css provider: Make not subclassable

Part of being more explicit about what
we allow to be subclassed and what not.

1 files changed, 8 insertions, 0 deletions

diff --git a/gtk/gtkcssprovider.c b/gtk/gtkcssprovider.c
index f3dfa9922b..6d6571b59b 100644
--- a/gtk/gtkcssprovider.c
+++ b/gtk/gtkcssprovider.c
@@ -73,6 +73,14 @@
  * way back to 4.0.
  */
 
+struct _GtkCssProviderClass
+{
+  GObjectClass parent_class;
+
+  void (* parsing_error)                        (GtkCssProvider  *provider,
+                                                 GtkCssSection   *section,
+                                                 const GError *   error);
+};
 
 typedef struct GtkCssRuleset GtkCssRuleset;
 typedef struct _GtkCssScanner GtkCssScanner;