Custom virtualization viewPort and props

[imjhonny]

Hi,

I’m looking to customize Aria’s Virtualizer beyond layout—specifically the Rect used for calculating which items should be rendered, similar to how TanStack Virtualizer allows customization. I would like to:

• Add a viewPort prop that accepts a viewport reference and uses it within the layout calculations. The Rect it compares the position of items to

• Add an overscan prop to control how many items are rendered above and below the visible region, similar to other virtualizers

I tried following the example in the documentation to create a custom Layout, but I couldn’t find a way to define and access my own props within the class. Could you provide guidance or steps on how to properly extend and customize the Virtualizer?

Thanks!