The jabout.tcl library is distributed as part of the jstools package. It consists of one main procedure and a number of subsidiary procedures used by the jstools applications. It contains procedures to manage an `about' panel, with information about your application. (Actually, it can be used as a general¡purpose richtext display mechanism.)
This document describes jabout.tcl version 3.6/3.0.
Usage
Accessing the Library
In order to use the jabout.tcl library, it (and any other libraries it depends on) must be in your Tcl auto_path, described in tclvars(n). Information about how to arrange that, and other conventions common to the jstools libraries, is in the Usage section of The jstools Libraries.
Specifying Text
The Tcl¡syntax format for specifying richtext is defined by the jrichtext.tcl library, which jabout.tcl uses.
Credits and Copyright
Author
Jay Sekora
js@bu.edu
http://shore.net/~js/
Copyright
The library is copyright ⌐ 1992-1994 by Jay Sekora, but may be freely copied and modified for non¡commercial purposes. (Please contact me if you want to use it for a commercial purpose, this may be OK under some circumstances.)
Overview
Procedures
j:about - create an about box
j:about:button - add a button to an about box
j:about_jay - return rich¡text describing me
j:about_tktcl - return rich¡text describing Tk and Tcl
j:about
Usage
j:about name [options] richtext
Options
-title title (default About)
Arguments
name is the name of the about¡box window
richtext is the rich¡text content of the about box
title is the window¡manager title for the about box
Example
j:about .telephones -title "About Telephones" {
j:rt:hl "Telephones"
j:rt:cr
j:rt:rm "Telephones are extremely useful, "
j:rt:rm "but also sometimes extremely "
j:rt:it "annoying"
j:rt:rm " devices for communicating "
j:rt:rm "over long distances."
}
Description
This procedure creates and displays a new about panel containing richtext. The about panel's toplevel widget will be named name. (It's window¡manager title will be title, if specified.) The about box will have a button labelled `OK' in the lower right which will destroy the panel. (The OK button is the default button, so the user can invoke it by pressing Return.)
j:about:button
Usage
j:about:button aboutbox label richtext
Arguments
aboutbox is the name of the about panel to add the button to
label is the text to display on the button
richtext is the richtext the button should display in the about box
Example
j:about:button .about "Copyright" {
j:rt:rm "Copyright \251 1776 by George Washington"
j:rt:cr
j:rt:rm "All Rights Reserved."
}
Description
This procedure is used to add buttons to an existing about panel, so your users can choose among several topics for the about panel. If you only want your about panel to display one piece of text, you don't need to call this procedure, but if you have several topics - for instance, general information about your program, a copyright notice, and a list of contributing authors - you can add buttons to the about panel for each topic.
The button will be packed to the left of the `OK' button (or any previously¡added buttons), and will be labelled with label. When invoked, it will display richtext in the about panel, replacing any text that was displayed before. (For this reason, if you add buttons to an about panel, one of the buttons should typically redisplay the initial contents of the panel.
j:about_jay
Usage
j:about_jay
Description
This procedure returns richtext (as defined by the jrichtext.tcl library) describing me. It's in the library as a convenience, so I can call it from all the jstools applications.
j:about_tktcl
Usage
j:about_tktcl
Example
j:about:button .about "Tk and Tcl" [j:about_tktcl]
Description
This procedure returns richtext describing Tk and Tcl. The text is currently:
Tk and Tcl
This application is written in wish, a scripting shell for X Windows
applications based on the Tk toolkit, which in turn is based on
the Tcl language and scripting library, all amazingly useful tools
by John Ousterhout of Sun Microsystems.
The Internet newsgroup comp.lang.tcl is devoted to Tcl and related
tools, and a Tk/Tcl FAQ (`Frequently Asked Questions') is periodically
posted. The latest distributions are available on the FTP site
ftp.cs.berkeley.edu, and ftp.aud.alcatel.com has the FAQ
and user¡contributed scripts.
A longer example
This is a simplified version of the code that generates the about panel for the jedit application:
set about_editor {
j:rt:hl "jedit"
j:rt:cr
j:rt:rm "by Jay Sekora, "
j:rt:tt "js@bu.edu"
j:rt:par
j:rt:rm "A customisable text editor for X Windows."
j:rt:cr
j:rt:rm "Version 3.2."
}
j:about .about $about_editor
j:about:button .about {About jedit} $about_editor
j:about:button .about {About The Author} [j:about_jay]
j:about:button .about {About Tk and Tcl} [j:about_tktcl]
Evolution
Feel free to report bugs (and feature requests) to me, <js@bu.edu>, and I will try to deal with them. Also, feel free to fix bugs or add features on your own and let me know how you did it.
Bugs and Limitations
* Having to add a button for each topic is clumsy. It would be better if the argument to j:about were a list of topics and corresponding richtext, and there were a one¡of¡many selector of some kind to view different topics.
Future Directions
* The fonts used in a j:about panel should be configurable by the user. Perhaps the same is true of the size of the panel.
