updated BeatModel.java to fix midi/synth bug that was causing the bea…

…t to not work well

src/headfirst/designpatterns/combined/djview/BeatModel.java

@@ -2,35 +2,37 @@
 
 import javax.sound.midi.*;
 
+import java.io.File;
+import java.io.IOException;
+
 import java.util.*;
 
 public class BeatModel implements BeatModelInterface, MetaEventListener {
 	Sequencer sequencer;
-	List<BeatObserver> beatObservers = new ArrayList<BeatObserver>();
-	List<BPMObserver> bpmObservers = new ArrayList<BPMObserver>();
+	ArrayList<BeatObserver> beatObservers = new ArrayList<BeatObserver>();
+	ArrayList<BPMObserver> bpmObservers = new ArrayList<BPMObserver>();
 	int bpm = 90;
 	Sequence sequence;
 	Track track;
 
 	public void initialize() {
 		setUpMidi();
-		buildTrackAndStart();
 	}
 
 	public void on() {
 		System.out.println("Starting the sequencer");
-		sequencer.start();
 		setBPM(90);
+		sequencer.start();
 	}
 
 	public void off() {
-		setBPM(0);
 		sequencer.stop();
+		setBPM(0);
 	}
 
 	public void setBPM(int bpm) {
 		this.bpm = bpm;
-		sequencer.setTempoInBPM(getBPM());
+		sequencer.setTempoInBPM(bpm);
 		notifyBPMObservers();
 	}
 
@@ -84,6 +86,7 @@ public void removeObserver(BPMObserver o) {
 
 
 	public void meta(MetaMessage message) {
+		System.out.println(message.getType());
 		if (message.getType() == 47) {
 			beatEvent();
 			sequencer.start();
@@ -93,55 +96,23 @@ public void meta(MetaMessage message) {
 
 	public void setUpMidi() {
 		try {
+			Synthesizer synth = MidiSystem.getSynthesizer();
+			synth.loadAllInstruments(synth.getDefaultSoundbank());
+
 			sequencer = MidiSystem.getSequencer();
+			this.sequence = MidiSystem.getSequence(new File("test.mid"));
 			sequencer.open();
-			sequencer.addMetaEventListener(this);
-			sequence = new Sequence(Sequence.PPQ,4);
-			track = sequence.createTrack();
+			sequencer.setSequence(sequence);
+			sequencer.setTempoFactor(1f);
+			sequencer.addMetaEventListener(meta -> {
+				if (meta.getType() == 47) { 
+					sequencer.setTickPosition(0);
+					sequencer.start();
+				}
+			});
 			sequencer.setTempoInBPM(getBPM());
-			sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
 		} catch(Exception e) {
 			e.printStackTrace();
 		}
 	} 
-
-	public void buildTrackAndStart() {
-		int[] trackList = {35, 0, 46, 0};
-
-		sequence.deleteTrack(null);
-		track = sequence.createTrack();
-
-		makeTracks(trackList);
-		track.add(makeEvent(192,9,1,0,4));      
-		try {
-			sequencer.setSequence(sequence);                    
-		} catch(Exception e) {
-			e.printStackTrace();
-		}
-	} 
-
-	public void makeTracks(int[] list) {        
-
-		for (int i = 0; i < list.length; i++) {
-			int key = list[i];
-
-			if (key != 0) {
-				track.add(makeEvent(144,9,key, 100, i));
-				track.add(makeEvent(128,9,key, 100, i+1));
-			}
-		}
-	}
-
-	public  MidiEvent makeEvent(int comd, int chan, int one, int two, int tick) {
-		MidiEvent event = null;
-		try {
-			ShortMessage a = new ShortMessage();
-			a.setMessage(comd, chan, one, two);
-			event = new MidiEvent(a, tick);
-
-		} catch(Exception e) {
-			e.printStackTrace(); 
-		}
-		return event;
-	}
 }