vert_pack.gravity = 1;
widget.signal_autosize_changed.connect(sigc::mem_fun(this, &Slot::autosize_changed));
widget.signal_visibility_changed.connect(sigc::mem_fun(this, &Slot::visibility_changed));
vert_pack.gravity = 1;
widget.signal_autosize_changed.connect(sigc::mem_fun(this, &Slot::autosize_changed));
widget.signal_visibility_changed.connect(sigc::mem_fun(this, &Slot::visibility_changed));