Why do none of the FXScrollArea derived widgets have a frame?
The short answer is that FXScrollArea is derived from FXComposite, and FXComposite does not support a frame. The longer and more accurate answer is a bit more complicated. The FXScrollArea widget, and its derivatives, present a small view of a larger content. The content may be a drawing, but sometimes also other widgets are involved, for example in the case of FXIconList. It is necessary to clip all drawing to the visible viewport of the FXScrollArea. This is made possible by making sure the FXScrollArea’s scroll bars and scroll corners are always the topmost three children, and positioned so as to leave a simple rectangular viewport area in which the content is shown. If FXScrollArea would draw borders or padding around itself, this would necessarily not be covered by the scroll bars and scroll corner; however that would present a problem as any content or sub-windows of the content would be drawn on top of the FXScrollArea’s borders. Thus, FXScrollArea does not support borders. If y
