Problem For/Each statement (or the problem is the MouseListener...)

Question

Hi guys,
I'm making a program in java for school.
Now I have this:
          for(Stap2TrampolineModel trampoline : lijstTrampolines)
               trampoline = new Stap2TrampolineModel(0,215,100,"Poing",lijstKinderen); //model
               trampolineView = new Stap2TrampolineView(trampoline); //view
               trampolineController = new Stap2TrampolineController(trampoline, trampolineView); //controller
               trampolineView.setBounds(trampoline.getXInvoer(),trampoline.getYInvoer(),trampoline.getFormaat()+1,20);
               add(trampolineView);
               repaint();
and in the mouselistener this:
public void mouseClicked( MouseEvent e )
          System.out.println(lijstTrampolines.size());
          // Onderzoek of met de rechterknop is geklikt
if( e.isMetaDown() )
     // x = e.getX(); (for later needs)
//y = e.getY(); (for later needs)
lijstTrampolines.add(trampoline);
repaint();
The program should display a "trampoline" when I click...but it doesnt. It is added to the list, because I can see that in the console because of the System.out.println
But it doesn't show the display I want. When I delete the for each statement, it does show the "trampoline". So the mouselistener works (it gets added when I click) and the arraylist works (it shows that in the console), but the for each statement doesnt work...
Anyone knows how to solve this problem?

Answer 1

Where is this foreach loop located? In inialisation presumably. But that's over and done with when your mouseListener is called. I'd guess your list is empty when the loop is called, and it does nothing.
Your mouse listener, when it adds a trampoline must also add a trampoline view object. And the repaints don't do you any good, use revalidate() after adding a trampoline view to recalculate the layout.