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keylistener not working after clicking button

I have a keylistener attached to my frame in java, i can detect key presses when I hit any key, a strange thing is happening however. My game is a minesweeper game, I have a restart button that basically clears the board and remines it. The weird thing is when I click the button with the mouse everything clears fine and the board is remined but the keylistener stops working. Even stranger I have a jmenuitem that basically does a automated click of the button. So its like restartbutton.doclick()

if i click the jmenuitem to restart it restarts fine clears everything and the keylistener still functions. I can even see the button being clicked. Any ideas why this could be happening?

Thanks

this is attached to my main frame. this is the listener that stops working after clicking the button.

frame.addKeyListener(new KeyListener(){


       public void keyReleased(KeyEvent e){


       }

       public void keyPressed(KeyEvent e){

       System.out.println("hey");
       int keycode = e.getKeyCode();

       if(e.isControlDown() & keycode==KeyEvent.VK_C){

      balh blah balh
       }

       }

       public void keyTyped(KeyEvent e){


       }

       });
like image 540
user541597 Avatar asked Nov 10 '11 02:11

user541597


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How do I use KeyListener?

A Simple KeyListener Java Class Create a new KeyListener object. Override the methods that correspond to the key events you want to monitor e.g keyPressed , keyReleased , keyTyped . Create a JTextField component. Use it's addKeyListener method to add to it the KeyListener you've created.

What is the difference between keyTyped and keyPressed?

keyPressed is fired whenever any key press occurs. keyTyped is fired when a key is pressed that can be converted into a unicode character.

What is KeyListener in Java?

The listener interface for receiving keyboard events (keystrokes). The class that is interested in processing a keyboard event either implements this interface (and all the methods it contains) or extends the abstract KeyAdapter class (overriding only the methods of interest).


2 Answers

Suggestions:

  • Yours is a focus issue, where the KeyListener stops working because the container it is listening to has lost focus to the JButton.
  • One solution is to make the JButton not able to gain focus by calling setFocusable(false) on it.
  • But I recommend that you don't use a KeyListener at all if possible, but rather key bindings, since with bindings you don't have this issue and also it is a higher level construct.

Edit
Regarding:

what would be the best way to change that to a key binding?

Best would be to go through the Key Bindings tutorial and to implement the recommendations found there.

like image 126
Hovercraft Full Of Eels Avatar answered Sep 26 '22 06:09

Hovercraft Full Of Eels


this is focus problem, you can use this code to give focus again

getTopLevelAncestor().requestFocus();

like image 21
Emre Yardımcı Avatar answered Sep 25 '22 06:09

Emre Yardımcı