juce::AudioParameterFloat Class Reference

A subclass of AudioProcessorParameter that provides an easy way to create a parameter which maps onto a given NormalisableRange. More...

#include <juce_AudioParameterFloat.h>

Inheritance diagram for juce::AudioParameterFloat:

Collaboration diagram for juce::AudioParameterFloat:

Public Types
enum	Category {   genericParameter = (0 << 16) | 0,   inputGain = (1 << 16) | 0,   outputGain = (1 << 16) | 1,   inputMeter = (2 << 16) | 0,   outputMeter = (2 << 16) | 1,   compressorLimiterGainReductionMeter = (2 << 16) | 2,   expanderGateGainReductionMeter = (2 << 16) | 3,   analysisMeter = (2 << 16) | 4,   otherMeter = (2 << 16) | 5 }

Public Member Functions
	AudioParameterFloat (const String &parameterID, const String &name, NormalisableRange< float > normalisableRange, float defaultValue, const String &label=String(), Category category=AudioProcessorParameter::genericParameter, std::function< String(float value, int maximumStringLength)> stringFromValue=nullptr, std::function< float(const String &text)> valueFromString=nullptr)
	Creates a AudioParameterFloat with the specified parameters. More...
	AudioParameterFloat (String parameterID, String name, float minValue, float maxValue, float defaultValue)
	Creates a AudioParameterFloat with an ID, name, and range. More...
	~AudioParameterFloat () override
	Destructor. More...
void	addListener (Listener *newListener)
	Registers a listener to receive events when the parameter's state changes. More...
void	beginChangeGesture ()
	Sends a signal to the host to tell it that the user is about to start changing this parameter. More...
float	convertFrom0to1 (float v) const noexcept
	Denormalises and snaps a value based on the normalisable range. More...
float	convertTo0to1 (float v) const noexcept
	Normalises and snaps a value based on the normalisable range. More...
void	endChangeGesture ()
	Tells the host that the user has finished changing this parameter. More...
float	get () const noexcept
	Returns the parameter's current value. More...
virtual StringArray	getAllValueStrings () const
	Returns the set of strings which represent the possible states a parameter can be in. More...
virtual String	getCurrentValueAsText () const
	Returns the current value of the parameter as a String. More...
const NormalisableRange< float > &	getNormalisableRange () const override
	Returns the range of values that the parameter can take. More...
int	getParameterIndex () const noexcept
	Returns the index of this parameter in its parent processor's parameter list. More...
virtual bool	isAutomatable () const
	Returns true if the host can automate this parameter. More...
virtual bool	isBoolean () const
	Returns whether the parameter represents a boolean switch, typically with "On" and "Off" states. More...
virtual bool	isDiscrete () const
	Returns whether the parameter uses discrete values, based on the result of getNumSteps, or allows the host to select values continuously. More...
virtual bool	isMetaParameter () const
	Should return true if this parameter is a "meta" parameter. More...
virtual bool	isOrientationInverted () const
	This can be overridden to tell the host that this parameter operates in the reverse direction. More...
	operator float () const noexcept
	Returns the parameter's current value. More...
AudioParameterFloat &	operator= (float newValue)
	Changes the parameter's current value. More...
void	removeListener (Listener *listener)
	Removes a previously registered parameter listener. More...
void	sendValueChangedMessageToListeners (float newValue)
void	setValueNotifyingHost (float newValue)
	A processor should call this when it needs to change one of its parameters. More...

Public Attributes
const Category	category
	Provides access to the parameter's category. More...
const String	label
	Provides access to the parameter's label. More...
const String	name
	Provides access to the parameter's name. More...
const String	paramID
	Provides access to the parameter's ID string. More...
NormalisableRange< float >	range
	Provides access to the parameter's range. More...

Protected Member Functions
virtual void	valueChanged (float newValue)
	Override this method if you are interested in receiving callbacks when the parameter value changes. More...

