\inmodule QtBluetooth More...

#include <qlowenergydescriptor.h>

Collaboration diagram for QLowEnergyDescriptor:

Public Member Functions
	QLowEnergyDescriptor ()
	Construct a new QLowEnergyDescriptor.

	QLowEnergyDescriptor (const QLowEnergyDescriptor &other)
	Construct a new QLowEnergyDescriptor that is a copy of other.

	~QLowEnergyDescriptor ()
	Destroys the QLowEnergyDescriptor object.

QLowEnergyDescriptor &	operator= (const QLowEnergyDescriptor &other)
	Makes a copy of other and assigns it to this QLowEnergyDescriptor object.

bool	isValid () const
	Returns `true` if the QLowEnergyDescriptor object is valid, otherwise returns `false`.

QByteArray	value () const
	Returns the cached value of the descriptor.

QBluetoothUuid	uuid () const
	Returns the UUID of this descriptor if \l isValid() returns `true`; otherwise a \l {QUuid::isNull()}{null} UUID.

QString	name () const
	Returns the human-readable name of the descriptor.

QBluetoothUuid::DescriptorType	type () const
	Returns the type of the descriptor.

Friends
class	QLowEnergyCharacteristic

class	QLowEnergyService

class	QLowEnergyControllerPrivate

class	QLowEnergyControllerPrivateAndroid

class	QLowEnergyControllerPrivateBluez

class	QLowEnergyControllerPrivateBluezDBus

class	QLowEnergyControllerPrivateCommon

class	QLowEnergyControllerPrivateDarwin

class	QLowEnergyControllerPrivateWinRT

bool	operator== (const QLowEnergyDescriptor &a, const QLowEnergyDescriptor &b)
	Returns `true` if a is equal to b; otherwise `false`.

bool	operator!= (const QLowEnergyDescriptor &a, const QLowEnergyDescriptor &b)
	Returns `true` if a is not equal to b; otherwise `false`.

Detailed Description

\inmodule QtBluetooth

The QLowEnergyDescriptor class stores information about the Bluetooth Low Energy descriptor.

Since: 5.4

QLowEnergyDescriptor provides information about a Bluetooth Low Energy descriptor's name(), uuid(), and value(). Descriptors are encapsulated by Bluetooth Low Energy characteristics and provide additional contextual information about the characteristic (data format, notification activation and so on).

The descriptor value may be written via the QLowEnergyService instance that manages the service to which this descriptor belongs. The \l {QLowEnergyService::writeDescriptor()} function writes the new value. The \l {QLowEnergyService::descriptorWritten()} signal is emitted upon success. The cached value() of this object is updated accordingly.

See also: QLowEnergyService, QLowEnergyCharacteristic

Definition at line 18 of file qlowenergydescriptor.h.

Constructor & Destructor Documentation

◆ QLowEnergyDescriptor() [1/2]

QLowEnergyDescriptor::QLowEnergyDescriptor ( )

Construct a new QLowEnergyDescriptor.

A default-constructed instance of this class is always invalid.

Definition at line 45 of file qlowenergydescriptor.cpp.

◆ QLowEnergyDescriptor() [2/2]

QLowEnergyDescriptor::QLowEnergyDescriptor ( const QLowEnergyDescriptor & other )

Construct a new QLowEnergyDescriptor that is a copy of other.

The two copies continue to share the same underlying data which does not detach upon write.

Definition at line 56 of file qlowenergydescriptor.cpp.

References other().

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◆ ~QLowEnergyDescriptor()

QLowEnergyDescriptor::~QLowEnergyDescriptor ( )

Destroys the QLowEnergyDescriptor object.

Definition at line 84 of file qlowenergydescriptor.cpp.

Member Function Documentation

◆ isValid()

bool QLowEnergyDescriptor::isValid ( ) const

Returns true if the QLowEnergyDescriptor object is valid, otherwise returns false.

An invalid descriptor instance is not associated with any service (default-constructed) or the associated service is no longer valid due to a disconnect from the underlying Bluetooth Low Energy device, for example. Once the object is invalid it cannot become valid anymore.

Note: If a QLowEnergyDescriptor instance turns invalid due to a disconnect from the underlying device, the information encapsulated by the current instance remains as it was at the time of the disconnect. Therefore it can be retrieved after the disconnect event.

