Our second group container is called GroupLines and is used to position the child items into either 2 or 3 lines.
This new container is essential for copying the appearance you see in many of the tabs in Office 2007 applications. Below you can see the container used with a varying number of child button items. The left most group has just one item and each subsequent group to the right has one more child.
The group will automatically work out the best place to split the items onto the second line in order to minimize the total width. So the right most group above has been split after the first button so that the subsequent items are about the same width as the first item.
By default the group will show all items split over 2 lines/rows. For the future it can also split over 3 lines instead. This will be needed when there is not enough room in the tab to show everything and this group is asked to try and cramp up. This mimics the ability also seen in the Office 2007 apps.
Here you can see an example where the five buttons are split over 3 lines instead of the default 2.
