Professional Adobe® Flex® 3

Chapter 10. The Component Life Cycle and Class Hierarchy

Adobe Flex is built on the Adobe Flash platform. Understanding the relationship between Flex and Flash can help you write better and more engaging applications. Understanding how Flex works and the relationship between the Flex classes will make it easier to write applications and make them easier to maintain.

The Role of Flash in Flex Applications

The line between Flex and Flash can appear at first to be blurry. In fact, you might not even be aware of how Flash influences Flex. In short, the Flash Player provides the environment in which Flex applications run. This is also true of Adobe AIR applications, as the AIR runtime is analogous to the Flash Player runtime. The AIR runtime provides a desktop environment, whereas the Flash Player runtime provides a browser environment.

The basis of Flash is animation. If you know Flash or have even toyed with it for a bit, you'll know that you develop animations frame by frame on a timeline, exactly as a cartoonist does when creating a motion picture cartoon. On one frame you have a figure of bird, on the next frame the bird's wings move a bit, on the next frame they move a bit more, and so forth. The animation of a bird flapping its wings is then placed on the stage (the background of the movie) in one frame. On the next frame the bird (with wings flapping) is moved a bit, on the next frame it is moved a bit more, and so forth until the bird has moved from one side of the stage to the ...