| /* |
| * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.sound.midi; |
| |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| |
| import com.sun.media.sound.MidiUtils; |
| |
| /** |
| * A MIDI track is an independent stream of MIDI events (time-stamped MIDI data) |
| * that can be stored along with other tracks in a standard MIDI file. The MIDI |
| * specification allows only 16 channels of MIDI data, but tracks are a way to |
| * get around this limitation. A MIDI file can contain any number of tracks, |
| * each containing its own stream of up to 16 channels of MIDI data. |
| * <p> |
| * A {@code Track} occupies a middle level in the hierarchy of data played by a |
| * {@link Sequencer}: sequencers play sequences, which contain tracks, which |
| * contain MIDI events. A sequencer may provide controls that mute or solo |
| * individual tracks. |
| * <p> |
| * The timing information and resolution for a track is controlled by and stored |
| * in the sequence containing the track. A given {@code Track} is considered to |
| * belong to the particular {@link Sequence} that maintains its timing. For this |
| * reason, a new (empty) track is created by calling the |
| * {@link Sequence#createTrack} method, rather than by directly invoking a |
| * {@code Track} constructor. |
| * <p> |
| * The {@code Track} class provides methods to edit the track by adding or |
| * removing {@code MidiEvent} objects from it. These operations keep the event |
| * list in the correct time order. Methods are also included to obtain the |
| * track's size, in terms of either the number of events it contains or its |
| * duration in ticks. |
| * |
| * @author Kara Kytle |
| * @author Florian Bomers |
| * @see Sequencer#setTrackMute |
| * @see Sequencer#setTrackSolo |
| */ |
| public class Track { |
| |
| // TODO: use arrays for faster access |
| |
| // the list containing the events |
| private ArrayList<MidiEvent> eventsList = new ArrayList<>(); |
| |
| // use a hashset to detect duplicate events in add(MidiEvent) |
| private HashSet<MidiEvent> set = new HashSet<>(); |
| |
| private MidiEvent eotEvent; |
| |
| /** |
| * Package-private constructor. Constructs a new, empty Track object, which |
| * initially contains one event, the meta-event End of Track. |
| */ |
| Track() { |
| // start with the end of track event |
| MetaMessage eot = new ImmutableEndOfTrack(); |
| eotEvent = new MidiEvent(eot, 0); |
| eventsList.add(eotEvent); |
| set.add(eotEvent); |
| } |
| |
| /** |
| * Adds a new event to the track. However, if the event is already contained |
| * in the track, it is not added again. The list of events is kept in time |
| * order, meaning that this event inserted at the appropriate place in the |
| * list, not necessarily at the end. |
| * |
| * @param event the event to add |
| * @return {@code true} if the event did not already exist in the track and |
| * was added, otherwise {@code false} |
| */ |
| public boolean add(MidiEvent event) { |
| if (event == null) { |
| return false; |
| } |
| synchronized(eventsList) { |
| |
| if (!set.contains(event)) { |
| int eventsCount = eventsList.size(); |
| |
| // get the last event |
| MidiEvent lastEvent = null; |
| if (eventsCount > 0) { |
| lastEvent = eventsList.get(eventsCount - 1); |
| } |
| // sanity check that we have a correct end-of-track |
| if (lastEvent != eotEvent) { |
| // if there is no eot event, add our immutable instance again |
| if (lastEvent != null) { |
| // set eotEvent's tick to the last tick of the track |
| eotEvent.setTick(lastEvent.getTick()); |
| } else { |
| // if the events list is empty, just set the tick to 0 |
| eotEvent.setTick(0); |
| } |
| // we needn't check for a duplicate of eotEvent in "eventsList", |
| // since then it would appear in the set. |
| eventsList.add(eotEvent); |
| set.add(eotEvent); |
| eventsCount = eventsList.size(); |
| } |
| |
| // first see if we are trying to add |
| // and endoftrack event. |
| if (MidiUtils.isMetaEndOfTrack(event.getMessage())) { |
| // since end of track event is useful |
