Evas Smart: add ability to get usage count

SVN revision: 59341

legacy/evas/ChangeLog

@@ -327,3 +327,9 @@
 
 	* Textblock: Added evas_textblock_node_format_list_get. This is very
 	  useful for edje_entry that uses anchors in the text.
+
+2011-05-12  Carsten Haitzler (The Rasterman)
+
+	* Add smart instance usage count get function for ability to free
+        data from memory from a smart class if needed.
+

legacy/evas/src/lib/Evas.h

@@ -6708,6 +6708,28 @@ EAPI const Evas_Smart_Cb_Description *evas_smart_callback_description_find(const
  *        using regular memcpy().
  */
 EAPI Eina_Bool                        evas_smart_class_inherit_full       (Evas_Smart_Class *sc, const Evas_Smart_Class *parent_sc, unsigned int parent_sc_size) EINA_ARG_NONNULL(1, 2);
+
+/**
+ * Get the number of users of the smart instance
+ * 
+ * @param s The Evas_Smart to get the usage count of
+ * @return The number of uses of the smart instance
+ * 
+ * This function tells you how many more uses of the smart instance are in
+ * existance. This should be used before freeing/clearing any of the
+ * Evas_Smart_Class that was used to create the smart instance. The smart
+ * instance will refer to data in the Evas_Smart_Class used to create it and
+ * thus you cannot remove the original data until all users of it are gone.
+ * When the usage count goes to 0, you can evas_smart_free() the smart
+ * instance @p s and remove from memory any of the Evas_Smart_Class that
+ * was used to create the smart instance, if you desire. Removing it from
+ * memory without doing this will cause problems (crashes, undefined
+ * behavior etc. etc.), so either never remove the original 
+ * Evas_Smart_Class data from memory (have it be a constant structure and
+ * data), or use this API call and be very careful.
+ */
+EAPI int                              evas_smart_usage_get(const Evas_Smart *s);
+         
   /**
    * @def evas_smart_class_inherit
    * Easy to use version of evas_smart_class_inherit_full().

legacy/evas/src/lib/canvas/evas_smart.c

@@ -112,6 +112,16 @@ evas_smart_class_inherit_full(Evas_Smart_Class *sc, const Evas_Smart_Class *pare
    return 1;
 }
 
+EAPI int
+evas_smart_usage_get(const Evas_Smart *s)
+{
+   MAGIC_CHECK(s, Evas_Smart, MAGIC_SMART);
+   return 0;
+   MAGIC_CHECK_END();
+   return s->usage;
+}
+
+
 /* internal funcs */
 void
 evas_object_smart_use(Evas_Smart *s)