'\" Color=Green '\" '\" Copyright © 1996 Erick Gallesio - I3S-CNRS/ESSI '\" '\" Permission to use, copy, and/or distribute this software and its '\" documentation for any purpose and without fee is hereby granted, provided '\" that both the above copyright notice and this permission notice appear in '\" all copies and derived works. Fees for distribution or use of this '\" software or derived works may only be charged with express written '\" permission of the copyright holder. '\" This software is provided ``as is'' without express or implied warranty. '\" '\" Author: Erick Gallesio [eg@unice.fr] '\" Creation date: 19-Jul-1996 15:21 '\" Last file update: 19-Jul-1996 16:31 '\" '\" .so STk-man.macros .TH listener n 3.1 STk "Tk Built-In Commands" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME listener \- Create and manipulate listener widgets .SH SYNOPSIS (\fBlistener\fI \fIwidget\-name \fR?\fIoptions\fR?) .SH "WIDGET-SPECIFIC OPTIONS" .OP :command "" "" command Specifies a STk procedure to associate with the listener. This procedure is invoked when a complete s-expr is entered in the listener. This s-expr is passed as a string to the procedure. The procedure must return the string which will be inserted in response to the s-expr input. The default procedure is the Identity procdure. .OP :output-color "" "" output-color Specifies the color used the output lines .OP :prompt-color "" "" prompt-color Specifies the color used for the prompt .OP :prompt "" "" prompt Specifies the prompt used for reading s-expr. Defaults to "> " .BE .SH DESCRIPTION .PP The \fBlistener\fR procedure creates a new text window (given by the \fIwidget\-name\fR argument) and associates it bindiangs suitable for a listener. Since a listener is in fact a text widget, all the options of \fBtext\fR are applicable to a listener. The \fBlistener\fR procedure returns its \fIwidget\-name\fR argument. At the time this procedure is invoked, there must not exist a window named \fIwidget\-name\fR, but \fIwidget\-name\fR's parent must exist. .PP A listener is a widget for doing interactive I/O. Typical usage for this widget consists of a text window whose inputs are sent to the Scheme evaluator and whose result is displayed in the listener. An example for this is shown at the end of this page. .SH "WIDGET PROCEDURE" .PP All the \fBtext\fR procedure are avialble for a listener, plus .TP (\fBlistener-insert-string\fR \fIwidget-name str\fR) inserts the string \fIstr\fR just before the input prompt. .SH EXAMPLE Hereafter is a simple use of the listener widget which interact with the evaluator. .sp .CS (listener '.t :width 50 :height 10 :command (lambda (x) (eval-string x (global-environment)))) (pack .t) .CE .SH "DEFAULT BINDINGS" .PP The defaults bindings are identical to the \fBtext\fR bindings. .SH SEE ALSO text