| // for delays at the end of a track, we want to keep |
| // the tick value requested here if it is greater |
| // than the one on the eot we are maintaining. |
| // Otherwise, we only want a single eot event, so ignore. |
| if (event.getTick() > eotEvent.getTick()) { |
| eotEvent.setTick(event.getTick()); |
| } |
| return true; |
| } |
| |
| // prevent duplicates |
| set.add(event); |
| |
| // insert event such that events is sorted in increasing |
| // tick order |
| int i = eventsCount; |
| for ( ; i > 0; i--) { |
| if (event.getTick() >= (eventsList.get(i-1)).getTick()) { |
| break; |
| } |
| } |
| if (i == eventsCount) { |
| // we're adding an event after the |
| // tick value of our eot, so push the eot out. |
| // Always add at the end for better performance: |
| // this saves all the checks and arraycopy when inserting |
| |
| // overwrite eot with new event |
| eventsList.set(eventsCount - 1, event); |
| // set new time of eot, if necessary |
| if (eotEvent.getTick() < event.getTick()) { |
| eotEvent.setTick(event.getTick()); |
| } |
| // add eot again at the end |
| eventsList.add(eotEvent); |
| } else { |
| eventsList.add(i, event); |
| } |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Removes the specified event from the track. |
| * |
| * @param event the event to remove |
| * @return {@code true} if the event existed in the track and was removed, |
| * otherwise {@code false} |
| */ |
| public boolean remove(MidiEvent event) { |
| |
| // this implementation allows removing the EOT event. |
| // pretty bad, but would probably be too risky to |
| // change behavior now, in case someone does tricks like: |
| // |
| // while (track.size() > 0) track.remove(track.get(track.size() - 1)); |
| |
| // also, would it make sense to adjust the EOT's time |
| // to the last event, if the last non-EOT event is removed? |
| // Or: document that the ticks() length will not be reduced |
| // by deleting events (unless the EOT event is removed) |
| synchronized(eventsList) { |
| if (set.remove(event)) { |
| int i = eventsList.indexOf(event); |
| if (i >= 0) { |
| eventsList.remove(i); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Obtains the event at the specified index. |
| * |
| * @param index the location of the desired event in the event vector |
| * @return the event at the specified index |
| * @throws ArrayIndexOutOfBoundsException if the specified index is negative |
| * or not less than the current size of this track |
| * @see #size |
| */ |
| public MidiEvent get(int index) throws ArrayIndexOutOfBoundsException { |
| try { |
| synchronized(eventsList) { |
| return eventsList.get(index); |
| } |
| } catch (IndexOutOfBoundsException ioobe) { |
| throw new ArrayIndexOutOfBoundsException(ioobe.getMessage()); |
| } |
| } |
| |
| /** |
| * Obtains the number of events in this track. |
| * |
| * @return the size of the track's event vector |
| */ |
| public int size() { |
| synchronized(eventsList) { |
| return eventsList.size(); |
| } |
| } |
| |
| /** |
| * Obtains the length of the track, expressed in MIDI ticks. (The duration |
| * of a tick in seconds is determined by the timing resolution of the |
| * {@code Sequence} containing this track, and also by the tempo of the |
| * music as set by the sequencer.) |
| * |
| * @return the duration, in ticks |
| * @see Sequence#Sequence(float, int) |
| * @see Sequencer#setTempoInBPM(float) |
| * @see Sequencer#getTickPosition() |
| */ |
| public long ticks() { |
| long ret = 0; |
| synchronized (eventsList) { |
| if (eventsList.size() > 0) { |
| ret = (eventsList.get(eventsList.size() - 1)).getTick(); |
| } |
| } |
| return ret; |
| } |
| |
| private static class ImmutableEndOfTrack extends MetaMessage { |
| private ImmutableEndOfTrack() { |
| super(new byte[3]); |
| data[0] = (byte) META; |
| data[1] = MidiUtils.META_END_OF_TRACK_TYPE; |
| data[2] = 0; |
| } |
| |
| public void setMessage(int type, byte[] data, int length) throws InvalidMidiDataException { |
| throw new InvalidMidiDataException("cannot modify end of track message"); |
| } |
| } |
| } |