+#include "grob.hh"
+#include "grob-properties.hh"
+#include "paper-score.hh"
+#include "translator-dispatch-list.hh"
+#include "warn.hh"
+
+IMPLEMENT_LISTENER (Engraver_group, override);
+void
+Engraver_group::override (SCM sev)
+{
+ Stream_event *ev = Stream_event::unsmob (sev);
+
+ Grob_property_info (context (), ev->get_property ("symbol"))
+ .push (ev->get_property ("property-path"),
+ ev->get_property ("value"));
+}
+
+IMPLEMENT_LISTENER (Engraver_group, revert);
+void
+Engraver_group::revert (SCM sev)
+{
+ Stream_event *ev = Stream_event::unsmob (sev);
+
+ Grob_property_info (context (), ev->get_property ("symbol"))
+ .pop (ev->get_property ("property-path"));
+}