/**
 * jQuery custom checkboxes
 * 
 * Copyright (c) 2008 Khavilo Dmitry (http://widowmaker.kiev.ua/checkbox/)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * @version 1.1.0 Beta
 * @author Khavilo Dmitry
 * @mailto wm.morgun@gmail.com
**/

(function($) {

    $.fn.checkbox = function(options) {

        /* IE6 background flicker fix */
        try { document.execCommand('BackgroundImageCache', false, true); } catch (e) { }

        /* Default settings */
        var settings = {
            cls: 'jquery-checkbox',  /* checkbox  */
            empty: 'empty.png'  /* checkbox  */
        };

        /* Processing settings */
        settings = $.extend(settings, options || {});

        /* Adds check/uncheck & disable/enable events */
        var addEvents = function(object) {
            var checked = object.checked;
            var disabled = object.disabled;
            var $object = $(object);

            if (object.stateInterval)
                clearInterval(object.stateInterval);

            object.stateInterval = setInterval(
				function() {
				    if (object.disabled != disabled)
				        $object.trigger((disabled = !!object.disabled) ? 'disable' : 'enable');
				    if (object.checked != checked)
				        $object.trigger((checked = !!object.checked) ? 'check' : 'uncheck');
				},
				10 /* in miliseconds. Low numbers this can decrease performance on slow computers, high will increase responce time */
			);
            return $object;
        }
        
        /* Wrapping all passed elements */
        return this.each(function() {
            var ch = this;
            var $ch = addEvents(ch); /* Adds custom eents and returns */

            if (ch.wrapper) {
                ch.wrapper.remove();
            }

            /* Creating div for checkbox and assigning "hover" event */
            ch.wrapper = $('<span class="' + settings.cls + '"><span class="mark"><img src="' + settings.empty + '" /></span></span>');
            ch.wrapperInner = ch.wrapper.children('span');
            ch.wrapper.hover(
				function() { ch.wrapperInner.addClass(settings.cls + '-hover'); },
				function() { ch.wrapperInner.removeClass(settings.cls + '-hover'); }
			);

            /* Wrapping checkbox */
            $ch.css({ position: 'absolute', zIndex: -1, visibility: 'hidden' }).after(ch.wrapper);

            /* Fixing IE6 label behaviour */
            var parents = $ch.parents('label');
            /* Creating "click" event handler for checkbox wrapper*/
            if (parents.length) {
                parents.click(function(e) { $ch.trigger('click', [e]); return ($.browser.msie && $.browser.version < 7); });
            }
            else {
                ch.wrapper.click(function(e) { $ch.trigger('click', [e]); });
            }

            delete parents;

            $ch.bind('disable', function() { ch.wrapperInner.addClass(settings.cls + '-disabled'); }).bind('enable', function() { ch.wrapperInner.removeClass(settings.cls + '-disabled'); });
            $ch.bind('check', function() { ch.wrapper.addClass(settings.cls + '-checked'); }).bind('uncheck', function() { ch.wrapper.removeClass(settings.cls + '-checked'); });

            /* Disable image drag-n-drop  */
            $('img', ch.wrapper).bind('dragstart', function() { return false; }).bind('mousedown', function() { return false; });

            /* Firefox div antiselection hack */
            if (window.getSelection)
                ch.wrapper.css('MozUserSelect', 'none');

            /* Applying checkbox state */
            if (ch.checked)
                ch.wrapper.addClass(settings.cls + '-checked');
            if (ch.disabled)
                ch.wrapperInner.addClass(settings.cls + '-disabled');
        });
    };
})(jQuery);