listener

Section: Tk Built-In Commands (n)
Updated: 3.1
Index Return to Main Contents
 

NAME

listener - Create and manipulate listener widgets  

SYNOPSIS

(listener widget-name ?options?)

 

WIDGET-SPECIFIC OPTIONS

[ :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. [ :output-color output-color ] Specifies the color used the output lines [ :prompt-color prompt-color ] Specifies the color used for the prompt [ :prompt prompt ] Specifies the prompt used for reading s-expr. Defaults to "> "

 

DESCRIPTION

The listener procedure creates a new text window (given by the widget-name argument) and associates it bindiangs suitable for a listener. Since a listener is in fact a text widget, all the options of text are applicable to a listener. The listener procedure returns its widget-name argument. At the time this procedure is invoked, there must not exist a window named widget-name, but widget-name's parent must exist.

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.

 

WIDGET PROCEDURE

All the text procedure are avialble for a listener, plus

(listener-insert-string widget-name str)
inserts the string str just before the input prompt.
 

EXAMPLE

Hereafter is a simple use of the listener widget which interact with the evaluator.

(listener '.t :width 50
              :height  10
              :command (lambda (x) 
                         (eval-string x (global-environment)))) (pack .t)  

DEFAULT BINDINGS

The defaults bindings are identical to the text bindings.

 

SEE ALSO

text


 

Index

NAME
SYNOPSIS
WIDGET-SPECIFIC OPTIONS
DESCRIPTION
WIDGET PROCEDURE
EXAMPLE
DEFAULT BINDINGS
SEE ALSO

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Time: 15:21:49 GMT, November 05, 2024