import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.text.MessageFormat;

@SuppressWarnings({"HardCodedStringLiteral", "MagicNumber"})
public class WindowPusher {
	public static void main(final String[] argv) {
		JFrame masterFrame = new JFrame("Master");
		JPanel masterPanel = new JPanel();
		masterFrame.setContentPane(masterPanel);

		masterPanel.setLayout(new BorderLayout());
		JButton pusherButton = new JButton("Push new window");
		masterPanel.add(pusherButton);

		pusherButton.addActionListener(new ActionListener() {
			private int myNextNumber = 1;

			public void actionPerformed(ActionEvent e) {
				JFrame frame = new JFrame(MessageFormat.format("Number: {0}", myNextNumber));
				frame.setSize(100, 100);
				frame.pack();
				frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
				frame.setVisible(true);
				myNextNumber++;
			}
		});

		masterFrame.setSize(100, 100);
		masterFrame.pack();
		masterFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
		masterFrame.setVisible(true);
	}
}