Private Member Functions
float	getDefaultValue () const override
	This should return the default value for this parameter. More...
int	getNumSteps () const override
	Returns the number of steps that this parameter's range should be quantised into. More...
String	getText (float, int) const override
	Returns a textual version of the supplied normalised parameter value. More...
float	getValue () const override
	Called by the host to find out the value of this parameter. More...
float	getValueForText (const String &) const override
	Should parse a string and return the appropriate value for it. More...
void	setValue (float newValue) override
	The host will call this method to change the value of a parameter. More...

Private Attributes
const float	defaultValue
std::function< String(float, int)>	stringFromValueFunction
float	value
std::function< float(const String &)>	valueFromStringFunction

Detailed Description

A subclass of AudioProcessorParameter that provides an easy way to create a parameter which maps onto a given NormalisableRange.

See also

AudioParameterInt, AudioParameterBool, AudioParameterChoice

{Audio}

Member Enumeration Documentation

Category

enum juce::AudioProcessorParameter::Category

inherited

Enumerator
genericParameter
inputGain	If your parameter is not a meter then you should use this category.
outputGain	Currently not used.
inputMeter	The following categories tell the host that this parameter is a meter level value and therefore read-only. Most hosts will display these type of parameters as a meter in the generic view of your plug-in. Pro-Tools will also show the meter in the mixer view.
outputMeter
compressorLimiterGainReductionMeter
expanderGateGainReductionMeter
analysisMeter
otherMeter

Constructor & Destructor Documentation

AudioParameterFloat() [1/2]

juce::AudioParameterFloat::AudioParameterFloat	(	const String &	parameterID,
		const String &	name,
		NormalisableRange< float >	normalisableRange,
		float	defaultValue,
		const String &	label = String(),
		Category	category = AudioProcessorParameter::genericParameter,
		std::function< String(float value, int maximumStringLength)>	stringFromValue = nullptr,
		std::function< float(const String &text)>	valueFromString = nullptr
	)

Creates a AudioParameterFloat with the specified parameters.

Parameters

parameterID	The parameter ID to use
name	The parameter name to use
normalisableRange	The NormalisableRange to use
defaultValue	The non-normalised default value
label	An optional label for the parameter's value
category	An optional parameter category
stringFromValue	An optional lambda function that converts a non-normalised value to a string with a maximum length. This may be used by hosts to display the parameter's value.
valueFromString	An optional lambda function that parses a string and converts it into a non-normalised value. Some hosts use this to allow users to type in parameter values.

AudioParameterFloat() [2/2]

juce::AudioParameterFloat::AudioParameterFloat	(	String	parameterID,
		String	name,
		float	minValue,
		float	maxValue,
		float	defaultValue
	)

Creates a AudioParameterFloat with an ID, name, and range.

On creation, its value is set to the default value. For control over skew factors, you can use the other constructor and provide a NormalisableRange.

~AudioParameterFloat()

juce::AudioParameterFloat::~AudioParameterFloat ( )

override

Destructor.

Member Function Documentation

addListener()

void juce::AudioProcessorParameter::addListener ( Listener *  newListener )

inherited

Registers a listener to receive events when the parameter's state changes.

If the listener is already registered, this will not register it again.

See also

removeListener

beginChangeGesture()

void juce::AudioProcessorParameter::beginChangeGesture ( )

inherited

Sends a signal to the host to tell it that the user is about to start changing this parameter.

This allows the host to know when a parameter is actively being held by the user, and it may use this information to help it record automation. If you call this, it must be matched by a later call to endChangeGesture().

convertFrom0to1()

float juce::RangedAudioParameter::convertFrom0to1 ( float  v ) const

inlinenoexceptinherited

Denormalises and snaps a value based on the normalisable range.

References juce::jlimit().

convertTo0to1()

float juce::RangedAudioParameter::convertTo0to1 ( float  v ) const

inlinenoexceptinherited

Normalises and snaps a value based on the normalisable range.

endChangeGesture()

void juce::AudioProcessorParameter::endChangeGesture ( )

inherited

Tells the host that the user has finished changing this parameter.

