highlightedColumn property
Index into labels of a column to emphasize — e.g. a "today" highlight —
or null (the default) to highlight nothing. The widget stays
date-agnostic: a consumer building a calendar maps DateTime.now() to a
column index itself and passes it here (see ADR 0001 / #46), so no
DateTime enters the public API. An out-of-range index highlights nothing.
Implementation
int? highlightedColumn;