After a long and busy weekend and two days off, I continued the last two days. Here is the current status.
The nodes don't attach correctly, but they attach, the GUI is starting to get some shape.
The nodes are being drawn and can be attached in the graph, though as you can see, the positioning is still off and I haven't yet figured out why. Also, if you do connect graphs, this new connection is not yet added to the backend representation of the flow-graph.
It can be noted, that I work iterative as you can see. I always keep a running version and and new features to this build. I refactor every now and then, but I guess I should do this more often. At the moment is function the main priority.
So far the application doesn't have any actions, during the weekend I will work on the implemenation of the "run"-button. Once this is done, you can start the app, it shows your hardcoded graph and on click you can make it work. I have some scribbles for the GUI, but I haven't spent much time on it yet.