Protect against a wacky failure I witnessed.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@1106 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/swing/dnd/DnDManager.java

@@ -1,5 +1,5 @@
 //
-// $Id: DnDManager.java,v 1.13 2002/10/28 19:19:43 ray Exp $
+// $Id: DnDManager.java,v 1.14 2003/04/30 23:03:52 ray Exp $
 
 package com.samskivert.swing.dnd;
 
@@ -9,6 +9,7 @@ import java.awt.Cursor;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.GraphicsEnvironment;
+import java.awt.IllegalComponentStateException;
 import java.awt.Image;
 import java.awt.Point;
 import java.awt.Rectangle;
@@ -373,6 +374,8 @@ public class DnDManager
 
         int x = event.getX();
         int y = event.getY();
+
+        try {
             Point p = event.getComponent().getLocationOnScreen();
             p.translate(x, y);
 
@@ -384,6 +387,10 @@ public class DnDManager
                     return;  // still autoscrolling
                 }
             }
+        } catch (IllegalComponentStateException icse) {
+            // the component could no longer be on screen
+            // don't complain, just stop autoscroll
+        }
 
         // stop autoscrolling
         _scrollComp = null;