49 * <code>{@link Sequence#createTrack}</code> method, rather than by directly invoking a
50 * <code>Track</code> constructor.
51 * <p>
52 * The <code>Track</code> class provides methods to edit the track by adding
53 * or removing <code>MidiEvent</code> objects from it. These operations keep
54 * the event list in the correct time order. Methods are also
55 * included to obtain the track's size, in terms of either the number of events
56 * it contains or its duration in ticks.
57 *
58 * @see Sequencer#setTrackMute
59 * @see Sequencer#setTrackSolo
60 *
61 * @author Kara Kytle
62 * @author Florian Bomers
63 */
64 public class Track {
65
66 // TODO: use arrays for faster access
67
68 // the list containing the events
69 private ArrayList eventsList = new ArrayList();
70
71 // use a hashset to detect duplicate events in add(MidiEvent)
72 private HashSet set = new HashSet();
73
74 private MidiEvent eotEvent;
75
76
77 /**
78 * Package-private constructor. Constructs a new, empty Track object,
79 * which initially contains one event, the meta-event End of Track.
80 */
81 Track() {
82 // start with the end of track event
83 MetaMessage eot = new ImmutableEndOfTrack();
84 eotEvent = new MidiEvent(eot, 0);
85 eventsList.add(eotEvent);
86 set.add(eotEvent);
87 }
88
89 /**
90 * Adds a new event to the track. However, if the event is already
91 * contained in the track, it is not added again. The list of events
92 * is kept in time order, meaning that this event inserted at the
93 * appropriate place in the list, not necessarily at the end.
94 *
95 * @param event the event to add
96 * @return <code>true</code> if the event did not already exist in the
97 * track and was added, otherwise <code>false</code>
98 */
99 public boolean add(MidiEvent event) {
100 if (event == null) {
101 return false;
102 }
103 synchronized(eventsList) {
104
105 if (!set.contains(event)) {
106 int eventsCount = eventsList.size();
107
108 // get the last event
109 MidiEvent lastEvent = null;
110 if (eventsCount > 0) {
111 lastEvent = (MidiEvent) eventsList.get(eventsCount - 1);
112 }
113 // sanity check that we have a correct end-of-track
114 if (lastEvent != eotEvent) {
115 // if there is no eot event, add our immutable instance again
116 if (lastEvent != null) {
117 // set eotEvent's tick to the last tick of the track
118 eotEvent.setTick(lastEvent.getTick());
119 } else {
120 // if the events list is empty, just set the tick to 0
121 eotEvent.setTick(0);
122 }
123 // we needn't check for a duplicate of eotEvent in "eventsList",
124 // since then it would appear in the set.
125 eventsList.add(eotEvent);
126 set.add(eotEvent);
127 eventsCount = eventsList.size();
128 }
129
130 // first see if we are trying to add
131 // and endoftrack event.
132 if (MidiUtils.isMetaEndOfTrack(event.getMessage())) {
133 // since end of track event is useful
134 // for delays at the end of a track, we want to keep
135 // the tick value requested here if it is greater
136 // than the one on the eot we are maintaining.
137 // Otherwise, we only want a single eot event, so ignore.
138 if (event.getTick() > eotEvent.getTick()) {
139 eotEvent.setTick(event.getTick());
140 }
141 return true;
142 }
143
144 // prevent duplicates
145 set.add(event);
146
147 // insert event such that events is sorted in increasing
148 // tick order
149 int i = eventsCount;
150 for ( ; i > 0; i--) {
151 if (event.getTick() >= ((MidiEvent)eventsList.get(i-1)).getTick()) {
152 break;
153 }
154 }
155 if (i == eventsCount) {
156 // we're adding an event after the
157 // tick value of our eot, so push the eot out.
158 // Always add at the end for better performance:
159 // this saves all the checks and arraycopy when inserting
160
161 // overwrite eot with new event
162 eventsList.set(eventsCount - 1, event);
163 // set new time of eot, if necessary
164 if (eotEvent.getTick() < event.getTick()) {
165 eotEvent.setTick(event.getTick());
166 }
167 // add eot again at the end
168 eventsList.add(eotEvent);
169 } else {
170 eventsList.add(i, event);
171 }
203 return true;
204 }
205 }
206 }
207 return false;
208 }
209
210
211 /**
212 * Obtains the event at the specified index.
