I want to make a progressbar that can display multiple "groups of values".

Example:
If have a group that 0% to 10% is not "filled".
A group from 10% to 50% is "filled".
A group from 50% to 70% is not "filled".
The last group from 70% to 100% "filled".

Or something like this image:


I think I'll need to subclass the QProgressBar but, how I can do this ?
PaintEvent ? How to have the same "fill pattern" of the progress bar ?