This allows the host to know when a parameter is actively being held by the user, and it may use this information to help it record automation. A call to this method must follow a call to beginChangeGesture().

get()

float juce::AudioParameterFloat::get ( ) const

inlinenoexcept

Returns the parameter's current value.

getAllValueStrings()

virtual StringArray juce::AudioProcessorParameter::getAllValueStrings ( ) const

virtualinherited

Returns the set of strings which represent the possible states a parameter can be in.

If you are hosting a plug-in you can use the result of this function to populate a ComboBox listing the allowed values.

If you are implementing a plug-in then you do not need to override this.

getCurrentValueAsText()

virtual String juce::AudioProcessorParameter::getCurrentValueAsText ( ) const

virtualinherited

Returns the current value of the parameter as a String.

This function can be called when you are hosting plug-ins to get a more specialsed textual represenation of the current value from the plug-in, for example "On" rather than "1.0".

If you are implementing a plug-in then you should ignore this function and instead override getText.

getDefaultValue()

float juce::AudioParameterFloat::getDefaultValue ( ) const

overrideprivatevirtual

This should return the default value for this parameter.

Implements juce::AudioProcessorParameter.

Reimplemented in juce::AudioProcessorValueTreeState::Parameter.

getNormalisableRange()

const NormalisableRange<float>& juce::AudioParameterFloat::getNormalisableRange ( ) const

inlineoverridevirtual

Returns the range of values that the parameter can take.

Implements juce::RangedAudioParameter.

getNumSteps()

int juce::AudioParameterFloat::getNumSteps ( ) const

overrideprivatevirtual

Returns the number of steps that this parameter's range should be quantised into.

If you want a continuous range of values, don't override this method, and allow the default implementation to return AudioProcessor::getDefaultNumParameterSteps().

If your parameter is boolean, then you may want to make this return 2.

The value that is returned may or may not be used, depending on the host. If you want the host to display stepped automation values, rather than a continuous interpolation between successive values, you should override isDiscrete to return true.

See also

isDiscrete

Reimplemented from juce::AudioProcessorParameter.

Reimplemented in juce::AudioProcessorValueTreeState::Parameter.

getParameterIndex()

int juce::AudioProcessorParameter::getParameterIndex ( ) const

inlinenoexceptinherited

Returns the index of this parameter in its parent processor's parameter list.

getText()

String juce::AudioParameterFloat::getText ( float  normalisedValue, int    ) const

overrideprivatevirtual

Returns a textual version of the supplied normalised parameter value.

The default implementation just returns the floating point value as a string, but this could do anything you need for a custom type of value.

Reimplemented from juce::AudioProcessorParameter.

getValue()

float juce::AudioParameterFloat::getValue ( ) const

overrideprivatevirtual

Called by the host to find out the value of this parameter.

Hosts will expect the value returned to be between 0 and 1.0.

This could be called quite frequently, so try to make your code efficient. It's also likely to be called by non-UI threads, so the code in here should be thread-aware.

Implements juce::AudioProcessorParameter.

getValueForText()

float juce::AudioParameterFloat::getValueForText ( const String &  text ) const

overrideprivatevirtual

Should parse a string and return the appropriate value for it.

Implements juce::AudioProcessorParameter.

isAutomatable()

virtual bool juce::AudioProcessorParameter::isAutomatable ( ) const

virtualinherited

Returns true if the host can automate this parameter.

By default, this returns true.

Reimplemented in juce::AudioProcessorValueTreeState::Parameter.

isBoolean()

virtual bool juce::AudioProcessorParameter::isBoolean ( ) const

virtualinherited

Returns whether the parameter represents a boolean switch, typically with "On" and "Off" states.

This information may or may not be used, depending on the host. If you want the host to display a switch, rather than a two item dropdown menu, override this method to return true. You also need to override isDiscrete() to return true and getNumSteps() to return 2.

