str: Add function xstrdup_if_nonnull() and introduce many users.

[pspp] / src / output / output-item.c

diff --git a/src/output/output-item.c b/src/output/output-item.c
index e1c889ffe33b09967f3bcf798198ed825363fe05..cd37031b654b628711fc63dafc4faca3cf795e8b 100644 (file)
--- a/src/output/output-item.c
+++ b/src/output/output-item.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2009 Free Software Foundation, Inc.
+   Copyright (C) 2009, 2011 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -16,15 +16,18 @@
 
 #include <config.h>
 
-#include <output/output-item-provider.h>
+#include "output/output-item-provider.h"
 
 #include <assert.h>
 #include <stdlib.h>
 
-#include <libpspp/assertion.h>
-#include <libpspp/cast.h>
+#include "libpspp/assertion.h"
+#include "libpspp/cast.h"
+#include "libpspp/str.h"
 
-#include "xalloc.h"
+#include "gl/xalloc.h"
+
+#include "gettext.h"
 \f
 /* Increases ITEM's reference count, indicating that it has an additional
    owner.  An output item that is shared among multiple owners must not be
@@ -46,7 +49,11 @@ output_item_unref (struct output_item *item)
     {
       assert (item->ref_cnt > 0);
       if (--item->ref_cnt == 0)
-        item->class->destroy (item);
+        {
+          char *label = item->label;
+          item->class->destroy (item);
+          free (label);
+        }
     }
 }
 
@@ -57,17 +64,34 @@ output_item_is_shared (const struct output_item *item)
 {
   return item->ref_cnt > 1;
 }
-\f
-/* Initializes ITEM as an output item of the specified CLASS, initially with a
-   reference count of 1.
 
-   An output item is an abstract class, that is, a plain output_item is not
-   useful on its own.  Thus, this function is normally called from the
-   initialization function of some subclass of output_item. */
+/* Returns the label for ITEM, which the caller must not modify or free. */
+const char *
+output_item_get_label (const struct output_item *item)
+{
+  return item->label ? item->label : item->class->get_label (item);
+}
+
+/* Sets the label for ITEM to LABEL.  The caller retains ownership of LABEL.
+   If LABEL is nonnull, it overrides any previously set label and the default
+   label.  If LABEL is null, ITEM will now use its default label.
+
+   ITEM must not be shared. */
+void
+output_item_set_label (struct output_item *item, const char *label)
+{
+  output_item_set_label_nocopy (item, xstrdup_if_nonnull (label));
+}
+
+/* Sets the label for ITEM to LABEL, transferring ownership of LABEL to ITEM.
+   If LABEL is nonnull, it overrides any previously set label and the default
+   label.  If LABEL is null, ITEM will now use its default label.
+
+   ITEM must not be shared. */
 void
-output_item_init (struct output_item *item,
-                  const struct output_item_class *class)
+output_item_set_label_nocopy (struct output_item *item, char *label)
 {
-  item->class = class;
-  item->ref_cnt = 1;
+  assert (!output_item_is_shared (item));
+  free (item->label);
+  item->label = label;
 }