Multiple UI components have animations effects on Vista. We need to implement that for WinLaf on Vista.
Vista might have transition for every PART on every STATE change. This
fix implements this for swing. It tracks the current state for every
(component, PART) and triggers animation if needed. Where animation is
alpha-blending of the skin in new STATE over the skin in the old STATE
with the alpha value which depends on the time animation has started and on
transition duration which we take from the theme.
This fix affects only Windows Look and Feel on Vista platform.
There is a system property to disable it - swing.disablevistaanimation.