KeyListener receives the "key-hit" before my JTextField does..?

Question

Hi. I got a JTextField, and to that field I have added a Keylistener. Inside the keyPressed method, I ask the method to print (System.out.println) whats inside the JTextField.. If I hit a letter, it seems as the Keylistener receives this key-hit before the JTextField is updated.. I have to hit two letters to see the first one..

All I need to do is to make every letter upper-case as they are inputted.. This I am trying to do by listening to every key (I also listen to the ENTER key for other reasons) and then do a textfield.setText(textfield.getText().toUpperCase());

Answer 1

Use a DocumentFilter to alter the text as it comes in.

Not the prettiest source and it's not 100% correct, just showing how it works. See the original here

((AbstractDocument)textField.getDocument()).setDocumentFilter(new UppercaseDocumentFilter());

  class UppercaseDocumentFilter extends DocumentFilter {
        public void insertString(DocumentFilter.FilterBypass fb, int offset,
                                 String text, AttributeSet attr)
                throws BadLocationException {

            fb.insertString(offset, text.toUpperCase(), attr);
        }

        public void replace(DocumentFilter.FilterBypass fb, int offset, int length,
                            String text, AttributeSet attrs)
                throws BadLocationException {

            fb.replace(offset, length, text.toUpperCase(), attrs);
        }
    }

Answer 2

Try using the underlying document:

textfield.getDocument().addDocumentListener(yourListener);

Answer 3

I know its not so popular to answer your own question.. but I guess I found the solution.. Instead of doing all the upper-casing in the keyPressed method, I do it in the keyReleased :)