/* 

* Auto Expanding Text Area (1.2.2)

* by Chrys Bader (www.chrysbader.com)

* chrysb@gmail.com

*

* Special thanks to:

* Jake Chapa - jake@hybridstudio.com

* John Resig - jeresig@gmail.com

*

* Copyright (c) 2008 Chrys Bader (www.chrysbader.com)

* Licensed under the GPL (GPL-LICENSE.txt) license. 

*

*

* NOTE: This script requires jQuery to work.  Download jQuery at www.jquery.com

*

*/



(function(jQuery) {



    var self = null;



    jQuery.fn.autogrow = function(o) {

        return this.each(function() {

            new jQuery.autogrow(this, o);

        });

    };





    /**

     * The autogrow object.

     *

     * @constructor

     * @name jQuery.autogrow

     * @param Object e The textarea to create the autogrow for.

     * @param Hash o A set of key/value pairs to set as configuration properties.

     * @cat Plugins/autogrow

     */



    jQuery.autogrow = function(e, o) {

        this.options = o || {};

        this.dummy = null;

        this.interval = null;

        this.line_height = this.options.lineHeight || parseInt(jQuery(e).css('line-height'));

        this.min_height = this.options.minHeight || parseInt(jQuery(e).css('min-height'));

        this.max_height = this.options.maxHeight || parseInt(jQuery(e).css('max-height')); ;

        this.textarea = jQuery(e);



        if (this.line_height == NaN)

            this.line_height = 0;



        // Only one textarea activated at a time, the one being used

        this.init();

    };



    jQuery.autogrow.fn = jQuery.autogrow.prototype = {

        autogrow: '1.2.2'

    };



    jQuery.autogrow.fn.extend = jQuery.autogrow.extend = jQuery.extend;



    jQuery.autogrow.fn.extend({



        init: function() {

            var self = this;

            this.textarea.css({ overflow: 'hidden', display: 'block' });

            this.textarea.bind('focus', function() { self.startExpand() }).bind('blur', function() { self.stopExpand() });

            this.checkExpand();

        },



        startExpand: function() {

            var self = this;

            this.interval = window.setInterval(function() { self.checkExpand() }, 400);

        },



        stopExpand: function() {

            clearInterval(this.interval);

        },



        checkExpand: function() {



            if (this.dummy == null) {

                this.dummy = jQuery('<div></div>');

                this.dummy.css({

                    'font-size': this.textarea.css('font-size'),

                    'font-family': this.textarea.css('font-family'),

                    'width': this.textarea.css('width'),

                    'padding': this.textarea.css('padding'),

                    'line-height': this.line_height + 'px',

                    'overflow-x': 'hidden',

                    'position': 'absolute',

                    'top': 0,

                    'left': -9999

                }).appendTo('body');

            }



            // Strip HTML tags

            var html = this.textarea.val().replace(/(<|>)/g, '');



            // IE is different, as per usual

            if ($.browser.msie) {

                html = html.replace(/\n/g, '<BR>new');

            }

            else {

                html = html.replace(/\n/g, '<br>new');

            }



            if (this.dummy.html() != html) {

                this.dummy.html(html);



                if (this.max_height > 0 && (this.dummy.height() + this.line_height > this.max_height)) {

                    this.textarea.css('overflow-y', 'auto');

                }

                else {

                    this.textarea.css('overflow-y', 'hidden');

                    if (this.textarea.height() < this.dummy.height() + this.line_height || (this.dummy.height() < this.textarea.height())) {

                        this.textarea.animate({ height: (this.dummy.height() + this.line_height) + 'px' }, 100);

                    }

                }

            }

        }



    });

})(jQuery);