Symbols

Symbols

A symbol is a reusable object used/created in Flash. A Symbol can be reused throughout your movie or imported and used in other movies. There are three types of symbols: Graphics, Buttons, and Movie clips.

A copy of a symbol used in the movie is called an Instance, which can have its own independent properties (like color, size, function, etc.) different from the original symbol. All symbols used in a flash movie are stored in the Library from where you can drag-and-drop new instances of the symbols into your movie. When a symbol is edited all of its instances get updated, but changing the properties, effects or dimensions of an instance of a symbol does not affect the original symbol or other instances.

The three types of Symbols

Graphic symbols

are reusable static images that are used mainly to create animations. Any drawn vector/plain text/imported bitmap (photo), or combinations of these, can be converted into a single controllable object: as a graphic symbol. They have only one frame in their timeline.

Button symbols

are used for timeline navigation - They add interactivity to the movie and respond to mouse clicks, key press or rollovers/rollout, and other actions. You define the graphics associated with various button states (Up/Over/Down/Hit), and then assign actions to the instance of a button. They have 4 frames in their timeline - one each for the up, over and down states, and one to define the hit area of the button.

Movie clip symbols

are reusable pieces of flash animation - consisting of one or more graphic/button symbols - thus they are flash movies within your flash movie. They have their own non-restricted Timeline (any number of layers and frames - just like the main timeline) that plays independent of the main movie's Timeline. The best thing about using movie clips is that you can control them from actionscript - you can change their dimensions, position, color, alpha, and other properties and can even duplicate and delete them.