X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fcontext-property.cc;h=08ade8f954391ab4eec71e482063fa370e523663;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=5234d1113fccc00ccd1b9421697609bb72ea5f13;hpb=c790b5919ec06fb292e380a2d3d7856e86f16417;p=lilypond.git

diff --git a/lily/context-property.cc b/lily/context-property.cc
index 5234d1113f..08ade8f954 100644
--- a/lily/context-property.cc
+++ b/lily/context-property.cc
@@ -4,7 +4,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 2004--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  (c) 2004--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
 */
 
 #include "context.hh"
@@ -16,13 +16,15 @@
 #include "spanner.hh"
 #include "warn.hh"
 
-
+/*
+  like execute_general_pushpop_property(), but typecheck
+  grob_property_path and context_property.
+*/
 void
 general_pushpop_property (Context *context,
 			  SCM context_property,
 			  SCM grob_property_path,
-			  SCM new_value			  
-			  )
+			  SCM new_value)
 {
   if (!scm_is_symbol (context_property)
       || !scm_is_symbol (scm_car (grob_property_path)))
@@ -32,13 +34,12 @@ general_pushpop_property (Context *context,
 	assert (false);
     }
 
-  execute_general_pushpop_property (context, context_property,
+  sloppy_general_pushpop_property (context, context_property,
 				    grob_property_path, new_value);
 }
 
 
 /*
-  
   Grob descriptions (ie. alists with layout properties) are
   represented as a (ALIST . BASED-ON) pair, where BASED-ON is the
   alist defined in a parent context. BASED-ON should always be a tail
@@ -49,8 +50,6 @@ general_pushpop_property (Context *context,
   indicates nested alists, eg. '(beamed-stem-lengths details)
   
 */
-
-
 void
 execute_override_property (Context *context,
 			   SCM context_property,
@@ -92,10 +91,10 @@ execute_override_property (Context *context,
 					 new_value);
     }
 
-  // it's tempting to replace the head of the list if it's the same
-  // property. However, we have to keep this info around, in case we have to
-  // \revert back to it.
-  
+  /* it's tempting to replace the head of the list if it's the same
+   property. However, we have to keep this info around, in case we have to
+   \revert back to it.
+  */
   target_alist = scm_acons (symbol, new_value, target_alist);
 
   bool ok = true;
@@ -115,37 +114,35 @@ execute_override_property (Context *context,
     }
 }
 
+/*
+  do a pop (indicated by new_value==SCM_UNDEFINED) or push
+ */
 void
-execute_revert_property (Context *context,
-			 SCM context_property,
-			 SCM grob_property_path);
-
-void
-execute_general_pushpop_property (Context *context,
-				  SCM context_property,
-				  SCM grob_property_path,
-				  SCM new_value
-				  )
+sloppy_general_pushpop_property (Context *context,
+				 SCM context_property,
+				 SCM grob_property_path,
+				 SCM new_value)
 {
-  if (new_value != SCM_UNDEFINED)
+  if (new_value == SCM_UNDEFINED)
+    execute_revert_property (context, context_property,
+			     grob_property_path);
+  else
     execute_override_property (context, context_property,
 			       grob_property_path,
 			       new_value);
-  else
-    execute_revert_property (context, context_property,
-			     grob_property_path);
 }
 
+/*
+  Revert the property given by property_path.
+*/
 void
 execute_revert_property (Context *context,
 			 SCM context_property,
 			 SCM grob_property_path)
 {
-  /*
-    revert.
-  */
   SCM current_context_val = SCM_EOL;
-  if (context->where_defined (context_property, &current_context_val) == context)
+  if (context->where_defined (context_property, &current_context_val)
+      == context)
     {
       SCM current_alist = scm_car (current_context_val);
       SCM daddy = scm_cdr (current_context_val);
@@ -158,11 +155,12 @@ execute_revert_property (Context *context,
 	}
       
       SCM symbol = scm_car (grob_property_path);
-
       if (scm_is_pair (scm_cdr (grob_property_path)))
 	{
 	  SCM current_sub_alist = ly_assoc_get (symbol, current_alist, SCM_EOL);
-	  SCM new_val = nested_property_revert_alist (current_sub_alist, scm_cdr (grob_property_path));
+	  SCM new_val
+	    = nested_property_revert_alist (current_sub_alist,
+					    scm_cdr (grob_property_path));
 	    
 	  if (scm_is_pair (current_alist)
 	      && scm_caar (current_alist) == symbol
@@ -179,17 +177,20 @@ execute_revert_property (Context *context,
 	  if (new_alist == daddy)
 	    context->unset_property (context_property);
 	  else
-	    context->set_property (context_property, scm_cons (new_alist, daddy));
+	    context->set_property (context_property,
+				   scm_cons (new_alist, daddy));
 	}
     }
 }
-
+/*
+  Convenience: a push/pop grob property using a single grob_property
+  as argument.
+*/
 void
 execute_pushpop_property (Context *context,
 			  SCM context_property,
 			  SCM grob_property,
-			  SCM new_value
-			  )
+			  SCM new_value)
 {
   general_pushpop_property (context, context_property,
 			    scm_list_1 (grob_property),
@@ -214,14 +215,14 @@ apply_property_operations (Context *tg, SCM pre_init_ops)
 	  SCM context_prop = scm_car (entry);
 	  SCM val = scm_cadr (entry);
 	  SCM grob_prop_path = scm_cddr (entry);
-	  execute_general_pushpop_property (tg, context_prop, grob_prop_path, val);
+	  sloppy_general_pushpop_property (tg, context_prop, grob_prop_path, val);
 	}
       else if (type == ly_symbol2scm ("pop"))
 	{
 	  SCM context_prop = scm_car (entry);
 	  SCM val = SCM_UNDEFINED;
 	  SCM grob_prop_path = scm_cdr (entry);
-	  execute_general_pushpop_property (tg, context_prop, grob_prop_path, val);
+	  sloppy_general_pushpop_property (tg, context_prop, grob_prop_path, val);
 	}
       else if (type == ly_symbol2scm ("assign"))
 	tg->set_property (scm_car (entry), scm_cadr (entry));