src/Tools/jEdit/src/info_dockable.scala

 
 import isabelle._
 
 import scala.actors.Actor._
 
-import scala.swing.{FlowPanel, Button, CheckBox}
+import scala.swing.{FlowPanel, Button}
 import scala.swing.event.ButtonClicked
 
 import java.lang.System
 import java.awt.BorderLayout
 import java.awt.event.{ComponentEvent, ComponentAdapter, WindowFocusListener, WindowEvent}