\inmodule QtBluetooth More...

#include <qbluetoothservicediscoveryagent.h>

Inheritance diagram for QBluetoothServiceDiscoveryAgent:

Collaboration diagram for QBluetoothServiceDiscoveryAgent:

Public Types
enum	Error { NoError = QBluetoothDeviceDiscoveryAgent::NoError , InputOutputError = QBluetoothDeviceDiscoveryAgent::InputOutputError , PoweredOffError = QBluetoothDeviceDiscoveryAgent::PoweredOffError , InvalidBluetoothAdapterError = QBluetoothDeviceDiscoveryAgent::InvalidBluetoothAdapterError , MissingPermissionsError = QBluetoothDeviceDiscoveryAgent::MissingPermissionsError , UnknownError = QBluetoothDeviceDiscoveryAgent::UnknownError }
	This enum describes errors that can occur during service discovery. More...

enum	DiscoveryMode { MinimalDiscovery , FullDiscovery }
	This enum describes the service discovery mode. More...

Public Slots
void	start (DiscoveryMode mode=MinimalDiscovery)
	Starts service discovery.

void	stop ()
	Stops the service discovery process.

void	clear ()
	Clears the results of previous service discoveries and resets \l uuidFilter().

Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals
void	serviceDiscovered (const QBluetoothServiceInfo &info)
	This signal is emitted when the Bluetooth service described by info is discovered.

void	finished ()
	This signal is emitted when the Bluetooth service discovery completes.

void	canceled ()
	This signal is triggered when the service discovery was canceled via a call to \l stop().

void	errorOccurred (QBluetoothServiceDiscoveryAgent::Error error)
	This signal is emitted when an error occurs.

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QBluetoothServiceDiscoveryAgent (QObject *parent=nullptr)
	Constructs a new QBluetoothServiceDiscoveryAgent with parent.

	QBluetoothServiceDiscoveryAgent (const QBluetoothAddress &deviceAdapter, QObject *parent=nullptr)
	Constructs a new QBluetoothServiceDiscoveryAgent for deviceAdapter and with parent.

	~QBluetoothServiceDiscoveryAgent ()
	Destructor for QBluetoothServiceDiscoveryAgent.

bool	isActive () const
	Returns `true` if the service discovery is currently active; otherwise returns `false`.

Error	error () const
	Returns the type of error that last occurred.

QString	errorString () const
	Returns a human-readable description of the last error that occurred during the service discovery.

QList< QBluetoothServiceInfo >	discoveredServices () const
	Returns the list of all discovered services.

void	setUuidFilter (const QList< QBluetoothUuid > &uuids)
	Sets the UUID filter to uuids.

void	setUuidFilter (const QBluetoothUuid &uuid)
	This is an overloaded member function, provided for convenience.

QList< QBluetoothUuid >	uuidFilter () const
	Returns the UUID filter.

bool	setRemoteAddress (const QBluetoothAddress &address)
	Sets the remote device address to address.

QBluetoothAddress	remoteAddress () const
	Returns the remote device address.

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

virtual bool	eventFilter (QObject watched, QEvent event)
	Filters events if this object has been installed as an event filter for the watched object.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Additional Inherited Members
Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

\inmodule QtBluetooth

The QBluetoothServiceDiscoveryAgent class enables you to query for Bluetooth services.

Since: 5.2

The discovery process relies on the Bluetooth Service Discovery Process (SDP). The following steps are required to query the services provided by all contactable Bluetooth devices:

\list

create an instance of QBluetoothServiceDiscoveryAgent,
connect to either the serviceDiscovered() or finished() signals,
and call start(). \endlist

By default a minimal service discovery is performed. In this mode, the returned \l QBluetoothServiceInfo objects are guaranteed to contain only device and service UUID information. Depending on platform and device capabilities, other service information may also be available. The minimal service discovery mode relies on cached SDP data of the platform. Therefore it is possible that this discovery does not find a device although it is physically available. In such cases a full discovery must be performed to force an update of the platform cache. However for most use cases a minimal discovery is adequate as it is much quicker and other classes which require up-to-date information such as QBluetoothSocket::connectToService() will perform additional discovery if required. If the full service information is required, pass \l FullDiscovery as the discoveryMode parameter to start().

This class may internally utilize \l QBluetoothDeviceDiscoveryAgent to find unknown devices.

The service discovery may find Bluetooth Low Energy services too if the target device is a combination of a classic and Low Energy device. Those devices are required to advertise their Low Energy services via SDP. If the target device only supports Bluetooth Low Energy services, it is likely to not advertise them via SDP. The \l QLowEnergyController class should be utilized to perform the service discovery on Low Energy devices.

On iOS, this class cannot be used because the platform does not expose an API which may permit access to QBluetoothServiceDiscoveryAgent related features.

