QRadioTuner Class

The QRadioTuner class provides an interface to the systems analog radio device. More...

Header:	#include <QRadioTuner>
qmake:	QT += multimedia
Inherits:	QMediaObject

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

• List of all members, including inherited members

Public Types

enum	Band { AM, FM, SW, LW, FM2 }
enum	Error { NoError, ResourceError, OpenError, OutOfRangeError }
enum	SearchMode { SearchFast, SearchGetStationId }
enum	State { ActiveState, StoppedState }
enum	StereoMode { ForceStereo, ForceMono, Auto }

Properties

antennaConnected : const bool band : Band frequency : int muted : bool radioData : QRadioData* const searching : const bool

signalStrength : const int state : const State stereo : const bool stereoMode : StereoMode volume : int

Public Functions

	QRadioTuner(QObject *parent = nullptr)
virtual	~QRadioTuner()
QRadioTuner::Band	band() const
QRadioTuner::Error	error() const
QString	errorString() const
int	frequency() const
QPair<int, int>	frequencyRange(QRadioTuner::Band band) const
int	frequencyStep(QRadioTuner::Band band) const
bool	isAntennaConnected() const
bool	isBandSupported(QRadioTuner::Band band) const
bool	isMuted() const
bool	isSearching() const
bool	isStereo() const
QRadioData *	radioData() const
void	setStereoMode(QRadioTuner::StereoMode mode)
int	signalStrength() const
QRadioTuner::State	state() const
QRadioTuner::StereoMode	stereoMode() const
int	volume() const

Reimplemented Public Functions

virtual QMultimedia::AvailabilityStatus

availability() const override

Public Slots

void	cancelSearch()
void	searchAllStations(QRadioTuner::SearchMode searchMode = QRadioTuner::SearchFast)
void	searchBackward()
void	searchForward()
void	setBand(QRadioTuner::Band band)
void	setFrequency(int frequency)
void	setMuted(bool muted)
void	setVolume(int volume)
void	start()
void	stop()

Signals

void	antennaConnectedChanged(bool connectionStatus)
void	bandChanged(QRadioTuner::Band band)
void	error(QRadioTuner::Error error)
void	frequencyChanged(int frequency)
void	mutedChanged(bool muted)
void	searchingChanged(bool searching)
void	signalStrengthChanged(int strength)
void	stateChanged(QRadioTuner::State state)
void	stationFound(int frequency, QString stationId)
void	stereoStatusChanged(bool stereo)
void	volumeChanged(int volume)

Detailed Description

You can control the systems analog radio device using this interface, for example:

radio = new QRadioTuner;
connect(radio, SIGNAL(frequencyChanged(int)), this, SLOT(freqChanged(int)));
if (radio->isBandSupported(QRadioTuner::FM)) {
    radio->setBand(QRadioTuner::FM);
    radio->setFrequency(yourRadioStationFrequency);
    radio->setVolume(100);
    radio->start();
}

The radio object will emit signals for any changes in state such as: bandChanged(), frequencyChanged(), stereoStatusChanged(), searchingChanged(), signalStrengthChanged(), volumeChanged(), mutedChanged().

You can change between the frequency bands using setBand() however it is recommended that you check to make sure the band is available first using isBandSupported().

See also QRadioData and Radio Overview.

Member Type Documentation

enum QRadioTuner::Band

Enumerates radio frequency bands.

Constant	Value	Description
QRadioTuner::AM	0	520 to 1610 kHz, 9 or 10kHz channel spacing, extended 1610 to 1710 kHz
QRadioTuner::FM	1	87.5 to 108.0 MHz, except Japan 76-90 MHz
QRadioTuner::SW	2	1.711 to 30.0 MHz, divided into 15 bands. 5kHz channel spacing
QRadioTuner::LW	3	148.5 to 283.5 kHz, 9kHz channel spacing (Europe, Africa, Asia)
QRadioTuner::FM2	4	range not defined, used when area supports more than one FM range.

enum QRadioTuner::Error

Enumerates radio tuner error conditions.

Constant	Value	Description
QRadioTuner::NoError	0	No errors have occurred.
QRadioTuner::ResourceError	1	There is no radio service available.
QRadioTuner::OpenError	2	Unable to open radio device.
QRadioTuner::OutOfRangeError	3	An attempt to set a frequency or band that is not supported by radio device.

enum QRadioTuner::SearchMode

Enumerates how the radio tuner should search for stations.

Constant	Value	Description
QRadioTuner::SearchFast	0	Use only signal strength when searching.
QRadioTuner::SearchGetStationId	1	After finding a strong signal, wait for the RDS station id (PI) before continuing.

enum QRadioTuner::State

Enumerates radio tuner states.

