styleproperty: Default to transparent background-color

diff --git a/gtk/gtkstyleproperty.c b/gtk/gtkstyleproperty.c
index 483feaab02a3289cbc08c166920a6f9da16e42ff..a27d0775a4f81cbf4340dd7e46ac5b650232afd6 100644 (file)
--- a/gtk/gtkstyleproperty.c
+++ b/gtk/gtkstyleproperty.c
@@ -2156,6 +2156,16 @@ border_image_width_default_value (GtkStyleProperties *props,
 {
 }
 
+static void
+background_color_default_value (GtkStyleProperties *props,
+                                GtkStateFlags       state,
+                                GValue             *value)
+{
+  GdkRGBA transparent_black = { 0, 0, 0, 0 };
+
+  g_value_set_boxed (value, &transparent_black);
+}
+
 static void
 border_color_default_value (GtkStyleProperties *props,
                             GtkStateFlags       state,
@@ -2561,7 +2571,7 @@ gtk_style_property_init (void)
                                           NULL,
                                           NULL,
                                           NULL,
-                                          NULL,
+                                          background_color_default_value,
                                           NULL);
 
   _gtk_style_property_register           (g_param_spec_boxed ("font-family",