This class contains a ValueTree that is used to manage an AudioProcessor's entire state. More...

#include <juce_AudioProcessorValueTreeState.h>

Inheritance diagram for juce::AudioProcessorValueTreeState:

Collaboration diagram for juce::AudioProcessorValueTreeState:

[legend]

Classes
class	ButtonAttachment
	An object of this class maintains a connection between a Button and a parameter in an AudioProcessorValueTreeState. More...

class	ComboBoxAttachment
	An object of this class maintains a connection between a ComboBox and a parameter in an AudioProcessorValueTreeState. More...

struct	Listener
	A listener class that can be attached to an AudioProcessorValueTreeState. More...

class	Parameter
	A parameter class that maintains backwards compatibility with deprecated AudioProcessorValueTreeState functionality. More...

class	ParameterLayout
	A class to contain a set of RangedAudioParameters and AudioProcessorParameterGroups containing RangedAudioParameters. More...

class	SliderAttachment
	An object of this class maintains a connection between a Slider and a parameter in an AudioProcessorValueTreeState. More...

struct	StringRefLessThan

Public Member Functions
	AudioProcessorValueTreeState (AudioProcessor &processorToConnectTo, UndoManager *undoManagerToUse)
	This constructor is discouraged and will be deprecated in a future version of JUCE! Use the other constructor instead. More...

	AudioProcessorValueTreeState (AudioProcessor &processorToConnectTo, UndoManager *undoManagerToUse, const Identifier &valueTreeType, ParameterLayout parameterLayout)
	Creates a state object for a given processor, and sets up all the parameters that will control that processor. More...

	~AudioProcessorValueTreeState () override
	Destructor. More...

void	addParameterListener (StringRef parameterID, Listener *listener)
	Attaches a callback to one of the parameters, which will be called when the parameter changes. More...

ValueTree	copyState ()
	Returns a copy of the state value tree. More...

RangedAudioParameter *	createAndAddParameter (std::unique_ptr< RangedAudioParameter > parameter)
	This function adds a parameter to the attached AudioProcessor and that parameter will be managed by this AudioProcessorValueTreeState object. More...

RangedAudioParameter *	getParameter (StringRef parameterID) const noexcept
	Returns a parameter by its ID string. More...

Value	getParameterAsValue (StringRef parameterID) const
	Returns a Value object that can be used to control a particular parameter. More...

NormalisableRange< float >	getParameterRange (StringRef parameterID) const noexcept
	Returns the range that was set when the given parameter was created. More...

std::atomic< float > *	getRawParameterValue (StringRef parameterID) const noexcept
	Returns a pointer to a floating point representation of a particular parameter which a realtime process can read to find out its current value. More...

void	removeParameterListener (StringRef parameterID, Listener *listener)
	Removes a callback that was previously added with addParameterCallback(). More...

void	replaceState (const ValueTree &newState)
	Replaces the state value tree. More...

Public Attributes
AudioProcessor &	processor
	A reference to the processor with which this state is associated. More...

ValueTree	state
	The state of the whole processor. More...

UndoManager *const	undoManager
	Provides access to the undo manager that this object is using. More...

Private Member Functions
void	addParameterAdapter (RangedAudioParameter &)

std::unique_ptr< RangedAudioParameter >	createParameter (const String &, const String &, const String &, NormalisableRange< float >, float, std::function< String(float)>, std::function< float(const String &)>, bool, bool, bool, AudioProcessorParameter::Category, bool)
	Code that looks like this: More...

bool	flushParameterValuesToValueTree ()

ParameterAdapter *	getParameterAdapter (StringRef) const

int	getTimerInterval () const noexcept
	Returns the timer's interval. More...

bool	isTimerRunning () const noexcept
	Returns true if the timer is currently running. More...

void	setNewState (ValueTree)

void	startTimer (int intervalInMilliseconds) noexcept
	Starts the timer and sets the length of interval required. More...

