Resizing

Like the Invisible Bean area at the bottom of the Bean hierarchy, the Class Structure View can be resized or even removed completely.
There are two icons on the far right of the toolbar:
Show the method editors only - this will make the Class Structure View disappear and your hierarchy use its space

Show both method editors and class view - this will return the Class Structure View and resize your view of your hierarchy accordingly

Normally there is a border separating your hierarchy and the class structure view. By clicking on this bar, and dragging the mouse, you can resize the area allocated to each.