Is there a way to get keyboard events without JFrame?

Question

I want to get my program to unhide main window when user presses some shortcut. Is there a way to get the global key events, not only the ones which happened when focus was inside application frame?

score 4 · Accepted Answer · answered Jan 05 '11 at 21:07

4

This might do what you want. Note that this code is checking for a Ctr-F keystroke. I use this code to open up a find dialog from anything in the application. I'm pretty sure that the app has to have focus though. Something to try at least...

AWTEventListener listener = new AWTEventListener() {
  @Override
  public void eventDispatched(AWTEvent event) {
    try {
      KeyEvent evt = (KeyEvent)event;
      if(evt.getID() == KeyEvent.KEY_PRESSED && evt.getModifiers() == KeyEvent.CTRL_MASK && evt.getKeyCode() == KeyEvent.VK_F) {

      }
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
};

            Toolkit.getDefaultToolkit().addAWTEventListener(listener, AWTEvent.KEY_EVENT_MASK);

EDIT: I think I understand what you want. Basically when the app does NOT have focus. If so then you'll probably have to hook into the OS events with a native API (JNI) but that forces you to a specific OS...

answered Jan 05 '11 at 21:07

Merky

494
2
4

Sad. I hoped there will be some platform-independent way :( – Rogach Jan 05 '11 at 21:20
Make sure to check the link that altanis provided below. That has a little discussion about (possibly) why it is not in Java. Something about maybe OSX does not have that. I have not done enough OSX programming to know if that is true or false though... – Merky Jan 05 '11 at 21:29
This is what I call "slipshod" answer. This code is **useless** as it is. You must implement it with the appropriate import(s) and use of this kbd listener! In short, a fully workable code! Moreover, I don't think that it workds w/o using a Jframe or other kind of frame. This is definitely a "downvote" case, however, I never do it. I prefer commenting on it. – Apostolos Feb 04 '22 at 11:06

score 4 · Answer 2 · edited May 23 '17 at 12:08

4

This might be useful. I'm not sure if there is one library that will work for Windows/Linux/Mac. For Windows you will need some external library that uses native code to create a keyboard hook. I have no idea how to do it on the other OSes.

edited May 23 '17 at 12:08

Community

1
1

answered Jan 05 '11 at 21:15

Sebastian Łaskawiec

2,667
15
33

score -3 · Answer 3 · answered Aug 04 '19 at 16:43

-3

A solution to do this by using a JFrame is to set his opacity to 0.0 and to add the Keylistener to it. But the user will see an icon in his shortcut bar...

answered Aug 04 '19 at 16:43

Sama Rive

26
1

This method will not allow the user to interact with windows behind the JFrame. And the JFrame would still have to be in focus. – Coding Mason Feb 24 '21 at 05:33

Is there a way to get keyboard events without JFrame?

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