See also: QBluetoothDeviceDiscoveryAgent, QLowEnergyController

Definition at line 25 of file qbluetoothservicediscoveryagent.h.

Member Enumeration Documentation

◆ DiscoveryMode

enum QBluetoothServiceDiscoveryAgent::DiscoveryMode

This enum describes the service discovery mode.

\value MinimalDiscovery Performs a minimal service discovery. The QBluetoothServiceInfo objects returned may be incomplete and are only guaranteed to contain device and service UUID information. Since a minimal discovery relies on cached SDP data it may not find a physically existing device until a FullDiscovery is performed. \value FullDiscovery Performs a full service discovery.

Enumerator
MinimalDiscovery
FullDiscovery

Definition at line 43 of file qbluetoothservicediscoveryagent.h.

◆ Error

enum QBluetoothServiceDiscoveryAgent::Error

This enum describes errors that can occur during service discovery.

\value NoError No error has occurred. \value PoweredOffError The Bluetooth adaptor is powered off, power it on before doing discovery. \value InputOutputError Writing or reading from the device resulted in an error. \value [since 5.3] InvalidBluetoothAdapterError The passed local adapter address does not match the physical adapter address of any local Bluetooth device. \value [since 6.4] MissingPermissionsError The operating system requests permissions which were not granted by the user. \value UnknownError An unknown error has occurred.

Enumerator
NoError
InputOutputError
PoweredOffError
InvalidBluetoothAdapterError
MissingPermissionsError
UnknownError

Definition at line 31 of file qbluetoothservicediscoveryagent.h.

Constructor & Destructor Documentation

◆ QBluetoothServiceDiscoveryAgent() [1/2]

QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent ( QObject * parent = nullptr )

explicit

Constructs a new QBluetoothServiceDiscoveryAgent with parent.

The search is performed via the local default Bluetooth adapter.

Definition at line 124 of file qbluetoothservicediscoveryagent.cpp.

◆ QBluetoothServiceDiscoveryAgent() [2/2]

QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent	(	const QBluetoothAddress &	deviceAdapter,
		QObject *	parent = nullptr )

explicit

Constructs a new QBluetoothServiceDiscoveryAgent for deviceAdapter and with parent.

It uses deviceAdapter for the service search. If deviceAdapter is default constructed the resulting QBluetoothServiceDiscoveryAgent object will use the local default Bluetooth adapter.

If a deviceAdapter is specified that is not a local adapter \l error() will be set to \l InvalidBluetoothAdapterError. Therefore it is recommended to test the error flag immediately after using this constructor.

Note: On WinRT the passed adapter address will be ignored.; On Android passing any deviceAdapter address is meaningless as Android 6.0 or later does not publish the local Bluetooth address anymore. Subsequently, the passed adapter address can never be matched against the local adapter address. Therefore the subsequent call to \l start() will always trigger \l InvalidBluetoothAdapterError.

See also: error()

Definition at line 149 of file qbluetoothservicediscoveryagent.cpp.

References QBluetoothLocalDevice::allDevices(), QBluetoothServiceDiscoveryAgentPrivate::error, QBluetoothServiceDiscoveryAgentPrivate::errorString, InvalidBluetoothAdapterError, and tr.

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◆ ~QBluetoothServiceDiscoveryAgent()

QBluetoothServiceDiscoveryAgent::~QBluetoothServiceDiscoveryAgent ( )

Destructor for QBluetoothServiceDiscoveryAgent.

Definition at line 170 of file qbluetoothservicediscoveryagent.cpp.

References disconnect(), isActive(), and stop().

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Member Function Documentation

◆ canceled

QBluetoothServiceDiscoveryAgent::canceled ( )

signal

This signal is triggered when the service discovery was canceled via a call to \l stop().

◆ clear

void QBluetoothServiceDiscoveryAgent::clear ( )

slot

Clears the results of previous service discoveries and resets \l uuidFilter().

This function does nothing during an ongoing service discovery (see \l isActive()).

See also: discoveredServices()

Definition at line 353 of file qbluetoothservicediscoveryagent.cpp.

References d, and isActive().

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◆ discoveredServices()

QList< QBluetoothServiceInfo > QBluetoothServiceDiscoveryAgent::discoveredServices ( ) const

Returns the list of all discovered services.

This list of services accumulates newly discovered services from multiple calls to \l start(). Unless \l clear() is called the list cannot decrease in size. This implies that if a remote Bluetooth device moves out of range in between two subsequent calls to \l start() the list may contain stale entries.

Note: The list of services should always be cleared before the discovery mode is changed.

See also: clear()

Definition at line 192 of file qbluetoothservicediscoveryagent.cpp.

References d.

◆ error()

QBluetoothServiceDiscoveryAgent::Error QBluetoothServiceDiscoveryAgent::error ( ) const

Returns the type of error that last occurred.

