The one position a set of selected marks was read from, or null.
Every layer built from the named worksheet is tried -- every layer at all
when the event names none -- and every selected mark is resolved against it.
The answer is a position only when all of the marks resolve to the same one:
a multi-mark selection that spans several positions names no single place
to land, and an ambiguous mark names two.
The one position a set of selected marks was read from, or
null.Every layer built from the named worksheet is tried -- every layer at all when the event names none -- and every selected mark is resolved against it. The answer is a position only when all of the marks resolve to the same one: a multi-mark selection that spans several positions names no single place to land, and an ambiguous mark names two.