Java tutorial
//package com.java2s; import java.awt.Component; import java.awt.Container; import java.awt.event.KeyListener; public class Main { public static void addKeyListener(Component p_c, KeyListener p_listener) { if (p_c != null) { p_c.addKeyListener(p_listener); Component[] cs = null; if (p_c instanceof Container) { cs = ((Container) p_c).getComponents(); } for (int i = 0; i < cs.length; i++) { addKeyListener(cs[i], p_listener); } } } }