!7

p {
  JDesktopPane desktop = jDesktopPane();
  final JTextField tfInput = jCenteredTextField();
  showFrame(northAndCenter(tfInput, desktop));
  installInternalFrameSwitcher_v3(desktop).shouldSwitch =
    func -> bool { isFocusedComponent(tfInput) };
  addInternalFrame(desktop, "Test", jTextArea());
  addInternalFrame(desktop, "Test 2", jTextArea());
  addInternalFrame(desktop, "Test 3", jTextArea());
}