KeyListeners: Automatic Focus?

Quote:

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Originally Posted by Norm

Before when?
Are you looking at my post #22?

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I think I got it working. I put a keyListener on the mainFrame to the class ListenForKeys and method keyTyped(KeyEven ke)

It looks like this (and yes I know this is repetitive but it was an easy solution):

Code :

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  class ListenForKeys extends KeyAdapter {
    public void keyTyped(KeyEvent ke) {
      char keyChar = ke.getKeyChar();
      String key = Character.toString(keyChar);
      if(key.equals("0")) {
        JButton b = mainButtonList.get(9);
        b.doClick();
      } else if(key.equals("1")) {
        JButton b = mainButtonList.get(6);
        b.doClick();
      } else if(key.equals("2")) {
        JButton b = mainButtonList.get(7);
        b.doClick();
      } else if(key.equals("3")) {
        JButton b = mainButtonList.get(8);
        b.doClick();
      } else if(key.equals("4")) {
        JButton b = mainButtonList.get(3);
        b.doClick();
      } else if(key.equals("5")) {
        JButton b = mainButtonList.get(4);
        b.doClick();
      } else if(key.equals("6")) {
        JButton b = mainButtonList.get(5);
        b.doClick();
      } else if(key.equals("7")) {
        JButton b = mainButtonList.get(0);
        b.doClick();
      } else if(key.equals("8")) {
        JButton b = mainButtonList.get(1);
        b.doClick();
      } else if(key.equals("9")) {
        JButton b = mainButtonList.get(2);
        b.doClick();
      } else if(key.equals("+")) {
        JButton b = operators.get(0);
        b.doClick();
      } else if(key.equals("-")) {
        JButton b = operators.get(1);
        b.doClick();
      } else if(key.equals("x")||key.equals("*")) {
        JButton b = operators.get(2);
        b.doClick();
      } else if(key.equals("/")) {
        JButton b = operators.get(3);
        b.doClick();
      }
      System.out.println(key);
    }
  }

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One problem though... how do I register a keyStroke for the ENTER key? The VK_ENTER key code doesn't seem to work... it just keeps adding line breaks in the console.

With repeating code like you have, there must be a way to put all that in an array or a HashMap.

Quote:

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Originally Posted by Norm

With repeating code like you have, there must be a way to put all that in an array or a HashMap.

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If you have a suggestion please let me know. I haven't learned about HashMaps so I... well honestly have no clue what they are.

I'm not sure how I would put all those conditional statements in an array. Again, if you have a suggestion, I would love to hear it. I write too much repetitive code. You would be helping me quite a bit.

Give HashMaps a key and they return a value associated with that key.

Code :

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  ...
} else if(key.equals("3")) {
        JButton b = mainButtonList.get(8);
 ...

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vs

Code :

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  JButton b = theHashMap.get(key);  // get the Button associated with the key

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You load the HashMap by associating the button with the key.

Quote:

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Originally Posted by Norm

Give HashMaps a key and they return a value associated with that key.

Code :

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  ...
} else if(key.equals("3")) {
        JButton b = mainButtonList.get(8);
 ...

---

vs

Code :

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  JButton b = theHashMap.get(key);  // get the Button associated with the key

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You load the HashMap by associating the button with the key.

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What does that replace in this code to make it more efficient?

And by the way, do you know how to get the program to register a key event for the ENTER key? I can't get it to respond... it just adds line breaks in the console.

keyCode VK_ENTER doesn't work either. Unless I did it wrong.

Quote:

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What does that replace in this code to make it more efficient?

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Post #26 has over 26 if/else if and assignment statements.
You can replace ALL of them with the one statement in post #29
However you have to load the HashMap so its not that much less code.

This worked for me:

Code :

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    addKeyAccelerator(buttonPanel, dbc, "action2", KeyEvent.VK_ENTER, 0);

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Quote:

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Originally Posted by Norm

Post #26 has over 26 if/else if and assignment statements.
You can replace ALL of them with the one statement in post #29
However you have to load the HashMap so its not that much less code.

This worked for me:

Code :

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    addKeyAccelerator(buttonPanel, dbc, "action2", KeyEvent.VK_ENTER, 0);

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I'm not very familiar with HashMaps so I guess I will just stick with the current code structure in #26.

I'm using KeyListeners in the main JFrame. I either need a character or keyCode for the ENTER key but the keyCode didn't appear to work.

EDIT: Just noticed the API states that the keyCode method call returns VK_UNDEFINED for keyTyped events. There's my problem! I guess I will just make a keyReleased event response for the ENTER key.

I use if/else statements A LOT in Java programming. If you have a better/more advanced way of doing things, PLEASE tell me. You will make my life so much easier.