UI Windows

Windows are used for inventory and container interfaces — a different system from custom pages. See Player Inventory for the inventory API and ItemStack documentation.

Note

Windows are specifically for inventory slots and item transactions. Use custom pages when you don’t need item slots.

Window Types

Type	Purpose
Container	Generic container with slots
PocketCrafting	2x2 crafting grid
BasicCrafting	3x3 crafting grid
DiagramCrafting	Recipe book interface
StructuralCrafting	Building/structure crafting
Processing	Furnace-like processing
Memories	Memory storage UI

Opening a Window

Player player = store.getComponent(ref, Player.getComponentType());
WindowManager windowManager = player.getWindowManager();

ItemContainer container = new ItemContainer(27);
ContainerWindow window = new ContainerWindow(container);
windowManager.openWindow(ref, window, store);

Closing Windows

// close by window ID
windowManager.closeWindow(ref, windowId, store);

// close all windows
windowManager.closeAllWindows(ref, store);

Window Validation

Windows can validate they’re still valid (player in range, block still exists):

public class MyWindow extends ContainerWindow implements ValidatedWindow {

    @Override
    public boolean validate(Ref<EntityStore> ref, ComponentAccessor<EntityStore> accessor) {
        // return false to auto-close the window
        return this.block.exists() && this.isPlayerInRange(ref, accessor);
    }
}

Item Containers

Windows work with ItemContainer for slot management:

ItemContainer container = new ItemContainer(slotCount);

// get/set items
ItemStack item = container.getItem(slot);
container.setItem(slot, itemStack);

// listen for changes
container.addListener((slot, oldItem, newItem) -> {
    // slot changed
});

Window Actions

Handle player interactions:

Action	Purpose
CraftRecipeAction	Craft a recipe
TierUpgradeAction	Upgrade item tier
SelectSlotAction	Select a slot

Block Windows

For windows attached to blocks (chests, furnaces):

public class ChestWindow extends ContainerBlockWindow {

    public ChestWindow(BlockRef blockRef, ItemContainer container) {
        super(blockRef, container);
    }

    // window auto-closes if block is destroyed
}

Container Windows

ContainerWindow opens an item container that the player can move items into and out of. Use this for actual item storage — chests, crates, shared stashes.

ItemContainer storage = new ItemContainer(27);
ContainerWindow window = new ContainerWindow(storage);
player.getPageManager().setPageWithWindows(ref, store, Page.Bench, true, window);

window.registerCloseEvent(event -> {
    // save contents, clean up, etc.
});

setPageWithWindows() opens the window and switches the client to the Bench page. The player can move items between the window container and their inventory.

Coming from Bukkit-based Minecraft server modding?

In Bukkit, “chest GUIs” (using inventory slots as buttons) are a common workaround because there’s no real UI API. Hytale has a proper UI system — use custom pages with markup and styling for menus, dialogs, and interactive interfaces. Only use ContainerWindow when the player needs to move actual items.

Crafting Windows

Crafting windows extend CraftingWindow. See Crafting & Recipes for the full recipe system, bench types, and crafting events.

Window Class	Bench Type	Description
SimpleCraftingWindow	Crafting	Grid-based, any-order ingredients
DiagramCraftingWindow	DiagramCrafting	Slot-based with diagrams
StructuralCraftingWindow	StructuralCrafting	1 input -> multiple output options
ProcessingBenchWindow	Processing	Fuel-based, runs without player