void	startTimerHz (int timerFrequencyHz) noexcept
	Starts the timer with an interval specified in Hertz. More...

void	stopTimer () noexcept
	Stops the timer. More...

void	timerCallback () override
	The user-defined callback routine that actually gets called periodically. More...

void	updateParameterConnectionsToChildTrees ()

void	valueTreeChildAdded (ValueTree &, ValueTree &) override
	This method is called when a child sub-tree is added. More...

virtual void	valueTreeChildOrderChanged (ValueTree &parentTreeWhoseChildrenHaveMoved, int oldIndex, int newIndex)
	This method is called when a tree's children have been re-shuffled. More...

virtual void	valueTreeChildRemoved (ValueTree &parentTree, ValueTree &childWhichHasBeenRemoved, int indexFromWhichChildWasRemoved)
	This method is called when a child sub-tree is removed. More...

virtual void	valueTreeParentChanged (ValueTree &treeWhoseParentHasChanged)
	This method is called when a tree has been added or removed from a parent. More...

void	valueTreePropertyChanged (ValueTree &, const Identifier &) override
	This method is called when a property of this tree (or of one of its sub-trees) is changed. More...

void	valueTreeRedirected (ValueTree &) override
	This method is called when a tree is made to point to a different internal shared object. More...

Static Private Member Functions
static void	callAfterDelay (int milliseconds, std::function< void()> functionToCall)
	Invokes a lambda after a given number of milliseconds. More...

static void	callPendingTimersSynchronously ()
	For internal use only: invokes any timers that need callbacks. More...

Private Attributes
std::map< StringRef, std::unique_ptr< ParameterAdapter >, StringRefLessThan >	adapterTable

const Identifier	idPropertyID { "id" }

size_t	positionInQueue = (size_t) -1

int	timerPeriodMs = 0

const Identifier	valuePropertyID { "value" }

CriticalSection	valueTreeChanging

const Identifier	valueType { "PARAM" }

Detailed Description

This class contains a ValueTree that is used to manage an AudioProcessor's entire state.

It has its own internal class of parameter object that is linked to values within its ValueTree, and which are each identified by a string ID.

You can get access to the underlying ValueTree object via the state member variable, so you can add extra properties to it as necessary.

It also provides some utility child classes for connecting parameters directly to GUI controls like sliders.

The favoured constructor of this class takes a collection of RangedAudioParameters or AudioProcessorParameterGroups of RangedAudioParameters and adds them to the attached AudioProcessor directly.

The deprecated way of using this class is as follows:

1) Create an AudioProcessorValueTreeState, and give it some parameters using createAndAddParameter(). 2) Initialise the state member variable with a type name.

The deprecated constructor will be removed from the API in a future version of JUCE!

@tags{Audio}

Constructor & Destructor Documentation

◆ AudioProcessorValueTreeState() [1/2]

juce::AudioProcessorValueTreeState::AudioProcessorValueTreeState	(	AudioProcessor &	processorToConnectTo,
		UndoManager *	undoManagerToUse,
		const Identifier &	valueTreeType,
		ParameterLayout	parameterLayout
	)

Creates a state object for a given processor, and sets up all the parameters that will control that processor.

You should not assign a new ValueTree to the state, or call createAndAddParameter, after using this constructor.

Note that each AudioProcessorValueTreeState should be attached to only one processor, and must have the same lifetime as the processor, as they will have dependencies on each other.

The ParameterLayout parameter has a set of constructors that allow you to add multiple RangedAudioParameters and AudioProcessorParameterGroups containing RangedAudioParameters to the AudioProcessorValueTreeState inside this constructor.

