/**
* A simple caps lock detection plugin for jQuery. Inspired by the "24 ways:
* Capturing Caps Lock" article by Stuart Landridge
* (http://24ways.org/2007/capturing-caps-lock).
*
* @author Michael J. I. Jackson <mjijackson@gmail.com>
* @copyright 2008 Michael J. I. Jackson
* @license http://www.opensource.org/licenses/mit-license.php
* @version 1.0.0
*/

/**
* Sets up a keypress listener on the selected elements that can be used to
* handle situations where the caps lock may be activated (for example, on a
* password field). The callback will be called in the scope of the current
* element with one parameter - a boolean indicating whether or not the caps
* lock is on.
*
* @param Function cb The callback function to call
* @return jQuery The jQuery object
* @public
*/
jQuery.fn.caps = function(cb){
    return this.keypress(function(e){
        var w = e.which ? e.which : (e.keyCode ? e.keyCode : -1);
        var s = e.shiftKey ? e.shiftKey : (e.modifiers ? !!(e.modifiers & 4) : false);
        var c = ((w >= 65 && w <= 90) && !s) || ((w >= 97 && w <= 122) && s);
        cb.call(this, c);
    });
};