Simple Tristate Checkbox

jquery-simple-tristate.js

/*!
* Edited By Daniel Teixeira
*
* Tri-State checkbox
*
* Copyright 2011, http://webworld-develop.blogspot.com/
* Artistic License 2.0
* http://www.opensource.org/licenses/artistic-license-2.0
*
* Date: Fr Apr 22 08:00:00 2011 -0200
**/

(function ($) {
    var settings = { classes: { checkbox: "customcheck", checked: "customcheckfull", partial: "customcheckpartial", unchecked: "customchecknone"} };

    var methods =
    {
        init: function (options) {
            return this.each(function () {
                if (options) { $.extend(settings, options); }

                var main = $(this).hide();
                var ch = settings.classes.checked;
                var part = settings.classes.partial;
                var unch = settings.classes.unchecked;
                var start = unch;

                if (main.is(":checked")) {
                    start = ch;
                }

                var $this = $("<span class='" + settings.classes.checkbox + " " + start + "'></span>").insertBefore(main);

                $this.click(function () {
                    if ($this.hasClass(ch)) {
                        $this.removeClass(ch).addClass(part);
                        main.attr("checked", "maybe");
                    }
                    else if ($this.hasClass(part)) {
                        $this.removeClass(part).addClass(unch);
                        main.attr("checked", false);
                    }
                    else if ($this.hasClass(unch)) {
                        $this.removeClass(unch).addClass(ch);
                        main.attr("checked", false);
                    }
                });
            });
        }
    };

    $.fn.tristate = function (method) {
        if (methods[method]) {
            return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
        }
        else if (typeof method === 'object' || !method) {
            return methods.init.apply(this, arguments);
        }
    }
})(jQuery);