Had a seemingly rare requirement for an accordion that the designer could specify which sections were open and closed by default -- requires the accordion to calculate height of several elements rather than just, for example, a heading

smoothAccordion.js

/**
 * @file
 *
 * 
 *
 */

(function ($) {
	
	Drupal.behaviors.listen_to_open = function (item) {
		item.find('.accordion-trigger a').click(
			function () {
				var closedOpen = false;
				// if this one is open, just close it
				if (item.hasClass('accordion-open')) {
					Drupal.behaviors.smoothAccordionCloseItems();
				} else {
					// close all others, then open this one
					Drupal.behaviors.smoothAccordionCloseItems();
					Drupal.behaviors.smoothAccordionOpenItems(item);
				}
				
				return false;
			}
		)
	}

	Drupal.behaviors.smoothAccordionCloseItems = function () {
		$('.accordion-open').each(
			function () {
				$this = $(this);
				$this.animate({
					height: $this.attr('data-close-height'),
				})
				.removeClass('accordion-open').addClass('accordion-closed');
			}
		)
	}

	Drupal.behaviors.smoothAccordionOpenItems = function (item) {
		if (item == undefined) {
			// @todo open all
			//$('.multi-image-wrapper, .accordion-item-body');
		}
		else {
			Drupal.behaviors.smoothAccordionAnimateOpen(item);
		}
		
	}

	Drupal.behaviors.smoothAccordionAnimateOpen = function(items) {
		// loop through each and open
        var bodyHeight;
        var targetHeight;
		for (var i = 0; i < items.length; i++) {
			$item = $(items[i]);
			$item.animate({
				height: $item.attr('data-open-height')
			}).removeClass('accordion-closed').addClass('accordion-open');
		}
	}

	Drupal.behaviors.smoothAccordionAddDataHeight = function (accordions) {
		// for each accordion, get the aggregate height of all elements
		// that should not be closed and store them for use later
		
		// meh. check for product showcase
		//  @todo clean up
		$ps = $('.product-showcase-accordion');
		$pro = $('.promotions-accordion');
		
		var $this;
		accordions.each(
			function() {
				$this = $(this);

				if ($ps.length > 0 || $pro.length > 0) {
					var bodyHeight = $this.find('.product-showcase-copy-container').height();
				} else {
					var bodyHeight = $this.height();
				}
				var imgHeight = $this.find('img:first').height()*1.25;
				var closedHeight = 0;
				//var openHeight = $this.height() + $this.find('img:first').height()*1.25;
				var openHeight = bodyHeight > imgHeight ? bodyHeight : imgHeight;

				$this.find('.accordion-no-close').each(
					function () {
						closedHeight += $(this).height();
						console.log(closedHeight);
						if($ps.length > 0) {
							closedHeight += 15;
						}
						if( $pro.length > 0) {
							closedHeight += 5;
						}
					}
				)
				$this.attr('data-close-height', closedHeight).attr('data-open-height', openHeight);
			}
		)
		// with all set, close the accordions
		accordions.addClass('accordion-open');
		Drupal.behaviors.smoothAccordionCloseItems();
	}
	
	Drupal.behaviors.smoothAccordion = {
		attach: function (context, settings) {
			// close everything
			var $accordions = $('.accordion-group');
			$(window).load(function() {
				Drupal.behaviors.smoothAccordionAddDataHeight($accordions);
				$accordions.each(
					function() {
						Drupal.behaviors.listen_to_open($(this));
					}
				)
			})

		}
	}
}(jQuery));