Axel,

that doesn't solve the problem. I need to know 'before' I call the update() of my canvasitem if the item would be in the paint region, once I get the paint() event it is too late since I have to provide the data by then.

I have to call update() once my system has new data available, however, I DON'T want to call update() if the item is obscured and won't be seen. Once I call update() the entire item (QCanvasItem) will be in the paint region anyway, so the decision to call update has to be made prior to the paint event (which hopefully never happens if the item is obscured to begin with). I hope I stated the problem correctly.

Thanks,
Tom