Incular Docs

PopScope guards its subtree against pops; NavigatorPopHandlerController gives nested navigators first refusal with an optional result handler.

use incular::prelude::*;

fn main() {
    let controller = NavigatorPopHandlerController::new();
    controller.set_enabled(true);
    controller.set_can_pop(false);
    let guarded = controller.can_pop();
    let app = Application::new(move |_cx| {
        Container::builder()
            .padding(EdgeInsets::all(24.0))
            .alignment(Alignment::CENTER)
            .child(
                PopScope::new(Text::new("Guarded"))
                    .can_pop(guarded)
                    .on_pop_invoked(|_did_pop| println!("pop attempted")),
            )
            .build()
            .into()
    })
    .expect("valid application");
    incular::run(app).expect("run application");
}

Related: Back Dispatch, Navigator.