YourAudioProcessor()
    : apvts (*this, &undoManager, "PARAMETERS",
             { std::make_unique<AudioParameterFloat> ("a", "Parameter A", NormalisableRange<float> (-100.0f, 100.0f), 0),
               std::make_unique<AudioParameterInt> ("b", "Parameter B", 0, 5, 2) })

To add parameters programmatically you can call add repeatedly on a ParameterLayout instance:

AudioProcessorValueTreeState::ParameterLayout createParameterLayout()
{
    AudioProcessorValueTreeState::ParameterLayout layout;
 
    for (int i = 1; i < 9; ++i)
        layout.add (std::make_unique<AudioParameterInt> (String (i), String (i), 0, i, 0));
 
    return layout;
}
 
YourAudioProcessor()
    : apvts (*this, &undoManager, "PARAMETERS", createParameterLayout())
{
}

Parameters

processorToConnectTo	The Processor that will be managed by this object
undoManagerToUse	An optional UndoManager to use; pass nullptr if no UndoManager is required
valueTreeType	The identifier used to initialise the internal ValueTree
parameterLayout	An object that holds all parameters and parameter groups that the AudioProcessor should use.

◆ AudioProcessorValueTreeState() [2/2]

juce::AudioProcessorValueTreeState::AudioProcessorValueTreeState	(	AudioProcessor &	processorToConnectTo,
		UndoManager *	undoManagerToUse
	)

This constructor is discouraged and will be deprecated in a future version of JUCE! Use the other constructor instead.

Creates a state object for a given processor.

The UndoManager is optional and can be a nullptr. After creating your state object, you should add parameters with the createAndAddParameter() method. Note that each AudioProcessorValueTreeState should be attached to only one processor, and must have the same lifetime as the processor, as they will have dependencies on each other.

◆ ~AudioProcessorValueTreeState()

juce::AudioProcessorValueTreeState::~AudioProcessorValueTreeState ( )

override

Destructor.

Member Function Documentation

◆ addParameterAdapter()

void juce::AudioProcessorValueTreeState::addParameterAdapter ( RangedAudioParameter & )

private

◆ addParameterListener()

void juce::AudioProcessorValueTreeState::addParameterListener	(	StringRef	parameterID,
		Listener *	listener
	)

Attaches a callback to one of the parameters, which will be called when the parameter changes.

◆ callAfterDelay()

static void juce::Timer::callAfterDelay	(	int	milliseconds,
		std::function< void()>	functionToCall
	)

staticinherited

Invokes a lambda after a given number of milliseconds.

◆ callPendingTimersSynchronously()

static void juce::Timer::callPendingTimersSynchronously ( )

staticinherited

For internal use only: invokes any timers that need callbacks.

Don't call this unless you really know what you're doing!

◆ copyState()

ValueTree juce::AudioProcessorValueTreeState::copyState ( )

Returns a copy of the state value tree.

The AudioProcessorValueTreeState's ValueTree is updated internally on the message thread, but there may be cases when you may want to access the state from a different thread (getStateInformation is a good example). This method flushes all pending audio parameter value updates and returns a copy of the state in a thread safe way.

Note: This method uses locks to synchronise thread access, so whilst it is thread-safe, it is not realtime-safe. Do not call this method from within your audio processing code!

◆ createAndAddParameter()

RangedAudioParameter* juce::AudioProcessorValueTreeState::createAndAddParameter ( std::unique_ptr< RangedAudioParameter > parameter )

This function adds a parameter to the attached AudioProcessor and that parameter will be managed by this AudioProcessorValueTreeState object.

◆ createParameter()

std::unique_ptr<RangedAudioParameter> juce::AudioProcessorValueTreeState::createParameter	(	const String &	,
		const String &	,
		const String &	,
		NormalisableRange< float >	,
		float	,
		std::function< String(float)>	,
		std::function< float(const String &)>	,
		bool	,
		bool	,
		bool	,
		AudioProcessorParameter::Category	,
		bool
	)

private

Code that looks like this:

auto paramA = apvts.createParameter ("a", "Parameter A", {}, { -100, 100 }, ...);
auto paramB = apvts.createParameter ("b", "Parameter B", {}, { 0, 5 }, ...);
addParameterGroup (std::make_unique<AudioProcessorParameterGroup> ("g1", "Group 1", " | ", std::move (paramA), std::move (paramB)));
apvts.state = ValueTree (Identifier ("PARAMETERS"));