If the service discovery is done for a single \l remoteAddress() it will return errors that occurred while trying to discover services on that device. If the \l remoteAddress() is not set and devices are discovered by a scan, errors during service discovery on individual devices are not saved and no signals are emitted. In this case, errors are fairly normal as some devices may not respond to discovery or may no longer be in range. Such errors are suppressed. If no services are returned, it can be assumed no services could be discovered.

Any possible previous errors are cleared upon restarting the discovery.

Definition at line 389 of file qbluetoothservicediscoveryagent.cpp.

References d.

◆ errorOccurred

void QBluetoothServiceDiscoveryAgent::errorOccurred ( QBluetoothServiceDiscoveryAgent::Error error )

signal

This signal is emitted when an error occurs.

The error parameter describes the error that occurred.

Since: 6.2

◆ errorString()

QString QBluetoothServiceDiscoveryAgent::errorString ( ) const

Returns a human-readable description of the last error that occurred during the service discovery.

See also: error(), errorOccurred()

Definition at line 402 of file qbluetoothservicediscoveryagent.cpp.

References d.

◆ finished

QBluetoothServiceDiscoveryAgent::finished ( )

signal

This signal is emitted when the Bluetooth service discovery completes.

Unlike the \l QBluetoothDeviceDiscoveryAgent::finished() signal this signal will even be emitted when an error occurred during the service discovery. Therefore it is recommended to check the \l errorOccurred() signal to evaluate the success of the service discovery discovery.

Referenced by QBluetoothSocket::doDeviceDiscovery().

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◆ isActive()

bool QBluetoothServiceDiscoveryAgent::isActive ( ) const

Returns true if the service discovery is currently active; otherwise returns false.

An active discovery can be stopped by calling \l stop().

Definition at line 370 of file qbluetoothservicediscoveryagent.cpp.

References d, and QBluetoothServiceDiscoveryAgentPrivate::Inactive.

Referenced by ~QBluetoothServiceDiscoveryAgent(), clear(), setRemoteAddress(), and stop().

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◆ remoteAddress()

QBluetoothAddress QBluetoothServiceDiscoveryAgent::remoteAddress ( ) const

Returns the remote device address.

If \l setRemoteAddress() is not called, the function will return a default constructed \l QBluetoothAddress.

See also: setRemoteAddress()

Definition at line 273 of file qbluetoothservicediscoveryagent.cpp.

References QBluetoothServiceDiscoveryAgentPrivate::deviceAddress.

◆ serviceDiscovered

QBluetoothServiceDiscoveryAgent::serviceDiscovered ( const QBluetoothServiceInfo & info )

signal

This signal is emitted when the Bluetooth service described by info is discovered.

Note: The passed \l QBluetoothServiceInfo parameter may contain a Bluetooth Low Energy service if the target device advertises the service via SDP. This is required from device which support both, classic Bluetooth (BaseRate) and Low Energy services.

See also: QBluetoothDeviceInfo::coreConfigurations()

Referenced by QBluetoothSocket::doDeviceDiscovery().

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◆ setRemoteAddress()

bool QBluetoothServiceDiscoveryAgent::setRemoteAddress ( const QBluetoothAddress & address )

Sets the remote device address to address.

If address is default constructed, services will be discovered on all contactable Bluetooth devices. A new remote address can only be set while there is no service discovery in progress; otherwise this function returns false.

On some platforms the service discovery might lead to pairing requests. Therefore it is not recommended to do service discoveries on all devices. This function can be used to restrict the service discovery to a particular device.

See also: remoteAddress()

Definition at line 257 of file qbluetoothservicediscoveryagent.cpp.

References QBluetoothServiceDiscoveryAgentPrivate::deviceAddress, and isActive().

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◆ setUuidFilter() [1/2]

void QBluetoothServiceDiscoveryAgent::setUuidFilter ( const QBluetoothUuid & uuid )

This is an overloaded member function, provided for convenience.

Sets the UUID filter to a list containing the single element uuid. The matching applies to the service's \l {QBluetoothServiceInfo::ServiceId}{ServiceId} and \l {QBluetoothServiceInfo::ServiceClassIds} {ServiceClassIds} attributes.

See also: uuidFilter()

Definition at line 225 of file qbluetoothservicediscoveryagent.cpp.

References d.

◆ setUuidFilter() [2/2]

void QBluetoothServiceDiscoveryAgent::setUuidFilter ( const QList< QBluetoothUuid > & uuids )

Sets the UUID filter to uuids.

Only services matching the UUIDs in uuids will be returned. The matching applies to the service's \l {QBluetoothServiceInfo::ServiceId}{ServiceId} and \l {QBluetoothServiceInfo::ServiceClassIds} {ServiceClassIds} attributes.

An empty UUID list is equivalent to a list containing only QBluetoothUuid::ServiceClassUuid::PublicBrowseGroup.