What is DataBuffer? And how do you render the data in the GUI thread?

Thank you.

Here is the actual code that is working for me.

CleoArea *cArea = new CleoArea; connect(ui->actionZoom_In, &QAction::triggered, cArea, &CleoArea::updateAll);

I have verified that updateAll is being called by the signal slot mechanism. Unfortunately, updateAll does not itself function properly when the mouse cursor is not over the central widget, which is another problem.

I will mark this thread as Solved and if need be, open a new one on the mouse cursor location issue.

Thank you again. This forum is much appreciated.