Definition at line 173 of file qlowenergydescriptor.cpp.

References QLowEnergyService::InvalidService, QSharedPointer< T >::isNull(), and QLowEnergyServicePrivate::state.

Referenced by MyClass::enableCharNotifications(), QLowEnergyControllerPrivateBluezDBus::readDescriptor(), and QLowEnergyControllerPrivateBluezDBus::writeDescriptor().

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◆ name()

QString QLowEnergyDescriptor::name ( ) const

Returns the human-readable name of the descriptor.

The name is based on the descriptor's \l type(). The complete list of descriptor types can be found under \l {https://developer.bluetooth.org/gatt/descriptors/Pages/DescriptorsHomePage.aspx}{Bluetooth.org Descriptors}.

The returned string is empty if the \l type() is unknown.

See also: type(), QBluetoothUuid::descriptorToString()

Definition at line 247 of file qlowenergydescriptor.cpp.

References QBluetoothUuid::descriptorToString(), and type().

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◆ operator=()

QLowEnergyDescriptor & QLowEnergyDescriptor::operator= ( const QLowEnergyDescriptor & other )

Makes a copy of other and assigns it to this QLowEnergyDescriptor object.

The two copies continue to share the same service and controller details.

Definition at line 93 of file qlowenergydescriptor.cpp.

References other().

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◆ type()

QBluetoothUuid::DescriptorType QLowEnergyDescriptor::type ( ) const

Returns the type of the descriptor.

See also: name()

Definition at line 257 of file qlowenergydescriptor.cpp.

References QBluetoothUuid::CharacteristicAggregateFormat, QBluetoothUuid::CharacteristicExtendedProperties, QBluetoothUuid::CharacteristicPresentationFormat, QBluetoothUuid::CharacteristicUserDescription, QBluetoothUuid::ClientCharacteristicConfiguration, QBluetoothUuid::ExternalReportReference, ok, QBluetoothUuid::ReportReference, QBluetoothUuid::ServerCharacteristicConfiguration, QBluetoothUuid::toUInt16(), QBluetoothUuid::UnknownDescriptorType, uuid(), and QBluetoothUuid::ValidRange.

Referenced by name().

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◆ uuid()

QBluetoothUuid QLowEnergyDescriptor::uuid ( ) const

Returns the UUID of this descriptor if \l isValid() returns true; otherwise a \l {QUuid::isNull()}{null} UUID.

Definition at line 188 of file qlowenergydescriptor.cpp.

References QLowEnergyServicePrivate::characteristicList, and QSharedPointer< T >::isNull().

Referenced by type(), QLowEnergyService::writeDescriptor(), and QLowEnergyControllerPrivateBluezDBus::writeDescriptor().

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◆ value()

QByteArray QLowEnergyDescriptor::value ( ) const

Returns the cached value of the descriptor.

The cached descriptor value may be updated using \l QLowEnergyService::writeDescriptor() or \l QLowEnergyService::readDescriptor().

Definition at line 223 of file qlowenergydescriptor.cpp.

References QLowEnergyServicePrivate::characteristicList, QSharedPointer< T >::isNull(), and QByteArray().

Referenced by QLowEnergyControllerPrivateBluezDBus::readDescriptor().

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Friends And Related Symbol Documentation

◆ operator!=

bool QLowEnergyDescriptor::operator!=	(	const QLowEnergyDescriptor &	a,
		const QLowEnergyDescriptor &	b )

friend

Returns true if a is not equal to b; otherwise false.

Two QLowEnergyDescriptor instances are considered to be equal if they refer to the same descriptor on the same remote Bluetooth Low Energy device or both instances have been default-constructed.

Definition at line 30 of file qlowenergydescriptor.h.

◆ operator==

bool QLowEnergyDescriptor::operator==	(	const QLowEnergyDescriptor &	a,
		const QLowEnergyDescriptor &	b )

friend

Returns true if a is equal to b; otherwise false.

Two QLowEnergyDescriptor instances are considered to be equal if they refer to the same descriptor on the same remote Bluetooth Low Energy device or both instances have been default-constructed.

Definition at line 26 of file qlowenergydescriptor.h.