face down top of deck card goes away when deck is empty

src/play.rs

@@ -1,6 +1,11 @@
 use bevy::{prelude::*, utils::RandomState};
 
-use crate::{deck::Card, menu::UiMessage, setup::AnimationStore, view::ViewState};
+use crate::{
+    deck::Card,
+    menu::UiMessage,
+    setup::{AnimationStore, TopCard},
+    view::ViewState,
+};
 
 pub struct PlayPlugin;
 
@@ -194,13 +199,25 @@ fn serve_cards(
     _trigger: Trigger<ServeCards>,
     in_deck: Query<(Entity, &Card, &DeckOrder)>,
     spots: Query<&PlayLocation>,
+    mut top_card: Single<&mut Visibility, With<TopCard>>,
     mut commands: Commands,
 ) {
     info!(
         "Serving cards from deck ({} cards left)",
         in_deck.iter().len()
     );
+    if in_deck.is_empty() {
+        commands.trigger(UiMessage("Deck's empty!".into()));
+        top_card.toggle_visible_hidden();
+        top_card.toggle_inherited_hidden();
+        return;
+    }
+
     let mut n = in_deck.iter().len().saturating_sub(1);
+    if n == 0 {
+        top_card.toggle_visible_hidden();
+        top_card.toggle_inherited_hidden();
+    }
 
     // Iterate over every x, y play location
     for this_x in 0..=3 {
@@ -216,6 +233,11 @@ fn serve_cards(
                     .iter()
                     .find(|(_entity, _deck_card, order)| order.0 == n as u8);
                 n = n.saturating_sub(1);
+                if n == 0 {
+                    top_card.toggle_visible_hidden();
+                    top_card.toggle_inherited_hidden();
+                }
+
                 // If that search was fruitful, pull the card from the deck and play it
                 if let Some((e, _, _)) = candidate {
                     commands

src/setup.rs

@@ -32,6 +32,9 @@ pub(crate) struct AnimationStore {
     pub store: HashMap<String, (AnimationGraphHandle, AnimationNodeIndex)>,
 }
 
+#[derive(Component)]
+pub(crate) struct TopCard;
+
 /// Setup drawing our cards on the screen
 pub(crate) fn setup_cards(
     mut commands: Commands,
@@ -69,7 +72,12 @@ pub(crate) fn setup_cards(
                     image: server.load("cards.png"),
                     ..default()
                 };
-                parent.spawn((top_card_transform, top_card_sprite, Visibility::Inherited));
+                parent.spawn((
+                    top_card_transform,
+                    top_card_sprite,
+                    Visibility::Inherited,
+                    TopCard,
+                ));
             }
             Deck::iter_shuffled()
                 .enumerate()