feat: better error handling

errors during the upload are now shown in a separate user-friendly alert
dialog, and you can also choose to upload the file to no folder

src/relm.rs

@@ -0,0 +1,82 @@
+use relm4::{
+    SimpleComponent,
+    adw::{self, prelude::*},
+    gtk::glib::clone,
+};
+
+pub struct Dialog {
+    window: adw::ApplicationWindow,
+    visible: bool,
+    heading: String,
+    body: String,
+}
+
+#[derive(Debug)]
+pub enum DialogInput {
+    Show { heading: String, body: String },
+    Dismiss,
+}
+
+pub struct DialogWidgets {
+    dialog: adw::AlertDialog,
+}
+
+impl SimpleComponent for Dialog {
+    type Init = adw::ApplicationWindow;
+    type Root = adw::AlertDialog;
+    type Widgets = DialogWidgets;
+    type Input = DialogInput;
+    type Output = ();
+
+    fn init_root() -> Self::Root {
+        let dialog = adw::AlertDialog::builder().close_response("ok").build();
+        dialog.add_response("ok", "OK");
+        dialog
+    }
+
+    fn init(
+        window: Self::Init,
+        root: Self::Root,
+        sender: relm4::ComponentSender<Self>,
+    ) -> relm4::ComponentParts<Self> {
+        let model = Self {
+            window,
+            visible: false,
+            heading: String::new(),
+            body: String::new(),
+        };
+
+        root.connect_response(
+            None,
+            clone!(
+                #[strong]
+                sender,
+                move |_, _| sender.input(DialogInput::Dismiss)
+            ),
+        );
+
+        let widgets = DialogWidgets { dialog: root };
+
+        relm4::ComponentParts { model, widgets }
+    }
+
+    fn update(&mut self, message: Self::Input, _sender: relm4::ComponentSender<Self>) {
+        match message {
+            DialogInput::Show { heading, body } => {
+                self.heading = heading;
+                self.body = body;
+                self.visible = true;
+            }
+            DialogInput::Dismiss => self.visible = false,
+        }
+    }
+
+    fn update_view(&self, widgets: &mut Self::Widgets, _sender: relm4::ComponentSender<Self>) {
+        widgets.dialog.set_heading(Some(&self.heading));
+        widgets.dialog.set_body(&self.body);
+
+        if self.visible {
+            widgets.dialog.present(Some(&self.window));
+        }
+    }
+}