In truth, many of the functions we're going to cover in this chapter are superficial in nature. They add some whizz-bang transitions that are not strictly essential. There are two lines of defense for criticism. Firstly, a good developer understands that users are not machines—they're people—and a little bit of whizz-bang is good for everyone. Secondly, and perhaps more scientifically, it's much better to have a transition to signify a change than simply have something appear. A transition draws the eye and gives the user the opportunity to consume the visual cue that was presented.
A sudden change on screen results in a "what happened" response; a smooth transition provides a hint as to what's going on. As we tour the various features of Ext.Fx
, bear in mind that they can be used for more than just eye-candy; they're great for adding value to your user experience.