src/Tools/jEdit/src/session_build.scala

 import org.gjt.sp.jedit.View
 
 
 object Session_Build
 {
-  def check_dialog(view: View)
+  def check_dialog(view: View): Unit =
   {
     val options = PIDE.options.value
     Isabelle_Thread.fork() {
       try {
         if (JEdit_Sessions.session_no_build ||

     layout_panel.layout(scroll_text) = BorderPanel.Position.Center
     layout_panel.layout(action_panel) = BorderPanel.Position.South
 
     setContentPane(layout_panel.peer)
 
-    private def set_actions(cs: Component*)
+    private def set_actions(cs: Component*): Unit =
     {
       action_panel.contents.clear
       action_panel.contents ++= cs
       layout_panel.revalidate
       layout_panel.repaint

           set_actions(button)
           button.peer.getRootPane.setDefaultButton(button.peer)
         }
       }
 
-    private def conclude()
+    private def conclude(): Unit =
     {
       setVisible(false)
       dispose()
     }
 

     /* close */
 
     setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE)
 
     addWindowListener(new WindowAdapter {
-      override def windowClosing(e: WindowEvent) {
+      override def windowClosing(e: WindowEvent): Unit =
+      {
         if (_return_code.isDefined) conclude()
         else stopping()
       }
     })
 
-    private def stopping()
+    private def stopping(): Unit =
     {
       progress.stop
       set_actions(new Label("Stopping ..."))
     }