The QNearFieldTarget class provides an interface for communicating with a target device. More...

#include <qnearfieldtarget.h>

Inheritance diagram for QNearFieldTarget:

Collaboration diagram for QNearFieldTarget:

Classes
class	RequestId
	\inmodule QtNfc \inheaderfile QNearFieldTarget More...

class	RequestIdPrivate

Public Types
enum	Type { ProprietaryTag , NfcTagType1 , NfcTagType2 , NfcTagType3 , NfcTagType4 , NfcTagType4A , NfcTagType4B , MifareTag }
	This enum describes the type of tag the target is detected as. More...

enum	AccessMethod { UnknownAccess = 0x00 , NdefAccess = 0x01 , TagTypeSpecificAccess = 0x02 , AnyAccess = 0xff }
	This enum describes the access methods a near field target supports. More...

enum	Error { NoError , UnknownError , UnsupportedError , TargetOutOfRangeError , NoResponseError , ChecksumMismatchError , InvalidParametersError , ConnectionError , NdefReadError , NdefWriteError , CommandError , TimeoutError }
	This enum describes the error codes that a near field target reports. More...

Signals
void	disconnected ()
	This signal is emitted when the near field target moves out of proximity.

void	ndefMessageRead (const QNdefMessage &message)
	This signal is emitted when a complete NDEF message has been read from the target.

void	requestCompleted (const QNearFieldTarget::RequestId &id)
	This signal is emitted when a request id completes.

void	error (QNearFieldTarget::Error error, const QNearFieldTarget::RequestId &id)
	This signal is emitted when an error occurs while processing request id.

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
	QNearFieldTarget (QObject *parent=nullptr)
	Constructs a new near field target with parent.

	~QNearFieldTarget ()
	Destroys the near field target.

QByteArray	uid () const
	Returns the UID of the near field target.

Type	type () const
	Returns the type of tag type of this near field target.

AccessMethods	accessMethods () const
	Returns the access methods supported by this near field target.

bool	disconnect ()

bool	hasNdefMessage ()
	Returns `true` if at least one NDEF message is stored on the near field target; otherwise returns `false`.

RequestId	readNdefMessages ()
	Starts reading NDEF messages stored on the near field target.

RequestId	writeNdefMessages (const QList< QNdefMessage > &messages)
	Writes the NDEF messages in messages to the target.

int	maxCommandLength () const

RequestId	sendCommand (const QByteArray &command)
	Sends command to the near field target.

bool	waitForRequestCompleted (const RequestId &id, int msecs=5000)
	Waits up to msecs milliseconds for the request id to complete.

QVariant	requestResponse (const RequestId &id) const
	Returns the decoded response for request id.

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`.

Protected Member Functions
	QNearFieldTarget (QNearFieldTargetPrivate backend, QObject parent=nullptr)

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)

Friends
class	QNearFieldManagerPrivateImpl

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

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 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

The QNearFieldTarget class provides an interface for communicating with a target device.

\inmodule QtNfc

Since: 5.2

QNearFieldTarget provides a generic interface for communicating with an NFC target device. Both NFC Forum devices and NFC Forum Tag targets are supported by this class. All target specific classes subclass this class.

The type() function can be used to get the type of the target device. The uid() function returns the unique identifier of the target. The AccessMethods flags returns from the accessMethods() function can be tested to determine which access methods are supported by the target.

If the target supports NdefAccess, hasNdefMessage() can be called to test if the target has a stored NDEF message, readNdefMessages() and writeNdefMessages() functions can be used to get and set the NDEF message.

If the target supports TagTypeSpecificAccess, sendCommand() can be used to send a single proprietary command to the target and retrieve the response.

Definition at line 21 of file qnearfieldtarget.h.

Member Enumeration Documentation

◆ AccessMethod

enum QNearFieldTarget::AccessMethod

This enum describes the access methods a near field target supports.

\value UnknownAccess The target supports an unknown access type. \value NdefAccess The target supports reading and writing NDEF messages using readNdefMessages() and writeNdefMessages(). \value TagTypeSpecificAccess The target supports sending tag type specific commands using sendCommand(). \value AnyAccess The target supports any of the known access types.

Enumerator
UnknownAccess
NdefAccess
TagTypeSpecificAccess
AnyAccess

Definition at line 41 of file qnearfieldtarget.h.

◆ Error

enum QNearFieldTarget::Error

This enum describes the error codes that a near field target reports.

