CrossFade
The Cross Fade transition widget performs a simple fade between the two pieces of content.

Duration
The time taken to perform the crossfade in seconds.
Overlap
- If true, then the transition will start duration milliseconds early and end at the end of the current piece of content. The new content will also be started at at the same time meaning they will overlap playback by duration milliseconds.
- If false, the current content will finish, then the transition will occur. The new content will be started when the transition starts.