Book Image

ExtGWT Rich Internet Application Cookbook

By : Odili Charles Opute , Oded Nissan
Book Image

ExtGWT Rich Internet Application Cookbook

By: Odili Charles Opute , Oded Nissan

Overview of this book

<p>Get ready to build the next generation Gmail, Facebook, or Meebo, with HTML5 and Server Push, taking advantage of the power and versatility of Java with ExtGWT. Sencha Ext GWT takes GWT to the next level, giving you high-performance widgets, feature-rich templates and layouts, advanced charting, data loaders and stores,&nbsp; accessibility, and much more.<br /><br /><i>ExtGWT Rich Internet Application Cookbook will teach you to quickly build&nbsp; stunning functionality into your own apps with ExtGWT</i>.<br /><br />This is a catalog of practical solutions to get your ExtGWT web app up and running in no time, with tips for persistence and best practices. You begin by playing with panels, windows, and tabs, to learn the essentials. Next, you engage yourself with forms, buttons, toolbars and menus to build on further. Dealing with the UI and the trees will follow to help you make stunning user interfaces. Then you will be taught to work with Listview, Views, and Gridpanels, the more complex problems. The book will then deal with charts, visualization, and drag and drop to take you to the next level. Finally, you will wind up with serialization, persistence, and custom theming. Now, you are an expert!</p>
Table of Contents (22 chapters)
ExtGWT Rich Internet Application Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Event Handling — Making Those GUIs Do Something
Jakarta Commons-FileUpload

Summary


To respond to events, we create listener objects.

  • A listener is an object whose class implements an appropriate interface; in GXT it's the Listener interface

  • SelectionListener is a listener implementation used to listen for selections such as button presses

  • The method handleEvent(), or componentSelected() in the case of a button, contains the code to run when the event is fired

  • The listener is attached to a GUI component using the addListener() method or addSelectionListener() for a button

As of version 2.0, GWT uses handlers for its event handling. GXT version 3.0 will move from using listeners to using handlers, so that it will be compatible with the GWT event handling mechanism. This compatibility will also allow GXT 3.0 to add support for GWT UIBinder. UIBinder is used for building a UI in a declarative way, using an XML file, in order to cut down on boilerplate code and provide more flexible layouts.