How to make a method that disables JButton?

Question

I am trying to make a method that disables JButtons.

The JButtons are in an array in the form of a grid, JButton [int][int] and th

Answer 1

I did some changes in your code:

1. public static JFrame f = new JFrame("BS"); JFrame shouldn't be static and should have a more meaningful name (like frame for example).

2. final JButton[][] coordinates = new JButton[15][15]; moved this array as a class member and made it non final and also changed the name to buttons as it's easier to know what it is (coordinates to me, sounds more like an array of Point or int)

After that I added an ActionListener, see How to use Actions tutorial.

private ActionListener listener = e -> {
    //Loops through the whole array in both dimensions
    for (int i = 0; i < buttons.length; i++) {
        for (int j = 0; j < buttons[i].length; j++) {
            if (e.getSource().equals(buttons[i][j])) { //Find the JButton that was clicked
                if (isStartButton) { //startButton is a boolean variable that tells us if this is the first button clicked or not
                    startXCoord = i;
                    startYCoord = j;
                } else {
                    endXCoord = i;
                    endYCoord = j;
                    disableButtons(); //Only when we have clicked twice we disable all the buttons in between
                }
                isStartButton = !isStartButton; //In every button click we change the value of this variable
                break; //No need to keep looking if we found our clicked button. Add another one with a condition to skip the outer loop.
            }
        }
    }
};

And a method called disableButtons() which disables all the buttons between the 2 clicked buttons:

private void disableButtons() {
    compareCoords(); //This method checks if first button clicked is after 2nd one.
    for (int i = startXCoord; i <= endXCoord; i++) {
        for (int j = startYCoord; j <= endYCoord; j++) {
            buttons[i][j].setEnabled(false); //We disable all buttons in between
        }
    }
}

At the end our code ends like this:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.CompoundBorder;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;

public class DisableButtonsInBetween {

    private JFrame frame = new JFrame(getClass().getSimpleName());
    private JButton[][] buttons;

    private int startXCoord = -1;
    private int startYCoord = -1;
    private int endXCoord = -1;
    private int endYCoord = -1;
    private boolean isStartButton = true;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new DisableButtonsInBetween().initializeGui();
            }
        });
    }

    void initializeGui() {
        JPanel gui = new JPanel(new BorderLayout(3, 1));
        // This is the array of the JButtons in the form of a grid
        JPanel pane;
        buttons = new JButton[15][15];

        // set up the main GUI
        gui.setBorder(new EmptyBorder(5, 5, 5, 5));
        pane = new JPanel(new GridLayout(0, 15));

        pane.setBorder(new CompoundBorder(new EmptyBorder(15, 15, 15, 15), new LineBorder(Color.BLACK)));

        JPanel boardConstrain = new JPanel(new GridBagLayout());
        boardConstrain.add(pane);
        gui.add(boardConstrain);

        // The making of the grid
        for (int ii = 0; ii < buttons.length; ii++) {
            for (int jj = 0; jj < buttons[ii].length; jj++) {
                buttons[jj][ii] = new JButton();

                ImageIcon icon = new ImageIcon(new BufferedImage(30, 30, BufferedImage.TYPE_INT_ARGB));
                buttons[jj][ii].setIcon(icon);
                buttons[jj][ii].addActionListener(listener);

                pane.add(buttons[jj][ii]);
            }
        }

        frame.add(gui);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.pack();
        frame.setMinimumSize(frame.getSize());
        frame.setVisible(true);
    }

    //The ActionListener is what gets called when you click a JButton
    private ActionListener listener = e -> {
        //These for loops are done to identify which button was clicked.
        for (int i = 0; i < buttons.length; i++) {
            for (int j = 0; j < buttons[i].length; j++) {
                if (e.getSource().equals(buttons[i][j])) {
                    if (isStartButton) {
                        //We save the coords of the 1st button clicked
                        startXCoord = i;
                        startYCoord = j;
                    } else {
                        //We save the coords of the 2nd button clicked and call the disableButtons method
                        endXCoord = i;
                        endYCoord = j;
                        disableButtons();
                    }
                    isStartButton = !isStartButton;
                    break;
                }
            }
        }
    };

    //This method disables all the buttons between the 2 that were clicked
    private void disableButtons() {
        compareCoords();
        for (int i = startXCoord; i <= endXCoord; i++) {
            for (int j = startYCoord; j <= endYCoord; j++) {
                buttons[i][j].setEnabled(false);
            }
        }
    }

    //This method compares the coords if the 2nd button was before (in its coords) than the 1st one it switched their coords
    private void compareCoords() {
        if (endXCoord < startXCoord) {
            int aux = startXCoord;
            startXCoord = endXCoord;
            endXCoord = aux;
        }
        if (endYCoord < startYCoord) {
            int aux = startYCoord;
            startYCoord = endYCoord;
            endYCoord = aux;
        } 
    }
}

I hope this is what you were trying to do... if not please clarify.

I do not have the arrow operator, " -> ". I think it requires a higher Java. Is there a way to replace this?

For Java 7 and lower use this for the ActionListener:

private ActionListener listener = new ActionListener() {    
    @Override
    public void actionPerformed(ActionEvent e) {
        for (int i = 0; i < buttons.length; i++) {
            for (int j = 0; j < buttons[i].length; j++) {
                if (e.getSource().equals(buttons[i][j])) {
                    if (isStartButton) {
                        startXCoord = i;
                        startYCoord = j;
                    } else {
                        endXCoord = i;
                        endYCoord = j;
                        disableButtons();
                    }
                    isStartButton = !isStartButton;
                    break;
                }
            }
        }
    }
};