The axis of the header this overlay sits on (row or column).
OptionalchildrenThe layer's content — VirtualDivs, RangeRects, floats — hosted inside the layer's
boundary div. Children stack by DOM order within the layer (law 1).
OptionalclassClass forwarded to the inner layer's host box (devtools identification).
The body's entire range (full rows × full columns) — the header projects every pick across the
opposite axis with it. Typically sheet.getEntireRange().getCoords().
OptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalonOptionalscrollScroll a header cell into view during a pick drag (incl. held-still auto-scroll) — routed through the
sheet so the body scrolls. Supplied by SheetHeaderElement; see HeaderSelectionLayer.scrollIntoView.
OptionalstyleStyle for the layer's boundary div — e.g. display: 'none' or opacity to hide or fade a layer.
The boundary's own placement (position, inset, pointer-events: none) comes from the grid;
overriding it here breaks the layer's containment.
OptionalzExplicit stacking override, read by normalizeLayers off the grid-child element to sort the
layer list (higher sorts later = on top; omitted ⇒ declaration order). It is honored ONLY at the
grid-children level — the layer's actual dispatch slot always comes from the resulting order
index (via LayerOrderContext), never from this raw number, so paint order and event
order can never disagree.
Props for SheetReferenceHeaderLayer.