diff -r 36f1581b43e2 -r 40dbf1a7526a ui/common/context.h
--- a/ui/common/context.h	Sun Jan 24 12:39:05 2016 +0100
+++ b/ui/common/context.h	Sun Jan 24 18:47:39 2016 +0100
@@ -55,11 +55,14 @@
     void (*set_document)(UiContext *ctx, void *document);
     void (*detach_document)(UiContext *ctx, void *document);
     
-    char         *title;
+    char          *title;
     
 #ifdef UI_GTK
     GtkAccelGroup *accel_group;
 #endif
+    
+    ui_callback   close_callback;
+    void          *close_data;
 };
 
 struct UiVar {