+ if (_have_control) {
+ start_stop_button.set_sensitive(true);
+ start_stop_button.show();
+ if (engine_running) {
+ start_stop_button.set_text("Stop");
+ update_devices_button.set_sensitive(false);
+ use_buffered_io_button.set_sensitive(false);
+ } else {
+ if (backend->can_request_update_devices()) {
+ update_devices_button.show();
+ } else {
+ update_devices_button.hide();
+ }
+ if (backend->can_use_buffered_io()) {
+ use_buffered_io_button.show();
+ } else {
+ use_buffered_io_button.hide();
+ }
+ start_stop_button.set_text("Start");
+ update_devices_button.set_sensitive(true);
+ use_buffered_io_button.set_sensitive(true);
+ }
+ } else {
+ update_devices_button.set_sensitive(false);
+ update_devices_button.hide();
+ use_buffered_io_button.set_sensitive(false);
+ use_buffered_io_button.hide();
+ start_stop_button.set_sensitive(false);
+ start_stop_button.hide();
+ }
+
+ if (engine_running && _have_control) {
+ input_device_combo.set_sensitive (false);
+ output_device_combo.set_sensitive (false);
+ device_combo.set_sensitive (false);
+ driver_combo.set_sensitive (false);