how to make cursor can enter jtextfield but the only way to give it a text is click a button?

Question

i have jTextfield and jButton..

how to

• user can click on jTextfield(mouse can enter/exited on jtextfield), but if user typing something it will not do

Answer 1

in the key listener of the jTextfield, in the keyTyped event, check the e.getKeyChar() if it is the backspace, if not, do e.consume(); it will cancel the event

the keychar for backspace is 8

here is an example:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;


public class ConsumeExceptForBackSpace extends JFrame {

    private boolean canWrite = false;

    public ConsumeExceptForBackSpace() {
        super();

        JButton b = new JButton("Click");
        JTextField f = new JTextField("");
        this.setLayout(new BorderLayout());
        this.add(b, BorderLayout.CENTER);
        this.add(f, BorderLayout.SOUTH);

        b.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                canWrite = !canWrite;
            }
        });

        f.addKeyListener(new KeyListener() {

            @Override
            public void keyTyped(KeyEvent e) {
                if(e.getKeyChar() != KekEvent.VK_BACK_SPACE && !canWrite) e.consume();
            }

            @Override
            public void keyReleased(KeyEvent e) {

            }

            @Override
            public void keyPressed(KeyEvent e) {

            }
        });

        this.pack();
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setVisible(true);
    }

    public static void main(String[] args) {
        new ConsumeExceptForBackSpace();
    }
}