Save and load creative toolbars with the toolbar keys

crates/horizon-client/src/game.rs

@@ -34,6 +34,7 @@ mod consume;
 mod control;
 mod copper_golems;
 mod creaking;
+mod creative_hotbar;
 mod creatures;
 mod crossbow;
 pub(crate) mod cushions;
@@ -11471,7 +11472,7 @@ impl Game<'_> {
             | KeyCode::Digit9
                 if self.screen == Screen::Playing =>
             {
-                self.selected = match key {
+                let slot = match key {
                     KeyCode::Digit1 => 0,
                     KeyCode::Digit2 => 1,
                     KeyCode::Digit3 => 2,
@@ -11482,6 +11483,15 @@ impl Game<'_> {
                     KeyCode::Digit8 => 7,
                     _ => 8,
                 };
+                // Minecraft.handleKeybinds: a creative player holding the load
+                // or save toolbar key loads or saves a toolbar instead (load
+                // first when both are held).
+                let load = self.mapped_key_down("key.loadToolbarActivator");
+                if self.creative && (load || self.mapped_key_down("key.saveToolbarActivator")) {
+                    self.hotbar_load_or_save(slot, load);
+                } else {
+                    self.selected = slot;
+                }
             }
             _ => {}
         }

crates/horizon-client/src/game/creative_hotbar.rs

@@ -0,0 +1,39 @@
+//! The creative toolbars, `hotbar.nbt` beside `options.txt`: hold the save or
+//! load key and press a hotbar key (`Minecraft.handleKeybinds`).
+use super::Game;
+use horizon_client::{hotbar, keybinds, text::Text};
+
+impl Game<'_> {
+    /// Whether the key bound to `mapping` is held.
+    pub(super) fn mapped_key_down(&self, mapping: &str) -> bool {
+        keybinds::key_code(self.settings.keys.get(mapping))
+            .is_some_and(|k| self.physical_keys.contains(&k))
+    }
+
+    /// `CreativeModeInventoryScreen.handleHotbarLoadOrSave` for the hotbar key
+    /// `index`: load puts the saved row in the hotbar (the creative slot
+    /// packets follow from the inventory change), save stores the hotbar and
+    /// says so on the action bar.
+    pub(super) fn hotbar_load_or_save(&mut self, index: usize, load: bool) {
+        let path = Self::options_path().with_file_name("hotbar.nbt");
+        let known = |id: &str| self.res.items().get(id).is_some();
+        let mut rows = hotbar::load(&path, &known);
+        if load {
+            for (slot, stack) in rows[index].iter().enumerate() {
+                self.inventory[slot] = stack.clone();
+            }
+            return;
+        }
+        rows[index] = self.inventory[..hotbar::SIZE].to_vec();
+        let _ = hotbar::save(&path, &rows);
+        let key = |mapping: &str| keybinds::display_name(self.settings.keys.get(mapping));
+        let message = Text::translate(
+            "inventory.hotbarSaved",
+            &[
+                key("key.loadToolbarActivator"),
+                key(&format!("key.hotbar.{}", index + 1)),
+            ],
+        );
+        self.titles.set_overlay(message, false);
+    }
+}

crates/horizon-client/src/hotbar.rs

@@ -119,3 +119,23 @@ pub fn load(path: &Path, known: &dyn Fn(&str) -> bool) -> Vec<Hotbar> {
         _ => (0..GROUPS).map(|_| empty()).collect(),
     }
 }
+
+/// `HotbarManager.save`: the nine rows with the current data version, each
+/// stack as `ItemStack.OPTIONAL_CODEC` writes it (an empty one is `{}`).
+pub fn save(path: &Path, rows: &[Hotbar]) -> crate::Result<()> {
+    let mut entries = vec![(
+        JavaString::from("DataVersion"),
+        Tag::Int(horizon_world::DATA_VERSION),
+    )];
+    for (i, row) in rows.iter().enumerate() {
+        let stacks = row.iter().map(|s| match s {
+            Some(s) => save::item_to_nbt(s),
+            None => Tag::compound(Vec::<(&str, Tag)>::new()),
+        });
+        entries.push((
+            JavaString::from(i.to_string().as_str()),
+            Tag::List(stacks.collect()),
+        ));
+    }
+    save::write_dat(path, Tag::compound(entries))
+}