Retrieving Information from a Dialog via Modality

• A modal dialog blocks all input to all other windows of the application except those that have the dialog for a parent
• When a modal dialog is shown the calling thread blocks until the dialog is hidden.

import java.awt.*;
import java.awt.event.*;

public class YesNo implements ActionListener {

  private Button yes = new Button("Yes");
  private Button no  = new Button("No");
  private boolean result;

  public static boolean ask(Frame parent, String message) {
  
    Dialog d = new Dialog(parent, true);
    d.add(BorderLayout.CENTER, new Label(message));
    Panel p = new Panel();
    d.setLayout(new FlowLayout());
    YesNo listener = new YesNo();
    yes.addActionListener(listener);
    p.add(listener.yes);
    no.addActionListener(listener);
    p.add(listener.no);
    d.add(BorderLayout.SOUTH, p);
    d.pack();
    d.setLocation(100, 200);
    d.setVisible(true);
    return listener.result;
  
  }  
  
  public void actionPerformed(ActionEvent evt) {
    if (evt.getSource == yes) result = true;
    else result = false;
    this.setVisible(false);
    this.dispose();
  }
  
}