[ACCEPTED]-How can I listen for key presses (within Java Swing) across all components?-keylistener

Accepted answer
Score: 64

It is possible.

  .addKeyEventDispatcher(new KeyEventDispatcher() {
      public boolean dispatchKeyEvent(KeyEvent e) {
        System.out.println("Got key event!");
        return false;

That will grab all key events. Returning 8 false allows the keyboard focus manager 7 to resume normal key event dispatching to 6 the various components.

If you want to 5 catch key combos, you can keep a set of 4 "pressed keys." Whenever a key is pressed, add 3 it to the set and check what keys are already 2 in the set. When a key is released, remove 1 it from the set.

Score: 0

I don't think there is a way to add a "global" key 6 listener like you are wanting to do. This 5 forum post with a similar question backs me up. You 4 are just going to have to add them to each 3 component. This should only need to be done 2 once though, so I guess you can just get 1 it over with and move on.

Score: 0

Very simple my friend: All you have to 6 do is create a class KeyEventDispatcher 5 and register to KeyboardFocusManager C.1

Then 4 parse and extract state and key info see: C.2 Strangely 3 enough though, you have to get the KEY STATE 2 via ThatEvent.getID();


///////////////////////////////////////////////////////////////////////////////////////////   C.1)
         KeyDispatcher        ThisKeyDispatcher  = new KeyDispatcher();

         KeyboardFocusManager ThisKbFocusMngr = KeyboardFocusManager 
                                              . getCurrentKeyboardFocusManager();

         ThisKbFocusMngr                      . addKeyEventDispatcher(ThisKeyDispatcher);
         return ThisKeyDispatcher;

public static class KeyDispatcher implements KeyEventDispatcher {

  public boolean dispatchKeyEvent(final KeyEvent ThatEvent) {

     KeyboardFocusManager ThisKbFocusMngr    = null;
     Component            ThisComponent      = null;
     Container            ThisRoot           = null;
     Window               ThisWindow         = null;
     int                  ThisKeyStateEvent  = 0;

     try {
        ThisKbFocusMngr       = KeyboardFocusManager  . getCurrentKeyboardFocusManager();
        ThisComponent         = ThisKbFocusMngr       . getFocusOwner();
        ThisRoot              = ThisKbFocusMngr       . getCurrentFocusCycleRoot();
        ThisWindow            = ThisKbFocusMngr       . getActiveWindow();
        ThisKeyStateEvent     = ThatEvent.getID();   // i.e.  KeyEvent.KEY_RELEASED

        if(false                           == ThatEvent.isConsumed()) {
           boolean       RetBool          = false;
           if((KeyEvent.VK_BACK           == ThatEvent.getKeyCode())) {
              RetBool                      = true;
           } else {
              RetBool                      = m_CallSomeoneEvent(ThatEvent);
           if(RetBool) {
              return true;
     catch( Throwable e ) {
        LogThis(". ", e);
     return false;

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