build: autogenerate enum/flags string getter/builders

Each enum will have its own #_get_string (),
and each flags will have its own #_build_string_from_mask ().

2 files changed, 95 insertions, 15 deletions

diff --git a/build-aux/mm-enums-template.c b/build-aux/mm-enums-template.c
index 1e789c396..7f12c2c59 100644
--- a/build-aux/mm-enums-template.c
+++ b/build-aux/mm-enums-template.c
@@ -7,30 +7,96 @@
 /*** END file-production ***/
 
 /*** BEGIN value-header ***/
+static const G@Type@Value @enum_name@_values[] = {
+/*** END value-header ***/
+/*** BEGIN value-production ***/
+    { @VALUENAME@, "@VALUENAME@", "@valuenick@" },
+/*** END value-production ***/
+/*** BEGIN value-tail ***/
+    { 0, NULL, NULL }
+};
+
+/* Define type-specific symbols */
+#undef IS_ENUM
+#undef IS_FLAGS
+#define IS_@TYPE@
+
 GType
 @enum_name@_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+    static volatile gsize g_define_type_id__volatile = 0;
 
-  if (g_once_init_enter (&g_define_type_id__volatile))
-    {
-      static const G@Type@Value values[] = {
-/*** END value-header ***/
+    if (g_once_init_enter (&g_define_type_id__volatile)) {
+        GType g_define_type_id =
+            g_@type@_register_static (g_intern_static_string ("@EnumName@"),
+                                      @enum_name@_values);
+        g_once_init_leave (&g_define_type_id__volatile, g_define_type_id);
+    }
 
-/*** BEGIN value-production ***/
-        { @VALUENAME@, "@VALUENAME@", "@valuenick@" },
-/*** END value-production ***/
+    return g_define_type_id__volatile;
+}
 
-/*** BEGIN value-tail ***/
-        { 0, NULL, NULL }
-      };
-      GType g_define_type_id =
-        g_@type@_register_static (g_intern_static_string ("@EnumName@"), values);
-      g_once_init_leave (&g_define_type_id__volatile, g_define_type_id);
+/* Enum-specific method to get the value as a string.
+ * We get the nick of the GEnumValue. Note that this will be
+ * valid even if the GEnumClass is not referenced anywhere. */
+#if defined IS_ENUM
+const gchar *
+@enum_name@_get_string (@EnumName@ val)
+{
+    guint i;
+
+    for (i = 0; @enum_name@_values[i].value_nick; i++) {
+        if (val == @enum_name@_values[i].value)
+            return @enum_name@_values[i].value_nick;
+    }
+
+    return NULL;
+}
+#endif /* IS_ENUM */
+
+/* Flags-specific method to build a string with the given mask.
+ * We get a comma separated list of the nicks of the GFlagsValues.
+ * Note that this will be valid even if the GFlagsClass is not referenced
+ * anywhere. */
+#if defined IS_FLAGS
+gchar *
+@enum_name@_build_string_from_mask (@EnumName@ mask)
+{
+    guint i;
+    gboolean first = TRUE;
+    GString *str = NULL;
+
+    for (i = 0; @enum_name@_values[i].value_nick; i++) {
+        /* We also look for exact matches */
+        if (mask == @enum_name@_values[i].value) {
+            if (str)
+                g_string_free (str, TRUE);
+            return g_strdup (@enum_name@_values[i].value_nick);
+        }
+
+        /* Build list with single-bit masks */
+        if (mask & @enum_name@_values[i].value) {
+            guint c;
+            gulong number = @enum_name@_values[i].value;
+
+            for (c = 0; number; c++)
+                number &= number - 1;
+
+            if (c == 1) {
+                if (!str)
+                    str = g_string_new ("");
+                g_string_append_printf (str, "%s%s",
+                                        first ? "" : ", ",
+                                        @enum_name@_values[i].value_nick);
+                if (first)
+                    first = FALSE;
+            }
+        }
     }
 
-  return g_define_type_id__volatile;
+    return (str ? g_string_free (str, FALSE) : NULL);
 }
+#endif /* IS_FLAGS */
 
 /*** END value-tail ***/
 
diff --git a/build-aux/mm-enums-template.h b/build-aux/mm-enums-template.h
index df4aa01f7..13db2a6d8 100644
--- a/build-aux/mm-enums-template.h
+++ b/build-aux/mm-enums-template.h
@@ -13,6 +13,20 @@ G_BEGIN_DECLS
 /*** BEGIN value-header ***/
 GType @enum_name@_get_type (void) G_GNUC_CONST;
 #define @ENUMPREFIX@_TYPE_@ENUMSHORT@ (@enum_name@_get_type ())
+
+/* Define type-specific symbols */
+#undef IS_ENUM
+#undef IS_FLAGS
+#define IS_@TYPE@
+
+#if defined IS_ENUM
+const gchar *@enum_name@_get_string (@EnumName@ val);
+#endif
+
+#if defined IS_FLAGS
+gchar *@enum_name@_build_string_from_mask (@EnumName@ mask);
+#endif
+
 /*** END value-header ***/
 
 /*** BEGIN file-tail ***/