X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fcontext-property.cc;h=62e04a27323a5b136194c0607954e2b53e35c197;hb=47db9a3883d726ca53e2133a3b2298f78dd6a32e;hp=369037381aba5b67ef8d5f01996c1d6e357ed9ba;hpb=00b9619cea1020f6773f23df8764ef85ee2912bf;p=lilypond.git

diff --git a/lily/context-property.cc b/lily/context-property.cc
index 369037381a..62e04a2732 100644
--- a/lily/context-property.cc
+++ b/lily/context-property.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2004--2014 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 2004--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -59,14 +59,13 @@ typecheck_grob (SCM symbol, SCM value)
     return typecheck_grob (symbol, upc->unpure_part ())
       && typecheck_grob (symbol, upc->pure_part ());
   return ly_is_procedure (value)
-    || Simple_closure::unsmob (value)
+    || Simple_closure::is_smob (value)
     || type_check_assignment (symbol, value, ly_symbol2scm ("backend-type?"));
 }
 
 class Grob_properties : public Simple_smob<Grob_properties>
 {
 public:
-  static int print_smob (SCM, SCM, scm_print_state *);
   SCM mark_smob ();
   static const char type_p_name_[];
 private:
@@ -106,14 +105,6 @@ Grob_properties::mark_smob ()
   return cooked_from_;
 }
 
-int
-Grob_properties::print_smob (SCM /*smob*/, SCM port, scm_print_state *)
-{
-  scm_puts ("#<Grob_properties>", port);
-
-  return 1;
-}
-
 LY_DEFINE (ly_make_grob_properties, "ly:make-grob-properties",
            1, 0, 0, (SCM alist),
            "This packages the given property list @var{alist} in"
@@ -199,18 +190,21 @@ Grob_property_info::create ()
   alist defined in a parent context. BASED-ON should always be a tail
   of ALIST.
 
-  Push or pop (depending on value of VAL) a single entry from a
+  Push a single entry from a
   translator property list by name of PROP.  GROB_PROPERTY_PATH
   indicates nested alists, eg. '(beamed-stem-lengths details)
+
+  Return value can be passed to matched_pop and will only cancel the
+  same override then.
 */
-void
+SCM
 Grob_property_info::push (SCM grob_property_path, SCM new_value)
 {
   /*
     Don't mess with MIDI.
   */
   if (!create ())
-    return;
+    return SCM_EOL;
 
   SCM symbol = scm_car (grob_property_path);
   SCM rest = scm_cdr (grob_property_path);
@@ -218,10 +212,12 @@ Grob_property_info::push (SCM grob_property_path, SCM new_value)
     {
       // poor man's typechecking
       if (typecheck_grob (symbol, nested_create_alist (rest, new_value))) {
-        props_->alist_ = scm_acons (grob_property_path, new_value, props_->alist_);
+        SCM cell = scm_cons (grob_property_path, new_value);
+        props_->alist_ = scm_cons (cell, props_->alist_);
         props_->nested_++;
+        return cell;
       }
-      return;
+      return SCM_EOL;
     }
 
   /* it's tempting to replace the head of the list if it's the same
@@ -230,7 +226,34 @@ Grob_property_info::push (SCM grob_property_path, SCM new_value)
   */
 
   if (typecheck_grob (symbol, new_value))
-    props_->alist_ = scm_acons (symbol, new_value, props_->alist_);
+    {
+      SCM cell = scm_cons (symbol, new_value);
+      props_->alist_ = scm_cons (cell, props_->alist_);
+      return cell;
+    }
+  return SCM_EOL;
+}
+
+void
+Grob_property_info::matched_pop (SCM cell)
+{
+  if (!scm_is_pair (cell))
+    return;
+  if (!check ())
+    return;
+  SCM current_alist = props_->alist_;
+  SCM daddy = props_->based_on_;
+  for (SCM p = current_alist; !scm_is_eq (p, daddy); p = scm_cdr (p))
+    {
+      if (scm_is_eq (scm_car (p), cell))
+        {
+          if (scm_is_pair (scm_car (cell)))
+            props_->nested_--;
+          props_->alist_ = partial_list_copy (current_alist, p, scm_cdr (p));
+          return;
+        }
+    }
+  return;
 }
 
 /*