InAppNotification: Remove reduntant Overlay.

hammond-gtk/src/app.rs

@@ -171,7 +171,7 @@ impl App {
 
                     let text = "Marked all episodes as listened";
                     let notif = InAppNotification::new(text.into(), callback, sender.clone());
-                    overlay.add_overlay(&notif.overlay);
+                    overlay.add_overlay(&notif.revealer);
                     // We need to display the notification after the widget is added to the overlay
                     // so there will be a nice animation.
                     notif.show();

hammond-gtk/src/appnotif.rs

@@ -10,8 +10,7 @@ use std::sync::mpsc::Sender;
 
 #[derive(Debug, Clone)]
 pub struct InAppNotification {
-    pub overlay: gtk::Overlay,
-    revealer: gtk::Revealer,
+    pub revealer: gtk::Revealer,
     text: gtk::Label,
     undo: gtk::Button,
     close: gtk::Button,
@@ -21,14 +20,12 @@ impl Default for InAppNotification {
     fn default() -> Self {
         let builder = gtk::Builder::new_from_resource("/org/gnome/hammond/gtk/inapp_notif.ui");
 
-        let overlay: gtk::Overlay = builder.get_object("overlay").unwrap();
         let revealer: gtk::Revealer = builder.get_object("revealer").unwrap();
         let text: gtk::Label = builder.get_object("text").unwrap();
         let undo: gtk::Button = builder.get_object("undo").unwrap();
         let close: gtk::Button = builder.get_object("close").unwrap();
 
         InAppNotification {
-            overlay,
             revealer,
             text,
             undo,