can instead create the APVTS like this, avoiding the two-step initialization process and leveraging one of JUCE's pre-built parameter types (or your own custom type derived from RangedAudioParameter):

using Parameter = AudioProcessorValueTreeState::Parameter;
YourAudioProcessor()
    : apvts (*this, &undoManager, "PARAMETERS",
             { std::make_unique<AudioProcessorParameterGroup> ("g1", "Group 1", " | ",
                   std::make_unique<Parameter> ("a", "Parameter A", "", NormalisableRange<float> (-100, 100), ...),
                   std::make_unique<Parameter> ("b", "Parameter B", "", NormalisableRange<float> (0, 5), ...)) })

◆ flushParameterValuesToValueTree()

bool juce::AudioProcessorValueTreeState::flushParameterValuesToValueTree ( )

private

◆ getParameter()

RangedAudioParameter* juce::AudioProcessorValueTreeState::getParameter ( StringRef parameterID ) const

noexcept

Returns a parameter by its ID string.

◆ getParameterAdapter()

ParameterAdapter* juce::AudioProcessorValueTreeState::getParameterAdapter ( StringRef ) const

private

◆ getParameterAsValue()

Value juce::AudioProcessorValueTreeState::getParameterAsValue ( StringRef parameterID ) const

Returns a Value object that can be used to control a particular parameter.

◆ getParameterRange()

NormalisableRange<float> juce::AudioProcessorValueTreeState::getParameterRange ( StringRef parameterID ) const

noexcept

Returns the range that was set when the given parameter was created.

◆ getRawParameterValue()

std::atomic<float>* juce::AudioProcessorValueTreeState::getRawParameterValue ( StringRef parameterID ) const

noexcept

Returns a pointer to a floating point representation of a particular parameter which a realtime process can read to find out its current value.

Note that calling this method from within AudioProcessorValueTreeState::Listener::parameterChanged() is not guaranteed to return an up-to-date value for the parameter.

◆ getTimerInterval()

int juce::Timer::getTimerInterval ( ) const

inlinenoexceptinherited

Returns the timer's interval.

Returns: the timer's interval in milliseconds if it's running, or 0 if it's not.

Referenced by juce::CarbonViewWrapperComponent::setOurSizeToEmbeddedViewSize().

◆ isTimerRunning()

bool juce::Timer::isTimerRunning ( ) const

inlinenoexceptinherited

Returns true if the timer is currently running.

◆ removeParameterListener()

void juce::AudioProcessorValueTreeState::removeParameterListener	(	StringRef	parameterID,
		Listener *	listener
	)

Removes a callback that was previously added with addParameterCallback().

◆ replaceState()

void juce::AudioProcessorValueTreeState::replaceState ( const ValueTree & newState )

Replaces the state value tree.

The AudioProcessorValueTreeState's ValueTree is updated internally on the message thread, but there may be cases when you may want to modify the state from a different thread (setStateInformation is a good example). This method allows you to replace the state in a thread safe way.

Note: This method uses locks to synchronise thread access, so whilst it is thread-safe, it is not realtime-safe. Do not call this method from within your audio processing code!

◆ setNewState()

void juce::AudioProcessorValueTreeState::setNewState ( ValueTree )

private

◆ startTimer()

void juce::Timer::startTimer ( int intervalInMilliseconds )

noexceptinherited

Starts the timer and sets the length of interval required.

If the timer is already started, this will reset it, so the time between calling this method and the next timer callback will not be less than the interval length passed in.

Parameters

intervalInMilliseconds the interval to use (any value less than 1 will be rounded up to 1)

Referenced by juce::StandalonePluginHolder::init(), juce::CarbonViewWrapperComponent::setOurSizeToEmbeddedViewSize(), and juce::DeviceChangeDetector::triggerAsyncDeviceChangeCallback().

