21.4 Incremental Redisplay Stream Protocol

redisplayable-stream-p  stream [Generic Function]

Returns true for any stream that maintains an output history and supports the incremental redisplay protocol, otherwise returns false. [annotate]


stream-redisplaying-p  stream [Generic Function]

Returns true if the stream is currently doing redisplay (that is, is inside of a call to redisplay), otherwise returns false. [annotate]


incremental-redisplay  stream position erases moves draws erase-overlapping move-overlapping [Generic Function]

Performs the incremental update on stream according to the difference set comprised by erases, moves, draws, erase-overlapping, and move-overlapping, which are values returned by compute-difference-set. position is a point object that represents the start position of the topmost output record that will be redisplayed. [annotate]

incremental-redisplay can be called on any extended output stream. [annotate]