enum_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));
real_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));
integer_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));
enum_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));
real_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));
integer_widget->signal_activate().connect(sigc::mem_fun(*this,&Widget_ValueBase::activate));