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Flash – Symbols
Symbols play an important role in the optimization of flash files. These symbols once
created or imported can be reused number of times in the main flash movie without increasing the file size. This is one of the highlights of Flash.
It is advised by many tutors and flash users that if used intelligently these symbols can reduce lot of repetitive work. Once created they are placed in the library. From here you can use as many times as your movie demands. A copy of a symbol used in the movie is called an instance of that symbol. It is a good practice to therefore name the instances so that there is no mistake if one has to edit later.
A point to be noted here is, once the symbol is edited or modified in any manner all its
instances will also get modified. But if an instance is modified the symbol does not loose its properties. So if you need to make global changes then modify the symbol itself.
Here is the summary of 3 types of symbols available in Flash.
1. Graphic symbols
Graphics can be either vector based ( drawn in flash itself ) or can be imported ( created in other applications – bitmap / vector ) into the library via file >> Import method. Once turned into a graphic symbol these occupy a single frame. Graphic symbols are used for the following
a. For animations.
b. For Rollover effects.
c. For backgrounds.
2. Button symbols
Buttons are common in all web applications / websites. This is the second symbol offered by flash. To create a button goto Insert menu and choose the button option. A button symbol has 4 states, up-over-down and hit. They add interactivity to the movies. You can asign graphics, movies orsimple animations for various states. You can also create hot spots by creating invisible buttons. They are used for
b. Jumping from one movie to other OR fetching a new URL.
c. Creating website menus.
3. Movie Clip Symbols :
Movie clip symbols are a seperate entitiy. They have their own timeline and are independant in nature. You can have movies within movies. They can be controlled via actionscript. They are used for
a. Creating flash websites.
b. Creating buttons.
c. Standalone animations.