2 files changed, 9 insertions, 0 deletions
diff --git a/src/Gtk/Signal.dcl b/src/Gtk/Signal.dcl
index e4ce83b..d9e4a7d 100644
--- a/src/Gtk/Signal.dcl
+++ b/src/Gtk/Signal.dcl
@@ -3,6 +3,7 @@ definition module Gtk.Signal
 from System._Pointer import :: Pointer
 
 from Gtk.State import :: GtkM, :: GtkState
+from Gtk.Tune import class tune
 from Gtk.Widgets import class gtkWidget
 
 class signalHandler h
@@ -10,6 +11,8 @@ where
 	signalName :: !h -> String
 	signalHandler :: !h -> SignalHandlerInternal
 
+:: SignalHandler = E.h: SignalHandler h & signalHandler h
+
 :: GSignalHandler
 	= DestroyHandler  !(GtkM ())
 	| ActivateHandler !(GtkM ())
@@ -22,6 +25,8 @@ instance signalHandler GSignalHandler
 
 installSignalHandler :: !h !w -> GtkM w | signalHandler h & gtkWidget w
 
+instance tune w SignalHandler | gtkWidget w
+
 saveState :: GtkM ()
 retrieveState :: GtkM GtkState
 handleSignal :: !Int !{#Int} -> Int
diff --git a/src/Gtk/Signal.icl b/src/Gtk/Signal.icl
index e51614c..040d6f7 100644
--- a/src/Gtk/Signal.icl
+++ b/src/Gtk/Signal.icl
@@ -36,6 +36,10 @@ installSignalHandler handler widget =
 			-> g_signal_connect 2 (toPtr (gtkWidget widget)) (signalName handler) id) >>|
 	pure widget
 
+instance tune w SignalHandler | gtkWidget w
+where
+	tune (SignalHandler handler) widget = installSignalHandler handler widget
+
 // NB: low-level hacking to use and modify the GtkState from within callbacks.
 // We use a CAF to keep track of the state. In runGtk, the state is saved with
 // saveState. This state is retrieved with retrieveState there (to check