Macromedia Studio 8 [Electronic resources] : Training from the Source نسخه متنی

Working with the Library

Every Flash file has a Library, which is a container for all the assets that you can reuse in the movie. These assets can include vector graphics and text; imported bitmaps, sounds, and video; and special Flash objects, such as buttons. The idea behind the Library is a one-to-many concept. That is, one item (in the Library) can be deployed many times on the stage (in one or more frames). The user downloads the item only once, no matter how many times it appears in the movie. And because all the copies on the stage refer to the original version in the Library, if you change the original version in the Library all the copies on the stage are updated instantly.

Flash can store two categories of assets in the Library: imported assets, such as bitmaps, sounds, and video files; and symbols. Symbols in Flash are special kinds of objects, which have unique capabilities. Flash has three types of symbols:

Graphic symbols are static images that are saved as symbols for reuse in the movie. Graphic symbols are often used when animating an element.

Button symbols are used to create interactive buttons that respond to mouse clicks, rollovers, and other events. Typically, button symbols are paired with ActionScript, so that the movie can respond to the actions of the user.

Movie clip symbols are the most powerful of the three symbols. They are essentially Flash movies nested inside the main Flash movie. They have their own timelines, can hold animations, and can be scripted using ActionScript.

The source, or parent, version of an item in the Library is called a symbol. A copy, or child, of that item on the stage is called an instance. Thus, to create an animation of a ball falling, you'll typically create the ball as a symbol and store it in the Library. Then you'll create several instances of the ball on the stage, in different frames, and use them to create the animation.

Now that you understand the underlying architectural benefits of the Library, it's a good time to open it.

The Library opens as a panel, usually on the right side of the screen. Although you haven't put anything in the Library, it already contains a couple of items. These were inserted into the Library when you imported the images earlier in this lesson. When you select an item in the Library, a preview is displayed in the top portion of the panel.

Because your logo is now in the Library, there's no need to import it again for the second and third screens. It's now one of the movie's assets. You'll simply take it from the Library.