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

/*
A modal dialog box that allows the invoker to block waiting
for a response.  With this primitive implementation, the
creating/invoking context must dispose of the dialog after
use--an instance cannot be reused.
*/

public class BlockingDialog extends Dialog
    implements ActionListener {
  boolean stillWaiting = true;

  public BlockingDialog(Frame parent, String title, boolean modal) {
    super(parent, title, modal);
    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        finish();
      }
    });
  }

  public void actionPerformed(ActionEvent e) {
    finish();
  }

  public void finish() {
    responded();
    setVisible(false);
  }

  public synchronized void waitForResponse() {
    try {
      while (stillWaiting)
        wait();
    }
    catch (Exception e) {}
  }

  public synchronized void responded() {
    stillWaiting = false;
    notifyAll();
  }
}