Add hook for state changes on a playback

1 files changed, 7 insertions, 1 deletions

diff --git a/guile/starlet/state.scm b/guile/starlet/state.scm
index 35db6bd..a9aa6b4 100644
--- a/guile/starlet/state.scm
+++ b/guile/starlet/state.scm
@@ -50,7 +50,8 @@
             sel
             selection-hook
             value->number
-            atomically-overlay-state!))
+            atomically-overlay-state!
+            update-state!))
 
 
 ;; A "state" is an atomically-updating container for an immutable
@@ -83,6 +84,11 @@
         col)))
 
 
+(define-method (update-state! (state <starlet-state>))
+  ;; Basic state object needs no updates
+  #f)
+
+
 (define-method (set-in-state! (state <starlet-state>)
                               (fix <fixture>)
                               (attr <colour-component-id>)