From: David Nalesnik <david.nalesnik@gmail.com>
Date: Sat, 14 Feb 2015 20:45:07 +0000 (-0600)
Subject: Add Scheme function to return column associated with Item.
X-Git-Tag: release/2.19.16-1~2^2~5
X-Git-Url: https://git.donarmstrong.com/?p=lilypond.git;a=commitdiff_plain;h=2245ccb1308303639f07ccbbc6788957993248cc

Add Scheme function to return column associated with Item.

The C++ function Paper_column::get_column is used frequently,
and it makes sense to have a Scheme function which performs
the same task.  An example of a practical application
is the request by users to return the location of a particular
grob in a score: this is done by examining the PaperColumn
or NonMusicalPaperColumn associated with the grob.
---

diff --git a/lily/item-scheme.cc b/lily/item-scheme.cc
index 0e6b71ef30..24ccf5bf0d 100644
--- a/lily/item-scheme.cc
+++ b/lily/item-scheme.cc
@@ -19,6 +19,7 @@
 */
 
 #include "item.hh"
+#include "paper-column.hh"
 
 LY_DEFINE (ly_item_p, "ly:item?",
            1, 0, 0, (SCM g),
@@ -39,3 +40,17 @@ LY_DEFINE (ly_item_break_dir, "ly:item-break-dir",
   Item *me = Item::unsmob (it);
   return scm_from_int (me->break_status_dir ());
 }
+
+LY_DEFINE (ly_item_get_column, "ly:item-get-column",
+           1, 0, 0, (SCM it),
+           "Return the @code{PaperColumn} or @code{NonMusicalPaperColumn}"
+           " associated with this @code{Item}.")
+{
+  LY_ASSERT_SMOB (Item, it, 1);
+  Item *me = Item::unsmob (it);
+
+  if (Paper_column *col = me->get_column ())
+    return col->self_scm ();
+
+  return SCM_EOL;
+}