The Java Developers Almanac 1.4

Home > List of Packages > javax.swing.text [49 examples] > Actions and Key Bindings [5 examples]

e1004. Overriding Many Default Typed Key Bindings in a JTextComponent

See e1003 Overriding a Few Default Typed Key Bindings in a JTextComponent for information about default typed key bindings in a text component.

There are two ways to override the default key bindings in a text component. This example demonstrates a technique when many characters need to be overridden. This example converts all lowercase characters to uppercase. See e1004 Overriding Many Default Typed Key Bindings in a JTextComponent for a technique suitable for overriding a few characters.

    JTextField component = new JTextField();
    component.addKeyListener(new MyKeyListener());
    
    public class MyKeyListener extends KeyAdapter {
        public void keyTyped(KeyEvent evt) {
            JTextComponent c = (JTextComponent)evt.getSource();
            char ch = evt.getKeyChar();
    
            if (Character.isLowerCase(ch)) {
                try {
                    c.getDocument().insertString(
                        c.getCaretPosition(), ""+Character.toUpperCase(ch), null);
                    evt.consume();
                } catch (BadLocationException e) {
                }
            }
        }
    }