public interface Sequencer extends MidiDevice
A hardware or software device that plays back a MIDI
is known as a sequencer. A MIDI sequence contains lists of time-stamped MIDI data, such as might be read from a standard MIDI file. Most sequencers also provide functions for creating and editing sequences. sequence
The Sequencer
interface includes methods for the following basic MIDI sequencer operations:
Sequencer
has access to: Sequencer.SyncMode
, addMetaEventListener(javax.sound.midi.MetaEventListener)
, ControllerEventListener
, Receiver
, Transmitter
, MidiDevice
Modifier and Type | Interface and Description |
---|---|
static class |
Sequencer.SyncMode A |
MidiDevice.Info
static final int LOOP_CONTINUOUSLY
A value indicating that looping should continue indefinitely rather than complete after a specific number of loops.
setLoopCount(int)
, Constant Field Valuesvoid setSequence(Sequence sequence) throws InvalidMidiDataException
Sets the current sequence on which the sequencer operates.
This method can be called even if the Sequencer
is closed.
sequence
- the sequence to be loaded.InvalidMidiDataException
- if the sequence contains invalid MIDI data, or is not supported.void setSequence(InputStream stream) throws IOException, InvalidMidiDataException
Sets the current sequence on which the sequencer operates. The stream must point to MIDI file data.
This method can be called even if the Sequencer
is closed.
stream
- stream containing MIDI file data.IOException
- if an I/O exception occurs during reading of the stream.InvalidMidiDataException
- if invalid data is encountered in the stream, or the stream is not supported.Sequence getSequence()
Obtains the sequence on which the Sequencer is currently operating.
This method can be called even if the Sequencer
is closed.
null
if no sequence is currently set.void start()
Starts playback of the MIDI data in the currently loaded sequence. Playback will begin from the current position. If the playback position reaches the loop end point, and the loop count is greater than 0, playback will resume at the loop start point for the number of repetitions set with setLoopCount
. After that, or if the loop count is 0, playback will continue to play to the end of the sequence.
The implementation ensures that the synthesizer is brought to a consistent state when jumping to the loop start point by sending appropriate controllers, pitch bend, and program change events.
IllegalStateException
- if the Sequencer
is closed.setLoopStartPoint(long)
, setLoopEndPoint(long)
, setLoopCount(int)
, stop()
void stop()
Stops recording, if active, and playback of the currently loaded sequence, if any.
IllegalStateException
- if the Sequencer
is closed.start()
, isRunning()
boolean isRunning()
Indicates whether the Sequencer is currently running. The default is false
. The Sequencer starts running when either
or start()
is called. startRecording()
isRunning
then returns true
until playback of the sequence completes or
is called.stop()
true
if the Sequencer is running, otherwise false
void startRecording()
Starts recording and playback of MIDI data. Data is recorded to all enabled tracks, on the channel(s) for which they were enabled. Recording begins at the current position of the sequencer. Any events already in the track are overwritten for the duration of the recording session. Events from the currently loaded sequence, if any, are delivered to the sequencer's transmitter(s) along with messages received during recording.
Note that tracks are not by default enabled for recording. In order to record MIDI data, at least one track must be specifically enabled for recording.
IllegalStateException
- if the Sequencer
is closed.startRecording()
, recordEnable(javax.sound.midi.Track, int)
, recordDisable(javax.sound.midi.Track)
void stopRecording()
Stops recording, if active. Playback of the current sequence continues.
