Emit a critical warning if features are not initialized

If you forgot to call clutter_init() then you currently end up with a
warning saying that the stage cannot be initialized because the backend
does not support multiple stages. Clearly not useful.

We can catch some of the missing initialization in the features API,
since we will likely end up asking for a feature at some point.

1 files changed, 10 insertions, 1 deletions

diff --git a/clutter/clutter-feature.c b/clutter/clutter-feature.c
index 74bf87ba0..282783e2e 100644
--- a/clutter/clutter-feature.c
+++ b/clutter/clutter-feature.c
@@ -131,7 +131,10 @@ gboolean
 clutter_feature_available (ClutterFeatureFlags feature)
 {
   if (G_UNLIKELY (!__features))
-    return FALSE;
+    {
+      g_critical ("Unable to check features. Have you initialized Clutter?");
+      return FALSE;
+    }
 
   return (__features->flags & feature);
 }
@@ -148,6 +151,12 @@ clutter_feature_available (ClutterFeatureFlags feature)
 ClutterFeatureFlags
 clutter_feature_get_all (void)
 {
+  if (G_UNLIKELY (!__features))
+    {
+      g_critical ("Unable to check features. Have you initialized Clutter?");
+      return FALSE;
+    }
+
   return __features->flags;
 }