360 Chapter 21 – Interactivity
Flash
Web Design in a Nutshell, eMatter Edition
For more information (and to download a demo copy), visit Macromedia’s site at
http://www.flash.com/.Be sure to visit the gallery for examples of Flash used as
navigation interfaces, interactive buttons, and even games.
Advantages
Many aspects of the Flash file format make it ideal for adding interactive content to
web pages:
Small file size
As mentioned above, Flash’s vector format means small files and quick
downloads.
Scalable
Flash images and animations can be resized with no loss of detail, making it
easy to fill the whole browser window with a Flash interface without adding
to the file size. Flash can be used to create static images, such as maps, where
zooming into finer detail is desirable.
High image quality
Real-time anti-aliasing smoothes the edges of graphics and text, regardless of
the display size. Users can zoom in on vector graphics with no loss of image
quality.
Streaming technology
Flash files start playing quickly and continue to play as they download. There
is no special server software required.
Integrated sound
Flash is a good way to bring background sound and user-triggered sound
effects to a web site. RealFlash (introduced below) enables Flash animation to
be synchronized with high-quality streaming audio.
Interactivity
Incorporating interactivity into a Flash file is done without scripting. Designers
can easily create their own navigation interfaces and interactive graphics and
animations without prior knowledge of programming languages.
Well-supported format
The Flash player required to play Flash files is available for Windows 3.1/95/
98/NT and MacOS platforms. The Flash format is also natively supported by
WebTV. Alternatively, Flash content can be played via ActiveX controls (for IE
on Windows 95/98/NT) or with the Flash Player Java Edition (on any Java-
enabled browser). All future versions of the Netscape browser, from version
4.06 and beyond, will contain the Flash player.
Scriptable
You can use JavaScript commands to control a Flash element on your page.
The following are just a few of the Flash functions that can be called from
JavaScript:
Play() starts playing the animation.
StopPlay() stops the animation.
Rewind() goes to the first frame.
GotoFrame(intframeNum) goes to a specific frame of the movie.