Clarify the action propagation behaviour in custom control development guide

Change-Id: I492c0e5275f89ea4370b5c22e33d4f1af4f4750f

diff --git a/docs/content/programming-guide/type-registration.h b/docs/content/programming-guide/type-registration.h
index bef67d0..e9912ef 100644 (file)
--- a/docs/content/programming-guide/type-registration.h
+++ b/docs/content/programming-guide/type-registration.h
@@ -184,6 +184,10 @@ bool MyControl::DoAction(
 }
 @endcode
 
+If the action is not performed by the derived class, it will be propagated to the base class.
+For example, in the above case, MyControl can perform "action1" so should return true, but it
+cannot perform "action4" so should return false and propagate the action to Control.
+
 @section register-property Registering a Property
 
 DALi has a property system which can be extended by registering more properties through the type