root / trunk / plugins / mousewheel / jquery.mousewheel.js @ 2124

/* Copyright (c) 2006 Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * Thanks to: http://adomas.org/javascript-mouse-wheel/ for some pointers.
 * Thanks to: Mathias Bank(http://www.mathias-bank.de) for a scope bug fix.
 *
 * $LastChangedDate$
 * $Rev$
 *
 * Version: 2.2
 */

(function($) {
    
$.fn.extend({
    
    /**
     * Apply the mousewheel event to the elements in the jQuery object.
     * The handler function should be prepared to take the event object
     * and a param called 'delta'. The 'delta' param is a number
     * either > 0 or < 0. > 0 = up and < 0 = down.
     *
     * The pageX, pageY, clientX and clientY event properties
     * are fixed in Firefox.
     *
     * @example $("p").mousewheel(function(event, delta){
     *   if (delta > 0)
     *     // do something on mousewheel scroll up
     *   else if (delta < 0)
     *     //do something on mousewheel scroll down
     * });
     *
     * @name mousewheel
     * @type jQuery
     * @param Function handler A function to call when onmousewheel fires. Should take two params: event and delta.
     * @cat Plugins/Mousewheel
     * @author Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
     */
    mousewheel: function(f) {
        if (!f.guid) f.guid = $.event.guid++;
        if (!$.event._mwCache) $.event._mwCache = [];
        
        return this.each( function() {
            if (this._mwHandlers) return this._mwHandlers.push(f);
            else this._mwHandlers = [];
            
            this._mwHandlers.push(f);
            
            var s = this;
            
            this._mwHandler = function(e) {
                e = $.event.fix(e || window.event);
                $.extend(e, this._mwCursorPos || {});
                var delta = 0, returnValue = true;
                
                if (e.wheelDelta)  delta = e.wheelDelta/120;
                if (e.detail)      delta = -e.detail/3;
                if (window.opera)  delta = -e.wheelDelta;
                
                for (var i=0; i<s._mwHandlers.length; i++)
                    if (s._mwHandlers[i])
                        if ( s._mwHandlers[i].call(s, e, delta) === false ) {
                            returnValue = false;
                            e.preventDefault();
                            e.stopPropagation();
                        }
                
                return returnValue;
            };
            
            if ($.browser.mozilla && !this._mwFixCursorPos) {
                // fix pageX, pageY, clientX and clientY for mozilla
                this._mwFixCursorPos = function(e) {
                    this._mwCursorPos = {
                        pageX: e.pageX,
                        pageY: e.pageY,
                        clientX: e.clientX,
                        clientY: e.clientY
                    };
                };
                $(this).bind('mousemove', this._mwFixCursorPos);
            }
            
            if (this.addEventListener)
                if ($.browser.mozilla) this.addEventListener('DOMMouseScroll', this._mwHandler, false);
                else                   this.addEventListener('mousewheel',     this._mwHandler, false);
            else
                this.onmousewheel = this._mwHandler;
            
            $.event._mwCache.push( $(this) );
        });
    },
    
    /**
     * This method removes one or all applied mousewheel events from the elements.
     * You can remove a single handler function by passing it as the first param.
     * If you do not pass anything, it will remove all handlers.
     *
     * @name unmousewheel
     * @param Function handler The handler function to remove from the mousewheel event.
     * @type jQuery
     * @cat Plugins/Mousewheel
     * @author Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
     */
    unmousewheel: function(f) {
        return this.each( function() {
            if ( f && this._mwHandlers ) {
                for (var i=0; i<this._mwHandlers.length; i++)
                    if (this._mwHandlers[i] && this._mwHandlers[i].guid == f.guid)
                        delete this._mwHandlers[i];
            } else {
                if ($.browser.mozilla && !this._mwFixCursorPos)
                    $(this).unbind('mousemove', this._mwFixCursorPos);
                    
                if (this.addEventListener)
                    if ($.browser.mozilla) this.removeEventListener('DOMMouseScroll', this._mwHandler, false);
                    else                   this.removeEventListener('mousewheel',     this._mwHandler, false);
                else
                    this.onmousewheel = null;
                    
                this._mwHandlers = this._mwHandler = this._mwFixCursorPos = this._mwCursorPos = null;
            }
        });
    }
});

// clean-up
$(window)
    .one('unload', function() {
        var els = $.event._mwCache || [];
        for (var i=0; i<els.length; i++)
            els[i].unmousewheel();
    });
    
})(jQuery);