The QSoundEffect class provides a way to play low latency sound effects. More...

Inheritance diagram for QSoundEffect:

Public Types
enum	Loop

enum	Status

Public Signals
void	categoryChanged ()

void	loadedChanged ()

void	loopCountChanged ()

void	loopsRemainingChanged ()

void	mutedChanged ()

void	playingChanged ()

void	sourceChanged ()

void	statusChanged ()

void	volumeChanged ()

Public Signals inherited from QObject
void	destroyed (QObject *obj=nullptr)

void	objectNameChanged (const QString &objectName)

Public Slots
void	play ()

void	stop ()

Public Slots inherited from QObject
void	deleteLater ()

Public Methods
	QSoundEffect (QObject *parent=nullptr)

	~QSoundEffect ()

QString	category () const

bool	isLoaded () const

bool	isMuted () const

bool	isPlaying () const

int	loopCount () const

int	loopsRemaining () const

void	setCategory (const QString &category)

void	setLoopCount (int loopCount)

void	setMuted (bool muted)

void	setSource (const QUrl &url)

void	setVolume (qreal volume)

QUrl	source () const

Status	status () const

qreal	volume () const

Public Methods inherited from QObject
	QObject (QObject *parent=nullptr)

	~QObject ()

bool	blockSignals (bool block)

const QList< QObject * > &	children () const

bool	connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QString >	dynamicPropertyNames () const

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

template<typename T >
T	findChild (const QString &childName=QString ()) const

template<class T >
QList< T >	findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<class T >
QList< T >	findChildren (const QString &childName=QString (), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

bool	inherits (const QString &className) const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const

bool	isWindowType () const

void	killTimer (int id)

const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

QString	objectName () const

QObject *	parent () const

template<class T = QVariant>
T	property (const QString &name) const

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const QString &name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

QThread *	thread () const

Static Public Methods
static QStringList	supportedMimeTypes ()

Static Public Methods inherited from QObject
static bool	connect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

static bool	connect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())

static bool	connect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, std::nullptr_t, const QObject receiver, std::nullptr_t)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...))

template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)

static QMetaObject &	staticMetaObject ()

static QString	tr (const char text, const char comment=nullptr, std::optional< int > numArg=std::optional< int >())

Properties
	category

	loops

	loopsRemaining

	muted

	playing

	source

	status

	volume

Properties inherited from QObject
	objectName

Additional Inherited Members
Protected Methods inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signalMethod) const

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signalMethod) const

bool	isSignalConnected (const QMetaMethod &signalMethod) const

int	receivers (const QString &signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Related Functions inherited from QObject
T	qobject_cast (QObject *object)

	QObjectList

Detailed Description

This class allows you to play uncompressed audio files (typically WAV files) in a generally lower latency way, and is suitable for "feedback" type sounds in response to user actions (e.g. virtual keyboard sounds, positive or negative feedback for popup dialogs, or game sounds). If low latency is not important, consider using the QMediaPlayer class instead, since it supports a wider variety of media formats and is less resource intensive.

The following example shows how a looping, somewhat quiet sound effect can be played.

QSoundEffect effect;
effect.setSource(QUrl::fromLocalFile("engine.wav"));
effect.setLoopCount(QSoundEffect::Infinite);
effect.setVolume(0.25f);
effect.play();

Typically the sound effect should be reused, which allows all the parsing and preparation to be done ahead of time, and only triggered when necessary. This assists with lower latency audio playback. Since QSoundEffect requires slightly more resources to achieve lower latency playback, the platform may limit the number of simultaneously playing sound effects.

class MyGame {
 
   public:
      MyGame()
         : m_explosion(this)
      {
            m_explosion.setSource(QUrl::fromLocalFile("explosion.wav"));
            m_explosion.setVolume(0.25f);
 
            // Set up click handling etc.
            connect(clickSource, SIGNAL(clicked()), &m_explosion, SLOT(play()));
      }
 
   private:
      QSoundEffect m_explosion;
};

Member Enumeration Documentation

enum QSoundEffect::Loop

Constant	Value	Description
`QSoundEffect::Infinite`	`0`	Used as a parameter to setLoopCount() for infinite looping

enum QSoundEffect::Status

Constant	Value	Description
`QSoundEffect::Null`	`0`	source has been set or the source is null.
`QSoundEffect::Loading`	`0`	SoundEffect is trying to load the source.
`QSoundEffect::Ready`	`0`	Source is loaded and ready for play.
`QSoundEffect::Error`	`0`	An error occurred during operation, such as failure of loading the source.

Constructor & Destructor Documentation

QSoundEffect::QSoundEffect ( QObject * parent = nullptr )

explicit

Creates a QSoundEffect with the given parent.

QSoundEffect::~QSoundEffect ( )

Destroys this sound effect.

Method Documentation

QString QSoundEffect::category ( ) const

Returns the current category for this sound effect.

Some platforms can perform different audio routing for different categories, or may allow the user to set different volume levels for different categories. This setting will be ignored on platforms that do not support audio categories.

