JUCE: AudioProcessorListener Class Reference

JUCE

Classes | Public Member Functions | List of all members
AudioProcessorListener Class Referenceabstract
juce_audio_processors » processors

Base class for listeners that want to know about changes to an AudioProcessor. More...

`#include <juce_AudioProcessorListener.h>`

## Classes
struct | ChangeDetails
| Provides details about aspects of an AudioProcessor which have changed. More...

## Public Member Functions
virtual | ~AudioProcessorListener ()=default
| Destructor. More...
virtual void | audioProcessorParameterChanged (AudioProcessor *processor, int parameterIndex, float newValue)=0
| Receives a callback when a parameter is changed. More...
virtual void | audioProcessorChanged (AudioProcessor *processor, const ChangeDetails &details)=0
| Called to indicate that something else in the plugin has changed, like its program, number of parameters, etc. More...
virtual void | audioProcessorParameterChangeGestureBegin (AudioProcessor *processor, int parameterIndex)
| Indicates that a parameter change gesture has started. More...
virtual void | audioProcessorParameterChangeGestureEnd (AudioProcessor *processor, int parameterIndex)
| Indicates that a parameter change gesture has finished. More...

## Detailed Description

Base class for listeners that want to know about changes to an AudioProcessor.

Use AudioProcessor::addListener() to register your listener with an AudioProcessor.

See also
  AudioProcessor

## Constructor & Destructor Documentation

## ◆ ~AudioProcessorListener()

virtual AudioProcessorListener::~AudioProcessorListener | ( |  | ) |
| virtualdefault

Destructor.

## Member Function Documentation

## ◆ audioProcessorParameterChanged()

virtual void AudioProcessorListener::audioProcessorParameterChanged | ( | AudioProcessor * | processor,
|  | int | parameterIndex,
|  | float | newValue
| ) |  |
| pure virtual

Receives a callback when a parameter is changed.

IMPORTANT NOTE: This will be called synchronously when a parameter changes, and many audio processors will change their parameter during their audio callback. This means that not only has your handler code got to be completely thread-safe, but it's also got to be VERY fast, and avoid blocking. If you need to handle this event on your message thread, use this callback to trigger an AsyncUpdater or ChangeBroadcaster which you can respond to on the message thread.

## ◆ audioProcessorChanged()

virtual void AudioProcessorListener::audioProcessorChanged | ( | AudioProcessor * | processor,
|  | const ChangeDetails & | details
| ) |  |
| pure virtual

Called to indicate that something else in the plugin has changed, like its program, number of parameters, etc.

IMPORTANT NOTE: This will be called synchronously, and many audio processors will call it during their audio callback. This means that not only has your handler code got to be completely thread-safe, but it's also got to be VERY fast, and avoid blocking. If you need to handle this event on your message thread, use this callback to trigger an AsyncUpdater or ChangeBroadcaster which you can respond to later on the message thread.

## ◆ audioProcessorParameterChangeGestureBegin()

virtual void AudioProcessorListener::audioProcessorParameterChangeGestureBegin | ( | AudioProcessor * | processor,
|  | int | parameterIndex
| ) |  |
| virtual

Indicates that a parameter change gesture has started.

E.g. if the user is dragging a slider, this would be called when they first press the mouse button, and audioProcessorParameterChangeGestureEnd would be called when they release it.

IMPORTANT NOTE: This will be called synchronously, and many audio processors will call it during their audio callback. This means that not only has your handler code got to be completely thread-safe, but it's also got to be VERY fast, and avoid blocking. If you need to handle this event on your message thread, use this callback to trigger an AsyncUpdater or ChangeBroadcaster which you can respond to later on the message thread.

See also
  audioProcessorParameterChangeGestureEnd

## ◆ audioProcessorParameterChangeGestureEnd()

virtual void AudioProcessorListener::audioProcessorParameterChangeGestureEnd | ( | AudioProcessor * | processor,
|  | int | parameterIndex
| ) |  |
| virtual

Indicates that a parameter change gesture has finished.

E.g. if the user is dragging a slider, this would be called when they release the mouse button.

IMPORTANT NOTE: This will be called synchronously, and many audio processors will call it during their audio callback. This means that not only has your handler code got to be completely thread-safe, but it's also got to be VERY fast, and avoid blocking. If you need to handle this event on your message thread, use this callback to trigger an AsyncUpdater or ChangeBroadcaster which you can respond to later on the message thread.

See also
  audioProcessorParameterChangeGestureBegin

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

- juce_AudioProcessorListener.h