devices.push_back(&dev);
dev.signal_button_press.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_press), index));
dev.signal_button_release.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_release), index));
devices.push_back(&dev);
dev.signal_button_press.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_press), index));
dev.signal_button_release.connect(sigc::bind(sigc::mem_fun(this, &Hub::button_release), index));