refactor: 将课程各步骤拆分到 features/lesson/steps/

lesson_flow.dart 保留流程状态、公共脚手架与小组件，预习/听/说/读/写/独立表达六个步骤各自成为 part 文件。代码仅搬移并经 dart format 格式化，无用户可见变化。 Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-16 17:23:26 +09:00
parent 8302977351
commit be70ad2a29
7 changed files with 1097 additions and 1025 deletions
@@ -0,0 +1,151 @@
+part of '../lesson_flow.dart';
+
+class _SpeakingStep extends StatefulWidget {
+  const _SpeakingStep({
+    required this.state,
+    required this.text,
+    required this.keepRecording,
+    required this.onContinue,
+  });
+  final String text;
+  final AppState state;
+  final bool keepRecording;
+  final VoidCallback onContinue;
+
+  @override
+  State<_SpeakingStep> createState() => _SpeakingStepState();
+}
+
+class _SpeakingStepState extends State<_SpeakingStep>
+    with VoiceAnswerMixin<_SpeakingStep> {
+  String transcript = '';
+
+  @override
+  AppState get voiceState => widget.state;
+
+  @override
+  void dispose() {
+    disposeVoiceAnswer(keepRecording: widget.keepRecording);
+    super.dispose();
+  }
+
+  Future<void> _toggleMic() async {
+    if (aiVoiceRecording) {
+      await finishVoiceInput(
+        noSpeech: '未识别到清晰发音，请重试或点击“播放示范音”。',
+        onTranscript: (text) => transcript = text,
+      );
+      return;
+    }
+
+    await VoiceService.instance.stopRecordingPlayback();
+    if (mounted) setState(() => playingRecording = false);
+    if (!widget.keepRecording) {
+      await VoiceService.instance.deleteRecording(recordingPath);
+    }
+
+    final recordStarted = await startVoiceInput();
+    if (!recordStarted || !mounted) return;
+    setState(() => recordingPath = null);
+    showVoiceMessage('已启动麦克风录音，跟读完成后再次点击，AI 将自动转写发音。');
+  }
+
+  Future<void> _togglePlayRecording() async {
+    if (playingRecording) {
+      await VoiceService.instance.stopRecordingPlayback();
+      if (mounted) setState(() => playingRecording = false);
+      return;
+    }
+    if (recordingPath == null) {
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(const SnackBar(content: Text('请先使用麦克风跟读，录音完成后即可播放。')));
+      return;
+    }
+    await playRecording();
+  }
+
+  @override
+  Widget build(BuildContext context) => _LessonScaffold(
+    step: 3,
+    child: SpacedColumn(
+      children: [
+        const Eyebrow('跟读'),
+        Text('先听，再说。', style: Theme.of(context).textTheme.headlineMedium),
+        LexiconText(
+          widget.text,
+          state: widget.state,
+          textAlign: TextAlign.center,
+          style: const TextStyle(fontSize: 30, fontWeight: FontWeight.w600),
+        ),
+        Text(
+          '/es - eɪtʃ - iː - en/',
+          style: Theme.of(context).textTheme.bodyMedium,
+        ),
+        SectionCard(
+          tint: AppColors.surfaceMuted,
+          child: _AudioRow(label: '播放示范音', speech: widget.text),
+        ),
+        const SectionCard(
+          tint: AppColors.warm,
+          child: Text(
+            '字母之间留一个短停顿。先清楚，不必快。',
+            style: TextStyle(color: AppColors.warmInk),
+          ),
+        ),
+        SecondaryButton(
+          label: transcribing
+              ? '正在 AI 识别发音…'
+              : (listening ? '停止录音并识别' : '使用麦克风跟读'),
+          onPressed: transcribing ? null : _toggleMic,
+        ),
+        SecondaryButton(
+          label: playingRecording ? '停止播放' : '播放跟读',
+          onPressed: (listening || transcribing) ? null : _togglePlayRecording,
+        ),
+        if (recordingPath != null)
+          SectionCard(
+            tint: AppColors.softGreen,
+            child: SpacedColumn(
+              spacing: 8,
+              children: [
+                Text(widget.keepRecording ? '录音已保存在本机。' : '本次跟读录音仅在离开此步骤前保留。'),
+                Row(
+                  children: [
+                    Expanded(
+                      child: OutlinedButton.icon(
+                        onPressed: (listening || transcribing)
+                            ? null
+                            : _togglePlayRecording,
+                        icon: Icon(
+                          playingRecording ? Icons.stop : Icons.play_arrow,
+                        ),
+                        label: Text(playingRecording ? '停止播放' : '播放跟读'),
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    IconButton(
+                      tooltip: '删除录音',
+                      onPressed: (listening || transcribing)
+                          ? null
+                          : deleteRecording,
+                      icon: const Icon(Icons.delete_outline),
+                    ),
+                  ],
+                ),
+              ],
+            ),
+          ),
+        if (transcript.isNotEmpty)
+          SectionCard(child: Text("设备转写：$transcript\n请确认它是否接近你刚才说的内容。")),
+        const SectionCard(
+          child: Text('转写不确定或与原句不符时，可重说或继续文字练习；这一步只算跟读练习，不作为独立口语证据。'),
+        ),
+        PrimaryButton(
+          label: transcript.isEmpty ? '我已跟读，继续' : '确认并继续',
+          onPressed: widget.onContinue,
+        ),
+      ],
+    ),
+  );
+}