code: private JComponent createPanelWithDecoration()
      {
          StringBuffer columnLayout = new StringBuffer();
          if (this.leftDecoration != null)
              columnLayout.insert(0, "[]");
          columnLayout.append("[grow]");
          if (this.rightDecoration != null)
              columnLayout.append("[]");
  
          JPanel panel = new JPanel(new MigLayout("insets 0", columnLayout.toString(), "")) {
              public void requestFocus() {
                  NumberBinding.this.numberField.requestFocus();
              }
  
          };
          if (this.leftDecoration != null)
          {
              panel.add(new JLabel(this.leftDecoration));
          }
          panel.add(this.numberField, "grow");
          if (this.rightDecoration != null)
          {
              panel.add(new JLabel(this.rightDecoration));
          }
          return panel;
      }
docs: Create a panel with (possibly) decorations on both sides.
  
  TODO This leaves one problem: when validating and eg coloring/adding overlay the
  panel is used instead of the inputfield. There could be an interface that
  returns the correct component to be handled while validating.
  
  @return a decorated component which contains the inputfield.