◆ startTimerHz()

void juce::Timer::startTimerHz ( int timerFrequencyHz )

noexceptinherited

Starts the timer with an interval specified in Hertz.

This is effectively the same as calling startTimer (1000 / timerFrequencyHz).

Referenced by juce::AnimatedPosition< Behaviour >::endDrag(), juce::AnimatedPosition< Behaviour >::nudge(), and juce::AnimatedPosition< Behaviour >::timerCallback().

◆ stopTimer()

void juce::Timer::stopTimer ( )

noexceptinherited

Stops the timer.

No more timer callbacks will be triggered after this method returns.

Note that if you call this from a background thread while the message-thread is already in the middle of your callback, then this method will cancel any future timer callbacks, but it will return without waiting for the current one to finish. The current callback will continue, possibly still running some of your timer code after this method has returned.

Referenced by juce::AnimatedPosition< Behaviour >::beginDrag(), juce::CarbonViewWrapperComponent::setOurSizeToEmbeddedViewSize(), juce::AnimatedPosition< Behaviour >::setPosition(), juce::DeviceChangeDetector::timerCallback(), juce::AnimatedPosition< Behaviour >::timerCallback(), and juce::StandalonePluginHolder::~StandalonePluginHolder().

◆ timerCallback()

void juce::AudioProcessorValueTreeState::timerCallback ( )

overrideprivatevirtual

The user-defined callback routine that actually gets called periodically.

It's perfectly ok to call startTimer() or stopTimer() from within this callback to change the subsequent intervals.

Implements juce::Timer.

◆ updateParameterConnectionsToChildTrees()

void juce::AudioProcessorValueTreeState::updateParameterConnectionsToChildTrees ( )

private

◆ valueTreeChildAdded()

void juce::AudioProcessorValueTreeState::valueTreeChildAdded	(	ValueTree &	parentTree,
		ValueTree &	childWhichHasBeenAdded
	)

overrideprivatevirtual

This method is called when a child sub-tree is added.

Note that when you register a listener to a tree, it will receive this callback for child changes in both that tree and any of its children, (recursively, at any depth). If your tree has sub-trees but you only want to know about changes to the top level tree, just check the parentTree parameter to make sure it's the one that you're interested in.

Reimplemented from juce::ValueTree::Listener.

◆ valueTreeChildOrderChanged()

virtual void juce::ValueTree::Listener::valueTreeChildOrderChanged	(	ValueTree &	parentTreeWhoseChildrenHaveMoved,
		int	oldIndex,
		int	newIndex
	)

virtualinherited

This method is called when a tree's children have been re-shuffled.

Note that when you register a listener to a tree, it will receive this callback for child changes in both that tree and any of its children, (recursively, at any depth). If your tree has sub-trees but you only want to know about changes to the top level tree, just check the parameter to make sure it's the tree that you're interested in.

Reimplemented in juce::ComponentBuilder, and juce::ValueTreeSynchroniser.

◆ valueTreeChildRemoved()

virtual void juce::ValueTree::Listener::valueTreeChildRemoved	(	ValueTree &	parentTree,
		ValueTree &	childWhichHasBeenRemoved,
		int	indexFromWhichChildWasRemoved
	)

virtualinherited

This method is called when a child sub-tree is removed.

Note that when you register a listener to a tree, it will receive this callback for child changes in both that tree and any of its children, (recursively, at any depth). If your tree has sub-trees but you only want to know about changes to the top level tree, just check the parentTree parameter to make sure it's the one that you're interested in.

Reimplemented in juce::ComponentBuilder, and juce::ValueTreeSynchroniser.

◆ valueTreeParentChanged()

virtual void juce::ValueTree::Listener::valueTreeParentChanged ( ValueTree & treeWhoseParentHasChanged )

virtualinherited

This method is called when a tree has been added or removed from a parent.

This callback happens when the tree to which the listener was registered is added or removed from a parent. Unlike the other callbacks, it applies only to the tree to which the listener is registered, and not to any of its children.

