Book Image

Learning Ext JS

By : Colin Ramsay, Shea Frederick, Steve 'Cutter' Blades
Book Image

Learning Ext JS

By: Colin Ramsay, Shea Frederick, Steve 'Cutter' Blades

Overview of this book

<p>As more and more of our work is done through a web browser, and more businesses build web rather than desktop applications, users want web applications that look and feel like desktop applications. Ext JS is a JavaScript library that makes it (relatively) easy to create desktop-style user interfaces in a web application, including multiple windows, toolbars, drop-down menus, dialog boxes, and much more. Both Commercial and Open Source licenses are available for Ext JS.<br /><br />Ext JS has the unique advantage of being the only client-side UI library that also works as an application development library. Learning Ext JS will help you create rich, dynamic, and AJAX-enabled web applications that look good and perform beyond the expectations of your users.<br /><br />From the building blocks of the application layout, to complex dynamic Grids and Forms, this book will guide you through the basics of using Ext JS, giving you the knowledge required to create rich user experiences beyond typical web interfaces. It will also provide you with the tools you need to use AJAX, by consuming server-side data directly into the many interfaces of the Ext JS component library.</p>
Table of Contents (16 chapters)
15
Index

Chapter 11. Drag-and-Drop

In the world of software development, desktop applications are still number one. Although web sites and, latterly, web applications are developing rapidly using frameworks such as Ext JS, they are yet to reach the level of complexity that we see in our most extensive desktop programs.

Drag-and-drop, the subject matter of this chapter, is a good example of this. Moving items across the screen using the mouse on a standard computer desktop is all-pervasive; it is available for a great many actions and it is available in virtually every application, even if this is in a limited form.

Part of the reason for this is that implementing drag-and-drop using JavaScript is pretty hard. Coming up with a consistent methodology for turning any element into a draggable widget that can then be placed on another element, and have it work in every browser, and have it support scrolling, and take into account iframes is, to say the least, problematic.

At the start of the Web...