add_focus_handler

Description:

[ Version ( deprecated = true , deprecated_since = "2.9.4" ) ]
public abstract uint add_focus_handler (FocusHandler handler)

Warning: add_focus_handler is deprecated since 2.9.4.

Add the specified handler to the set of functions to be called when this object receives focus events (in or out).

Note:

If you need to track when an object gains or lose the focus, use the state_change "focused" notification instead.

If the handler is already added it is not added again

this	The Component to attach the `handler` to
handler	The FocusHandler to be attached to this

a handler id which can be used in remove_focus_handler or zero if the handler was already added.