How do I add ActionEvent to JButtons? TicTacToe

Question

I'm new to coding and trying to create a simple tic-tac-toe game for class and I figured since I need to use GUI that i'd make the board a grid of buttons. Unfortunately I am having issues getting the buttons to do anything. I want to when someone clicks on it for it to become an X, and then the next person that clicks it becomes an O. Any help would be fantastic.

import javax.swing.*;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.JOptionPane;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.scene.layout.BorderPane;
import javafx.geometry.Pos;
import javafx.geometry.Insets;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.event.EventHandler;
import javafx.event.ActionEvent;
import java.awt.font.*;
import javafx.animation.TranslateTransition;
import javafx.scene.layout.GridPane;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;

public class ShadowT extends JFrame { 

   //creates 9 buttons
   private static JButton buttons[] = new JButton[9]; 
   //sets counter for amount of times a button has been clicked on
   public static int counter = 0;  
   public static String letter;

   public static void main(String[] args){
       //creates grid of 3x3
       int rows = 3;
       int cols = 3;
       ShadowT grid = new ShadowT(rows,cols);
       grid.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       grid.pack();
       grid.setVisible(true);
   }


   public ShadowT(int rows, int cols){
       //creates pane with grid and adds in the buttons 
       Container pane = getContentPane();
       pane.setLayout(new GridLayout(rows,cols));
       for(int i = 0; i < 9; i++){
           JButton button = new JButton(Integer.toString((i+1)));
           pane.add(button); 
       }
   }  
}

score 0 · Answer 1 · 2018-12-13T16:27:34.467

Each JButton needs an ActionListener (possibly the same), with a custom actionPerformed method.

For instance, for a JButton called button1, you could write

button1.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        /* do some stuff when the button is clicked */
    }
});

See also How to Write an Action Listener in the Java Tutorial, and if you need it, How to add action listener that listens to multiple buttons here on SO.

Here is an example:

import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class Grid extends JFrame implements ActionListener {
    private static JButton buttons[][];
    public static int counter = 0;

    public static void main(String[] args){
        Grid grid = new Grid(3, 3);
        grid.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        grid.pack();
        grid.setVisible(true);
    }

    public Grid(int rows, int cols) {
        Container pane = getContentPane();
        pane.setLayout(new GridLayout(rows, cols));
        buttons = new JButton[rows][cols];

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                JButton button = new JButton(i + "," + j);

                button.addActionListener(this);
                pane.add(button);
                buttons[i][j] = button;
            }
        }
    }

    public void actionPerformed(ActionEvent e) {
        Object o = e.getSource();
        if (o instanceof JButton) {
            JOptionPane.showMessageDialog(null, ((JButton)o).getText());
        }
    }
}

score 0 · Answer 2 · answered Dec 13 '18 at 16:20

Here is an example of a bare bones Java GUI application - not perfect but to just to demo what you need to.

You need to implements ActionListener and write actionPerformed() required when implementing ActionListener.

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

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

public class HandleActionEventsForJButton extends JFrame implements ActionListener {

    private static final long serialVersionUID = 1L;

    public HandleActionEventsForJButton() {

        // set flow layout for the frame
        this.getContentPane().setLayout(new FlowLayout());

        JButton button1 = new JButton("Yes");
        JButton button2 = new JButton("No");

        //set action listeners for buttons
        button1.addActionListener(this);
        button2.addActionListener(this);

        //add buttons to the frame
        add(button1);
        add(button2);

    }

    @Override
    public void actionPerformed(ActionEvent ae) {
        String action = ae.getActionCommand();
        if (action.equals("Yes")) {
            System.out.println("Yes Button pressed!");
        }
        else if (action.equals("No")) {
            System.out.println("No Button pressed!");
        }
    }

    private static void createAndShowGUI() {

  //Create and set up the window.

  JFrame frame = new HandleActionEventsForJButton();

  //Display the window.

  frame.pack();

  frame.setVisible(true);

  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    public static void main(String[] args) {

  //Schedule a job for the event-dispatching thread:

  //creating and showing this application's GUI.

  javax.swing.SwingUtilities.invokeLater(new Runnable() {

public void run() {

    createAndShowGUI(); 

}

  });
    }

}

How do I add ActionEvent to JButtons? TicTacToe

2 Answers2