VirtualItem

The VirtualItem object represents a single item returned by the virtualizer. It contains information you need to render the item in the coordinate space within your virtualizer's scrollElement and other helpful properties/functions.

tsx
export interface VirtualItem {
  key: string | number | bigint
  index: number
  start: number
  end: number
  size: number
}
export interface VirtualItem {
  key: string | number | bigint
  index: number
  start: number
  end: number
  size: number
}

The following properties and methods are available on each VirtualItem object:

key

tsx
key: string | number | bigint
key: string | number | bigint

The unique key for the item. By default this is the item index, but should be configured via the getItemKey Virtualizer option.

index

tsx
index: number
index: number

The index of the item.

start

tsx
start: number
start: number

The starting pixel offset for the item. This is usually mapped to a css property or transform like top/left or translateX/translateY.

end

tsx
end: number
end: number

The ending pixel offset for the item. This value is not necessary for most layouts, but can be helpful so we've provided it anyway.

size

tsx
size: number
size: number

The size of the item. This is usually mapped to a css property like width/height. Before an item is measured with the VirtualItem.measureElement method, this will be the estimated size returned from your estimateSize virtualizer option. After an item is measured (if you choose to measure it at all), this value will be the number returned by your measureElement virtualizer option (which by default is configured to measure elements with getBoundingClientRect()).

lane

tsx
lane: number
lane: number

The lane index of the item. In regular lists it will always be set to 0 but becomes useful for masonry layouts (see variable examples for more details).

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