SwingUtilities.convertPointFromScreen(p, glassPane);
glassPane.setPoint(p);
p = (Point) dsde.getLocation().clone();
SwingUtilities.convertPointFromScreen(p, descriptor.getManager());
ToolWindowAnchor newAnchor = descriptor.getToolWindowAnchor(p);
if (newAnchor != lastAnchor) {
Rectangle dirtyRegion = glassPane.getRepaintRect();
glassPane.setDraggingImage(null);
glassPane.repaint(dirtyRegion);