Struct Inventory 

pub struct Inventory {
    pub held_slot: u8,
    pub slots: [Slot; 36],
    pub cursor: Slot,
}

Player inventory — 36 slots (27 main + 9 hotbar).

Slot layout matches Minecraft’s raw player inventory:

• Slots 0–8: hotbar
• Slots 9–35: main inventory (3 rows of 9)

This matches the SetPlayerInventory packet (1.21.4) directly — no slot conversion needed when syncing individual slots.

For the player inventory window (SetContainerContent), slots remap: window 9-35 = main (our 9-35, same), window 36-44 = hotbar (our 0-8).

Fields

held_slot: u8

Currently selected hotbar index (0-8).

slots: [Slot; 36]

All 36 inventory slots (0-8 hotbar, 9-35 main).

cursor: Slot

Item currently held on the mouse cursor (in an open window).

Implementations

impl Inventory

pub const HOTBAR_START: usize = 0

First hotbar slot index within slots.

pub const MAIN_START: usize = 9

First main inventory slot index within slots.

pub fn empty() -> Self

Creates an empty inventory with slot 0 selected.

pub fn held_item(&self) -> &Slot

Returns the currently held item (from the hotbar).

pub fn hotbar(&self) -> &[Slot]

Returns a reference to the hotbar (9 slots).

pub fn hotbar_mut(&mut self) -> &mut [Slot]

Returns a mutable reference to the hotbar (9 slots).

pub fn window_to_index(window_slot: i16) -> Option<usize>

Converts a protocol window slot to an internal slot index.

Window layout: 9-35 = main, 36-44 = hotbar. Internal layout: 0-8 = hotbar, 9-35 = main.

pub fn index_to_window(index: usize) -> Option<i16>

Converts an internal slot index to a protocol window slot.

pub fn try_insert(&mut self, item_id: i32, count: i32) -> Option<usize>

Tries to insert an item into the inventory.

Searches hotbar first (for convenience), then main inventory. Tries matching stacks (count < 64) first, then empty slots. Returns Some(internal_index) if inserted, None if full.

pub fn to_protocol_slots(&self) -> Vec<Slot>

Builds the 46-slot protocol representation for SetContainerContent.

Window slot layout for player inventory (id=0): 0 = crafting output, 1-4 = crafting grid, 5-8 = armor, 9-35 = main inventory, 36-44 = hotbar, 45 = offhand.

Trait Implementations

impl Clone for Inventory

fn clone(&self) -> Inventory

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Inventory

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Component for Inventory