In the following program, why does hitting the a key print "hello, world" while hitting CTRL+a doesn't?
import java.awt.event.*;
import javax.swing.*;
public class KeyStrokeTest {
public static void main(String[] args) {
JPanel panel = new JPanel();
/* add a new action named "foo" to the panel's action map */
panel.getActionMap().put("foo", new AbstractAction() {
public void actionPerformed(ActionEvent e) {
System.out.println("hello, world");
}
});
/* connect two keystrokes with the newly created "foo" action:
- a
- CTRL-a
*/
InputMap inputMap = panel.getInputMap();
inputMap.put(KeyStroke.getKeyStroke(Character.valueOf('a'), 0), "foo");
inputMap.put(KeyStroke.getKeyStroke(Character.valueOf('a'), InputEvent.CTRL_DOWN_MASK), "foo");
/* display the panel in a frame */
JFrame frame = new JFrame();
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.setVisible(true);
}
}
How could I fix it that CTRL+a works as well?
I find it easier to use:
KeyStroke a = KeyStroke.getKeyStroke("A");
KeyStroke controlA = KeyStroke.getKeyStroke("control A");
or:
KeyStroke controlA = KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK);