+void
+IOSelector::set_button_sensitivity ()
+{
+ if (for_input) {
+
+ if (io->input_maximum() < 0 || io->input_maximum() > (int) io->n_inputs()) {
+ add_port_button.set_sensitive (true);
+ } else {
+ add_port_button.set_sensitive (false);
+ }
+
+ } else {
+
+ if (io->output_maximum() < 0 || io->output_maximum() > (int) io->n_outputs()) {
+ add_port_button.set_sensitive (true);
+ } else {
+ add_port_button.set_sensitive (false);
+ }
+
+ }
+
+ if (for_input) {
+ if (io->n_inputs() && (io->input_minimum() < 0 || io->input_minimum() < (int) io->n_inputs())) {
+ remove_port_button.set_sensitive (true);
+ } else {
+ remove_port_button.set_sensitive (false);
+ }
+
+ } else {
+ if (io->n_outputs() && (io->output_minimum() < 0 || io->output_minimum() < (int) io->n_outputs())) {
+ remove_port_button.set_sensitive (true);
+ } else {
+ remove_port_button.set_sensitive (false);
+ }
+ }
+}
+
+