Another day of work on the project. My major attention is at the algorithms, that check the workflow. It's still work in progress, but I don't have to pay attention to the order in which the units are listed. It's checked and sorted automatically.
I also did some work on the connections. Reconnecting nodes automatically creates new connections and deletes the old ones.
I added some simple FileDropper to the GPanel, so I can Drag'n drop image files and it creates a suited source unit. Obviously I develop on Mac, so these things look always nice while being handy.
Work will continue the next 4 days.
Here is the current GUI: