简单的HTML5音乐播放器(带歌词滚动)

 

首先需要整理好lrc格式的歌词放到script标签中以供程序处理。然后把音乐链接放到audio的src属性里就可以了。

源码：

HTML部分

<div class="container">
     <audio id="player" src="test.mp3" loop controls preload></audio>
     <div id="lrcArea"></div>
</div>

<script id="lrc" type="text">
//lrc歌词
</script>

JS部分

var musicPlayer = function() {
    return this.init.apply(this, arguments);
};

musicPlayer.prototype = {
    constructor: musicPlayer,
    init: function(options) {
        if (isEmptyObj(options) || typeof options !== 'object') return;
        this.player = options.player;
        this.lrc = options.lrc;
        this.lrcArea = options.lrcArea;
        //用于保存歌词
        this.lrcArr = [];
        //用于保存时间戳
        this.timestamp = [];
        //处理歌词
        this.handleLrc(this.lrc);
        var that = this;

        this.player.addEventListener('play',
        function() {
            that.play();
        },
        false);

        this.player.addEventListener('pause',
        function() {
            that.pause();
        },
        false);

        //歌词索引
        this.idx = 0;
    },
    //格式化歌词
    handleLrc: function(lrc) {
        var re = /([.+])(.+)?/gm,
        ul = cEl('ul'),
        frag = document.createDocumentFragment(),
        tmpArr,
        i,
        len;
        this.lrcArea.innerHTML = '';
        frag.appendChild(ul);
        ul.id = 'c';
        this.lrcArea.appendChild(frag);

        var txt = lrc.replace(re,
        function(a, b, c) {
            return b + (c === undefined ? ' ': c) + '
';
        });

        tmpArr = txt.split('
');

        //处理歌词
        for (i = 0, len = tmpArr.length; i < len; i++) {
            var item = trim(tmpArr[i]);
            if (item.length > 0) {
                this.lrcArr.push(item);
            }
        }

        frag = document.createDocumentFragment();

        for (i = 0, len = this.lrcArr.length; i < len; i++) {
            var li = cEl('li');
            if (i === 0) {
                li.className = 'cur';
            }
            li.innerHTML = this.lrcArr[i].replace(/[.+]/i, '');
            //处理时间
            this.timestamp.push(this.lrcArr[i].replace(re,
            function(a, b, c) {
                return b;
            }).replace('[', '').replace(']', ''));
            frag.appendChild(li);
        }

        ul.appendChild(frag);
        this.li = $('lrcArea').getElementsByTagName('li');
    },
    //播放
    play: function() {
        this.stop = false;
        var that = this,
        player = this.player,
        i, len;

        this.t = setInterval(function() {
            if (that.stop) return;
            that.curTime = player.currentTime;

            for (i = 0, len = that.timestamp.length - 1; i < len; i++) {
                var prevTime = that.formatTimeStamp(that.timestamp[i]),
                nextTime = that.formatTimeStamp(that.timestamp[i + 1]);
                //当前播放时间与前后歌词时间比较，如果位于这两者之间则转到该歌词
                if (parseFloat(that.curTime) > prevTime && parseFloat(that.curTime) < nextTime) {
                    that.scrollToLrc(i);
                    return;
                }
            }
        },
        300);
    },
    //暂停
    pause: function() {
        this.stop = true;
        clearInterval(this.t);
    },
    //格式化时间
    formatTimeStamp: function(timestamp) {
        var re = /([0-9]+):([0-9]+).([0-9]+)/i,
        seconds = timestamp.replace(re,
        function(a, b, c, d) {
            return Number(b * 60) + Number(c) + parseFloat('0.' + d);
        });
        return seconds;
    },
    //歌词滚动
    scrollToLrc: function(idx) {
        var ds = getOffset(this.li[idx]).top,
        i,
        len;
        //如果歌词索引没有变动，则认为这句没有唱完，不处理
        if (this.idx === idx) return;
        //否则更新索引值并更新样式和位置
        this.idx = idx;
        for (i = 0, len = this.li.length; i < len; i++) {
            this.li[i].className = '';
        }
        this.li[idx].className = 'cur';
        this.lrcArea.scrollTop = ds - this.lrcArea.offsetHeight / 2;
    }
};

function $(id) {
    return typeof id === 'string' ? document.getElementById(id) : id;
}
function cEl(el) {
    return document.createElement(el);
}
function trim(str) {
    return str.replace(/(^s*)|(s*$)/g, "");
}
function isEmptyObj(o) {
    for (var p in o) return false;
    return true;
}
function getOffset(el) {
    var parent = el.offsetParent,
    left = el.offsetLeft,
    top = el.offsetTop;

    while (parent !== null) {
        left += parent.offsetLeft;
        top += parent.offsetTop;
        parent = parent.offsetParent;
    }

    return {
        left: left,
        top: top
    };
}

var p = new musicPlayer({
    player: $('player'),
    lrc: $('lrc').innerHTML,
    lrcArea: $('lrcArea')
});