volatile bool enabled = true;
transient JPanel buttons;

JComponent visualizeWithoutEnabled() { ret super.visualize(); }
  
JComponent dm_visualizeWithEnabled(JComponent main) {
  ret centerAndSouthWithMargins(main, makeControlArea());
}

JPanel makeControlArea() {
  ret buttons = jrightalignedline(makeEnabledCheckBox());
}

static JCheckBox makeEnabledCheckBox() {
  ret dm_fieldCheckBox('enabled);
}
  
void setEnabled(bool b) { setField(enabled := b); }

void addToControlArea(Component... components) {
  addComponentsFirst(buttons, components);
}