X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fengraver-group.cc;h=cf1832fe1fb73dd25f93e621e7a20d077485bbd0;hb=43e591c72387cd624d98ed48f63cfc063d857359;hp=9b5efb27797015c40e0b39fc5a24ff6d732eebae;hpb=7eef6e252aea1c29512a2df501aaa5c832f57038;p=lilypond.git

diff --git a/lily/engraver-group.cc b/lily/engraver-group.cc
index 9b5efb2779..cf1832fe1f 100644
--- a/lily/engraver-group.cc
+++ b/lily/engraver-group.cc
@@ -20,6 +20,7 @@
 #include "context.hh"
 #include "dispatcher.hh"
 #include "engraver-group.hh"
+#include "global-context.hh"
 #include "grob.hh"
 #include "grob-properties.hh"
 #include "paper-score.hh"
@@ -29,20 +30,49 @@
 void
 Engraver_group::override (SCM sev)
 {
-  Stream_event *ev = Stream_event::unsmob (sev);
+  Stream_event *ev = unsmob<Stream_event> (sev);
+  SCM sym = ev->get_property ("symbol");
+  Grob_property_info gpi (context (), sym);
 
-  Grob_property_info (context (), ev->get_property ("symbol"))
-    .push (ev->get_property ("property-path"),
-           ev->get_property ("value"));
+  if (to_boolean (ev->get_property ("once")))
+    {
+      SCM token = gpi.temporary_override (ev->get_property ("property-path"),
+                                          ev->get_property ("value"));
+      if (scm_is_pair (token))
+        if (Global_context *g = context ()->get_global_context ())
+          {
+            g->add_finalization (scm_list_4 (ly_context_matched_pop_property_proc,
+                                             context ()->self_scm (),
+                                             sym,
+                                             token));
+          }
+    }
+  else
+    gpi.push (ev->get_property ("property-path"),
+              ev->get_property ("value"));
 }
 
 void
 Engraver_group::revert (SCM sev)
 {
-  Stream_event *ev = Stream_event::unsmob (sev);
+  Stream_event *ev = unsmob<Stream_event> (sev);
+  SCM sym = ev->get_property ("symbol");
+  Grob_property_info gpi (context (), sym);
 
-  Grob_property_info (context (), ev->get_property ("symbol"))
-    .pop (ev->get_property ("property-path"));
+  if (to_boolean (ev->get_property ("once")))
+    {
+      SCM token = gpi.temporary_revert (ev->get_property ("property-path"));
+      if (scm_is_pair (token))
+        if (Global_context *g = context ()->get_global_context ())
+          {
+            g->add_finalization (scm_list_4 (ly_context_matched_pop_property_proc,
+                                             context ()->self_scm (),
+                                             sym,
+                                             token));
+          }
+    }
+  else
+    gpi.pop (ev->get_property ("property-path"));
 }
 
 void
@@ -117,7 +147,7 @@ Engraver_group::acknowledge_grobs ()
         }
 
       Engraver_dispatch_list *dispatch
-        = Engraver_dispatch_list::unsmob (acklist);
+        = unsmob<Engraver_dispatch_list> (acklist);
 
       if (dispatch)
         dispatch->apply (info);
@@ -136,7 +166,7 @@ Engraver_group::pending_grobs () const
   for (SCM s = context_->children_contexts ();
        scm_is_pair (s); s = scm_cdr (s))
     {
-      Context *c = Context::unsmob (scm_car (s));
+      Context *c = unsmob<Context> (scm_car (s));
       Engraver_group *group
         = dynamic_cast<Engraver_group *> (c->implementation ());
 
@@ -157,7 +187,7 @@ Engraver_group::do_announces ()
       for (SCM s = context ()->children_contexts ();
            scm_is_pair (s); s = scm_cdr (s))
         {
-          Context *c = Context::unsmob (scm_car (s));
+          Context *c = unsmob<Context> (scm_car (s));
           Engraver_group *group
             = dynamic_cast<Engraver_group *> (c->implementation ());
           if (group)