Member Function Documentation

QLowEnergyCharacteristic::QLowEnergyCharacteristic()

Construct a new QLowEnergyCharacteristic. A default-constructed instance of this class is always invalid.

See also isValid().

QLowEnergyCharacteristic::QLowEnergyCharacteristic(const QLowEnergyCharacteristic &other)

Construct a new QLowEnergyCharacteristic that is a copy of other.

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

QLowEnergyCharacteristic::~QLowEnergyCharacteristic()

Destroys the QLowEnergyCharacteristic object.

QLowEnergyDescriptor QLowEnergyCharacteristic::descriptor(const QBluetoothUuid &uuid) const

Returns the descriptor for uuid or an invalid QLowEnergyDescriptor instance.

See also descriptors().

QList<QLowEnergyDescriptor> QLowEnergyCharacteristic::descriptors() const

Returns the list of descriptors belonging to this characteristic; otherwise an empty list.

See also descriptor().

QLowEnergyHandle QLowEnergyCharacteristic::handle() const

Returns the handle of the characteristic's value attribute; or 0 if the handle cannot be accessed on the platform or if the characteristic is invalid.

Note: On macOS and iOS handles can differ from 0, but these values have no special meaning outside of internal/private API.

bool QLowEnergyCharacteristic::isValid() const

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

An invalid characteristic object is not associated with any service (default-constructed) or the associated service is no longer valid due to a disconnect from the underlying Bluetooth Low Energy device, for example.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 QLowEnergyCharacteristic 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.

QString QLowEnergyCharacteristic::name() const

Returns the human-readable name of the characteristic.

The name is based on the characteristic's uuid() which must have been standardized. The complete list of characteristic types can be found under Bluetooth.org Characteristics.

The returned string is empty if the uuid() is unknown.

See also QBluetoothUuid::characteristicToString().

QLowEnergyCharacteristic::PropertyTypes QLowEnergyCharacteristic::properties() const

Returns the properties of the characteristic.

The properties define the access permissions for the characteristic.

QBluetoothUuid QLowEnergyCharacteristic::uuid() const

Returns the UUID of the characteristic if isValid() returns true; otherwise a null UUID.

QByteArray QLowEnergyCharacteristic::value() const

Returns the cached value of the characteristic.

If the characteristic's properties() permit writing of new values, the value can be updated using QLowEnergyService::writeCharacteristic().

The cache is updated during the associated service's detail discovery, a successful read/write operation or when an update notification is received.

The returned QByteArray always remains empty if the characteristic does not have the read permission. In such cases only the QLowEnergyService::characteristicChanged() or QLowEnergyService::characteristicWritten() may provice information about the value of this characteristic.

bool QLowEnergyCharacteristic::operator!=(const QLowEnergyCharacteristic &other) const

Returns true if other is not equal to this QLowEnergyCharacteristic; otherwise false.

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

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

Makes a copy of other and assigns it to this QLowEnergyCharacteristic object. The two copies continue to share the same service and controller details.

bool QLowEnergyCharacteristic::operator==(const QLowEnergyCharacteristic &other) const

Returns true if other is equal to this QLowEnergyCharacteristic; otherwise false.

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