IllegalStateException
- if the Sequencer
is closed.startRecording()
, isRecording()
boolean isRecording()
Indicates whether the Sequencer is currently recording. The default is false
. The Sequencer begins recording when
is called, and then returns startRecording()
true
until
or stop()
is called.stopRecording()
true
if the Sequencer is recording, otherwise false
void recordEnable(Track track, int channel)
Prepares the specified track for recording events received on a particular channel. Once enabled, a track will receive events when recording is active.
track
- the track to which events will be recordedchannel
- the channel on which events will be received. If -1 is specified for the channel value, the track will receive data from all channels.IllegalArgumentException
- thrown if the track is not part of the current sequence.void recordDisable(Track track)
Disables recording to the specified track. Events will no longer be recorded into this track.
track
- the track to disable for recording, or null
to disable recording for all tracks.float getTempoInBPM()
Obtains the current tempo, expressed in beats per minute. The actual tempo of playback is the product of the returned value and the tempo factor.
getTempoFactor()
, setTempoInBPM(float)
, getTempoInMPQ()
void setTempoInBPM(float bpm)
Sets the tempo in beats per minute. The actual tempo of playback is the product of the specified value and the tempo factor.
bpm
- desired new tempo in beats per minutegetTempoFactor()
, setTempoInMPQ(float)
, getTempoInBPM()
float getTempoInMPQ()
Obtains the current tempo, expressed in microseconds per quarter note. The actual tempo of playback is the product of the returned value and the tempo factor.
getTempoFactor()
, setTempoInMPQ(float)
, getTempoInBPM()
void setTempoInMPQ(float mpq)
Sets the tempo in microseconds per quarter note. The actual tempo of playback is the product of the specified value and the tempo factor.
mpq
- desired new tempo in microseconds per quarter note.getTempoFactor()
, setTempoInBPM(float)
, getTempoInMPQ()
void setTempoFactor(float factor)
Scales the sequencer's actual playback tempo by the factor provided. The default is 1.0. A value of 1.0 represents the natural rate (the tempo specified in the sequence), 2.0 means twice as fast, etc. The tempo factor does not affect the values returned by
and getTempoInMPQ()
. Those values indicate the tempo prior to scaling. getTempoInBPM()
Note that the tempo factor cannot be adjusted when external synchronization is used. In that situation, setTempoFactor
always sets the tempo factor to 1.0.
factor
- the requested tempo scalargetTempoFactor()
float getTempoFactor()
Returns the current tempo factor for the sequencer. The default is 1.0.
setTempoFactor(float)
long getTickLength()
Obtains the length of the current sequence, expressed in MIDI ticks, or 0 if no sequence is set.
long getTickPosition()
Obtains the current position in the sequence, expressed in MIDI ticks. (The duration of a tick in seconds is determined both by the tempo and by the timing resolution stored in the
.)Sequence
setTickPosition(long)
void setTickPosition(long tick)
Sets the current sequencer position in MIDI ticks
tick
- the desired tick positiongetTickPosition()
long getMicrosecondLength()
Obtains the length of the current sequence, expressed in microseconds, or 0 if no sequence is set.
long getMicrosecondPosition()
Obtains the current position in the sequence, expressed in microseconds.
getMicrosecondPosition
in interface MidiDevice
setMicrosecondPosition(long)
void setMicrosecondPosition(long microseconds)
Sets the current position in the sequence, expressed in microseconds
microseconds
- desired position in microsecondsgetMicrosecondPosition()
void setMasterSyncMode(Sequencer.SyncMode sync)
Sets the source of timing information used by this sequencer. The sequencer synchronizes to the master, which is the internal clock, MIDI clock, or MIDI time code, depending on the value of sync
. The sync
argument must be one of the supported modes, as returned by
.getMasterSyncModes()
sync
- the desired master synchronization modeSequencer.SyncMode.INTERNAL_CLOCK
, Sequencer.SyncMode.MIDI_SYNC
, Sequencer.SyncMode.MIDI_TIME_CODE
, getMasterSyncMode()
Sequencer.SyncMode getMasterSyncMode()
Obtains the current master synchronization mode for this sequencer.
setMasterSyncMode(Sequencer.SyncMode)
, getMasterSyncModes()
Sequencer.SyncMode[] getMasterSyncModes()
Obtains the set of master synchronization modes supported by this sequencer.
