openshot-audio  0.1.2
Public Member Functions | List of all members
MidiMessageCollector Class Reference

#include <juce_MidiMessageCollector.h>

Inheritance diagram for MidiMessageCollector:
MidiKeyboardStateListener MidiInputCallback

Public Member Functions

 MidiMessageCollector ()
 
 ~MidiMessageCollector ()
 
void reset (double sampleRate)
 
void addMessageToQueue (const MidiMessage &message)
 
void removeNextBlockOfMessages (MidiBuffer &destBuffer, int numSamples)
 
void handleNoteOn (MidiKeyboardState *, int midiChannel, int midiNoteNumber, float velocity) override
 
void handleNoteOff (MidiKeyboardState *, int midiChannel, int midiNoteNumber) override
 
void handleIncomingMidiMessage (MidiInput *, const MidiMessage &) override
 
- Public Member Functions inherited from MidiKeyboardStateListener
 MidiKeyboardStateListener () noexcept
 
virtual ~MidiKeyboardStateListener ()
 
- Public Member Functions inherited from MidiInputCallback
virtual ~MidiInputCallback ()
 
virtual void handlePartialSysexMessage (MidiInput *source, const uint8 *messageData, int numBytesSoFar, double timestamp)
 

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 MidiKeyboardStateListener or a MidiInputCallback so it can easily use a midi input or keyboard component as its source.

See also
MidiMessage, MidiInput

Constructor & Destructor Documentation

◆ MidiMessageCollector()

MidiMessageCollector::MidiMessageCollector ( )

◆ ~MidiMessageCollector()

MidiMessageCollector::~MidiMessageCollector ( )

Destructor.

Member Function Documentation

◆ addMessageToQueue()

void 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().

◆ handleIncomingMidiMessage()

void MidiMessageCollector::handleIncomingMidiMessage ( MidiInput source,
const MidiMessage message 
)
overridevirtual

Receives an incoming message.

A MidiInput object will call this method when a midi event arrives. It'll be called on a high-priority system thread, so avoid doing anything time-consuming in here, and avoid making any UI calls. You might find the MidiBuffer class helpful for queueing incoming messages for use later.

Parameters
sourcethe MidiInput object that generated the message
messagethe incoming message. The message's timestamp is set to a value equivalent to (Time::getMillisecondCounter() / 1000.0) to specify the time when the message arrived.

Implements MidiInputCallback.

◆ handleNoteOff()

void MidiMessageCollector::handleNoteOff ( MidiKeyboardState source,
int  midiChannel,
int  midiNoteNumber 
)
overridevirtual

Called when one of the MidiKeyboardState's keys is released.

This will be called synchronously when the state is either processing a buffer in its MidiKeyboardState::processNextMidiBuffer() method, or when a note is being played with its MidiKeyboardState::noteOff() method.

Note that this callback could happen from an audio callback thread, so be careful not to block, and avoid any UI activity in the callback.

Implements MidiKeyboardStateListener.

◆ handleNoteOn()

void MidiMessageCollector::handleNoteOn ( MidiKeyboardState source,
int  midiChannel,
int  midiNoteNumber,
float  velocity 
)
overridevirtual

Called when one of the MidiKeyboardState's keys is pressed.

This will be called synchronously when the state is either processing a buffer in its MidiKeyboardState::processNextMidiBuffer() method, or when a note is being played with its MidiKeyboardState::noteOn() method.

Note that this callback could happen from an audio callback thread, so be careful not to block, and avoid any UI activity in the callback.

Implements MidiKeyboardStateListener.

◆ removeNextBlockOfMessages()

void 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 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.


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