javascript之水平横向滚动歌词同步的应用

参考地址：http://aboutplayer.com
代码如下:
var lrc0, lrc1, lrc2;
moveflag = false;
var top, bottom;
var lrcobj;
var lrctop;
predlt = 0;
curdlt = 0;

function lrcClass(tt)
{
  this.inr = [];

  this.oTime = 0;

  this.dts = -1;
  this.dte = -1;
  this.dlt = -1;
  this.ddh;
  this.fjh;

  if(/\[offset\:(\-?\d+)\]/i.test(tt))
    this.oTime = RegExp.$1/1000;

  tt = tt.replace(/\[\:\][^$\n]*(\n|$)/g,"$1");
  tt = tt.replace(/\[[^\[\]\:]*\]/g,"");
  tt = tt.replace(/\[[^\[\]]*[^\[\]\d]+[^\[\]]*\:[^\[\]]*\]/g,"");
  tt = tt.replace(/\[[^\[\]]*\:[^\[\]]*[^\[\]\d\.]+[^\[\]]*\]/g,"");
  tt = tt.replace(/<[^<>]*[^<>\d]+[^<>]*\:[^<>]*>/g,"");
  tt = tt.replace(/<[^<>]*\:[^<>]*[^<>\d\.]+[^<>]*>/g,"");

  while(/\[[^\[\]]+\:[^\[\]]+\]/.test(tt))
  {
    tt = tt.replace(/((\[[^\[\]]+\:[^\[\]]+\])+[^\[\r\n]*)[^\[]*/,"\n");
    var zzzt = RegExp.$1;
    /^(.+\])([^\]]*)$/.exec(zzzt);
    var ltxt = RegExp.$2;
    var eft = RegExp.$1.slice(1,-1).split("][");
    for(var ii=0; ii<eft.length; ii++)
    {
      var sf = eft[ii].split(":");
      var tse = parseInt(sf[0],10) * 60 + parseFloat(sf[1]);
      var sso = { t:[] , w:[] , n:ltxt }
      sso.t[0] = Math.round((tse-this.oTime)*1000)/1000;
      this.inr[this.inr.length] = sso;
    }
  }
  this.inr = this.inr.sort( function(a,b){return a.t[0]-b.t[0];} );

  for(var ii=0; ii<this.inr.length; ii++)
  {
    while(/<[^<>]+\:[^<>]+>/.test(this.inr[ii].n))
    {
      this.inr[ii].n = this.inr[ii].n.replace(/<(\d+)\:([\d\.]+)>/,"%=%");
      var tse = parseInt(RegExp.$1,10) * 60 + parseFloat(RegExp.$2);
      this.inr[ii].t[this.inr[ii].t.length] = Math.round((tse-this.oTime)*1000)/1000;
    }
    lrcbc1.innerHTML = "<font>"+ this.inr[ii].n.replace(/&/g,"&").replace(/</g,"<").replace(/>/g,">").replace(/%=%/g,"</font><font>") +" </font>";
    var fall = lrcbc1.getElementsByTagName("font");
    for(var wi=0; wi<fall.length; wi++)
      this.inr[ii].w[this.inr[ii].w.length] = fall[wi].offsetWidth;
    this.inr[ii].n = lrcbc1.innerText;
  }

  this.overtop = function()
  {
    var ii;
    for(ii=this.inr.length-1; ii>0 && this.inr[ii].t[0]>ffbb; ii--){}
    top = ii;
  }

  this.run = function(tme)
  {
    if(tme<this.dts || tme>=this.dte)
    {
      var ii;
      for(ii=this.inr.length-1; ii>=0 && this.inr[ii].t[0]>tme; ii--){}
      if(ii<0) return;
      this.ddh = this.inr[ii].t;
      this.fjh = this.inr[ii].w;
      this.dts = this.inr[ii].t[0];
      this.dte = (ii<this.inr.length-1)?this.inr[ii+1].t[0]:aboutplayer.currentMedia.duration;

      if(!movable)
      {
        lrctop = 140;
        lrcoll.style.pixelTop = 140;
        lowlight(lrcbox1);
        this.overtop();
        overbottom();
        for(var wi=1; wi<=this.inr.length; wi++)
        {
          eval("lrcbox"+wi).innerText = this.inr[wi-1].n;
          eval("lrcbc"+wi).innerText = this.inr[wi-1].n;
        }
        movable = true;
      }

      if(this.dlt>0) lowcolor(eval("lrcbc"+this.dlt));
      clearTimeout(lrc2);
      if(this.dlt==ii-1)
      {
        predlt = this.dlt+1;
        if(!ptms && predlt>0)
        {
          eval("lrcbc"+predlt).filters.alpha.opacity = 100;
          eval("lrcbc"+predlt).style.width = "100%";
          highcolor(0,this.dte-this.dts);
        }
        toposition(1,this.dte-this.dts);
      }
      if(ii-this.dlt>1 || ii-this.dlt<=-1)
      {
        if(this.dlt>=0) lowcolor(eval("lrcbc"+(this.dlt+1)));
        if(this.dlt==-1 || ii==0)
        {
          jumpto(ii-this.dlt-1);
          toposition(1,this.dte-this.dts);
        }
        else
          jumpto(ii-this.dlt);
      }
      if(this.dlt>=0) lowlight(eval("lrcbox"+(this.dlt+1)));
      this.dlt = ii;
      curdlt = ii;
      if(!drdc) highlight(eval("lrcbox"+(this.dlt+1)));
      if(drdc)
      {
        curlowcolor(eval("lrcbc"+(this.dlt+1)));
        curhighcolor(0,this.dte-this.dts);
      }
    }
    if(klok)
    {
      var bbw = 0;
      var ki;
      for(ki=0; ki<this.ddh.length && this.ddh[ki]<=tme; ki++)
        bbw += this.fjh[ki];
      var kt = ki-1;
      var sc = ((ki<this.ddh.length)?this.ddh[ki]:this.dte) - this.ddh[kt];
      var tc = tme - this.ddh[kt];
      bbw -= this.fjh[kt] - tc / sc * this.fjh[kt];
      if(bbw>eval("lrcbox"+(this.dlt+1)).offsetWidth)
        bbw = eval("lrcbox"+(this.dlt+1)).offsetWidth;
      eval("lrcbc"+(this.dlt+1)).style.width = Math.round(bbw);
    }
  }
  lrcbox1.innerText = "www.aboutplayer.com";
}

