Flash® Professional CS5 Bible

Chapter 6. Symbols, Instances, and the Library

IN THIS CHAPTER

• Working with library panels in Flash: The Document Library and External Libraries

• Organizing your Library and resolving conflicts

• Defining content types and managing assets

• Understanding basic symbol types: Graphic symbols, Button symbols, Movie Clips

• Linking and updating symbols with authortime shared libraries

Symbols are the key to file size efficiency and interactive power in Flash. A symbol is a reusable element that resides in the current movie's document Library, which you access with Window

Using symbols helps reduce the file size of your finished movie because Flash needs to save the symbol only once. Each time a given symbol is used in the project, Flash refers to its original profile. To support the variations of an instance, Flash needs to save information about the differences only — such as size, position, proportions, and color effects. If a separate graphic was used for each change, Flash would have to store a complete profile of all the information about that graphic — not just the changes, but also all of the points that specify what the original graphic looks like.

Furthermore, symbols can save you a lot of time and trouble, particularly when it comes to editing your movie. That's because changes made to a symbol are reflected in each instance of that symbol throughout the movie. Let's say that your logo changes ...