package basics.gui.toolkit;
import java.awt.AWTEvent;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.EventQueue;
import java.awt.MenuComponent;
import java.awt.MenuContainer;
import javax.swing.SwingUtilities;
/**
 * Taken from: http://www.javaworld.com/javaworld/javatips/jw-javatip87.html
 * @author Kyle Davis
 */
public class WaitCursorEventQueue extends EventQueue
{

public WaitCursorEventQueue(int delay)
{
   this.delay = delay;
   waitTimer = new WaitCursorTimer();
   waitTimer.setDaemon(true);
   waitTimer.start();
}

protected void dispatchEvent (AWTEvent event)
{
   waitTimer.startTimer(event.getSource());
   try
   {
      super.dispatchEvent(event);
   }
   finally
   {
      waitTimer.stopTimer();
   }
}
private int             delay;
private WaitCursorTimer waitTimer;

private class WaitCursorTimer extends Thread
{

synchronized void startTimer (Object source)
{
   this.source = source;
   notify();
}

synchronized void stopTimer ()
{
   if (parent == null) interrupt();
   else
   {
      parent.setCursor(null);
      parent = null;
   }
}

public synchronized void run ()
{
   while (true)
   {
      try
      {
         // wait for notification from startTimer()
         wait();
         // wait for event processing to reach the threshold, or
         // interruption from stopTimer()
         wait(delay);
         if (source instanceof Component) parent = SwingUtilities.getRoot((Component) source);
         else if (source instanceof MenuComponent)
         {
            MenuContainer mParent = ((MenuComponent) source).getParent();
            if (mParent instanceof Component) parent = SwingUtilities.getRoot((Component) mParent);
         }
         if (parent != null && parent.isShowing()) parent.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
      }
      catch (InterruptedException ie)
      {}
   }
}
private Object    source;
private Component parent;
}
}