Initial commit

lib/choose_audio.dart

@@ -0,0 +1,87 @@
+import 'package:audioplayers/audioplayers.dart';
+import 'package:flutter/material.dart';
+
+final audio = {
+  'Airi\'s first tutoring lesson': 'assets/audio/airis_first_tutoring_lesson.mp3',
+  'The helpful pharmacist': 'assets/audio/the_helpful_pharmacist.mp3',
+  'Yamete Kudasai': 'assets/audio/yamete_kudasai.mp3'
+};
+
+class ChooseAudio extends StatefulWidget {
+  String _before;
+
+  ChooseAudio(this._before, {Key? key}) : super(key: key);
+
+  @override
+  State<StatefulWidget> createState() => _ChooseAudioState();
+}
+
+class _ChooseAudioState extends State<ChooseAudio> {
+  final _player = AudioCache(prefix: '');
+  int _playIndex = -1;
+  AudioPlayer? _playing;
+
+  @override
+  Widget build(BuildContext context) {
+    return WillPopScope(
+      onWillPop: () async {
+        Navigator.pop(context, widget._before);
+        return true;
+      },
+      child: Scaffold(
+        appBar: AppBar(
+          title: const Text('Choose audio')
+        ),
+        body: ListView.separated(
+          itemBuilder: (BuildContext context, int index) {
+            MapEntry<String, String> item = audio.entries.elementAt(index);
+            if (index == _playIndex) {
+              if (_playing == null) {
+                play(item.value);
+              } else {
+                _playing!.stop().then((value) => play(item.value));
+              }
+            }
+            return ListTile(
+              leading: Radio(
+                activeColor: Theme.of(context).colorScheme.secondary,
+                value: item.value,
+                groupValue: widget._before,
+                onChanged: (String? value) {
+                  setState(() {
+                    widget._before = value!;
+                  });
+                }),
+              title: Text(item.key),
+              trailing: Icon(_playIndex == index ? Icons.stop_outlined : Icons.play_arrow_outlined),
+              onTap: () {
+                setState(() {
+                  _playIndex = index;
+                });
+              },
+            );
+          },
+          separatorBuilder: (BuildContext context, int index) => const Divider(),
+          itemCount: audio.length
+        ),
+      ),
+    );
+  }
+
+  @override
+  void dispose() {
+    if (_playing != null) {
+      _playing!.stop();
+    }
+    super.dispose();
+  }
+
+  void play(String path) async {
+    _playing = await _player.play(path);
+    _playing!.onPlayerCompletion.listen((event) {
+      setState(() {
+        _playIndex = -1;
+      });
+    });
+  }
+}