options - (object, optional) An object with options for the effect. See below.
fps - (number: defaults to 50) The frames per second for the transition.
frames - (number) The numbers of frames in the animation, defaults to the duration and fps calculations.
frameSkip - (boolean: defaults to true) If sets to true, it evaluates the current frame based on the current time.
unit - (string: defaults to false) The unit, e.g. 'px', 'em', or '%'. See Element:setStyle.
link - (string: defaults to ignore) Can be 'ignore', 'cancel' and 'chain'.
'ignore' - Any calls made to start while the effect is running will be ignored. (Synonymous with 'wait': true from 1.x)
'cancel' - Any calls made to start while the effect is running will take precedence over the currently running transition. The new transition will start immediately, canceling the one that is currently running. (Synonymous with 'wait': false from 1.x)
'chain' - Any calls made to start while the effect is running will be chained up, and will take place as soon as the current effect has finished, one after another.
duration - (number: defaults to 500) The duration of the effect in ms. Can also be one of:
'short' - 250ms
'normal' - 500ms
'long' - 1000ms
transition - (function: defaults to 'sine:in:out' The equation to use for the effect see Fx.Transitions. Also accepts a string in the following form:
transition[:in][:out] - for example, 'linear', 'quad:in', 'back:in', 'bounce:out', 'elastic:out', 'sine:in:out'
start - (function) The function to execute when the effect begins.
cancel - (function) The function to execute when you manually stop the effect.
complete - (function) The function to execute after the effect has processed.
chainComplete - (function) The function to execute when using link 'chain' (see options). It gets called after all effects in the chain have completed.
You cannot change the transition if you haven't included Fx.Transitions.js, (unless you plan on developing your own curve). ;)
The Fx Class is just a skeleton for other Classes to extend the basic functionality.