Code review request: disablable widget

[agluszak]

I wrote a function which takes a widget which "uses" a variable of type T and transforms it into a disablable widget which "uses" a variable of type Option<T>. If the widget becomes, disabled None is assigned to the variable and the old value is remembered.

pub fn disablable_ui<T, F>(value: &mut Option<T>, id: Id, ui: &mut Ui, widget: F) -> Response
where
    T: Clone + Default + Send + Sync + 'static,
    F: FnOnce(&mut T, &mut Ui) -> Response,
{
    let response = ui.horizontal(|ui| {
        let state_id = ui.id().with(id);

        let mut enabled = value.is_some();
        let previous_value = ui.data().get_temp::<T>(state_id).unwrap_or_default();

        let mut response = ui
            .add(egui::SelectableLabel::new(
                enabled,
                if enabled { "Disable" } else { "Enable" },
            ));

        if response.clicked() {
            enabled = !enabled;
            response.mark_changed();
        }

        if enabled {
            if value.is_none() {
                *value = Some(previous_value);
            }
            let value = value.as_mut().unwrap();
            let widget_response = ui.add_enabled_ui(true, |ui| widget(value, ui));
            ui.data().insert_temp(state_id, value.clone());
            response |= widget_response.inner;
        } else {
            *value = None;
            let mut value = previous_value;
            ui.add_enabled_ui(false, |ui| widget(&mut value, ui));
        }

        ui.data().insert_temp(state_id, enabled);
        response
    });
    response.inner | response.response
}

pub fn disablable<'value, T, F>(
    value: &'value mut Option<T>,
    id: Id,
    widget: F,
) -> impl egui::Widget + 'value
where
    T: Clone + Default + Send + Sync + 'static,
    F: FnOnce(&mut T, &mut Ui) -> Response + 'value,
{
    move |ui: &mut Ui| disablable_ui(value, id, ui, widget)
}

I'm pretty sure that the response handling can be simplified, especially that currently I pass the response in InnerResponse's inner field.