package mainz;

import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class myFrame extends JFrame implements MouseListener{

    JLabel label;


    myFrame(){
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(500, 500);
        this.setLayout(null);
        
        label = new JLabel();
        label.setBounds(0, 0, 100, 100);
        label.setBackground(Color.red);
        label.setOpaque(true);
        label.addMouseListener(this);

        this.add(label);
        this.setVisible(true);
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        label.setBackground(Color.yellow);
    }

    @Override
    public void mousePressed(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseEntered(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseExited(MouseEvent e) {

    }
}

I need a lot of help. This code looks perfectly fine and I even got some working code from a bro code tutorial yet it still didn't work. Is there a problem with my client because it's been working properly all this time. Thank you for any help. I've tried everything yet it still doesn't work

package mainz;

import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class myFrame extends JFrame implements MouseListener{

    JLabel label;


    myFrame(){
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(500, 500);
        this.setLayout(null);
        
        label = new JLabel();
        label.setBounds(0, 0, 100, 100);
        label.setBackground(Color.red);
        label.setOpaque(true);
        label.addMouseListener(this);

        this.add(label);
        this.setVisible(true);
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        label.setBackground(Color.yellow);
    }

    @Override
    public void mousePressed(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseEntered(MouseEvent e) {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void mouseExited(MouseEvent e) {

    }
}

I need a lot of help. This code looks perfectly fine and I even got some working code from a bro code tutorial yet it still didn't work. Is there a problem with my client because it's been working properly all this time. Thank you for any help. I've tried everything yet it still doesn't work

• java
• swing
• mouselistener
• mouse-listeners

Share Improve this question Follow edited Mar 6 at 5:56 Slaw 46.8k88 gold badges6262 silver badges100100 bronze badges asked Mar 6 at 5:42 Eyoel GeremewEyoel Geremew 3122 bronze badges 3

• And when should the mouse listener respond? When you click on the JFrame window or, when you click on the JLabel? – DevilsHnd - 退した Commented Mar 6 at 6:02
• 2 With label.addMouseListener(this); you put a listener on the label, if you click on it, it changes color... :) – Marce Puente Commented Mar 6 at 6:13
• The mouseClicked method is sensitive to the time between the mouse press and the mouse release. Using the mousePressed or mouseReleased methods is better. – Gilbert Le Blanc Commented Mar 6 at 15:19

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 1

As was stated, your program works just fine. You need to click on the label to have it change color. Also note that a mouse click includes a release. So it won't change color until you release the button. You may want to try mousePressed which responds immediately. Here are some other things you should be aware of.

• Class names should start with an upper case letter.

• In general it's bad practice to use null layouts and absolute positioning. Use a layout manager or write your own.

• Don't extend JFrame but do extend JPanel.. Then add the panel to an instance of JFrame.

• Not required but reduces code, use a MouseAdapter. This and other similar adapter classes have default, empty implementations. All you need to do is override the ones you need.

• Use SwingUtilities to start your program on the Event Dispatch Thread (EDT).

Here is your program, rewritten to include the above.

import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MyProgram extends JPanel {

    public JLabel label = new JLabel();
    public JFrame frame = new JFrame();

    public static void main(String[] args) {
        SwingUtilities.invokeLater(()->new MyProgram().start());
    }

    public void start() {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        label.setBackground(Color.red);
        label.setPreferredSize(new Dimension(100,100));
        label.setOpaque(true);
        setBackground(Color.white); // 
        label.addMouseListener(new MyMouseListener());
        add(label); // add label to panel
        frame.add(this); // add the panel to the frame
        frame.pack();  // resize and position components
        frame.setVisible(true);
    }
    @Override
    public Dimension getPreferredSize() {
       return new Dimension(500,500);
    }
    
    private class MyMouseListener extends MouseAdapter {
        @Override
        public void mouseClicked(MouseEvent e) {
            label.setBackground(Color.yellow);
        }
    }
}

For more information, check out the The Java Tutorials for using Swing and custom painting.