When i nest in gtkmm multiple Paned-Widgets there is always a border around the whole Paned and it can get really big and ugly (as seen in the picture). Is there any way to remove the border so there is only that seperator left? And is it possible to give that seperator an own style?
I found the problem. The problem wasnt the paned widget itself but the viewports i put in it as childs. Just set the the shadow type of the viewports to Gtk::SHADOW_NONE and no borders will be drawn at all.