\value NoError No error has occurred. \value UnknownError An unidentified error occurred. \value UnsupportedError The requested operation is unsupported by this near field target. \value TargetOutOfRangeError The target is no longer within range. \value NoResponseError The target did not respond. \value ChecksumMismatchError The checksum has detected a corrupted response. \value InvalidParametersError Invalid parameters were passed to a tag type specific function. \value ConnectionError Failed to connect to the target. \value NdefReadError Failed to read NDEF messages from the target. \value NdefWriteError Failed to write NDEF messages to the target. \value CommandError Failed to send a command to the target. \value TimeoutError The request could not be completed within the time specified in waitForRequestCompleted().

Enumerator
NoError
UnknownError
UnsupportedError
TargetOutOfRangeError
NoResponseError
ChecksumMismatchError
InvalidParametersError
ConnectionError
NdefReadError
NdefWriteError
CommandError
TimeoutError

Definition at line 50 of file qnearfieldtarget.h.

◆ Type

enum QNearFieldTarget::Type

This enum describes the type of tag the target is detected as.

\value ProprietaryTag An unidentified proprietary target tag. \value NfcTagType1 An NFC tag type 1 target. \value NfcTagType2 An NFC tag type 2 target. \value NfcTagType3 An NFC tag type 3 target. \value NfcTagType4 An NFC tag type 4 target. This value is used if the NfcTagType4 cannot be further refined by NfcTagType4A or NfcTagType4B below. \value NfcTagType4A An NFC tag type 4 target based on ISO/IEC 14443-3A. \value NfcTagType4B An NFC tag type 4 target based on ISO/IEC 14443-3B. \value MifareTag A Mifare target.

Enumerator
ProprietaryTag
NfcTagType1
NfcTagType2
NfcTagType3
NfcTagType4
NfcTagType4A
NfcTagType4B
MifareTag

Definition at line 29 of file qnearfieldtarget.h.

Constructor & Destructor Documentation

◆ QNearFieldTarget() [1/2]

QNearFieldTarget::QNearFieldTarget ( QObject * parent = nullptr )

explicit

Constructs a new near field target with parent.

Definition at line 216 of file qnearfieldtarget.cpp.

◆ ~QNearFieldTarget()

QNearFieldTarget::~QNearFieldTarget ( )

Destroys the near field target.

Definition at line 224 of file qnearfieldtarget.cpp.

References d.

◆ QNearFieldTarget() [2/2]

QNearFieldTarget::QNearFieldTarget	(	QNearFieldTargetPrivate *	backend,
		QObject *	parent = nullptr )

protected

Definition at line 391 of file qnearfieldtarget.cpp.

References QObject::connect(), d, disconnected(), QNearFieldTargetPrivate::disconnected(), error(), QNearFieldTargetPrivate::error(), ndefMessageRead(), QNearFieldTargetPrivate::ndefMessageRead(), requestCompleted(), and QNearFieldTargetPrivate::requestCompleted().

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Member Function Documentation

◆ accessMethods()

QNearFieldTarget::AccessMethods QNearFieldTarget::accessMethods ( ) const

Returns the access methods supported by this near field target.

Definition at line 259 of file qnearfieldtarget.cpp.

References d.

◆ disconnect()

bool QNearFieldTarget::disconnect ( )

Since: 5.9

Closes the connection to the target to enable communication with the target from a different instance. The connection will also be closed, when the QNearFieldTarget is destroyed. A connection to the target device is (re)created to process a command or read/write a NDEF messages.

Returns true only if an existing connection was successfully closed; otherwise returns false.

Definition at line 277 of file qnearfieldtarget.cpp.

References d.

◆ disconnected

void QNearFieldTarget::disconnected ( )

signal

This signal is emitted when the near field target moves out of proximity.

Referenced by QNearFieldTarget().

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◆ error

void QNearFieldTarget::error	(	QNearFieldTarget::Error	error,
		const QNearFieldTarget::RequestId &	id )

signal

This signal is emitted when an error occurs while processing request id.

The error parameter describes the error.

Referenced by QNearFieldTarget().

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◆ hasNdefMessage()

bool QNearFieldTarget::hasNdefMessage ( )

Returns true if at least one NDEF message is stored on the near field target; otherwise returns false.

Definition at line 288 of file qnearfieldtarget.cpp.

References d.

◆ maxCommandLength()

int QNearFieldTarget::maxCommandLength ( ) const

Since: 5.9

Returns the maximum number of bytes that can be sent with sendCommand. 0 will be returned if the target does not support sending tag type specific commands.

See also: sendCommand()

Definition at line 338 of file qnearfieldtarget.cpp.

References d.

◆ ndefMessageRead

void QNearFieldTarget::ndefMessageRead ( const QNdefMessage & message )

signal

This signal is emitted when a complete NDEF message has been read from the target.

See also: readNdefMessages()

Referenced by QNearFieldTarget(), and QNearFieldTargetPrivateImpl::readNdefMessages().

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◆ readNdefMessages()

QNearFieldTarget::RequestId QNearFieldTarget::readNdefMessages ( )

Starts reading NDEF messages stored on the near field target.

Returns a request id which can be used to track the completion status of the request. An invalid request id will be returned if the target does not support reading NDEF messages.

An ndefMessageRead() signal will be emitted for each NDEF message. The requestCompleted() signal will be emitted was all NDEF messages have been read. The error() signal is emitted if an error occurs.

Note: An attempt to read an NDEF message from a tag, that is in INITIALIZED state as defined by NFC Forum, will fail with the \l NdefReadError, as the tag is formatted to support NDEF but does not contain a message yet.

Definition at line 308 of file qnearfieldtarget.cpp.

References d.

◆ requestCompleted

void QNearFieldTarget::requestCompleted ( const QNearFieldTarget::RequestId & id )

signal

This signal is emitted when a request id completes.

See also: sendCommand()

Referenced by QNearFieldTarget().

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◆ requestResponse()

QVariant QNearFieldTarget::requestResponse ( const RequestId & id ) const

Returns the decoded response for request id.

If the request is unknown or has not yet been completed an invalid QVariant is returned.

Definition at line 381 of file qnearfieldtarget.cpp.

References d.

◆ sendCommand()

QNearFieldTarget::RequestId QNearFieldTarget::sendCommand ( const QByteArray & command )

Sends command to the near field target.

Returns a request id which can be used to track the completion status of the request. An invalid request id will be returned if the target does not support sending tag type specific commands.

The requestCompleted() signal will be emitted on successful completion of the request; otherwise the error() signal will be emitted.

Once the request completes successfully the response can be retrieved from the requestResponse() function. The response of this request will be a QByteArray.

See also: requestCompleted(), waitForRequestCompleted()

Definition at line 358 of file qnearfieldtarget.cpp.

References d.

◆ type()

QNearFieldTarget::Type QNearFieldTarget::type ( ) const

Returns the type of tag type of this near field target.

Definition at line 249 of file qnearfieldtarget.cpp.

References d.

◆ uid()

QByteArray QNearFieldTarget::uid ( ) const

Returns the UID of the near field target.

Note: On iOS, this function returns an empty QByteArray for a near field target discovered using NdefAccess method.

See also: QNearFieldTarget::AccessMethod

Definition at line 239 of file qnearfieldtarget.cpp.

References d.

◆ waitForRequestCompleted()

bool QNearFieldTarget::waitForRequestCompleted	(	const RequestId &	id,
		int	msecs = 5000 )

Waits up to msecs milliseconds for the request id to complete.

Returns true if the request completes successfully and the requestCompeted() signal is emitted; otherwise returns false.

Definition at line 370 of file qnearfieldtarget.cpp.

References d.

◆ writeNdefMessages()

QNearFieldTarget::RequestId QNearFieldTarget::writeNdefMessages ( const QList< QNdefMessage > & messages )

Writes the NDEF messages in messages to the target.

Returns a request id which can be used to track the completion status of the request. An invalid request id will be returned if the target does not support reading NDEF messages.

The requestCompleted() signal will be emitted when the write operation completes successfully; otherwise the error() signal is emitted.

Definition at line 323 of file qnearfieldtarget.cpp.

References d.

Friends And Related Symbol Documentation

◆ QNearFieldManagerPrivateImpl

friend class QNearFieldManagerPrivateImpl

friend

Definition at line 26 of file qnearfieldtarget.h.

The documentation for this class was generated from the following files:

qtconnectivity/src/nfc/qnearfieldtarget.h (664d2a1cf019f76adf433d41b1418e515ffce86c)
qtconnectivity/src/nfc/qnearfieldtarget.cpp (8fd383214b710a610edd18e9db5b029dbe030edc)

Classes

Public Types

Signals

Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ AccessMethod

◆ Error

◆ Type

Constructor & Destructor Documentation

◆ QNearFieldTarget() [1/2]

◆ ~QNearFieldTarget()

◆ QNearFieldTarget() [2/2]

Member Function Documentation

◆ accessMethods()

◆ disconnect()

◆ disconnected

◆ error

◆ hasNdefMessage()

◆ maxCommandLength()

◆ ndefMessageRead

◆ readNdefMessages()

◆ requestCompleted

◆ requestResponse()

◆ sendCommand()

◆ type()

◆ uid()

◆ waitForRequestCompleted()

◆ writeNdefMessages()

Friends And Related Symbol Documentation

◆ QNearFieldManagerPrivateImpl