/*
*
* Copyright (c) 2006-2010 Sam Collett (http://www.texotela.co.uk)
* Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
* and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
*
* Version 1.1.1
* Demo: http://www.texotela.co.uk/code/jquery/numeric/
*
*/
(function($) {
    /*
* Allows only valid characters to be entered into input boxes.
* Note: does not validate that the final text is a valid number
* (that could be done by another script, or server-side)
*
* @name numeric
* @param decimal Decimal separator (e.g. '.' or ',' - default is '.')
* @param callback A function that runs if the number is not valid (fires onblur)
* @author Sam Collett (http://www.texotela.co.uk)
* @example $(".numeric").numeric();
* @example $(".numeric").numeric(",");
* @example $(".numeric").numeric(null, callback);
*
*/
    $.fn.numeric = function(decimal, callback)
    {
        decimal = decimal || ".";
        callback = typeof callback == "function" ? callback : function(){};
        this.keypress(
            function(e)
            {
                var key = e.charCode ? e.charCode : e.keyCode ? e.keyCode : 0;
                // allow enter/return key (only when in an input box)
                if(key == 13 && this.nodeName.toLowerCase() == "input")
                {
                    return true;
                }
                else if(key == 13)
                {
                    return false;
                }
                var allow = false;
                // allow Ctrl+A
                if((e.ctrlKey && key == 97 /* firefox */) || (e.ctrlKey && key == 65) /* opera */) return true;
                // allow Ctrl+X (cut)
                if((e.ctrlKey && key == 120 /* firefox */) || (e.ctrlKey && key == 88) /* opera */) return true;
                // allow Ctrl+C (copy)
                if((e.ctrlKey && key == 99 /* firefox */) || (e.ctrlKey && key == 67) /* opera */) return true;
                // allow Ctrl+Z (undo)
                if((e.ctrlKey && key == 122 /* firefox */) || (e.ctrlKey && key == 90) /* opera */) return true;
                // allow or deny Ctrl+V (paste), Shift+Ins
                if((e.ctrlKey && key == 118 /* firefox */) || (e.ctrlKey && key == 86) /* opera */
                    || (e.shiftKey && key == 45)) return true;
                // if a number was not pressed
                if(key < 48 || key > 57)
                {
                    /* '-' only allowed at start */
                    if(key == 45 && this.value.length == 0) return true;
                    /* only one decimal separator allowed */
                    if(key == decimal.charCodeAt(0) && this.value.indexOf(decimal) != -1)
                    {
                        allow = false;
                    }
                    // check for other keys that have special purposes
                    if(
                        key != 8 /* backspace */ &&
                        key != 9 /* tab */ &&
                        key != 13 /* enter */ &&
                        key != 35 /* end */ &&
                        key != 36 /* home */ &&
                        key != 37 /* left */ &&
                        key != 39 /* right */ &&
                        key != 46 /* del */
                        )
                        {
                        allow = false;
                    }
                    else
                    {
                        // for detecting special keys (listed above)
                        // IE does not support 'charCode' and ignores them in keypress anyway
                        if(typeof e.charCode != "undefined")
                        {
                            // special keys have 'keyCode' and 'which' the same (e.g. backspace)
                            if(e.keyCode == e.which && e.which != 0)
                            {
                                allow = true;
                            }
                            // or keyCode != 0 and 'charCode'/'which' = 0
                            else if(e.keyCode != 0 && e.charCode == 0 && e.which == 0)
                            {
                                allow = true;
                            }
                        }
                    }
                    // if key pressed is the decimal and it is not already in the field
                    if(key == decimal.charCodeAt(0))
                    {
                        if(!this.containsDecimal)
                        {
                            allow = true;
                            this.containsDecimal = true;
                        }
                        else
                        {
                            allow = false;
                        }
                    }
                }
                else
                {
                    allow = true;
                }
                return allow;
            }
            )
        .blur(
            function()
            {
                var val = $(this).val();
                if(val != "")
                {
                    var re = new RegExp("^\\d+$|\\d*" + decimal + "\\d+");
                    if(!re.exec(val))
                    {
                        callback.apply(this);
                    }
                }
            }
            );
        return this;
    };

})(jQuery);