clarified signature;

--- a/src/Pure/Thy/presentation.scala	Sat Jul 30 13:06:19 2022 +0200
+++ b/src/Pure/Thy/presentation.scala	Sat Jul 30 13:44:26 2022 +0200
@@ -22,6 +22,7 @@
   abstract class HTML_Context {
     /* directory structure and resources */
 
+    def nodes: Nodes
     def root_dir: Path
     def theory_session(name: Document.Node.Name): Sessions.Info
 
@@ -32,8 +33,6 @@
     def files_path(name: Document.Node.Name, path: Path): Path =
       theory_dir(name) + Path.explode("files") + path.squash.html
 
-    def nodes: Nodes = Nodes.empty
-
 
     /* HTML content */
 

--- a/src/Tools/VSCode/src/preview_panel.scala	Sat Jul 30 13:06:19 2022 +0200
+++ b/src/Tools/VSCode/src/preview_panel.scala	Sat Jul 30 13:44:26 2022 +0200
@@ -30,6 +30,7 @@
                 else {
                   val html_context =
                     new Presentation.HTML_Context {
+                      override def nodes: Presentation.Nodes = Presentation.Nodes.empty
                       override def root_dir: Path = Path.current
                       override def theory_session(name: Document.Node.Name): Sessions.Info =
                         resources.sessions_structure(resources.session_base.theory_qualifier(name))

--- a/src/Tools/jEdit/src/document_model.scala	Sat Jul 30 13:06:19 2022 +0200
+++ b/src/Tools/jEdit/src/document_model.scala	Sat Jul 30 13:44:26 2022 +0200
@@ -315,8 +315,8 @@
         val snapshot = model.await_stable_snapshot()
         val html_context =
           new Presentation.HTML_Context {
+            override def nodes: Presentation.Nodes = Presentation.Nodes.empty
             override def root_dir: Path = Path.current
-
             override def theory_session(name: Document.Node.Name): Sessions.Info =
               PIDE.resources.sessions_structure(
                 PIDE.resources.session_base.theory_qualifier(name))