js大转盘 示例代码(jquery)

【实例截图】

【核心代码】

// VERSION: 2.2 LAST UPDATE: 13.03.2012
/* 
 * Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
 * 
 * Made by Wilq32, wilq32@gmail.com, Wroclaw, Poland, 01.2009
 * Website: http://code.google.com/p/jqueryrotate/ 
 */

// Documentation removed from script file (was kinda useless and outdated)

(function($) {
var supportedCSS,styles=document.getElementsByTagName("head")[0].style,toCheck="transformProperty WebkitTransform OTransform msTransform MozTransform".split(" ");
for (var a=0;a<toCheck.length;a  ) if (styles[toCheck[a]] !== undefined) supportedCSS = toCheck[a];
// Bad eval to preven google closure to remove it from code o_O
// After compresion replace it back to var IE = 'v' == '\v'
var IE = eval('"v"=="\v"');

jQuery.fn.extend({
    rotate:function(parameters)
    {
        if (this.length===0||typeof parameters=="undefined") return;
            if (typeof parameters=="number") parameters={angle:parameters};
        var returned=[];
        for (var i=0,i0=this.length;i<i0;i  )
            {
                var element=this.get(i);	
                if (!element.Wilq32 || !element.Wilq32.PhotoEffect) {

                    var paramClone = $.extend(true, {}, parameters); 
                    var newRotObject = new Wilq32.PhotoEffect(element,paramClone)._rootObj;

                    returned.push($(newRotObject));
                }
                else {
                    element.Wilq32.PhotoEffect._handleRotation(parameters);
                }
            }
            return returned;
    },
    getRotateAngle: function(){
        var ret = [];
        for (var i=0,i0=this.length;i<i0;i  )
            {
                var element=this.get(i);	
                if (element.Wilq32 && element.Wilq32.PhotoEffect) {
                    ret[i] = element.Wilq32.PhotoEffect._angle;
                }
            }
            return ret;
    },
    stopRotate: function(){
        for (var i=0,i0=this.length;i<i0;i  )
            {
                var element=this.get(i);	
                if (element.Wilq32 && element.Wilq32.PhotoEffect) {
                    clearTimeout(element.Wilq32.PhotoEffect._timer);
                }
            }
    }
});

// Library agnostic interface

Wilq32=window.Wilq32||{};
Wilq32.PhotoEffect=(function(){

	if (supportedCSS) {
		return function(img,parameters){
			img.Wilq32 = {
				PhotoEffect: this
			};
            
            this._img = this._rootObj = this._eventObj = img;
            this._handleRotation(parameters);
		}
	} else {
		return function(img,parameters) {
			// Make sure that class and id are also copied - just in case you would like to refeer to an newly created object
            this._img = img;

			this._rootObj=document.createElement('span');
			this._rootObj.style.display="inline-block";
			this._rootObj.Wilq32 = 
				{
					PhotoEffect: this
				};
			img.parentNode.insertBefore(this._rootObj,img);
			
			if (img.complete) {
				this._Loader(parameters);
			} else {
				var self=this;
				// TODO: Remove jQuery dependency
				jQuery(this._img).bind("load", function()
				{
					self._Loader(parameters);
				});
			}
		}
	}
})();

Wilq32.PhotoEffect.prototype={
    _setupParameters : function (parameters){
		this._parameters = this._parameters || {};
        if (typeof this._angle !== "number") this._angle = 0 ;
        if (typeof parameters.angle==="number") this._angle = parameters.angle;
        this._parameters.animateTo = (typeof parameters.animateTo==="number") ? (parameters.animateTo) : (this._angle); 

        this._parameters.step = parameters.step || this._parameters.step || null;
		this._parameters.easing = parameters.easing || this._parameters.easing || function (x, t, b, c, d) { return -c * ((t=t/d-1)*t*t*t - 1)   b; }
		this._parameters.duration = parameters.duration || this._parameters.duration || 1000;
        this._parameters.callback = parameters.callback || this._parameters.callback || function(){};
        if (parameters.bind && parameters.bind != this._parameters.bind) this._BindEvents(parameters.bind); 
	},
	_handleRotation : function(parameters){
          this._setupParameters(parameters);
          if (this._angle==this._parameters.animateTo) {
              this._rotate(this._angle);
          }
          else { 
              this._animateStart();          
          }
	},

	_BindEvents:function(events){
		if (events && this._eventObj) 
		{
            // Unbinding previous Events
            if (this._parameters.bind){
                var oldEvents = this._parameters.bind;
                for (var a in oldEvents) if (oldEvents.hasOwnProperty(a)) 
                        // TODO: Remove jQuery dependency
                        jQuery(this._eventObj).unbind(a,oldEvents[a]);
            }

            this._parameters.bind = events;
			for (var a in events) if (events.hasOwnProperty(a)) 
				// TODO: Remove jQuery dependency
					jQuery(this._eventObj).bind(a,events[a]);
		}
	},

	_Loader:(function()
	{
		if (IE)
		return function(parameters)
		{
			var width=this._img.width;
			var height=this._img.height;
			this._img.parentNode.removeChild(this._img);
							
			this._vimage = this.createVMLNode('image');
			this._vimage.src=this._img.src;
			this._vimage.style.height=height "px";
			this._vimage.style.width=width "px";
			this._vimage.style.position="absolute"; // FIXES IE PROBLEM - its only rendered if its on absolute position!
			this._vimage.style.top = "0px";
			this._vimage.style.left = "0px";

