displayMenu.java

package project;


import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedList;
import java.util.concurrent.CountDownLatch;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;

class displayMenu extends JFrame {
	static int idx = -1;
	CountDownLatch latch = new CountDownLatch(1);
	JFrame f;

	displayMenu(LinkedList<Node> ptr) {
		latch = new CountDownLatch(1);
		new JFrame("Button Centered Example");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		Toolkit toolkit = Toolkit.getDefaultToolkit();
		Dimension screenResolution = new Dimension(toolkit.getScreenSize());
		setSize(screenResolution);
		setTitle("Select Your Choice");
		GridBagConstraints gbc = new GridBagConstraints();
		gbc.insets = new Insets(8,8,8,8);

		int i = 1;

		gbc.gridx = 0;
		gbc.gridy = 0;

		JPanel jp = new JPanel(new GridBagLayout());
		for (Node a : ptr) {

			JButton b = new JButton(i + ") " + a.data);
			b.setPreferredSize(new Dimension(350, 70));
			b.addActionListener(new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					JButton clickedButton = (JButton) e.getSource();
					Character choice = clickedButton.getText().charAt(0);
					String a = choice.toString();
					displayMenu.idx = Integer.parseInt(a);
					setVisible(false);
					latch.countDown();
				}
			});

			b.setBackground(new Color(44, 59, 87));
			b.setForeground(new Color(197, 221, 232));
			jp.add(b, gbc);

			gbc.gridy = i++;

		}
	
		LineBorder lb = new LineBorder(new Color(15, 8, 61), 6);
		jp.setBorder(lb);
		jp.setBackground(new Color(197, 221, 235));
		add(jp, BorderLayout.CENTER);
		setVisible(true);

		try {
			// Wait for the user to click the button
			latch.await();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	int getIndex() {
		return idx;
	}
}