fix: show loading spinner during startup

src/main.rs

@@ -12,6 +12,7 @@ use relm4::{
     Component, ComponentController, Controller, RelmApp, Sender,
     adw::{self, prelude::*},
     gtk::{self, gio},
+    loading_widgets::LoadingWidgets,
     prelude::{AsyncComponent, AsyncComponentParts},
     tokio,
 };
@@ -264,8 +265,6 @@ impl AsyncComponent for Tyrolienne {
                 .forward(sender.input_sender(), |_| Message::Nothing),
         };
 
-        // TODO consider using the "loading" (?) mechanism from relm4
-        // https://relm4.org/book/stable/threads_and_async/async.html
         let folders = match zipline::get_folders(&model.config).await {
             Ok(v) => v,
             Err(e) => {
@@ -296,6 +295,21 @@ impl AsyncComponent for Tyrolienne {
         AsyncComponentParts { model, widgets }
     }
 
+    fn init_loading_widgets(root: Self::Root) -> Option<LoadingWidgets> {
+        relm4::view! {
+            #[local]
+            root {
+                #[name(spinner)]
+                gtk::Spinner {
+                    start: (),
+                    set_halign: gtk::Align::Center,
+                }
+            }
+        }
+
+        Some(LoadingWidgets::new(root, spinner))
+    }
+
     async fn update(
         &mut self,
         message: Self::Input,