Locked Cancel Slot

public class MyScreenHandler extends AbstractContainerMenu {
    private final Container container;

    public MyScreenHandler(MenuType<?> menuType, int syncId, Inventory inv) {
        super(menuType, syncId);
        this.container = new SimpleContainer(54); // A simple container with 54 slots (6 rows of 9)

        // Create the item that will be displayed in the locked cancel slot
        ItemStack cancel = new ItemStack(SrpxItems.CANCEL_ITEM);
        cancel.set(DataComponents.CUSTOM_NAME, MessageUtils.getDeserializedText("<dark_red><b><u>Cancel"));
        cancel.set(DataComponents.LORE, new ItemLore(List.of(
                MessageUtils.getDeserializedText("<red>Click to <b>close</b> this menu")
        )));

        // Add the locked cancel slot to the container
        for (int i = 0; i < 54; i++) {
            // Used to calculate the x and y position of the slot in the GUI
            int x = SlotUtils.getXPos(i);
            int y = SlotUtils.getYPos(i);

            if (i == 53) { // The last slot in the GUI (bottom right corner)
                container.setItem(i, cancel);
                /* With the Slots multiple constructors, you can easily configure the sound that is played when the slot is interacted with.
                 * Example:
                 * LockedCancelSlot(container, i, x, y) - Plays the default click sound from the SI: Essentials Common Cnfg when clicked
                 * LockedCancelSlot(container, i, x, y, false) - Disables the sound when clicked
                 * LockedCancelSlot(container, i, x, y, true, SoundType.PRIVATE, SoundSource.MASTER, SoundEvents.LEVER_CLICK, 0.8f, 1.0f) - Plays the lever click sound at volume 0.8 and pitch 1.0 for the player that clicked the slot
                 */
                this.addSlot(new LockedCancelSlot(container, i, x, y));
                continue; // Skip the rest of this loop iteration
            }

            // Fill up other slots (will break the GUI if not not all slots are filled up)
            // You could set this to ItemStack.EMPTY
            container.setItem(i, new ItemStack(Items.BLACK_STAINED_GLASS_PANE));
            // The locked slot doesn't allow any interactions with it (Read more about it on its page)
            this.addSlot(new LockedSlot(container, i, x, y));
        }
    }

    // Disallow quick moving items
    @Override
    public ItemStack quickMoveStack(Player player, int i) {
        return ItemStack.EMPTY;
    }

    @Override
    public boolean stillValid(Player player) {
        return true;
    }
}