import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JDialog;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Toolkit;
import java.io.IOException;

/**
 A break scheduler to remind users to give their eyes a rest every so many
 minutes.  On startup, this class pops up a dialog asking the user to schedule a
 break.  On scheduling, the dialog disappears for a specified number of minutes.
 After the time, it reappears and advises the user to take a break.  After
 taking a break, he can then schedule another break or quit the dialog.
 */
public class Breaktime {

   public static void main(String[] args) throws InterruptedException,
                                                 IOException {

      final int MINUTES_BETWEEN_BREAKS = 20;
      final int MINUTES_OF_BREAK = 3;

      JFrame frame = new JFrame();
      String msg = "Please take a break...\n" + 
                   "Do you want to schedule another break?";
      Object[] array = { msg };
      JOptionPane option_pane = new JOptionPane(array,
                                                JOptionPane.QUESTION_MESSAGE,
                                                JOptionPane.YES_NO_OPTION);
      Object[] options = { "Yes", "No",
                           "Beep after " + MINUTES_OF_BREAK + " minutes" };
      option_pane.setOptions(options);

      // Continue scheduling breaks indefinitely, until user stops scheduling
      // or closes the dialog.
      while (true) {

         JDialog dialog = option_pane.createDialog(frame, "Breaktime");
         dialog.setAlwaysOnTop(true);
         dialog.setVisible(true);
         Object result = option_pane.getValue();

         // Close or No
         if (result == null || result == options[1]) {
            System.exit(0);
         }

         // Signal end of break
         else if (result == options[2]) {
            Thread.sleep(MINUTES_OF_BREAK * 60 * 1000);
            Toolkit.getDefaultToolkit().beep();
         }

         // Schedule another break
         else if (result == options[0]) {
            Thread.sleep(MINUTES_BETWEEN_BREAKS * 60 * 1000);
         }
      }

   }
}