function overbottom()
{
  if(aboutplayer.currentMedia.duration>0)
  {
    var ii;
    for(ii=lrcobj.inr.length-1; ii>0 && lrcobj.inr[ii].t[0]-ffbb>=aboutplayer.currentMedia.duration; ii--){}
    bottom = ii;
  }
  else
    setTimeout("overbottom()",10);
}

function jumpto(nline)
{
  lrctop -= 20*nline;
  lrcoll.style.top = lrctop;
}

function toposition(step,dur)
{
  if(moveflag) return;
  lrcoll.style.top = lrctop--;
  if(step<20)
  {
    step++;
    setTimeout("toposition("+step+","+dur+");",dur*50);
  }
}

function highcolor(step,dur)
{
  if(moveflag) return;
  eval("lrcbc"+predlt).filters.alpha.opacity = 100-(step++)*10;
  if(step<10)
    lrc1 = setTimeout("highcolor("+step+","+dur+");",dur*100);
}

function curhighcolor(step,dur)
{
  if(moveflag) return;
  eval("lrcbc"+(curdlt+1)).filters.alpha.opacity = (step++)*10;
  if(step<10)
    lrc2 = setTimeout("curhighcolor("+step+","+dur+");",dur*100);
}

function highlight(lid)
{
  lid.style.color = "#00FF00";
}

function lowcolor(lid)
{
  clearTimeout(lrc1);
  lid.style.width = 0;
  lid.filters.alpha.opacity = 100;
}

function curlowcolor(lid)
{
  lid.filters.alpha.opacity = 0;
  lid.style.width = "100%";
}

function lowlight(lid)
{
  lid.style.color = "#0080C0";
}

function lrcrun(m)
{
  lrcobj = new lrcClass(m);
  lrc0 = setInterval("try {lrcobj.run(aboutplayer.controls.currentPosition+ffbb)} catch(hh){}",10);
}

MakeMovable(lrcollbox);
function MakeMovable(element)
{
  element.attachEvent("onmousedown",onmousedown); 
  element.attachEvent("onmouseup",onmouseup);
  element.attachEvent("onmousemove",onmousemove);
  flagmove = false;
  var s_y, o_y;
  curpot = 0;

  function onmousedown()
  {
    if(event.button!=1 || moveflag || !movable || !type || bottom==0) {flagmove = true; return;}
    clearTimeout(lrc0);
    if(curdlt>0) lowcolor(eval("lrcbc"+curdlt));
    lowcolor(eval("lrcbc"+(curdlt+1)));
    lowlight(eval("lrcbox"+(curdlt+1)));
    if(lrcoll.style.pixelTop>120-top*20) lrcoll.style.top = 120-top*20;
    if(lrcoll.style.pixelTop<120-bottom*20) lrcoll.style.top = 120-bottom*20;
    s_y = event.clientY;
    o_y = lrcoll.style.pixelTop;
    element.style.cursor = "n-resize";
    element.setCapture();
    moveflag = true;
  }

  function onmousemove()
  {
    if(event.button!=1 || !moveflag || flagmove) return;
    var offy = event.clientY-s_y;
    if(o_y+offy<=120-top*20 && o_y+offy>=120-bottom*20) lrcoll.style.top = o_y+offy;
    if(o_y+offy>120-top*20) lrcoll.style.top = 120-top*20;
    if(o_y+offy<120-bottom*20) lrcoll.style.top = 120-bottom*20;
    var pot = Math.floor((lrcoll.style.pixelTop-120)/-20);
    if(pot!=curpot)
    {
      lowlight(eval("lrcbox"+(curpot+1)));
      curpot = pot;
      highlight(eval("lrcbox"+(curpot+1)));
    }
  }

  function onmouseup()
  {
    if(!moveflag || flagmove) {flagmove = false; return;}
    if(aboutplayer.playState==3)
    {
      if(lrcoll.style.pixelTop<=120-top*20 && lrcoll.style.pixelTop>100-top*20)
        lrcobj.dte = -1;
      else
        lrcobj.dte = lrcobj.inr[Math.floor((lrcoll.style.pixelTop-120)/-20)-1].t[0];
      if(lrcobj.inr[Math.floor((lrcoll.style.pixelTop-120)/-20)].t[0]-ffbb<0)
        aboutplayer.controls.currentPosition = 0;
      else
        aboutplayer.controls.currentPosition = lrcobj.inr[Math.floor((lrcoll.style.pixelTop-120)/-20)].t[0]-ffbb;
      lrcobj.dlt = Math.floor((lrcoll.style.pixelTop-120)/-20);
      lrctop = lrcoll.style.pixelTop;
    }
    else
    {
      lowlight(eval("lrcbox"+(curpot+1)));
      highlight(eval("lrcbox"+(curdlt+1)));
      lrcoll.style.top = o_y;
    }
    lrc0 = setInterval("try {lrcobj.run(aboutplayer.controls.currentPosition+ffbb)} catch(hh){}",10);
    element.releaseCapture();
    element.style.cursor = "hand";
    moveflag = false;
  }
}