See also

isDiscrete getNumSteps

Reimplemented in juce::AudioProcessorValueTreeState::Parameter, and juce::AudioParameterBool.

isDiscrete()

virtual bool juce::AudioProcessorParameter::isDiscrete ( ) const

virtualinherited

Returns whether the parameter uses discrete values, based on the result of getNumSteps, or allows the host to select values continuously.

This information may or may not be used, depending on the host. If you want the host to display stepped automation values, rather than a continuous interpolation between successive values, override this method to return true.

See also

getNumSteps

Reimplemented in juce::AudioProcessorValueTreeState::Parameter, juce::AudioParameterChoice, and juce::AudioParameterBool.

isMetaParameter()

virtual bool juce::AudioProcessorParameter::isMetaParameter ( ) const

virtualinherited

Should return true if this parameter is a "meta" parameter.

A meta-parameter is a parameter that changes other params. It is used by some hosts (e.g. AudioUnit hosts). By default this returns false.

Reimplemented in juce::AudioProcessorValueTreeState::Parameter.

isOrientationInverted()

virtual bool juce::AudioProcessorParameter::isOrientationInverted ( ) const

virtualinherited

This can be overridden to tell the host that this parameter operates in the reverse direction.

(Not all plugin formats or hosts will actually use this information).

operator float()

juce::AudioParameterFloat::operator float ( ) const

inlinenoexcept

Returns the parameter's current value.

operator=()

AudioParameterFloat& juce::AudioParameterFloat::operator=

(

float

newValue

)

Changes the parameter's current value.

removeListener()

void juce::AudioProcessorParameter::removeListener ( Listener *  listener )

inherited

Removes a previously registered parameter listener.

See also

addListener

sendValueChangedMessageToListeners()

void juce::AudioProcessorParameter::sendValueChangedMessageToListeners ( float  newValue )

inherited

setValue()

void juce::AudioParameterFloat::setValue ( float  newValue )

overrideprivatevirtual

The host will call this method to change the value of a parameter.

The host may call this at any time, including during the audio processing callback, so your implementation has to process this very efficiently and avoid any kind of locking.

If you want to set the value of a parameter internally, e.g. from your editor component, then don't call this directly - instead, use the setValueNotifyingHost() method, which will also send a message to the host telling it about the change. If the message isn't sent, the host won't be able to automate your parameters properly.

The value passed will be between 0 and 1.0.

Implements juce::AudioProcessorParameter.

setValueNotifyingHost()

void juce::AudioProcessorParameter::setValueNotifyingHost ( float  newValue )

inherited

A processor should call this when it needs to change one of its parameters.

This could happen when the editor or some other internal operation changes a parameter. This method will call the setValue() method to change the value, and will then send a message to the host telling it about the change.

Note that to make sure the host correctly handles automation, you should call the beginChangeGesture() and endChangeGesture() methods to tell the host when the user has started and stopped changing the parameter.

valueChanged()

virtual void juce::AudioParameterFloat::valueChanged ( float  newValue )

protectedvirtual

Override this method if you are interested in receiving callbacks when the parameter value changes.

Member Data Documentation

category

const Category juce::AudioProcessorParameterWithID::category

inherited

Provides access to the parameter's category.

defaultValue

const float juce::AudioParameterFloat::defaultValue

private

label

const String juce::AudioProcessorParameterWithID::label

inherited

Provides access to the parameter's label.

name

const String juce::AudioProcessorParameterWithID::name

inherited

Provides access to the parameter's name.

paramID

const String juce::AudioProcessorParameterWithID::paramID

inherited

Provides access to the parameter's ID string.

range

NormalisableRange<float> juce::AudioParameterFloat::range

Provides access to the parameter's range.

stringFromValueFunction

std::function<String (float, int)> juce::AudioParameterFloat::stringFromValueFunction

private

value

float juce::AudioParameterFloat::value

private

valueFromStringFunction

std::function<float (const String&)> juce::AudioParameterFloat::valueFromStringFunction

private

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

• juce_AudioParameterFloat.h