partial-offset in snip%

Calculates a partial width for the snip, starting from the first snip item and continuing for a given number of items. The drawing context and snip's locations in editor coordinates are provided. See also get-extent.

The snip's editor is usually internally locked for writing and reflowing when this method is called (see also Locks).

• (send a-snip partial-offset dc x y len) -> real number
     dc : dc<%> object
     x : real number
     y : real number
     len : exact non-negative integer

  Calculates a partial width for the snip, starting from the first snip item and continuing for len items.