Global KeyListener in JFrame with JDK 1.4

Question

Hi!
I need to get some keyboard events in my JFrame or JDialog, no matter what subcomponent currently has the focus. I use this for example to display a help screen when the user hits F1.
In JDK 1.3 I wrote in my constructor:
this.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(KeyEvent e) {
this_keyPressed(e);
and then had a method
void this_keyPressed(KeyEvent e) { ... }
handling those events.
In JDK 1.4 this code only works, if I call this.requestFocus(), but since the user should be able to TAB through the frame and hit F1 in every textfield, button etc., this is no solution --- as soon as "this" loses the focus, it won't work any more.
I also tried using Key Bindings, but somehow I couldn't get it working.
I need a solution for this problem that works with 1.3 as well as with 1.4!! Do you have any ideas of how to do this?
Thanks for your help!!
Nicolas Michael <[email protected]>

Answer 1

looking at the source for Choice its not doing a great deal in add():
pItems is a vector, so I guess if there is anything that could be slow its the native call, but again this seems unlikely?
btw, if ur adding to the Choice box when its visible it will be a lot slower - is it possible to initialise before the applet is displayed?
asjf
ps. note the demo code above is adding numbers as strings, but I agree this shouldn't make any difference
//from java/awt/Choice.java (same from 1.2.1 to 1.4.1 - have not checked 1.1)
public void add(String item) {
   addItem(item);
public void addItem(String item) {
   synchronized (this) {
      addItemNoInvalidate(item);
   if (valid)
   invalidate();
private void addItemNoInvalidate(String item) {
   if (item == null) {
      throw new
      NullPointerException("cannot add null item to Choice");
   pItems.addElement(item);
   ChoicePeer peer = (ChoicePeer)this.peer;
   if (peer != null) {
      peer.addItem(item, pItems.size() - 1);
   if (selectedIndex < 0) {
      select(0);
}