OpenShot Audio Library | OpenShotAudio 0.3.2
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juce::MidiKeyboardState Class Reference

#include <juce_MidiKeyboardState.h>

Public Member Functions

void reset ()
 
bool isNoteOn (int midiChannel, int midiNoteNumber) const noexcept
 
bool isNoteOnForChannels (int midiChannelMask, int midiNoteNumber) const noexcept
 
void noteOn (int midiChannel, int midiNoteNumber, float velocity)
 
void noteOff (int midiChannel, int midiNoteNumber, float velocity)
 
void allNotesOff (int midiChannel)
 
void processNextMidiEvent (const MidiMessage &message)
 
void processNextMidiBuffer (MidiBuffer &buffer, int startSample, int numSamples, bool injectIndirectEvents)
 
void addListener (MidiKeyboardStateListener *listener)
 
void removeListener (MidiKeyboardStateListener *listener)
 

Detailed Description

Represents a piano keyboard, keeping track of which keys are currently pressed.

This object can parse a stream of midi events, using them to update its idea of which keys are pressed for each individual midi channel.

When keys go up or down, it can broadcast these events to listener objects.

It also allows key up/down events to be triggered with its noteOn() and noteOff() methods, and midi messages for these events will be merged into the midi stream that gets processed by processNextMidiBuffer().

Definition at line 86 of file juce_MidiKeyboardState.h.

Constructor & Destructor Documentation

◆ MidiKeyboardState()

juce::MidiKeyboardState::MidiKeyboardState ( )

Definition at line 26 of file juce_MidiKeyboardState.cpp.

◆ ~MidiKeyboardState()

juce::MidiKeyboardState::~MidiKeyboardState ( )

Definition at line 31 of file juce_MidiKeyboardState.cpp.

Member Function Documentation

◆ addListener()

void juce::MidiKeyboardState::addListener ( MidiKeyboardStateListener listener)

Registers a listener for callbacks when keys go up or down.

See also
removeListener

Definition at line 174 of file juce_MidiKeyboardState.cpp.

◆ allNotesOff()

void juce::MidiKeyboardState::allNotesOff ( int  midiChannel)

This will turn off any currently-down notes for the given midi channel.

If you pass 0 for the midi channel, it will in fact turn off all notes on all channels.

Calling this method will make calls to noteOff(), so can trigger synchronous callbacks and events being added to the midi stream.

Definition at line 110 of file juce_MidiKeyboardState.cpp.

Referenced by allNotesOff().

◆ isNoteOn()

bool juce::MidiKeyboardState::isNoteOn ( int  midiChannel,
int  midiNoteNumber 
) const
noexcept

Returns true if the given midi key is currently held down for the given midi channel.

The channel number must be between 1 and 16. If you want to see if any notes are on for a range of channels, use the isNoteOnForChannels() method.

Definition at line 43 of file juce_MidiKeyboardState.cpp.

Referenced by noteOff().

◆ isNoteOnForChannels()

bool juce::MidiKeyboardState::isNoteOnForChannels ( int  midiChannelMask,
int  midiNoteNumber 
) const
noexcept

Returns true if the given midi key is currently held down on any of a set of midi channels.

The channel mask has a bit set for each midi channel you want to test for - bit 0 = midi channel 1, bit 1 = midi channel 2, etc.

If a note is on for at least one of the specified channels, this returns true.

Definition at line 51 of file juce_MidiKeyboardState.cpp.

◆ noteOff()

void juce::MidiKeyboardState::noteOff ( int  midiChannel,
int  midiNoteNumber,
float  velocity 
)

Turns a specified note off.

This will cause a suitable midi note-off event to be injected into the midi buffer during the next call to processNextMidiBuffer().

It will also trigger a synchronous callback to the listeners to tell them that the key has gone up.

But if the note isn't actually down for the given channel, this method will in fact do nothing.

Definition at line 85 of file juce_MidiKeyboardState.cpp.

Referenced by allNotesOff().

◆ noteOn()

void juce::MidiKeyboardState::noteOn ( int  midiChannel,
int  midiNoteNumber,
float  velocity 
)

Turns a specified note on.

This will cause a suitable midi note-on event to be injected into the midi buffer during the next call to processNextMidiBuffer().

It will also trigger a synchronous callback to the listeners to tell them that the key has gone down.

Definition at line 57 of file juce_MidiKeyboardState.cpp.

◆ processNextMidiBuffer()

void juce::MidiKeyboardState::processNextMidiBuffer ( MidiBuffer buffer,
int  startSample,
int  numSamples,
bool  injectIndirectEvents 
)

Scans a midi stream for up/down events and adds its own events to it.

This will look for any up/down events and use them to update the internal state, synchronously making suitable callbacks to the listeners.

If injectIndirectEvents is true, then midi events to produce the recent noteOn() and noteOff() calls will be added into the buffer.

Only the section of the buffer whose timestamps are between startSample and (startSample + numSamples) will be affected, and any events added will be placed between these times.

If you're going to use this method, you'll need to keep calling it regularly for it to work satisfactorily.

To process a single midi event at a time, use the processNextMidiEvent() method instead.

Definition at line 143 of file juce_MidiKeyboardState.cpp.

◆ processNextMidiEvent()

void juce::MidiKeyboardState::processNextMidiEvent ( const MidiMessage message)

Looks at a key-up/down event and uses it to update the state of this object.

To process a buffer full of midi messages, use the processNextMidiBuffer() method instead.

Definition at line 126 of file juce_MidiKeyboardState.cpp.

Referenced by processNextMidiBuffer().

◆ removeListener()

void juce::MidiKeyboardState::removeListener ( MidiKeyboardStateListener listener)

Deregisters a listener.

See also
addListener

Definition at line 180 of file juce_MidiKeyboardState.cpp.

◆ reset()

void juce::MidiKeyboardState::reset ( )

Resets the state of the object.

All internal data for all the channels is reset, but no events are sent as a result.

If you want to release any keys that are currently down, and to send out note-up midi messages for this, use the allNotesOff() method instead.

Definition at line 36 of file juce_MidiKeyboardState.cpp.


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