+ Context *o = get_outlet ();
+ Music *m = get_music ();
+
+ send_stream_event (o, "UnsetProperty", m->origin (),
+ ly_symbol2scm ("symbol"), m->get_property ("symbol"),
+ ly_symbol2scm ("once"), m->get_property ("once"));
+
+ Simple_music_iterator::process (mom);
+}
+
+bool
+check_grob (Music *mus, SCM sym)
+{
+ bool g = to_boolean (scm_object_property (sym, ly_symbol2scm ("is-grob?")));
+
+ if (!g)
+ mus->origin ()->warning (_f ("not a grob name, `%s'",
+ ly_symbol2string (sym)));
+
+ return g;
+}
+
+SCM
+get_property_path (Music *m)
+{
+ SCM grob_property_path = m->get_property ("grob-property-path");
+
+ SCM eprop = m->get_property ("grob-property");
+ if (scm_is_symbol (eprop))
+ {
+ grob_property_path = scm_list_1 (eprop);
+ }
+
+ return grob_property_path;
+}
+
+void
+Push_property_iterator::process (Moment m)
+{
+ SCM sym = get_music ()->get_property ("symbol");
+ if (check_grob (get_music (), sym))
+ {
+ SCM grob_property_path = get_property_path (get_music ());
+ SCM val = get_music ()->get_property ("grob-value");
+ SCM once = get_music ()->get_property ("once");
+
+ if (to_boolean (get_music ()->get_property ("pop-first"))
+ && !to_boolean (once))
+ send_stream_event (get_outlet (), "Revert", get_music ()->origin (),
+ ly_symbol2scm ("symbol"), sym,
+ ly_symbol2scm ("property-path"), grob_property_path);
+
+ send_stream_event (get_outlet (), "Override", get_music ()->origin (),
+ ly_symbol2scm ("symbol"), sym,
+ ly_symbol2scm ("property-path"), grob_property_path,
+ ly_symbol2scm ("once"), once,
+ ly_symbol2scm ("value"), val);
+ }
+ Simple_music_iterator::process (m);
+}
+
+void
+Pop_property_iterator::process (Moment mom)
+{
+ Music *m = get_music ();
+ SCM sym = m->get_property ("symbol");
+
+ if (check_grob (m, sym))
+ {
+ SCM grob_property_path = get_property_path (m);
+
+ send_stream_event (get_outlet (), "Revert", m->origin (),
+ ly_symbol2scm ("symbol"), sym,
+ ly_symbol2scm ("once"), m->get_property ("once"),
+ ly_symbol2scm ("property-path"), grob_property_path);
+ }
+ Simple_music_iterator::process (mom);