FlowBox.setFilterFunc

By setting a filter function on the box one can decide dynamically which of the children to show.

For instance, to implement a search function that only shows the children matching the search terms.

The filter_func will be called for each child after the call, and it will continue to be called each time a child changes (via [gtk.flow_box_child.FlowBoxChild.changed]) or when [gtk.flow_box.FlowBox.invalidateFilter] is called.

Note that using a filter function is incompatible with using a model (see [gtk.flow_box.FlowBox.bindModel]).