// 设置语音播报对象
var Voice = function() {
	this.speak = window.speechSynthesis;
	this.voice = '';
	this.zh_CN = false;
	this._setLang();	// 获取并检测是否有中文的环境
};

// 播报语音		(调用发声的方法时请使用延时发声)
Voice.prototype.play = function(txt) {
	if(!this.zh_CN) {
		console.info('你的电脑不支持中文播报！');		
	}
	console.info(this.zh_CN);
	this.cancel();
	var to_speak = new SpeechSynthesisUtterance(txt);
	to_speak.voice = this.voice;	// 设定中文播报

	this.speak.speak(to_speak);
	
};

// 退出当前播报
Voice.prototype.cancel = function() {
	this.speak.cancel();
};

// 检查当前语言环境
Voice.prototype._setLang = function() {
	var _this = this;
	setTimeout(function(){
		var voices = _this.speak.getVoices();
		for(var i=0; i<voices.length; i++) {
			var _voices = voices[0];
			//console.info(_voices);
			if(_voices.lang === 'zh-CN') {
				_this.zh_CN = true;
				_this.voice = _voices;
			}
		}
	}, 0);
};

var voice = new Voice();