			/* Group minifying a small 1px precision problem when rotating object */
			this._container =  this.createVMLNode('group');
			this._container.style.width=width;
			this._container.style.height=height;
			this._container.style.position="absolute";
			this._container.setAttribute('coordsize',width-1 ',' (height-1)); // This -1, -1 trying to fix ugly problem with small displacement on IE
			this._container.appendChild(this._vimage);
			
			this._rootObj.appendChild(this._container);
			this._rootObj.style.position="relative"; // FIXES IE PROBLEM
			this._rootObj.style.width=width "px";
			this._rootObj.style.height=height "px";
			this._rootObj.setAttribute('id',this._img.getAttribute('id'));
			this._rootObj.className=this._img.className;			
		    this._eventObj = this._rootObj;	
		    this._handleRotation(parameters);	
		}
		else
		return function (parameters)
		{
			this._rootObj.setAttribute('id',this._img.getAttribute('id'));
			this._rootObj.className=this._img.className;
			
			this._width=this._img.width;
			this._height=this._img.height;
			this._widthHalf=this._width/2; // used for optimisation
			this._heightHalf=this._height/2;// used for optimisation
			
			var _widthMax=Math.sqrt((this._height)*(this._height)   (this._width) * (this._width));

			this._widthAdd = _widthMax - this._width;
			this._heightAdd = _widthMax - this._height;	// widthMax because maxWidth=maxHeight
			this._widthAddHalf=this._widthAdd/2; // used for optimisation
			this._heightAddHalf=this._heightAdd/2;// used for optimisation
			
			this._img.parentNode.removeChild(this._img);	
			
			this._aspectW = ((parseInt(this._img.style.width,10)) || this._width)/this._img.width;
			this._aspectH = ((parseInt(this._img.style.height,10)) || this._height)/this._img.height;
			
			this._canvas=document.createElement('canvas');
			this._canvas.setAttribute('width',this._width);
			this._canvas.style.position="relative";
			this._canvas.style.left = -this._widthAddHalf   "px";
			this._canvas.style.top = -this._heightAddHalf   "px";
			this._canvas.Wilq32 = this._rootObj.Wilq32;
			
			this._rootObj.appendChild(this._canvas);
			this._rootObj.style.width=this._width "px";
			this._rootObj.style.height=this._height "px";
            this._eventObj = this._canvas;
			
			this._cnv=this._canvas.getContext('2d');
            this._handleRotation(parameters);
		}
	})(),

	_animateStart:function()
	{	
		if (this._timer) {
			clearTimeout(this._timer);
		}
		this._animateStartTime =  new Date;
		this._animateStartAngle = this._angle;
		this._animate();
	},
    _animate:function()
    {
         var actualTime =  new Date;
         var checkEnd = actualTime - this._animateStartTime > this._parameters.duration;

         // TODO: Bug for animatedGif for static rotation ? (to test)
         if (checkEnd && !this._parameters.animatedGif) 
         {
             clearTimeout(this._timer);
         }
         else 
         {
             if (this._canvas||this._vimage||this._img) {
                 var angle = this._parameters.easing(0, actualTime - this._animateStartTime, this._animateStartAngle, this._parameters.animateTo - this._animateStartAngle, this._parameters.duration);
                 this._rotate((~~(angle*10))/10);
             }
             if (this._parameters.step) {
                this._parameters.step(this._angle);
             }
             var self = this;
             this._timer = setTimeout(function()
                     {
                     self._animate.call(self);
                     }, 10);
         }

         // To fix Bug that prevents using recursive function in callback I moved this function to back
         if (this._parameters.callback && checkEnd){
             this._angle = this._parameters.animateTo;
             this._rotate(this._angle);
             this._parameters.callback.call(this._rootObj);
         }
     },

	_rotate : (function()
	{
		var rad = Math.PI/180;
		if (IE)
		return function(angle)
		{
            this._angle = angle;
			this._container.style.rotation=(angle%360) "deg";
		}
		else if (supportedCSS)
		return function(angle){
            this._angle = angle;
			this._img.style[supportedCSS]="rotate(" (angle%360) "deg)";
		}
		else 
		return function(angle)
		{
            this._angle = angle;
			angle=(angle%360)* rad;
			// clear canvas	
			this._canvas.width = this._width this._widthAdd;
			this._canvas.height = this._height this._heightAdd;
						
			// REMEMBER: all drawings are read from backwards.. so first function is translate, then rotate, then translate, translate..
			this._cnv.translate(this._widthAddHalf,this._heightAddHalf);	// at least center image on screen
			this._cnv.translate(this._widthHalf,this._heightHalf);			// we move image back to its orginal 
			this._cnv.rotate(angle);										// rotate image
			this._cnv.translate(-this._widthHalf,-this._heightHalf);		// move image to its center, so we can rotate around its center
			this._cnv.scale(this._aspectW,this._aspectH); // SCALE - if needed ;)
			this._cnv.drawImage(this._img, 0, 0);							// First - we draw image
		}

	})()
}

if (IE)
{
Wilq32.PhotoEffect.prototype.createVMLNode=(function(){
document.createStyleSheet().addRule(".rvml", "behavior:url(#default#VML)");
		try {
			!document.namespaces.rvml && document.namespaces.add("rvml", "urn:schemas-microsoft-com:vml");
			return function (tagName) {
				return document.createElement('<rvml:'   tagName   ' class="rvml">');
			};
		} catch (e) {
			return function (tagName) {
				return document.createElement('<'   tagName   ' xmlns="urn:schemas-microsoft.com:vml" class="rvml">');
			};
		}		
})();
}

})(jQuery);