/*!
* jQuery transpose() plugin
*
* Version 1.2 (2 Aug 2011)
*
* Copyright (c) 2011 Robert Koritnik
* Licensed under the terms of the MIT license
* http://www.opensource.org/licenses/mit-license.php
*/

(function($) {

var keys = {
containerKey: "transposed",
itemKey: "pre-transpose-index"
};

$.fn.extend({

transpose: function() {
/// <summary>Transposes a set of floated elements so that they run in columns rather than rows.</summary>
/// <return type="jQuery">Returns the same jQuery set that this function was run on.</return>

// only transpose when there're enough items
if (this.length > 2)
{
var originalSet = this;
var containers = this.parent();

// transposition must be applied per container
containers.each(function() {

var dom = this;
var container = $(this);
if (typeof(container.data(keys.containerKey)) == "undefined")
{
container.data(keys.containerKey, true);
var items = originalSet.filter(function() {
return this.parentNode == dom;
});
var itemCount = items.length;
var newOrder;

// only transpose when there're enough items
if (itemCount > 2)
{
// calculate number of columns and rows
var cols;
var firstTop = items.eq(0).position().top;
for (cols = 1; cols < itemCount && firstTop == items.eq(cols).position().top; cols++);

var rows = parseInt(itemCount / cols) + 1;

// only apply transposition when there's enough items (more than one column and more than one row)
if (itemCount > cols && cols > 1)
{
var columnHeight = [];
for (var i = 0; i < cols; i++) columnHeight.push(rows - (i % cols < itemCount % cols ? 0 : 1));

newOrder = $();
var index = 0;
for (var i = 0; i < itemCount; i++)
{
newOrder = newOrder.add(items.eq(index).detach().data(keys.itemKey, index));
index += columnHeight[i % cols];
if (index >= itemCount) index++;
index = index % itemCount;
}

// add non-HTML line break after each element to preserve inline elements' spacing
newOrder.appendTo(container).after("\n");
}
}
}
});
}

return this;
}
});
})(jQuery);