Raxol.UI.Layout.ScrollContent behaviour (Raxol v2.6.0)

View Source

Behaviour for content sources that support cursor-based streaming.

Inspired by Pretext's layoutNextLine() cursor-based API, this behaviour allows scrollable containers (Viewport, Table) to request only the visible slice of content instead of materializing the full list.

Implementations can wrap in-memory lists, ETS tables, database queries, or streaming sources. The Viewport component uses this to render only visible elements without holding the entire dataset in memory.

Summary

Callbacks

item_height(state, index)

Returns the height (in rows) of the item at index. Defaults to 1.

slice(state, offset, count)

Returns a slice of items starting at offset with at most count items.

total_count(state)

Returns the total number of items in the content source.

Callbacks

item_height(state, index)

(optional) 
@callback item_height(state :: term(), index :: non_neg_integer()) :: pos_integer()

Returns the height (in rows) of the item at index. Defaults to 1.

slice(state, offset, count)

@callback slice(
  state :: term(),
  offset :: non_neg_integer(),
  count :: pos_integer()
) :: [map()]

Returns a slice of items starting at offset with at most count items.

total_count(state)

@callback total_count(state :: term()) :: non_neg_integer()

Returns the total number of items in the content source.