Sequencer.SyncMode.INTERNAL_CLOCK
, Sequencer.SyncMode.MIDI_SYNC
, Sequencer.SyncMode.MIDI_TIME_CODE
, getMasterSyncMode()
, setMasterSyncMode(Sequencer.SyncMode)
void setSlaveSyncMode(Sequencer.SyncMode sync)
Sets the slave synchronization mode for the sequencer. This indicates the type of timing information sent by the sequencer to its receiver. The sync
argument must be one of the supported modes, as returned by
.getSlaveSyncModes()
sync
- the desired slave synchronization modeSequencer.SyncMode.MIDI_SYNC
, Sequencer.SyncMode.MIDI_TIME_CODE
, Sequencer.SyncMode.NO_SYNC
, getSlaveSyncModes()
Sequencer.SyncMode getSlaveSyncMode()
Obtains the current slave synchronization mode for this sequencer.
setSlaveSyncMode(Sequencer.SyncMode)
, getSlaveSyncModes()
Sequencer.SyncMode[] getSlaveSyncModes()
Obtains the set of slave synchronization modes supported by the sequencer.
Sequencer.SyncMode.MIDI_SYNC
, Sequencer.SyncMode.MIDI_TIME_CODE
, Sequencer.SyncMode.NO_SYNC
void setTrackMute(int track, boolean mute)
Sets the mute state for a track. This method may fail for a number of reasons. For example, the track number specified may not be valid for the current sequence, or the sequencer may not support this functionality. An application which needs to verify whether this operation succeeded should follow this call with a call to
.getTrackMute(int)
track
- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.mute
- the new mute state for the track. true
implies the track should be muted, false
implies the track should be unmuted.getSequence()
boolean getTrackMute(int track)
Obtains the current mute state for a track. The default mute state for all tracks which have not been muted is false. In any case where the specified track has not been muted, this method should return false. This applies if the sequencer does not support muting of tracks, and if the specified track index is not valid.
track
- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.true
if muted, false
if not.void setTrackSolo(int track, boolean solo)
Sets the solo state for a track. If solo
is true
only this track and other solo'd tracks will sound. If solo
is false
then only other solo'd tracks will sound, unless no tracks are solo'd in which case all un-muted tracks will sound.
This method may fail for a number of reasons. For example, the track number specified may not be valid for the current sequence, or the sequencer may not support this functionality. An application which needs to verify whether this operation succeeded should follow this call with a call to
.getTrackSolo(int)
track
- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.solo
- the new solo state for the track. true
implies the track should be solo'd, false
implies the track should not be solo'd.getSequence()
boolean getTrackSolo(int track)
Obtains the current solo state for a track. The default mute state for all tracks which have not been solo'd is false. In any case where the specified track has not been solo'd, this method should return false. This applies if the sequencer does not support soloing of tracks, and if the specified track index is not valid.
track
- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.true
if solo'd, false
if not.boolean addMetaEventListener(MetaEventListener listener)
Registers a meta-event listener to receive notification whenever a meta-event is encountered in the sequence and processed by the sequencer. This method can fail if, for instance,this class of sequencer does not support meta-event notification.
listener
- listener to addtrue
if the listener was successfully added, otherwise false
removeMetaEventListener(javax.sound.midi.MetaEventListener)
, MetaEventListener
, MetaMessage
void removeMetaEventListener(MetaEventListener listener)
Removes the specified meta-event listener from this sequencer's list of registered listeners, if in fact the listener is registered.
listener
- the meta-event listener to removeaddMetaEventListener(javax.sound.midi.MetaEventListener)
int[] addControllerEventListener(ControllerEventListener listener, int[] controllers)
Registers a controller event listener to receive notification whenever the sequencer processes a control-change event of the requested type or types. The types are specified by the controllers
argument, which should contain an array of MIDI controller numbers. (Each number should be between 0 and 127, inclusive. See the MIDI 1.0 Specification for the numbers that correspond to various types of controllers.)
