resizable panels

How do I go about creating resizeable panels like those within XOJO. For example, the controls panel (right hand side).
I can’t see anything in the controls that seem to do this.

Those resizable panels are usually referred to as “splitters” and there are a few older projects and plugins that offer the functionality… Search on here and the old REALbasic forum to find them… Or write one yourself as a good project…

I use the Einhugur Windows Splitter, works really well on Windows and the Mac and has a lot of functionality built in.

+1 for Einhugur’s Splitter.

Also, if you download some demo controls by Jeremie Leroy (, in the source you will find a great open source splitter. Before using Einhugur’s splitter, I used Jeremie’s!