java documentlistener

Question

I'm trying to call method after changing text of JTextField.

textField.getDocument().addDocumentListener(new DocumentListener()
        {

            public void changedUpdate(DocumentEvent arg0) 
            {
                System.out.println("IT WORKS");
                panel.setPrice(panel.countTotalPrice(TabPanel.this));
            }
            public void insertUpdate(DocumentEvent arg0) 
            {

            }

            public void removeUpdate(DocumentEvent arg0) 
            {

            }
        });

When I call this method at another ActionListener, it works ok. But when I change text in text field, nothing happens. Even println. Any suggestions?

Geanticline

Are you trying to change the value in the textField? If so, you can't because document listeners can't change the value in the text field they're assigned to. – Melloney

Answer 1

The problem solved. changedUpdated method called only when other atributes (font, size, but not text) changed. To call method after every change of text, I should put the call into insertUpdate and removeUpdate methods. This way:

textField.getDocument().addDocumentListener(new DocumentListener()
        {

            public void changedUpdate(DocumentEvent arg0) 
            {

            }
            public void insertUpdate(DocumentEvent arg0) 
            {
                System.out.println("IT WORKS");
                panel.setPrice(panel.countTotalPrice(TabPanel.this));
            }

            public void removeUpdate(DocumentEvent arg0) 
            {
                System.out.println("IT WORKS");
                panel.setPrice(panel.countTotalPrice(TabPanel.this));
            }
        });

Geanticline

Answer 2

Try using an ActionListener:

textField.addActionListener(this);

...
public void actionPerformed(ActionEvent evt) {
   String s = textField.getText();
   System.out.println(s);
   ...
}

Spitball

Answer 3

I found this solution the fastest:

new JTextPane().addActionListener(new Key());

---

class Key extends KeyAdapter{
private static final Object lock = new Object();
        private static int keydiff=0;
        public void keyReleased(KeyEvent e) {
            switch(e.getKeyCode())
            {
                //IGNORE FUNCTIONAL KEYS
                case 38 :
                case 39 :
                case 37 :
                case 40 :
                case 17 :
                case 157 :
                case 10 : break;
                default : keydiff++;
            }

            if(keydiff!=0)
            {
              synchronized(lock){
                  keydiff=0;
                  //EVENT FIRED HERE
              }             
            }
        }
    }

It's much faster than:

.getDocument().addDocumentListener( .... changeUpdate())

Cheshvan

This is a bit dubious. What if you later make it possible to change the field contents without the keyboard? (eg. a "reset field" button or undo.) What about copy-and-paste? It's safer to use the proper method. – Comedic

Answer 4

Here is another solution to your problem. Instead of having to repeat the same code under each method, you could create a method and call that method for changedUpdate, insertUpdate, removeUpdate.

textField.getDocument().addDocumentListener(new DocumentListener()
    {

        public void changedUpdate(DocumentEvent arg0) 
        {
            printMyLines();
        }
        public void insertUpdate(DocumentEvent arg0) 
        {
            printMyLines();
        }

        public void removeUpdate(DocumentEvent arg0) 
        {
            printMyLines();
        }

        private void printMyLines()
        {
            System.out.println("IT WORKS");
            panel.setPrice(panel.countTotalPrice(TabPanel.this));
        }
    });

Rollicking