Items, progress displays, and slots

These controls render items already present in the machine helper entity's container_items collection. They do not create an inventory, move items, or choose an IO mode. The script and entity definition own that behavior; JSON UI only displays the corresponding collection index.

Item display controls

Element	Cell / renderer size	Hover	Intended use
uc.button_item_display	18 / 16	Button behavior	Small collection-backed button icon.
uc.item_display	18 / 16	No	Small read-only item or state frame.
uc.item_display_medium	34 / 32	No	Medium read-only item.
uc.item_display_large	50 / 48	No	Large read-only resource fill or illustration.
uc.item_display_hover	18 / 16	Yes	Small item with item tooltip and focus navigation.
uc.item_display_hover_medium	34 / 32	Yes	Medium item with tooltip.
uc.item_display_hover_large	50 / 48	Yes	Large item with tooltip; used by resource bars.
uc.progress_display	34 / 32	No	Animated progress-frame item. Focus navigation is disabled.
uc.output_item	26 / 26	Native slot	Large output item primitive.
uc.input_item	18 / 18	Native slot	Standard container item primitive.

Display a script-updated progress frame

{
  "progress@uc.progress_display": {
    "collection_index": 2,
    "offset": [28, 23]
  }
}

progress_display does not calculate progress. The machine script updates the item at index 2 to the correct frame identifier, and the UI renders that item.

Common item-renderer variables

The display controls expose the variables below. A wrapper may fix some values to its documented size.

Variable	Type	Default	Purpose
$cell_image_size	[number, number]	Depends on control	Overall cell image size.
$cell_overlay_ref	control reference	"common.cell_overlay"	Overlay used for stack count, durability, and storage indicators.
$stack_count_required	boolean	true	Enables the stack-count overlay.
$durability_bar_required	boolean	true	Enables the durability overlay when applicable.
$storage_bar_required	boolean	true	Enables the storage overlay when applicable.
$item_renderer	control reference	"common.item_renderer"	Minecraft item-renderer control.
$item_renderer_panel_size	[number, number]	Depends on control	Panel containing the rendered item.
$item_renderer_size	[number, number]	Depends on control	Rendered item size.
$item_renderer_offset	[number, number]	[0, 0]	Item offset inside its renderer panel.

Hover variants additionally accept:

Variable	Type	Default	Purpose
$button_ref	control reference	"uc.slot_button"	Button/tooltip implementation placed over the item.
$focus_id	string	""	Controller focus identifier.
$focus_override_up	string	""	Explicit focus destination when moving up.
$focus_override_down	string	""	Explicit focus destination when moving down.
$focus_override_left	string	""	Explicit focus destination when moving left.
$focus_override_right	string	""	Explicit focus destination when moving right.

Internal item primitives

uc._slot_visual and uc._slot_visual_hover implement the renderer, overlay, count, durability/storage bars, and focus bindings used by the public controls. _slot_visual_hover also accepts $button_ref. Their remaining variables are the common item-renderer and focus variables listed above.

Prefer a public item_display* wrapper unless you are building a new shared UI abstraction and need full control over the renderer internals.

Machine slots

Element	Size	Variables	What it displays
uc.input_slot	18x18	$slot_background_texture = textures/ui/slots/input_1_slot	Interactive container item with an input outline.
uc.fuel_slot	18x18	None	Interactive container item with the fuel outline.
uc.upgrade_slot	18x18	$show_slot_background = true	Interactive upgrade slot; its outline can be hidden.
uc.output_slot	26x26	$slot_background_texture = textures/ui/slots/output_1_slot	Larger interactive container item with an output outline.

Input, progress, and output

{
  "input@uc.input_slot": {
    "collection_index": 3,
    "offset": [0, 30]
  }
},
{
  "progress@uc.progress_display": {
    "collection_index": 2,
    "offset": [28, 23]
  }
},
{
  "output@uc.output_slot": {
    "collection_index": 4,
    "offset": [56, 26]
  }
}

Slot names are exact

The recognized numbered controls are input_1_slot through input_9_slot and output_1_slot through output_9_slot. Names such as input_1, input_2, or output_1 are not UI Core controls.

Numbered input aliases

uc.input_1_slot through uc.input_9_slot inherit uc.input_slot and set the matching outline texture. Use the number assigned by the machine's IO definition.

{
  "secondary_input@uc.input_2_slot": {
    "collection_index": 4,
    "offset": [18, 30]
  }
}

input_1_slot

input_2_slot

input_3_slot

input_4_slot

input_5_slot

input_6_slot

input_7_slot

input_8_slot

input_9_slot

Numbered output aliases

uc.output_1_slot through uc.output_9_slot inherit uc.output_slot and select the matching output outline.

output_1_slot

output_2_slot

output_3_slot

output_4_slot

output_5_slot

output_6_slot

output_7_slot

output_8_slot

output_9_slot

IO state outline textures

These textures are also consumed by uc.io_face_outline to explain the state encoded by an IO button item.

default

disabled / none

normal

both

upgrade

fuel

item resource

liquid resource

gas resource

energy