@Override
 protected void onExit() {
   formula =
       new CollisionFormula(
           textName.getText(),
           range.get(),
           function.get(),
           new CollisionConstraint(null, null, null, null));
 }
  @Override
  protected void createContent(Composite content) {
    final Composite composite = new Composite(content, SWT.NONE);
    composite.setLayout(new GridLayout(1, true));
    composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, false));

    textName = UtilSwt.createText(Messages.Dialog_TileCollision_Name, composite);
    textName.setText(DEFAULT_NAME);

    range.create(composite);
    function.create(composite);
  }
  /**
   * Load an existing formula and fill fields.
   *
   * @param formula The formula to load.
   */
  public void load(CollisionFormula formula) {
    textName.setText(formula.getName());

    range.load(formula.getRange());
    function.load(formula.getFunction());
  }