A horizontal line at a y value, scaled against one row axis (RTC's Baseline).
Its label anchors at the left, at the line's height.
Props
y value in the linked axis's units.
axisstringWhich <YAxis> (by id) to measure against; omit for the row's default axis.
editingbooleanWhen true, this mark is in single-annotation edit (the double-click
target): handles stay out, it's draggable, and it reads as level 1 — while
other marks stay static. Independent of the container's global
editAnnotations. Pair with onEditAnnotation (the consumer holds an
editingId and sets editing={editingId === id}).
hoveredbooleanControlled hover (OR'd with pointer hover) — lets a legend row light the mark
remotely. Pair with the container's onHoverAnnotation to sync both ways.
idstringStable consumer id — a click reports it via onSelectAnnotation.
indicatorbooleanAlso pin this baseline's value to its y-axis as an on-axis pill (in
the annotation colour) — the axis-edge counterpart of the near-line chip.
Default false. The pill always shows the formatted value (the axis
coordinate), never the custom label (which stays the near-line chip) — an
indicator reads like a tick.
labelstring | falseChip label. Omit to format value with that axis's formatter; pass false
(or '') to render no label chip.
labelPosition'center' | 'above'Where the label chip sits relative to the line: center (default) rides
on the line, vertically centred; above sits just on top of it.
labelSide'left' | 'right'Which side of the chart the near-line label chip sits. Default left.
onChange(value: number) => voidMake the baseline editable (in edit mode): dragging it vertically reports
the new value (controlled — wire it back to value).
selectablebooleanWhether the baseline responds to hover + selection (default true). When
false it's inert background context — drawn at the back (level 3) always.
selectedbooleanControlled selection — brightens to the front (level 1). Handles are an
edit-mode hover affordance, not a selection cue. Ignored if not selectable.