PyQt, Custom delegate for html format text causes jittery refreshing [GIF included]

[ChrisW67]

Try setting the clipping rectangle on the QPaintContext rather than the painter. You may find the layout engine can make a smarter choice of how to paint.

[anda_skoa]

Another potential slow down can be save/restore on a painter.
It is often faster to just "undo" the changes, e.g. translate back to "undo" the translation.

Cheers,
_

[DoTheEvo]

THANK YOU ALL FOR REPLYING!

It was my bad at the very beginning
I was doing setItemDelegate() on every keypress instead of just putting it there right after creating the listview

All is well