THE DETAILS

Step one .
Create the "Ring clip" movie clip:

If you examine the time line of the "Ring clip" in the library, you will see that I created the yellow ring by first drawing a yellow disk as saved it as a graphic symbol called "disk:"


I then created a black ring and saved it as graphic symbol called "mask:"

I then created an empty movie clip called "Ring clip." I then dragged the yellow disk onto a layer called "disk," and I dragged the black ring onto a layer called "mask." I then converted the layer labeled "mask" into a mask layer, and Voilà!: a yellow ring:


Step two . Make a list of "Ring clip" properties you want to be dynamic. Here's my list:
  • I want the ring to change size (i.e., I want to manipulate the _xscale & _yscale properties of a "Ring clip" movie clip instance).
  • I want the ring to "fade out" over time (i.e., I want to manipulate the _alpha property of a "Ring clip" movie clip instance). Once the ring completely fades out, it is dead.
  • I want to vary the rate of the change of these two properties, i.e., each "Ring clip" instance will grow or shrink and fade at its own rate.

Step three . Create an empty movie clip in the library called "Container clip."

I needed some way to manage the creation and initialization of 'instances' of the "Ring clip" movie clip, and I also needed a way to specify where the rings will be located on the stage. One way to do this is to use another movie clip that will serve to hold (or contain) "Ring clip" instances -- I used the "Container clip" movie clip for this purpose.

I then exported the "Container clip" for Actionscipt, made the 'Identifier' name be: "container" and the 'AS 2.0 Class' name be: "Container." (I always make the 'Identifier' and 'Class' names the same, but I start the class name with an upper case letter):

I then dragged the "Container clip" directly onto the stage. This automatically created an 'instance' of the "Container clip" on the stage. As you can see in the flash movie, the rings emanate from this point. Remember, the "Container clip" is empty ? the 'instance' of this movie clip on the stage will do nothing more than "hold" or "contain" instances of the "Ring clip" movie clip.

(Quick aside: note that I did not name the instance in the Properties dialog box ? I could have, but I don't need to: flash automatically generates a default instance name anyway if you don't supply one in the 'Properties' dialog box. Note that I could have also used the 'Identifier' name to attach an instance of the "Container clip" to the main time line, e.g., attachmovie ("container","myInstanceName", some leve), and then explicitly set the position of the instance on the stage, i.e., myInstanceName._x = 487; myInstanceName._y = 78).