o2oa-flutter/lib/common/utils/flutter_tts.dart

import 'dart:io';

import 'package:flutter_tts/flutter_tts.dart';

import '../models/index.dart';
import 'log_util.dart';



class FlutterTTSHelper {
  // 单例
  static final FlutterTTSHelper instance = FlutterTTSHelper._internal();
  factory FlutterTTSHelper() => instance;
  FlutterTTSHelper._internal();

  final FlutterTts _tts = FlutterTts();

  TtsState ttsState = TtsState.stopped;

  /// 初始化
  Future<void> init() async {
    await _tts.awaitSpeakCompletion(true);

    await _tts.setLanguage("zh-CN"); // 语言

    await _tts.setSpeechRate(0.5); // 语速

    await _tts.setVolume(0.8); // 声音

    _tts.setStartHandler(() {
      OLogger.i('FlutterTts start playing ......');
      ttsState = TtsState.playing;
    });

    _tts.setCompletionHandler(() {
      OLogger.i('FlutterTts play completion ......');
      ttsState = TtsState.stopped;
    });

    _tts.setCancelHandler(() {
      OLogger.i('FlutterTts cancel play ......');
      ttsState = TtsState.stopped;
    });

    _tts.setPauseHandler(() {
      OLogger.i('FlutterTts paused play ......');
      ttsState = TtsState.paused;
    });

    _tts.setContinueHandler(() {
      OLogger.i('FlutterTts Continue play ......');
      ttsState = TtsState.continued;
    });

    _tts.setErrorHandler((msg) {
      OLogger.e('FlutterTts error $msg');
      ttsState = TtsState.stopped;
    });
    OLogger.i('TTS init completed！');
  }

  /// 当前状态
  TtsState currentState() {
    return ttsState;
  }

  /// 开始说话
  Future<void> speak(String msg) async {
    if (ttsState != TtsState.stopped) {
      await stop();
    }
    if (Platform.isIOS) {
      await _tts.setSharedInstance(true);
      await _tts.setIosAudioCategory(IosTextToSpeechAudioCategory.ambientSolo, [IosTextToSpeechAudioCategoryOptions.defaultToSpeaker]);
    }
    final result = await _tts.speak(msg);
    OLogger.i('用户指令 TTS speak $result');
  }

  /// 结束说话
  Future<void> stop() async {
    final result = await _tts.stop();
    OLogger.i('用户指令 TTS  stoped $result');
  }
 
}