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.

A Track occupies a middle level in the hierarchy of data played by a Sequencer: sequencers play sequences, which contain tracks, which contain MIDI events. A sequencer may provide controls that mute or solo individual tracks.

The timing information and resolution for a track is controlled by and stored in the sequence containing the track. A given Track is considered to belong to the particular Sequence that maintains its timing. For this reason, a new (empty) track is created by calling the Sequence#createTrack method, rather than by directly invoking a Track constructor.

The Track class provides methods to edit the track by adding or removing 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.

Modifier and Type	Class and Description
private static class	Track.ImmutableEndOfTrack

Modifier and Type	Field and Description
private final MidiEvent	eotEvent
private final ArrayList<MidiEvent>	eventsList The list containing the events.
private final HashSet<MidiEvent>	set Use a hashset to detect duplicate events in add(MidiEvent).

Access	Constructor and Description
pack-priv	Track() Package-private constructor.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: `true` if the event did not already exist in the track and was added, otherwise `false` add(MidiEvent the event to add event) Adds a new event to the track.
public MidiEvent	Returns: the event at the specified index get(int the location of the desired event in the event vector index) Obtains the event at the specified index.
public boolean	Returns: `true` if the event existed in the track and was removed, otherwise `false` remove(MidiEvent the event to remove event) Removes the specified event from the track.
public int	Returns: the size of the track's event vector size() Obtains the number of events in this track.
public long	Returns: the duration, in ticks ticks() Obtains the length of the track, expressed in MIDI ticks.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

eotEvent	back to summary
private final MidiEvent eotEvent

eventsList	back to summary
private final ArrayList<MidiEvent> eventsList The list containing the events.

set	back to summary
private final HashSet<MidiEvent> set Use a hashset to detect duplicate events in add(MidiEvent).

Constructor Detail

Track	back to summary
pack-priv Track() Package-private constructor. Constructs a new, empty Track object, which initially contains one event, the meta-event End of Track.

Method Detail

add back to summary

add	back to summary
public boolean add(MidiEvent event) 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. Parameters event:MidiEvent the event to add Returns:boolean `true` if the event did not already exist in the track and was added, otherwise `false`

public boolean add(MidiEvent event)

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.

Parameters

event:MidiEvent: the event to add

Returns:boolean

true if the event did not already exist in the track and was added, otherwise false

get back to summary

get	back to summary
public MidiEvent get(int index) throws ArrayIndexOutOfBoundsException Obtains the event at the specified index. Parameters index:int the location of the desired event in the event vector Returns:MidiEvent the event at the specified index Exceptions ArrayIndexOutOfBoundsException: if the specified index is negative or not less than the current size of this track See Also `size`

public MidiEvent get(int index) throws ArrayIndexOutOfBoundsException

Obtains the event at the specified index.

Parameters

index:int: the location of the desired event in the event vector

Returns:MidiEvent

the event at the specified index

Exceptions

ArrayIndexOutOfBoundsException:: if the specified index is negative or not less than the current size of this track

See Also

size

remove back to summary

remove	back to summary
public boolean remove(MidiEvent event) Removes the specified event from the track. Parameters event:MidiEvent the event to remove Returns:boolean `true` if the event existed in the track and was removed, otherwise `false`

public boolean remove(MidiEvent event)

Removes the specified event from the track.

Parameters

event:MidiEvent: the event to remove

Returns:boolean

true if the event existed in the track and was removed, otherwise false

size	back to summary
public int size() Obtains the number of events in this track. Returns:int the size of the track's event vector

size

back to summary

public int size()

Obtains the number of events in this track.

Returns:int: the size of the track's event vector

ticks back to summary

ticks	back to summary
public long ticks() 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 `Sequence` containing this track, and also by the tempo of the music as set by the sequencer.) Returns:long the duration, in ticks See Also `Sequence#Sequence(float, int)`, `Sequencer#setTempoInBPM(float)`, `Sequencer#getTickPosition()`

public long ticks()

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 Sequence containing this track, and also by the tempo of the music as set by the sequencer.)

Returns:long: the duration, in ticks
See Also: Sequence#Sequence(float, int), Sequencer#setTempoInBPM(float), Sequencer#getTickPosition()

javax.sound.midi back to summary

private Class Track.ImmutableEndOfTrack

Class Inheritance

extends MetaMessage

java.lang.Object
javax.sound.midi.MidiMessage
javax.sound.midi.MetaMessage
javax.sound.midi.Track.ImmutableEndOfTrack

Field Summary

Inherited from javax.sound.midi.MetaMessage:: META

Constructor Summary

Access	Constructor and Description
private	ImmutableEndOfTrack()

Method Summary

Modifier and Type	Method and Description
public void	setMessage(int type, byte[] data, int length) Overrides javax.sound.midi.MetaMessage.setMessage. Sets the message parameters for a `MetaMessage`.

Inherited from javax.sound.midi.MetaMessage:: clone getData getType

Constructor Detail

ImmutableEndOfTrack	back to summary
private ImmutableEndOfTrack()

Method Detail

setMessage back to summary

setMessage	back to summary
public void setMessage(int type, byte[] data, int length) throws InvalidMidiDataException Overrides javax.sound.midi.MetaMessage.setMessage. Doc from javax.sound.midi.MetaMessage.setMessage. Sets the message parameters for a `MetaMessage`. Since only one status byte value, `0xFF`, is allowed for meta-messages, it does not need to be specified here. Calls to `getStatus` return `0xFF` for all meta-messages. The `type` argument should be a valid value for the byte that follows the status byte in the `MetaMessage`. The `data` argument should contain all the subsequent bytes of the `MetaMessage`. In other words, the byte that specifies the type of `MetaMessage` is not considered a data byte. Annotations @Override Exceptions InvalidMidiDataException: if the parameter values do not specify a valid MIDI meta message

public void setMessage(int type, byte[] data, int length) throws InvalidMidiDataException

Overrides javax.sound.midi.MetaMessage.setMessage.

Doc from javax.sound.midi.MetaMessage.setMessage.

Sets the message parameters for a MetaMessage. Since only one status byte value, 0xFF, is allowed for meta-messages, it does not need to be specified here. Calls to getStatus return 0xFF for all meta-messages.

The type argument should be a valid value for the byte that follows the status byte in the MetaMessage. The data argument should contain all the subsequent bytes of the MetaMessage. In other words, the byte that specifies the type of MetaMessage is not considered a data byte.

Annotations

@Override

Exceptions

InvalidMidiDataException:: if the parameter values do not specify a valid MIDI meta message

public final Class Track

Nested and Inner Type Summary

Field Summary

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Method Summary

Field Detail

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Method Detail

private Class Track.ImmutableEndOfTrack

Field Summary

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Method Summary

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Method Detail