Constant	Value	Description
QRadioTuner::ActiveState	0	The tuner is started and active.
QRadioTuner::StoppedState	1	The tuner device is stopped.

enum QRadioTuner::StereoMode

Enumerates radio tuner policy for receiving stereo signals.

Constant	Value	Description
QRadioTuner::ForceStereo	0	Provide stereo mode, converting if required.
QRadioTuner::ForceMono	1	Provide mono mode, converting if required.
QRadioTuner::Auto	2	Uses the stereo mode matching the station.

Member Function Documentation

QRadioTuner::QRadioTuner(QObject *parent = nullptr)

Constructs a radio tuner based on a media service allocated by the default media service provider.

The parent is passed to QMediaObject.

[signal] void QRadioTuner::bandChanged(QRadioTuner::Band band)

Signals a radio tuner's band has changed.

Note: Notifier signal for property band.

[slot] void QRadioTuner::cancelSearch()

Stops scanning for a signal.

See also searchForward(), searchBackward(), and searching.

[signal] void QRadioTuner::error(QRadioTuner::Error error)

Signals that an error occurred.

Note: Signal error is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(radioTuner, QOverload<QRadioTuner::Error>::of(&QRadioTuner::error),
    [=](QRadioTuner::Error error){ /* ... */ });

[signal] void QRadioTuner::frequencyChanged(int frequency)

Signals that the frequency a radio tuner is tuned to has changed.

Note: Notifier signal for property frequency.

[signal] void QRadioTuner::mutedChanged(bool muted)

Signals that the muted state of a radio tuner's audio output has changed.

Note: Notifier signal for property muted.

[slot] void QRadioTuner::searchAllStations(QRadioTuner::SearchMode searchMode = QRadioTuner::SearchFast)

Search all stations in current band

Emits QRadioTuner::stationFound(int, QString) for every found station. After searching is completed, QRadioTuner::searchingChanged(bool) is emitted (false). If searchMode is set to SearchGetStationId, searching waits for station id (PI) on each frequency.

See also searchForward(), searchBackward(), and searching.

[slot] void QRadioTuner::searchBackward()

Starts a backwards scan for a signal, starting from the current frequency.

See also searchForward(), cancelSearch(), and searching.

[slot] void QRadioTuner::searchForward()

Starts a forward scan for a signal, starting from the current frequency.

See also searchBackward(), cancelSearch(), and searching.

[signal] void QRadioTuner::searchingChanged(bool searching)

Signals that the searching state of a radio tuner has changed.

Note: Notifier signal for property searching.

[slot] void QRadioTuner::setBand(QRadioTuner::Band band)

Sets a radio tuner's frequency band.

Changing the band will reset the frequency to the new band's minimum frequency.

Note: Setter function for property band.

See also band().

[slot] void QRadioTuner::setFrequency(int frequency)

Sets a radio tuner's frequency.

If the tuner is set to a frequency outside the current band, the band will be changed to one occupied by the new frequency.

Note: Setter function for property frequency.

See also frequency().

[signal] void QRadioTuner::signalStrengthChanged(int strength)

Signals that the strength of the signal received by a radio tuner has changed.

Note: Notifier signal for property signalStrength.

[slot] void QRadioTuner::start()

Activate the radio device.

[signal] void QRadioTuner::stateChanged(QRadioTuner::State state)

This signal is emitted when the state changes to state.

Note: Notifier signal for property state.

[signal] void QRadioTuner::stationFound(int frequency, QString stationId)

Signals that a station was found in frequency with stationId Program Identification code.

[signal] void QRadioTuner::stereoStatusChanged(bool stereo)

Signals that the stereo state of a radio tuner has changed.

Note: Notifier signal for property stereo.

[slot] void QRadioTuner::stop()

Deactivate the radio device.

[signal] void QRadioTuner::volumeChanged(int volume)

Signals that the volume of a radio tuner's audio output has changed.

Note: Notifier signal for property volume.

[virtual] QRadioTuner::~QRadioTuner()

Destroys a radio tuner.

[override virtual] QMultimedia::AvailabilityStatus QRadioTuner::availability() const

Reimplements: QMediaObject::availability() const.

Returns the availability of the radio tuner.

QRadioTuner::Error QRadioTuner::error() const

Returns the error state of a radio tuner.

See also errorString().

QString QRadioTuner::errorString() const

Returns a description of a radio tuner's error state.

See also error().

QPair<int, int> QRadioTuner::frequencyRange(QRadioTuner::Band band) const

Returns a frequency band's minimum and maximum frequency.

int QRadioTuner::frequencyStep(QRadioTuner::Band band) const

Returns the number of Hertz to increment the frequency by when stepping through frequencies within a given band.

bool QRadioTuner::isBandSupported(QRadioTuner::Band band) const

Identifies if a frequency band is supported by a radio tuner.

Returns true if the band is supported, and false if it is not.