Page 193	Table of Contents	Index	Page 195
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E

CHAPTER 22. EXTENDED STREAM INPUT

gesture will wait for input to become available. If no input is available, stream-read-gesturewill return two values, nil and :timeout.

If the boolean peek-p is true, then the returned gesture will be left in the stream's input buffer.

input-wait-test is a function of one argument, the stream. The function should return true when
there is input to process, otherwise it should return false. This argument will be passed on to
stream-input-wait. stream-read-gesture will bind *input-wait-test* to input-wait-test.

input-wait-handler is a function of one argument, the stream. It is called when stream-input- waitreturns false (that is, no input is available). This option can be used in conjunction with
input-wait-test to handle conditions other than keyboard gestures, or to provide some sort of
interactive behavior (such as highlighting applicable presentations). stream-read-gesture will
bind *input-wait-handler* to input-wait-handler.

pointer-button-press-handler is a function of two arguments, the stream and a pointer button
press event. It is called when the user clicks a pointer button. stream-read-gesture will bind
*pointer-button-press-handler* to pointer-button-press-handler.

input-wait-test, input-wait-handler, and pointer-button-press-handler have dynamic extent.

=> stream-input-wait stream &key timeout input-wait-test [Generic Function]
Waits for input to become available on the extended input stream stream. timeout and input-
wait-test are as for stream-read-gesture.

=> unread-gesture gesture &key (stream *standard-input*) [Function]
Calls stream-unread-gesture on gesture and stream. These arguments are the same as for
stream-unread-gesture.

=> stream-unread-gesture stream gesture [Generic Function]
Places gesture back into the extended input stream stream's input buffer. The next call to
stream-read-gesture request will return the unread gesture. The gesture supplied must be the
most recent gesture read from the stream via read-gesture.

22.2.2 Extended Input Stream Conditions

=> *abort-gestures* [Variable]

A list of all of the gesture names that correspond to abort gestures. The exact global set of
standard abort gestures is unspecified, but must include the :abort gesture name.

=> abort-gesture [Condition]
This condition is signalled by read-gesture whenever an abort gesture (one of the gestures in
*abort-gestures* is read from the user.

Page 193	Table of Contents	Index	Page 195
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E