With this example we are going to see how to use Keymap and KeyStroke classes in a Java. These classes are useful when you want to bind a certain key stroke with the default button of the window.
In order to work with Keymap and KeyStroke:
- Use
KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false)method to get the “Enter” key stroke. - Use
Keymap.removeKeyStrokeBindingto remove a stroke from the keymap. - Now you can go ahead an do
JFrame.getRootPane().setDefaultButton(defaultButton)to set the default button of the window. The default button will be now pressed when you hit the “Enter” button.
Let’s see the code snippet that follows:
package com.javacodegeeks.snippets.desktop;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.Keymap;
public class DefaultSample {
private static void showUI() {
JFrame jFrame = new JFrame("");
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container container = jFrame.getContentPane();
JTextField txt = new JTextField();
container.add(txt, BorderLayout.NORTH);
ActionListener actListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent event) {
System.out.println(event.getActionCommand() + " selected");
}
};
JPanel jPane = new JPanel();
JButton defaultButton = new JButton("Hit Enter");
defaultButton.addActionListener(actListener);
jPane.add(defaultButton);
JButton otherButton = new JButton("Onother Button");
otherButton.addActionListener(actListener);
jPane.add(otherButton);
container.add(jPane, BorderLayout.SOUTH);
Keymap map = txt.getKeymap();
KeyStroke stroke = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false);
map.removeKeyStrokeBinding(stroke);
jFrame.getRootPane().setDefaultButton(defaultButton);
jFrame.setSize(350, 250);
jFrame.setVisible(true);
}
public static void main(String args[]) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
showUI();
}
});
}
}
This was Keymap and KeyStroke example
