It is clear that calling setValue() on Scrollbar-Adjustment from within configure-callback of drawing-area may not be a good idea, as the scrollbars are currently resizing and not accept new value. But on the other hand, I can not just use a own configure-callback for the scrollbars, as setvalue() may then be executed too early. SetValue() for scrollbars receives new size of drawingArea, so it has to be executed after drawingArea is resizes. So all that is not that easy, and such interactions are generally not covered by tutorials or the Krause book.
Maybe I have to emit a custom signal for this interaction?