fix: voice call, select audio input device (#7922)

Signed-off-by: fufesou <shuanglongchen@yeah.net>

flutter/lib/common/widgets/audio_input.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_hbb/common.dart';
+import 'package:flutter_hbb/models/platform_model.dart';
+
+typedef AudioINputSetDevice = void Function(String device);
+typedef AudioInputBuilder = Widget Function(
+    List<String> devices, String currentDevice, AudioINputSetDevice setDevice);
+
+class AudioInput extends StatelessWidget {
+  final AudioInputBuilder builder;
+
+  const AudioInput({Key? key, required this.builder}) : super(key: key);
+
+  static String getDefault() {
+    if (isWindows) return translate('System Sound');
+    return '';
+  }
+
+  static Future<String> getValue() async {
+    String device = await bind.mainGetOption(key: 'audio-input');
+    if (device.isNotEmpty) {
+      return device;
+    } else {
+      return getDefault();
+    }
+  }
+
+  static Future<void> setDevice(String device) async {
+    if (device == getDefault()) device = '';
+    await bind.mainSetOption(key: 'audio-input', value: device);
+  }
+
+  static Future<Map<String, Object>> getDevicesInfo() async {
+    List<String> devices = (await bind.mainGetSoundInputs()).toList();
+    if (isWindows) {
+      devices.insert(0, translate('System Sound'));
+    }
+    String current = await getValue();
+    return {'devices': devices, 'current': current};
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return futureBuilder(
+      future: getDevicesInfo(),
+      hasData: (data) {
+        String currentDevice = data['current'];
+        List<String> devices = data['devices'] as List<String>;
+        if (devices.isEmpty) {
+          return const Offstage();
+        }
+        return builder(devices, currentDevice, setDevice);
+      },
+    );
+  }
+}