ActionScript 3.0 Design Patterns.pdf - VideoTutorials-bg.com

Figure 1-1. Document class window
MovieClip class. A Sprite object has no Timeline, but a MovieClip class does. So
using Sprite objects save a bit of extra weight that the Timeline has.
Movie clip and button classes
In Flash CS3, MovieClip and Button objects you create using the Symbol dialog box
and store in the Library can be made available to work with ActionScript 3.0. Unlike
ActionScript 2.0 where MovieClip and Button symbols could be associated with a
class, with Flash CS3, they can be made into classes themselves. The object’s name
entered into the Name window when the symbols are created becomes the class
name for the object. (In past versions, references to a movie clip are made through an
instance name. You can still make those references, but in a different context.)
The advantage of this new procedure is that the symbol objects can be instantiated
just like any other class through the code, as long as the symbols are in the Library.
You don’t have to place them on the stage. They can be dynamically instantiated and
placed into a display array just like a dynamically generated object. Further, objects
contained within the MovieClip or Button can be addressed as a property just like
any other class.
While this book is in no way an introduction to Flash CS3, walking through one
example of this new way of creating a class with movie clips and buttons may be useful
to those new to Flash and experienced users alike. The following steps walk you
through this new feature:
1. Open a new Flash document and save it as rocket.fla.
2. Select Insert ➝ New Symbol from the menu bar to open the Create New Symbol
Dialog box. Enter Rocket in the Name window, and Click OK to enter the Symbol
Edit Mode.
3. In the Symbol Edit Mode, draw a rocket on the stage with the dimensions
W=89, H=14, as shown in Figure 1-2. Once finished, position the drawing at
X=0, Y=0. Click the Scene 1 icon to exit the Symbol Edit Mode.
The Pleasure of Doing Something Well | 7