When you try to connect an objects output with it's own input the simulation stops (doesn't make much sence to connect the objects this way but that causes exceptions).

@ Gevater_Tod4711: Yes you are right, I am trying to fix that. @Jet_Lennit: Maybe your cables aren't updated. That happens if you connect an activated switch with a gate. I will fix that, but that's the only way I am able to explain your message. For me it works fine.

I am not quite sure exactly what I did. I possibly had clicked on the same node twice. I think the main problem stems from the fact that you are using the mouse click function on the nodes to perform two different actions (changing its state and selecting it for possible connection). If you allowed dragging for creating the connections, it could also be used to easily change the node either end of the connector is hooked to (or to remove the connection altogether by not re-connecting to a node); and it would not interfere with the changing of the state of the nodes using mouse clicks.

Using the dragging also puts a definite limit on when a connection is being attempted (what I mean is that there will be a point in time when the attempt is started -- when dragging is detected, and a point in time when the attempt is completed -- when dragEnded). Another plus is you do not have to store the first node clicked on in a field in the world when using the dragging method.

I need help in everything, except calculating the DMF (I don´t have to make it), is possible that can you send me this project for use like a guide?

Do you have experience with greenfoot? If not you should first read the API (not everything, just the important things) and try it out, so that you get a feeling for it. If you know how the circuits work you can program the logics so far, but for the GUI, I will help you. I don't want to give the whole project away, but I can give you some of it, so that you know how it works.

OK, please help me with something, I´m lost in this project, according to my teacher, I need to use binary trees and I never have worked with them, any help is great for me.

I didn't used binary trees here, but I programmed a simple version of them last year in school with BlueJ. I can send you the class if you want (when I can find it). I can send you the code of some classes like the gates, too. It would be the best if you open a discussion like "Binary trees and Combinatorial curcuits", so that more users will help and code is better to see. I could explain you, how connecting the gates and all the stuff here works.

Yes, I know it from school. Thanks for the german link :) . But I don't simulate electricity here, I have only a boolean (on = true or false). Therefore I asked.

Really awesome. Do you mind giving me your email address so that i can ask you a few questions? You can share it via danpost's private messaging.