public void updateBPM() {
   if (model != null) {
     int bpm = model.getBPM();
     if (bpm == 0) {
       if (bpmOutputLabel != null) {
         bpmOutputLabel.setText("offline");
       }
     } else {
       if (bpmOutputLabel != null) {
         bpmOutputLabel.setText("Current BPM: " + model.getBPM());
       }
     }
   }
 }
 public BeatController(BeatModelInterface model) {
   this.model = model;
   view = new DJView(this, model);
   view.createView();
   view.createControls();
   view.disableStopMenuItem();
   view.enableStartMenuItem();
   model.initialize();
 }
 public DJView(ControllerInterface controller, BeatModelInterface model) {
   this.controller = controller;
   this.model = model;
   model.registerObserver((BeatObserver) this);
   model.registerObserver((BPMObserver) this);
 }
 public void setBPM(int bpm) {
   model.setBPM(bpm);
 }
 public void decreaseBPM() {
   int bpm = model.getBPM();
   model.setBPM(bpm - 1);
 }
 public void increaseBPM() {
   int bpm = model.getBPM();
   model.setBPM(bpm + 1);
 }
 public void stop() {
   model.off();
   view.disableStopMenuItem();
   view.enableStartMenuItem();
 }