panelSolutionText.add(this.jtextSolution, BorderLayout.CENTER);
final JScrollPane scrollSolutionText = new JScrollPane(this.jtextSolution, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
scrollSolutionText.setPreferredSize(new Dimension(10, 10)); //workaround for layout problem ?!?!
scrollSolutionText.setMinimumSize(new Dimension(10, 10)); //workaround for layout problem ?!?!
final RowGroup playSolutionGroup = new RowGroup();
final JCheckBox groupBox = new JCheckBox("show computed solutions");
groupBox.addItemListener(new ShowHideAction(playSolutionGroup));
final JPanel playPanel = new JPanel();
final DesignGridLayout playLayout = new DesignGridLayout(playPanel);