Scrollbar not visible in QML designer when maximizing window

When a scrollbar disappears when maximizing QtCreator the state view will not show all states within the current viewport.

1. Open a QML file
2. Maximize QtCreator
3. Switch to design mode
4. Add as many states as needed to fill up the state view, but stop before a scroll bar is needed
5. Now switch to non-maximized view
6. Notice that the state view has a scrollbar
7. Scroll the state view scroll bar completely to the right end
8. Maximize QtCreator again
9. Scollbar of state view disappears but the states keep not visible because they are still scrolled out of the view