FunctionPackage: cgToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 8.1
Unrevised from 8.0 to 8.1.
8.0 version

key-is-down-p

Arguments: virtual-key-code

Returns two values indicating whether a particular key on the keyboard is currently depressed. The argument should be either the char-int of some graphic character or the value of one of the symbols beginning with vk-. This check is done asynchronously.

The first value indicates whether the key is down now (true if it is, nil if it is not). The second returned value indicates whether the key has been pressed since the last time this function was called.

For a letter key, the key code is the char-int of the uppercase character shown on the key (and NOT the corresponding lowercase character). For a numeral key, it is the char-int of the numeral character. For any other key, the key code is the value of the vk- constant for that key (see key-names for a list of vk- constants); for keys that show both a shifted character and an unshifted character, this constant will be named after the unshifted character.

GTK Note

We have not found a way to ask whether a key is really down right now, and so key-is-down-p behaves just like key-was-down-p when called on GTK. And neither of these functions return the second value, which indicates whether the key has been pressed since the previous call.


Copyright (c) 1998-2009, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 8.1. This page was not revised from the 8.0 page.
Created 2009.7.29.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 8.1
Unrevised from 8.0 to 8.1.
8.0 version