src/Tools/VSCode/extension/src/protocol.ts

--- a/src/Tools/VSCode/extension/src/protocol.ts	Tue May 30 21:38:38 2017 +0200
+++ b/src/Tools/VSCode/extension/src/protocol.ts	Tue May 30 22:06:39 2017 +0200
@@ -44,3 +44,14 @@
 
 export const dynamic_output_type =
   new NotificationType<Dynamic_Output, void>("PIDE/dynamic_output")
+
+
+/* dynamic preview */
+
+export interface Dynamic_Preview
+{
+  content: string
+}
+
+export const dynamic_preview_type =
+  new NotificationType<Dynamic_Preview, void>("PIDE/dynamic_preview")