signal callback delegate or function to connect
void callback(string attName, gobject.value.Value attValue, gda.holder.Holder holder)
attName attribute's name (optional)
attValue attribute's value (optional)
holder the instance the signal is connected to (optional)
Yes.After to execute callback after default handler, No.After to execute before (default)
Signal ID
Connect to AttributeChanged signal.
Gets emitted when any holder's attribute has changed