set_filter_func

Sets the function used for filtering items.

If match_func is `NULL`, the filter matches all items.

If the filter func changes its filtering behavior, [method@Gtk.Filter.changed] needs to be called.

If a previous function was set, its user_destroy will be called.

Parameters:

this	a custom filter
match_func	function to filter items
user_data	user data to pass to match_func
user_destroy	destroy notify for user_data