Adobe® Flex® 3 Bible

Chapter 14. Controlling Animation

Flash Player was originally created as a platform for presenting animation over the Web. Future Splash Animator, the original ancestor of the Flash authoring environment and Flash Player, was a Java-based software product that was integrated into the browser in much the same manner as Flash Player is today.

Millions of Flash developers worldwide create compelling content designed for presentation in a Web application. Animation and related visual wizardry is the most common goal, and the most common result, of documents developed in the Flash authoring environment and distributed through Flash Player.

Animation in Flash depends largely on use of the timeline: a visual interface that allows the developer to create animations frame by frame or through a process known as tweening. Flex application developers don't have the timeline available to them. In fact, one of Macromedia's most important motivations in creating Flex was to free developers with a coding background from having to work with the timeline at all. But a Flex application is still distributed and viewed through Flash Player. So when it's time to move objects around the screen, a Flex developer needs code-based approaches to make it happen.

In this chapter, I describe the use of effects and triggers to define and execute animation in a Flex application. I also describe how to implement drag-and-drop interfaces to create an intuitive way to move data around an application.

Note

To use the sample ...