!7

p-substance {
  JFrame f1 = showFrame("Frame 1");
  JFrame f2 = moveToTopRightCorner(showFrame("Frame 2"));
  coActivate(f1, f2);
  //coActivate(f2, f1);
}

sclass Coactivator {
  long lastTime;
  int timeout = 100; // prohibit endless loop
  
  *(JFrame f1, final JFrame f2) {
    link(f1, f2, "zoom");
    link(f2, f1, "boom.");
  }
  
  void link(JFrame f1, final JFrame f2, fS text) {
    f1.addWindowListener(new WindowAdapter {
      public void windowActivated(WindowEvent e) {
        if (sysNow() >= lastTime+timeout) {
          lastTime = sysNow();
          print(text);
          f2.toFront();
        }
      }
    });
  }
}

svoid coActivate(JFrame f1, final JFrame f2) {
  new Coactivator(f1, f2);
}