213 * @param index the location of the desired event in the event vector
214 * @throws ArrayIndexOutOfBoundsException if the
215 * specified index is negative or not less than the current size of
216 * this track.
217 * @see #size
218 * @return the event at the specified index
219 */
220 public MidiEvent get(int index) throws ArrayIndexOutOfBoundsException {
221 try {
222 synchronized(eventsList) {
223 return (MidiEvent)eventsList.get(index);
224 }
225 } catch (IndexOutOfBoundsException ioobe) {
226 throw new ArrayIndexOutOfBoundsException(ioobe.getMessage());
227 }
228 }
229
230
231 /**
232 * Obtains the number of events in this track.
233 * @return the size of the track's event vector
234 */
235 public int size() {
236 synchronized(eventsList) {
237 return eventsList.size();
238 }
239 }
240
241
242 /**
243 * Obtains the length of the track, expressed in MIDI ticks. (The
244 * duration of a tick in seconds is determined by the timing resolution
245 * of the <code>Sequence</code> containing this track, and also by
246 * the tempo of the music as set by the sequencer.)
247 * @return the duration, in ticks
248 * @see Sequence#Sequence(float, int)
249 * @see Sequencer#setTempoInBPM(float)
250 * @see Sequencer#getTickPosition()
251 */
252 public long ticks() {
253 long ret = 0;
254 synchronized (eventsList) {
255 if (eventsList.size() > 0) {
256 ret = ((MidiEvent)eventsList.get(eventsList.size() - 1)).getTick();
257 }
258 }
259 return ret;
260 }
261
262 private static class ImmutableEndOfTrack extends MetaMessage {
263 private ImmutableEndOfTrack() {
264 super(new byte[3]);
265 data[0] = (byte) META;
266 data[1] = MidiUtils.META_END_OF_TRACK_TYPE;
267 data[2] = 0;
268 }
269
270 public void setMessage(int type, byte[] data, int length) throws InvalidMidiDataException {
271 throw new InvalidMidiDataException("cannot modify end of track message");
272 }
273 }
274
275 }
|
49 * <code>{@link Sequence#createTrack}</code> method, rather than by directly invoking a
50 * <code>Track</code> constructor.
51 * <p>
52 * The <code>Track</code> class provides methods to edit the track by adding
53 * or removing <code>MidiEvent</code> objects from it. These operations keep
54 * the event list in the correct time order. Methods are also
55 * included to obtain the track's size, in terms of either the number of events
56 * it contains or its duration in ticks.
57 *
58 * @see Sequencer#setTrackMute
59 * @see Sequencer#setTrackSolo
60 *
61 * @author Kara Kytle
62 * @author Florian Bomers
63 */
64 public class Track {
65
66 // TODO: use arrays for faster access
67
68 // the list containing the events
69 private ArrayList<MidiEvent> eventsList = new ArrayList<>();
70
71 // use a hashset to detect duplicate events in add(MidiEvent)
72 private HashSet<MidiEvent> set = new HashSet<>();
73
74 private MidiEvent eotEvent;
75
76
77 /**
78 * Package-private constructor. Constructs a new, empty Track object,
79 * which initially contains one event, the meta-event End of Track.
80 */
81 Track() {
82 // start with the end of track event
83 MetaMessage eot = new ImmutableEndOfTrack();
84 eotEvent = new MidiEvent(eot, 0);
85 eventsList.add(eotEvent);
86 set.add(eotEvent);
87 }
88
89 /**
90 * Adds a new event to the track. However, if the event is already
91 * contained in the track, it is not added again. The list of events
92 * is kept in time order, meaning that this event inserted at the
93 * appropriate place in the list, not necessarily at the end.
