ui improvements, grid and optimizations

src/midi.h

@@ -67,6 +67,13 @@ class Midi {
 				midi_outs[out_port->number] = out;
 			}
 		}
+		
+		void close_midi_out(MidiOutPort *out_port){
+			if(midi_outs.contains(out_port->number)){
+				midi_outs[out_port->number]->close_port();
+				midi_outs.erase(out_port->number);
+			}
+		}
 
 		void note(int midi_out, int channel, int note, int velocity, int gate){
 			if(!midi_outs.empty()){
@@ -89,6 +96,8 @@ class Midi {
 			for(auto& p : midi_out_ports){
 				if(p.enabled) {
 					open_midi_out(&p);
+				} else if(!p.enabled) {
+					close_midi_out(&p);
 				}
 			}
 		}