add unsupported dialogue to be shown if not all prerequisits are fulfilled

src/app.rs

@@ -11,8 +11,10 @@ use gtk::{gio, glib};
 
 use crate::config::{APP_ID, PROFILE};
 use crate::modals::about::AboutDialog;
+use crate::modals::unsupported::UnsupportedDialog;
 
 pub(super) struct App {
+    unsupported_dialog: Controller<UnsupportedDialog>,
     about_dialog: Controller<AboutDialog>,
 }
 
@@ -96,7 +98,15 @@ impl SimpleComponent for App {
             .launch(())
             .detach();
 
-        let model = Self { about_dialog };
+        let unsupported_dialog = UnsupportedDialog::builder()
+            .transient_for(root)
+            .launch(())
+            .detach();
+
+        let model = Self {
+            about_dialog,
+            unsupported_dialog,
+        };
 
         let widgets = view_output!();
 
@@ -116,6 +126,9 @@ impl SimpleComponent for App {
             })
         };
 
+        let sender = model.unsupported_dialog.sender().clone();
+        sender.send(()).unwrap();
+
         actions.add_action(shortcuts_action);
         actions.add_action(about_action);
         actions.register_for_widget(&widgets.main_window);

src/main.rs

@@ -42,6 +42,7 @@ fn main() {
     app.set_accelerators_for_action::<QuitAction>(&["<Control>q"]);
 
     let app = RelmApp::from_app(app);
+    relm4_icons::initialize_icons();
 
     app.run::<App>(());
 }

src/modals/mod.rs

@@ -1 +1,2 @@
 pub mod about;
+pub mod unsupported;

src/modals/unsupported.rs

@@ -0,0 +1,49 @@
+use adw::StatusPage;
+use gtk::prelude::GtkWindowExt;
+use relm4::view;
+use relm4::{adw, gtk, ComponentParts, ComponentSender, SimpleComponent};
+use relm4_icons::icon_name;
+pub struct UnsupportedDialog {}
+
+impl SimpleComponent for UnsupportedDialog {
+    type Init = ();
+    type Widgets = adw::Window;
+    type Input = ();
+    type Output = ();
+    type Root = adw::Window;
+
+    fn init_root() -> Self::Root {
+        adw::Window::builder().build()
+    }
+
+    fn init(
+        _: Self::Init,
+        root: &Self::Root,
+        _sender: ComponentSender<Self>,
+    ) -> ComponentParts<Self> {
+        let model = Self {};
+
+        view! {
+                    widgets = root.clone() {
+                        set_hide_on_close: true,
+                        set_modal: true,
+                        set_resizable: false,
+                        set_default_width: 400,
+
+                        StatusPage::new() {
+                            set_icon_name: Some(icon_name::ISSUE),
+                            set_title: "Missing requirements",
+                            set_description: Some("Make sure Toolbx and Gnome Terminal are installed."),
+                            set_child: Some(&gtk::Button::with_label("Goodbye!")),
+                        },
+                }
+        }
+        // TODO: when dialgue closes close application
+        // TODO: close application on button press
+        ComponentParts { model, widgets }
+    }
+
+    fn update_view(&self, dialog: &mut Self::Widgets, _sender: ComponentSender<Self>) {
+        dialog.present();
+    }
+}