94 *
95 * @param event the event to add
96 * @return <code>true</code> if the event did not already exist in the
97 * track and was added, otherwise <code>false</code>
98 */
99 public boolean add(MidiEvent event) {
100 if (event == null) {
101 return false;
102 }
103 synchronized(eventsList) {
104
105 if (!set.contains(event)) {
106 int eventsCount = eventsList.size();
107
108 // get the last event
109 MidiEvent lastEvent = null;
110 if (eventsCount > 0) {
111 lastEvent = eventsList.get(eventsCount - 1);
112 }
113 // sanity check that we have a correct end-of-track
114 if (lastEvent != eotEvent) {
115 // if there is no eot event, add our immutable instance again
116 if (lastEvent != null) {
117 // set eotEvent's tick to the last tick of the track
118 eotEvent.setTick(lastEvent.getTick());
119 } else {
120 // if the events list is empty, just set the tick to 0
121 eotEvent.setTick(0);
122 }
123 // we needn't check for a duplicate of eotEvent in "eventsList",
124 // since then it would appear in the set.
125 eventsList.add(eotEvent);
126 set.add(eotEvent);
127 eventsCount = eventsList.size();
128 }
129
130 // first see if we are trying to add
131 // and endoftrack event.
132 if (MidiUtils.isMetaEndOfTrack(event.getMessage())) {
133 // since end of track event is useful
134 // for delays at the end of a track, we want to keep
135 // the tick value requested here if it is greater
136 // than the one on the eot we are maintaining.
137 // Otherwise, we only want a single eot event, so ignore.
138 if (event.getTick() > eotEvent.getTick()) {
139 eotEvent.setTick(event.getTick());
140 }
141 return true;
142 }
143
144 // prevent duplicates
145 set.add(event);
146
147 // insert event such that events is sorted in increasing
148 // tick order
149 int i = eventsCount;
150 for ( ; i > 0; i--) {
151 if (event.getTick() >= (eventsList.get(i-1)).getTick()) {
152 break;
153 }
154 }
155 if (i == eventsCount) {
156 // we're adding an event after the
157 // tick value of our eot, so push the eot out.
158 // Always add at the end for better performance:
159 // this saves all the checks and arraycopy when inserting
160
161 // overwrite eot with new event
162 eventsList.set(eventsCount - 1, event);
163 // set new time of eot, if necessary
164 if (eotEvent.getTick() < event.getTick()) {
165 eotEvent.setTick(event.getTick());
166 }
167 // add eot again at the end
168 eventsList.add(eotEvent);
169 } else {
170 eventsList.add(i, event);
171 }
203 return true;
204 }
205 }
206 }
207 return false;
208 }
209
210
211 /**
212 * Obtains the event at the specified index.
213 * @param index the location of the desired event in the event vector
214 * @throws ArrayIndexOutOfBoundsException if the
215 * specified index is negative or not less than the current size of
216 * this track.
217 * @see #size
218 * @return the event at the specified index
219 */
220 public MidiEvent get(int index) throws ArrayIndexOutOfBoundsException {
221 try {
222 synchronized(eventsList) {
223 return eventsList.get(index);
224 }
225 } catch (IndexOutOfBoundsException ioobe) {
226 throw new ArrayIndexOutOfBoundsException(ioobe.getMessage());
227 }
228 }
229
230
231 /**
232 * Obtains the number of events in this track.
233 * @return the size of the track's event vector
234 */
235 public int size() {
236 synchronized(eventsList) {
237 return eventsList.size();
238 }
239 }
240
241
242 /**
243 * Obtains the length of the track, expressed in MIDI ticks. (The
244 * duration of a tick in seconds is determined by the timing resolution
245 * of the <code>Sequence</code> containing this track, and also by
246 * the tempo of the music as set by the sequencer.)
247 * @return the duration, in ticks
248 * @see Sequence#Sequence(float, int)
249 * @see Sequencer#setTempoInBPM(float)
250 * @see Sequencer#getTickPosition()
251 */
252 public long ticks() {
253 long ret = 0;
254 synchronized (eventsList) {
255 if (eventsList.size() > 0) {
256 ret = (eventsList.get(eventsList.size() - 1)).getTick();
257 }
258 }
259 return ret;
260 }
261
262 private static class ImmutableEndOfTrack extends MetaMessage {
263 private ImmutableEndOfTrack() {
264 super(new byte[3]);
265 data[0] = (byte) META;
266 data[1] = MidiUtils.META_END_OF_TRACK_TYPE;
267 data[2] = 0;
268 }
269
270 public void setMessage(int type, byte[] data, int length) throws InvalidMidiDataException {
271 throw new InvalidMidiDataException("cannot modify end of track message");
272 }
273 }
274
275 }
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