/**
 * VERSION: 2.3
 * DATE: 10/17/2009
 * ACTIONSCRIPT VERSION: 3.0 
 * UPDATES AND DOCUMENTATION AT: http://www.TweenMax.com
 **/
package com.greensock.plugins {
    import com.greensock.*;
    
    import flash.display.*;
/**
 * Tweening "autoAlpha" is exactly the same as tweening an object's "alpha" except that it ensures 
 * that the object's "visible" property is true until autoAlpha reaches zero at which point it will 
 * toggle the "visible" property to false. That not only improves rendering performance in the Flash Player, 
 * but also hides DisplayObjects so that they don't interact with the mouse. <br /><br />
 * 
 * <b>USAGE:</b><br /><br />
 * <code>
 *         import com.greensock.TweenLite; <br />
 *         import com.greensock.plugins.TweenPlugin; <br />
 *         import com.greensock.plugins.AutoAlphaPlugin; <br />
 *         TweenPlugin.activate([AutoAlphaPlugin]); //activation is permanent in the SWF, so this line only needs to be run once.<br /><br />
 * 
 *         TweenLite.to(mc, 2, {autoAlpha:0}); <br /><br />
 * </code>
 * 
 * <b>Copyright 2010, GreenSock. All rights reserved.</b> This work is subject to the terms in <a href="http://www.greensock.com/terms_of_use.html">http://www.greensock.com/terms_of_use.html</a> or for corporate Club GreenSock members, the software agreement that was issued with the corporate membership.
 * 
 * @author Jack Doyle, jack@greensock.com
 */
    public class AutoAlphaPlugin extends TweenPlugin {
        /** @private **/
        public static const API:Number = 1.0; //If the API/Framework for plugins changes in the future, this number helps determine compatibility
        
        /** @private **/
        protected var _target:Object;
        /** @private **/
        protected var _ignoreVisible:Boolean;
        
        /** @private **/
        public function AutoAlphaPlugin() {
            super();
            this.propName = "autoAlpha";
            this.overwriteProps = ["alpha","visible"];
        }
        
        /** @private **/
        override public function onInitTween(target:Object, value:*, tween:TweenLite):Boolean {
            _target = target;
            addTween(target, "alpha", target.alpha, value, "alpha");
            return true;
        }
        
        /** @private **/
        override public function killProps(lookup:Object):void {
            super.killProps(lookup);
            _ignoreVisible = Boolean("visible" in lookup);
        }
        
        /** @private **/
        override public function set changeFactor(n:Number):void {
            updateTweens(n);
            if (!_ignoreVisible) {
                _target.visible = Boolean(_target.alpha != 0);
            }
        }
        
    }
}