src/Tools/jEdit/src/text_overview.scala

   private var last_H = 0
 
   override def paintComponent(gfx: Graphics)
   {
     super.paintComponent(gfx)
-    Swing_Thread.assert {}
+    GUI_Thread.assert {}
 
     doc_view.rich_text_area.robust_body(()) {
       JEdit_Lib.buffer_lock(buffer) {
         val rendering = doc_view.get_rendering()
         val snapshot = rendering.snapshot