Book Image

Tcl/Tk 8.5 Programming Cookbook

Book Image

Tcl/Tk 8.5 Programming Cookbook

Overview of this book

With Tcl/Tk, you can create full-featured cross-platform applications in a simple and easy-to-understand way without any expensive development package; the only tools required are a simple text editor and your imagination. This practical cookbook will help you to efficiently interact with editors, debuggers, and shell type interactive programs using Tcl/Tk 8. This cookbook will comprehensively guide you through practical implementation of Tcl/Tk 8.5 commands and tools. This book will take you through all the steps needed to become a productive programmer in Tcl/Tk 8. Right from guiding you through the basics to creating a stand-alone application, it provides complete explanation of all the steps along with handy tips and tricks. The book begins with an introduction to the Tcl shell, syntax, variables, and programming best practices in the language. It then explores procedures and the flow of events with control constructs followed by advanced error trapping and recovery. From Chapter 4, a detailed study of string expressions and handling enables you to handle various string functions and use lists to expand the string functionality. The book then discusses in-depth the Tcl Dictionary and how to utilize it to store and retrieve data. File operations and Tk GUI handling are covered extensively along with a developing a real-world address book application to practice the concepts learned.
Table of Contents (20 chapters)
Tcl/Tk 8.5 Programming Cookbook
About the Author
About the Reviewers

Controlling layout with the pack command

Tk provides three methods of geometry management—pack, grid, and the rarely used place command. We will be covering the pack and grid commands. The pack command is the basic geometry manager for Tk. When invoked, the pack command instructs the packer to arrange the widgets as specified. The packer is a geometry manager that arranges the elements of a window in order around the edges. In the following examples, we will see how to use the pack command.

Based on the options provided when invoked the pack command assumes several forms. The syntactical options are as follows:



pack widget widget options

Behaves in the same manner as pack configure.

pack configure widget widget options:

This command accepts one or more widgets and pairs of options (if desired) to manage the pack.

-after parent: The parent provided must reference a valid Tk widget. The widget being packed will be loaded after the widget specified.