/**
 * SWFMouse - Mac MouseWheel Support for Flash & Ajax.
 * @version 1.1.1
 * @author jason m horwitz | sekati.com
 * Copyright (C) 2008  jason m horwitz, Sekat LLC. All Rights Reserved.
 * Released under the MIT License: http://www.opensource.org/licenses/mit-license.php
 */
 
 /**
  * SWFMouse offers Mac MouseWheel support for Flash & Ajax.
  * Natively it supports both swfObject (http://code.google.com/p/swfobject/)
  * as well as swfIN (http://code.google.com/p/swfin/).
  * @param swfInstance - the swfIN or swfObject instance.
  */
 function SWFMouse ( swfInstance ) {
        this.so = swfInstance;
        this.isSWFObject = (typeof swfobject != 'undefined')  ? true : false;
        this.isSWFIN = (typeof swfIN != 'undefined')  ? true : false;
        var isMac = navigator.appVersion.toLowerCase().indexOf( "mac" ) != -1;
        if (isMac) this.init();
        if (this.isSWFObject == true || this.isSWFIN == true) {
                if (isMac) this.init();
        } else {
                alert("SWFMouse Error: the constructor argument 'swfInstance' is not a supported type (SWFObject or swfIN).");
        }
 } 

SWFMouse.prototype = {  
        
        /**
         * Initialization: listen for browser mousewheel event.
         */
        init: function() {
                SWFMouse.instance = this;
                //alert("swfObject: "+this.isSWFObject+", swfIN: "+this.isSWFIN);
                if (window.addEventListener) window.addEventListener( 'DOMMouseScroll', SWFMouse.instance.wheel, false );
                window.onmousewheel = document.onmousewheel = SWFMouse.instance.wheel;
        },
        
        /**
         * constrain the value to confines. 
         */
        clamp: function( val, min, max ) {
                if( val < min ) return min;
                if( val > max ) return max;
                return val;
        },      
        
        /**
         * mousewheel event handler
         */
        handle: function( delta ){
                if (this.isSWFIN == true) {
                        document[ this.so.getSWFID() ].externalMouseEvent( delta );
                } else if (this.isSWFObject == true) {
                        document[ this.so.getObjectById( "id" ) ].externalMouseEvent( delta );
                }
        },
        
        /**
         * sanitize the mouse wheel event data & pass to handler.
         */
        wheel: function( event ){
                var delta = 0;
                if (event.wheelDelta) {
                        // internet explorer & opera
                        delta = event.wheelDelta / 120;
                        if (window.opera) delta = -delta;
                } else if (event.detail) {
                        // mozilla
                        delta = -event.detail / 3;
                }               
                // safari
        if(/AppleWebKit/.test( navigator.userAgent )) delta /= 3;
                // normalize the delta
                delta = SWFMouse.instance.clamp( delta );
                // pass to handler              
                if (delta) SWFMouse.instance.handle( delta );
                if (event.preventDefault) event.preventDefault();
                event.returnValue = false;
        }
};