Book Image

wxPython 2.8 Application Development Cookbook

By : Cody Precord
Book Image

wxPython 2.8 Application Development Cookbook

By: Cody Precord

Overview of this book

<p>In today’s world of desktop applications there is a great amount of incentive to be able to develop applications that can run in more than one environment. Currently there are a handful of options available for cross platform frameworks to develop desktop applications in Python. wxPython is one such cross- platform GUI toolkit for the Python programming language. It allows Python programmers to create programs with a complete, highly functional graphical user interface, simply and easily. wxPython code style has changed quite a bit over the years, and gotten much more Pythonic. The examples you will find in this book are right up to date and reflect this change in style.<br />This cookbook provides you with the latest recipes to quickly create robust, reliable, and reusable wxPython applications. These recipes will guide you from writing simple, basic wxPython scripts all the way through complex concepts, and also feature various design approaches and techniques in wxPython.<br /><br />The book starts off by covering a variety of topics from the most basic requirements of a wxPython application to some of the more in depth details of the inner workings of the framework laying the foundation for any wxPython application. It then explains event handling, basic and advanced user interface controls, designing and layout, creating dialogs, components and extending functionality, and so on. We conclude by learning how to build and manage applications for distribution.<br />For each of the recipes, there is an introductory example, then more advanced examples, and plenty of example code to develop and manage user-friendly applications. For more experienced developers, most recipes also include additional discussion of the solution, allowing you to further customize and enhance the component.</p>
Table of Contents (19 chapters)
wxPython 2.8 Application Development Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using Timers


A Timer is an object that can be created to send out events on a regular periodic basis. Typically, a Timer is used to run short, atomic tasks, such as status checks and updates, but can also be leveraged to keep the UI active during a long-running task by performing tasks in incremental steps instead of one long blocking call. However, since a Timer will run in the context of the main GUI thread, it is necessary to be able to design the execution of the long-running task to be able to be carried out in several smaller incremental steps, otherwise the UI will still become locked up while processing the TimerEvent. This recipe creates a simple framework for processing long-running tasks by using a Timer.

How to do it...

First, we will create a base class that defines an interface for tasks to derive from:

class TimerTaskBase(object):
    """Defines interface for long running task
    state machine.
    """
    TASK_STATE_PENDING, \
    TASK_STATE_RUNNING, \
    TASK_STATE_COMPLETE...