juce::MidiMessageCollector Class Reference

Collects incoming realtime MIDI messages and turns them into blocks suitable for processing by a block-based audio callback. More...

#include <juce_MidiMessageCollector.h>

Inheritance diagram for juce::MidiMessageCollector:

Collaboration diagram for juce::MidiMessageCollector:

Public Member Functions
	MidiMessageCollector ()
	Creates a MidiMessageCollector. More...
	~MidiMessageCollector () override
	Destructor. More...
void	addMessageToQueue (const MidiMessage &message)
	Takes an incoming real-time message and adds it to the queue. More...
void	ensureStorageAllocated (size_t bytes)
	Preallocates storage for collected messages. More...
void	handleIncomingMidiMessage (MidiInput *, const MidiMessage &) override
void	handleNoteOff (MidiKeyboardState *, int midiChannel, int midiNoteNumber, float velocity) override
void	handleNoteOn (MidiKeyboardState *, int midiChannel, int midiNoteNumber, float velocity) override
virtual void	handlePartialSysexMessage (MidiInput *source, const uint8 *messageData, int numBytesSoFar, double timestamp)
	Notification sent each time a packet of a multi-packet sysex message arrives. More...
void	removeNextBlockOfMessages (MidiBuffer &destBuffer, int numSamples)
	Removes all the pending messages from the queue as a buffer. More...
void	reset (double sampleRate)
	Clears any messages from the queue. More...

Private Attributes
bool	hasCalledReset = false
MidiBuffer	incomingMessages
double	lastCallbackTime = 0
CriticalSection	midiCallbackLock
double	sampleRate = 44100.0

Detailed Description

Collects incoming realtime MIDI messages and turns them into blocks suitable for processing by a block-based audio callback.

The class can also be used as either a MidiKeyboardState::Listener or a MidiInputCallback so it can easily use a midi input or keyboard component as its source.

See also

MidiMessage, MidiInput

@tags{Audio}

Constructor & Destructor Documentation

MidiMessageCollector()

juce::MidiMessageCollector::MidiMessageCollector

(

)

Creates a MidiMessageCollector.

~MidiMessageCollector()

juce::MidiMessageCollector::~MidiMessageCollector ( )

override

Destructor.

Member Function Documentation

addMessageToQueue()

void juce::MidiMessageCollector::addMessageToQueue

(

const MidiMessage &

message

)

Takes an incoming real-time message and adds it to the queue.

The message's timestamp is taken, and it will be ready for retrieval as part of the block returned by the next call to removeNextBlockOfMessages().

This method is fully thread-safe when overlapping calls are made with removeNextBlockOfMessages().

ensureStorageAllocated()

void juce::MidiMessageCollector::ensureStorageAllocated

(

size_t

bytes

)

Preallocates storage for collected messages.

This can be called before audio processing begins to ensure that there is sufficient space for the expected MIDI messages, in order to avoid allocations within the audio callback.

handleIncomingMidiMessage()

void juce::MidiMessageCollector::handleIncomingMidiMessage ( MidiInput *  , const MidiMessage &    )

overridevirtual

Implements juce::MidiInputCallback.

handleNoteOff()

void juce::MidiMessageCollector::handleNoteOff ( MidiKeyboardState *  , int  midiChannel, int  midiNoteNumber, float  velocity  )

overridevirtual

Implements juce::MidiKeyboardState::Listener.

handleNoteOn()

void juce::MidiMessageCollector::handleNoteOn ( MidiKeyboardState *  , int  midiChannel, int  midiNoteNumber, float  velocity  )

overridevirtual

Implements juce::MidiKeyboardState::Listener.

handlePartialSysexMessage()

virtual void juce::MidiInputCallback::handlePartialSysexMessage ( MidiInput *  source, const uint8 *  messageData, int  numBytesSoFar, double  timestamp  )

inlinevirtualinherited

Notification sent each time a packet of a multi-packet sysex message arrives.

If a long sysex message is broken up into multiple packets, this callback is made for each packet that arrives until the message is finished, at which point the normal handleIncomingMidiMessage() callback will be made with the entire message.

The message passed in will contain the start of a sysex, but won't be finished with the terminating 0xf7 byte.

References juce::ignoreUnused(), and juce::gl::source.

removeNextBlockOfMessages()

void juce::MidiMessageCollector::removeNextBlockOfMessages	(	MidiBuffer &	destBuffer,
		int	numSamples
	)

Removes all the pending messages from the queue as a buffer.

This will also correct the messages' timestamps to make sure they're in the range 0 to numSamples - 1.

This call should be made regularly by something like an audio processing callback, because the time that it happens is used in calculating the midi event positions.

This method is fully thread-safe when overlapping calls are made with addMessageToQueue().

Precondition: numSamples must be greater than 0.

reset()

void juce::MidiMessageCollector::reset

(

double

sampleRate

)

Clears any messages from the queue.

You need to call this method before starting to use the collector, so that it knows the correct sample rate to use.

Member Data Documentation

hasCalledReset

bool juce::MidiMessageCollector::hasCalledReset = false

private

incomingMessages

MidiBuffer juce::MidiMessageCollector::incomingMessages

private

lastCallbackTime

double juce::MidiMessageCollector::lastCallbackTime = 0

private

midiCallbackLock

CriticalSection juce::MidiMessageCollector::midiCallbackLock

private

sampleRate

double juce::MidiMessageCollector::sampleRate = 44100.0

private

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The documentation for this class was generated from the following file:

• juce_MidiMessageCollector.h