一个十分简短的Tween

说它短，是因为总共核心代码+注释不到100行。(需要声明一下的是此代码非原创，但略有修改，加了自已的部分注解)

function getEl(id) {

 ? document.getElementById(id) : id;

   3: }

/**

* @fileoverview Tween

*/

function Tween(C, B, A) {

if (C) {

this.time = parseInt(C * 1000)

  10:     }

if (B) {

this.transform = B

  13:     }

if (A) {

this.interval = A

  16:     }

  17: }

  18: Tween.prototype = {

  19:     interval: 40,

function(A) {

return 1 - Math.pow(1 - A, 3)

  22:     },

  23:     time: 1000,

function(A, E, D) {

this.transform;

function H() {

  27:             I += C;

//<==>(runTime / totalTime)

//Tween over

  30:                 A(1);

  31:                 E();

  32:                 clearInterval(B)

else {

  34:                 A(D(J) / G)

  35:             }

  36:         }

this.interval;

this.time;

var G = D(1);

var I = 0;

var B = setInterval(H, C);

return B

  43:     },

/**

    * C {id|dom}

    * F width

    * E height

    */

function(C, F, E, G) {

  50:         C = getEl(C);

var I = C.offsetLeft;

var H = C.offsetTop;

var B = C.style;

function A(J) {

;

  57:         }

function D() {

null;

  60:             G && G()

  61:         }

this.start(A, D)

  63:     },

/**

    * D {id|dom}

    * C start--opacity

    * A end--opacity

    * E complete--callback

    */

function(D, C, A, E) {

  71:         D = getEl(D);

var G = A - C;

var M = document.defaultView && document.defaultView.getComputedStyle;

function B(I) {

  75:             I = C + G * I;

if (!M) {                

if (I >= 1) {

;

true;

  80:                 }

  81:  

')';

else {

  84:                 D.style.opacity = I;

  85:             }

  86:         }

function F() {

null;

  89:             E && E()

  90:         }

this.start(B, F)

  92:     }

  93: };