/* 
 * 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)
 * Dual licensed under the MIT (MIT-LICENSE.txt)
 * and GPL (GPL-LICENSE.txt) licenses.
 *
 *
 * 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
                });
                this.dummy.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*2 > 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*2 ) + 'px' }, 100);
                    }
                }
            }
        }

    });
})(jQuery);