Having Problem With Click Listener in Java

Question

I'm making a chess-like game in java and I'm having an issue with the click events. The mouseClicked function isn't responding to my clicks on the window and for no apparent reason.

I have already tried a few things such as changing class names and using different functions but nothing has worked.

package main.game.com;

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

public class ClickEvent extends MouseAdapter {

    public void mouseClicked(MouseEvent e) {
            System.out.println("hello");
    }

}

---

package main.game.com;

import java.awt.Canvas;

public class Main extends Canvas {

    private static final long serialVersionUID = 1673528055664762143L;

    private static final int WIDTH = 416, HEIGHT = 439;

    public Main() {
        Window window = new Window(WIDTH, HEIGHT, "DARRAGH", this);
        this.addMouseListener(new ClickEvent());
    }   

---

package main.game.com;

import java.awt.Canvas;
import java.awt.Dimension;

import javax.swing.JFrame;

public class Window extends Canvas {

    private static final long serialVersionUID = 6733885629776844621L;

    public Window(int width, int height, String title, Main main) {

        JFrame frame = new JFrame(title);   

        frame.setPreferredSize(new Dimension(width, height));
        frame.setMaximumSize(new Dimension(width, height));
        frame.setMinimumSize(new Dimension(width, height));

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.add(main);
        frame.setVisible(true);
        main.start();

    }
}

The first set of code is my mouseAdapter library and the second is the first part of my main class containing the clickListener.

Answer 1

You're creating a Handler object, good, you're adding it to a Canvas object (the this -- why Canvas?), and you're creating a "top-level" window object which is in fact of Window type, but you never add the Canvas to the Window, nor do you appear to display the Window, so there is no reason to expect this code to in fact work.

Now, I'm guessing that there is more code out there that you're not showing us, and this may have relevance, and if so, do consider creating and posting an adequate MCVE for giving us the best understanding of your problem.

OK, I created a MCVE with your code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Main extends Canvas {

    private static final long serialVersionUID = 1673528055664762143L;

    private static final int WIDTH = 416, HEIGHT = 439;

    public Main() {
        Procode238Window window = new Procode238Window(WIDTH, HEIGHT, "DARRAGH", this);
        this.addMouseListener(new ClickEvent());
    }

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

}

class ClickEvent extends MouseAdapter {

    public void mouseClicked(MouseEvent e) {
        System.out.println("hello");
    }

}

// renamed to avoid clashing with the java.awt.Window class    
class Procode238Window extends Canvas {

    private static final long serialVersionUID = 6733885629776844621L;

    public Procode238Window(int width, int height, String title, Main main) {

        JFrame frame = new JFrame(title);

        frame.setPreferredSize(new Dimension(width, height));
        frame.setMaximumSize(new Dimension(width, height));
        frame.setMinimumSize(new Dimension(width, height));

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.add(main);
        frame.setVisible(true);
        // !! main.start();  // this method doesn't exist
    }
}

and it works

Note that:

• This whole code can be copied and pasted into a single IDE file and run and has the necessary main method, both needed for it to be an MCVE
• I've renamed the Window class to avoid a naming clash and confusing with the java.awt.Window class
• Your code calls the Main class's .start() method, a method not shown. Could this be causing problems?