The returned array contains the MIDI controller numbers for which the listener will now receive events. Some sequencers might not support controller event notification, in which case the array has a length of 0. Other sequencers might support notification for some controllers but not all. This method may be invoked repeatedly. Each time, the returned array indicates all the controllers that the listener will be notified about, not only the controllers requested in that particular invocation.
listener
- the controller event listener to add to the list of registered listenerscontrollers
- the MIDI controller numbers for which change notification is requestedremoveControllerEventListener(javax.sound.midi.ControllerEventListener, int[])
, ControllerEventListener
int[] removeControllerEventListener(ControllerEventListener listener, int[] controllers)
Removes a controller event listener's interest in one or more types of controller event. The controllers
argument is an array of MIDI numbers corresponding to the controllers for which the listener should no longer receive change notifications. To completely remove this listener from the list of registered listeners, pass in null
for controllers
. The returned array contains the MIDI controller numbers for which the listener will now receive events. The array has a length of 0 if the listener will not receive change notifications for any controllers.
listener
- old listenercontrollers
- the MIDI controller numbers for which change notification should be cancelled, or null
to cancel for all controllersaddControllerEventListener(javax.sound.midi.ControllerEventListener, int[])
void setLoopStartPoint(long tick)
Sets the first MIDI tick that will be played in the loop. If the loop count is greater than 0, playback will jump to this point when reaching the loop end point.
A value of 0 for the starting point means the beginning of the loaded sequence. The starting point must be lower than or equal to the ending point, and it must fall within the size of the loaded sequence.
A sequencer's loop start point defaults to start of the sequence.
tick
- the loop's starting position, in MIDI ticks (zero-based)IllegalArgumentException
- if the requested loop start point cannot be set, usually because it falls outside the sequence's duration or because the start point is after the end pointsetLoopEndPoint(long)
, setLoopCount(int)
, getLoopStartPoint()
, start()
long getLoopStartPoint()
Obtains the start position of the loop, in MIDI ticks.
setLoopStartPoint(long)
void setLoopEndPoint(long tick)
Sets the last MIDI tick that will be played in the loop. If the loop count is 0, the loop end point has no effect and playback continues to play when reaching the loop end point.
A value of -1 for the ending point indicates the last tick of the sequence. Otherwise, the ending point must be greater than or equal to the starting point, and it must fall within the size of the loaded sequence.
A sequencer's loop end point defaults to -1, meaning the end of the sequence.
tick
- the loop's ending position, in MIDI ticks (zero-based), or -1 to indicate the final tickIllegalArgumentException
- if the requested loop point cannot be set, usually because it falls outside the sequence's duration or because the ending point is before the starting pointsetLoopStartPoint(long)
, setLoopCount(int)
, getLoopEndPoint()
, start()
long getLoopEndPoint()
Obtains the end position of the loop, in MIDI ticks.
setLoopEndPoint(long)
void setLoopCount(int count)
Sets the number of repetitions of the loop for playback. When the playback position reaches the loop end point, it will loop back to the loop start point count
times, after which playback will continue to play to the end of the sequence.
If the current position when this method is invoked is greater than the loop end point, playback continues to the end of the sequence without looping, unless the loop end point is changed subsequently.
A count
value of 0 disables looping: playback will continue at the loop end point, and it will not loop back to the loop start point. This is a sequencer's default.
If playback is stopped during looping, the current loop status is cleared; subsequent start requests are not affected by an interrupted loop operation.
count
- the number of times playback should loop back from the loop's end position to the loop's start position, or LOOP_CONTINUOUSLY
to indicate that looping should continue until interruptedIllegalArgumentException
- if count
is negative and not equal to LOOP_CONTINUOUSLY
setLoopStartPoint(long)
, setLoopEndPoint(long)
, getLoopCount()
, start()
int getLoopCount()
Obtains the number of repetitions for playback.
setLoopCount(int)
, start()
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