JS封装运动框架（另一种写法）

function animate(obj, json, interval, sp, fn) {
clearInterval(obj.timer);
//var k = 0;
//var j = 0;
function getStyle(obj, arr) {
if(obj.currentStyle){
return obj.currentStyle[arr]; //针对ie
} else {
return document.defaultView.getComputedStyle(obj, null)[arr];
}
}
obj.timer = setInterval(function(){
//j ++;
var flag = true;
for(var arr in json) {
var icur = 0;
//k++;
if(arr == "opacity") {
icur = Math.round(parseFloat(getStyle(obj, arr))*100);
} else {
icur = parseInt(getStyle(obj, arr));
}
var speed = (json[arr] - icur) * sp;
speed = speed > 0 ? Math.ceil(speed): Math.floor(speed);
if(icur != json[arr]){
flag = false;
}
if(arr == "opacity"){
obj.style.filter = "alpha(opacity : '+(icur + speed)+' )";
obj.style.opacity = (icur + speed)/100;
}else {
obj.style[arr] = icur + speed + "px";
}
//console.log(j + "," + arr +":"+ flag);
}

if(flag){
clearInterval(obj.timer);
//console.log(j + ":" + flag);
//console.log("k = " + k);
//console.log("j = " + j);
//console.log("DONE");
if(fn){
fn();
}
}
},interval);
}