See also: setCategory()

void QSoundEffect::categoryChanged ( )

signal

The categoryChanged signal is emitted when the category property has changed.

bool QSoundEffect::isLoaded ( ) const

Returns whether the sound effect has finished loading the data for the source url.

bool QSoundEffect::isMuted ( ) const

Returns whether this sound effect is muted

bool QSoundEffect::isPlaying ( ) const

Returns true if the sound effect is currently playing, or false otherwise

void QSoundEffect::loadedChanged ( )

signal

The loadedChanged signal is emitted when the loading state has changed.

int QSoundEffect::loopCount ( ) const

Returns the total number of times that this sound effect will be played before stopping. Refer to the loopsRemaining() method for the number of loops currently remaining.

void QSoundEffect::loopCountChanged ( )

signal

The loopCountChanged signal is emitted when the initial number of loops has changed.

int QSoundEffect::loopsRemaining ( ) const

Returns the remaining number of loops.

void QSoundEffect::loopsRemainingChanged ( )

signal

The loopsRemainingChanged signal is emitted when the remaining number of loops has changed.

void QSoundEffect::mutedChanged ( )

signal

The mutedChanged signal is emitted when the mute state has changed.

void QSoundEffect::play ( )

slot

Start playback of the sound effect, looping the effect for the number of times as specified in the loops property.

void QSoundEffect::playingChanged ( )

signal

The playingChanged signal is emitted when the playing property has changed.

void QSoundEffect::setCategory ( const QString & category )

Sets the category of this sound effect to category. Some platforms can perform different audio routing for different categories, or may allow the user to set different volume levels for different categories.

This setting will be ignored on platforms that do not support audio categories.

If this setting is changed while a sound effect is playing it will only take effect when the sound effect has stopped playing.

See also: category()

void QSoundEffect::setLoopCount ( int loopCount )

Set the total number of times to play this sound effect to loopCount. Setting the loop count to 0 or 1 means the sound effect will be played only once. Pass QSoundEffect::Infinite to repeat indefinitely. The loop count can be changed while the sound effect is playing, in which case it will update the remaining loops to the new loopCount.

See also: loopsRemaining()

void QSoundEffect::setMuted ( bool muted )

Sets whether to mute this sound effect's playback.

If muted is true, playback will be muted (silenced), and otherwise playback will occur with the currently specified volume().

void QSoundEffect::setSource ( const QUrl & url )

Set the current URL to play to url.

void QSoundEffect::setVolume ( qreal volume )

Sets the volume to play the sound effect at to volume, from 0.0 (silent) to 1.0 (maximum volume).

QUrl QSoundEffect::source ( ) const

Returns the URL of the current source to play

void QSoundEffect::sourceChanged ( )

signal

The sourceChanged signal is emitted when the source has been changed.

QSoundEffect::Status QSoundEffect::status ( ) const

Returns the current status of this sound effect.

void QSoundEffect::statusChanged ( )

signal

This signal is emitted when the status property has changed.

void QSoundEffect::stop ( )

slot

Stop current playback.

QStringList QSoundEffect::supportedMimeTypes ( )

static

Returns a list of the supported mime types for this platform.

qreal QSoundEffect::volume ( ) const

Returns the current volume of this sound effect, from 0.0 (silent) to 1.0 (maximum volume).

void QSoundEffect::volumeChanged ( )

signal

This signal is emitted when the volume has changed.

Property Documentation

QSoundEffect::category

This property contains the category of this sound effect. Some platforms can perform different audio routing for different categories, or may allow the user to set different volume levels for different categories.

This setting will be ignored on platforms that do not support audio categories.

Properties	Class Methods
read	category
write	setCategory
notify	categoryChanged

QSoundEffect::loops

This property holds the number of times the sound is played. A value of 0 or 1 means the sound will be played only once, set to SoundEffect.Infinite to enable infinite looping.

The value can be changed while the sound effect is playing, in which case it will update the remaining loops to the new value.

Properties	Class Methods
read	loopCount
write	setLoopCount
notify	loopCountChanged

QSoundEffect::loopsRemaining

This property contains the number of loops remaining before the sound effect stops by itself, or QSoundEffect::Infinite if that is what has been set in QSoundEffect::loops.

Properties	Class Methods
read	loopsRemaining
notify	loopsRemainingChanged

QSoundEffect::muted

This property provides a way to control muting. A value of true will mute this effect.

Properties	Class Methods
read	isMuted
write	setMuted
notify	mutedChanged

QSoundEffect::playing

This property indicates whether the sound effect is playing or not.

Properties	Class Methods
read	isPlaying
notify	playingChanged

QSoundEffect::source

This property holds the url for the sound to play. For the SoundEffect to attempt to load the source, the URL must exist and the application must have read permission in the specified directory.

Properties	Class Methods
read	source
write	setSource
notify	sourceChanged

QSoundEffect::status

This property indicates the current status of the sound effect from the QSoundEffect::Status enumeration.

Properties	Class Methods
read	status
notify	statusChanged

QSoundEffect::volume

This property holds the volume of the sound effect playback, from 0.0 (silent) to 1.0 (maximum volume).

Properties	Class Methods
read	volume
write	setVolume
notify	volumeChanged

Public Types

Public Signals

Public Slots

Public Methods

Static Public Methods

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation

Property Documentation