How to Create a Flash MX Component - Page 2

What is a Component?

Functions have parameters that customize the actions performed within it. Similarly, movie clips can be 'parameterized' to customize the animation, by defining variables (or 'properties') within them and setting those values from outside the clip before or during the execution of the animation, such as the minimum and maximum values for a dial. Therefore, a movie clip can be thought of as a parameterized animation.

Flash 5 introduced SmartClips as an easy way to create parameterized animations. Flash MX Components are the next generation of SmartClips. SmartClips enabled the creation of animations in a straightforward way that promoted sharing, reuse, and workflow efficiency. The limitation of SmartClips, however, was that they didn't fit programmatically into ActionScript's object-oriented framework. The main contribution of Flash MX Components is to integrate the SmartClip concept into the framework.

In addition to the ability with SmartClips to define a custom user interface ("property inspector") for the parameters, Components introduce Live Preview, an optional mechanism created by the Component developer that lets the user see in the authoring environment what a component will look like when it is active in the presentation.

To demonstrate how to create a custom component, we are going to build a simple isosceles triangle component that has the following properties: base, height, tint color, and a boolean flag indicating whether or not to apply the tint color. It will also have methods to get and set these properties, as well as area. After we show how to make the component and a custom icon, we will show how to create a custom User Interface, and then how to make a Live Preview movie.