Reimplemented in juce::ComponentBuilder.

◆ valueTreePropertyChanged()

void juce::AudioProcessorValueTreeState::valueTreePropertyChanged	(	ValueTree &	treeWhosePropertyHasChanged,
		const Identifier &	property
	)

overrideprivatevirtual

This method is called when a property of this tree (or of one of its sub-trees) is changed.

Note that when you register a listener to a tree, it will receive this callback for property changes in that tree, and also for any of its children, (recursively, at any depth). If your tree has sub-trees but you only want to know about changes to the top level tree, simply check the tree parameter in this callback to make sure it's the tree you're interested in.

Reimplemented from juce::ValueTree::Listener.

◆ valueTreeRedirected()

void juce::AudioProcessorValueTreeState::valueTreeRedirected ( ValueTree & treeWhichHasBeenChanged )

overrideprivatevirtual

This method is called when a tree is made to point to a different internal shared object.

When operator= is used to make a ValueTree refer to a different object, this callback will be made.

Reimplemented from juce::ValueTree::Listener.

Member Data Documentation

◆ adapterTable

std::map<StringRef, std::unique_ptr<ParameterAdapter>, StringRefLessThan> juce::AudioProcessorValueTreeState::adapterTable

private

◆ idPropertyID

const Identifier juce::AudioProcessorValueTreeState::idPropertyID { "id" }

private

◆ positionInQueue

size_t juce::Timer::positionInQueue = (size_t) -1

privateinherited

◆ processor

AudioProcessor& juce::AudioProcessorValueTreeState::processor

A reference to the processor with which this state is associated.

◆ state

ValueTree juce::AudioProcessorValueTreeState::state

The state of the whole processor.

This must be initialised after all calls to createAndAddParameter(). You can replace this with your own ValueTree object, and can add properties and children to the tree. This class will automatically add children for each of the parameter objects that are created by createAndAddParameter().

◆ timerPeriodMs

int juce::Timer::timerPeriodMs = 0

privateinherited

◆ undoManager

UndoManager* const juce::AudioProcessorValueTreeState::undoManager

Provides access to the undo manager that this object is using.

◆ valuePropertyID

const Identifier juce::AudioProcessorValueTreeState::valuePropertyID { "value" }

private

◆ valueTreeChanging

CriticalSection juce::AudioProcessorValueTreeState::valueTreeChanging

private

◆ valueType

const Identifier juce::AudioProcessorValueTreeState::valueType { "PARAM" }

private

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

juce_AudioProcessorValueTreeState.h

Classes

Public Member Functions

Public Attributes

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ AudioProcessorValueTreeState() [1/2]

◆ AudioProcessorValueTreeState() [2/2]

◆ ~AudioProcessorValueTreeState()

Member Function Documentation

◆ addParameterAdapter()

◆ addParameterListener()

◆ callAfterDelay()

◆ callPendingTimersSynchronously()

◆ copyState()

◆ createAndAddParameter()

◆ createParameter()

◆ flushParameterValuesToValueTree()

◆ getParameter()

◆ getParameterAdapter()

◆ getParameterAsValue()

◆ getParameterRange()

◆ getRawParameterValue()

◆ getTimerInterval()

◆ isTimerRunning()

◆ removeParameterListener()

◆ replaceState()

◆ setNewState()

◆ startTimer()

◆ startTimerHz()

◆ stopTimer()

◆ timerCallback()

◆ updateParameterConnectionsToChildTrees()

◆ valueTreeChildAdded()

◆ valueTreeChildOrderChanged()

◆ valueTreeChildRemoved()

◆ valueTreeParentChanged()

◆ valueTreePropertyChanged()

◆ valueTreeRedirected()

Member Data Documentation

◆ adapterTable

◆ idPropertyID

◆ positionInQueue

◆ processor

◆ state

◆ timerPeriodMs

◆ undoManager

◆ valuePropertyID

◆ valueTreeChanging

◆ valueType