknownAction() {
+    binding.discoveryClicked(_fastpairPointer,
+        enumproto.DiscoveryAction.DISCOVERY_ACTION_UNKNOWN.value);
+  }
+}

fastpair/dart/binding/lib/listener.dart

@@ -15,7 +15,7 @@
 import 'dart:ffi';
 import 'dart:isolate';
 
-import 'package:mobile.flutter.contrib.disposable/disposable.dart';
+import 'package:auto_disposable/auto_disposable.dart';
 
 /// A convenience class for listening to a [ReceivePort].
 ///