Know when transition is finished on target screen

[bakjoul]

Hello,
Is there a way to know when the transition is finished on the newly displayed screen ?
I'm trying to load data once the transition is done, for it not to stutter while loading data at the same time. (It looks bad.)
I have to use a manually set a delay. I wish i could sync in with the transition end.
Btw, what is the default transition duration ?