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Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
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Public Types | Signals | Public Member Functions | List of all members
QNearFieldManager Class Reference

The QNearFieldManager class provides access to notifications for NFC events. More...

#include <qnearfieldmanager.h>

+ Inheritance diagram for QNearFieldManager:
+ Collaboration diagram for QNearFieldManager:

Public Types

enum class  AdapterState { Offline = 1 , TurningOn = 2 , Online = 3 , TurningOff = 4 }
 

Signals

void adapterStateChanged (QNearFieldManager::AdapterState state)
 
void targetDetectionStopped ()
 
void targetDetected (QNearFieldTarget *target)
 This signal is emitted whenever a target is detected.
 
void targetLost (QNearFieldTarget *target)
 This signal is emitted whenever a target moves out of proximity.
 
- 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

 QNearFieldManager (QObject *parent=nullptr)
 Constructs a new near field manager with parent.
 
 QNearFieldManager (QNearFieldManagerPrivate *backend, QObject *parent=nullptr)
 
 ~QNearFieldManager ()
 Destroys the near field manager.
 
bool isEnabled () const
 
bool isSupported (QNearFieldTarget::AccessMethod accessMethod=QNearFieldTarget::AnyAccess) const
 
bool startTargetDetection (QNearFieldTarget::AccessMethod accessMethod)
 Starts detecting targets and returns true if target detection started successfully; otherwise returns false.
 
void stopTargetDetection (const QString &errorMessage=QString())
 Stops detecting targets.
 
void setUserInformation (const QString &message)
 
- 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

- 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 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
 Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.
 
 
 
 \macro Q_CLASSINFO(Name, Value)
 

Detailed Description

The QNearFieldManager class provides access to notifications for NFC events.

\inmodule QtNfc

Since
5.2

NFC Forum devices support two modes of communications. The first mode, peer-to-peer communications, is used to communicate between two NFC Forum devices. The second mode, master/slave communications, is used to communicate between an NFC Forum device and an NFC Forum Tag or Contactless Card. The targetDetected() signal is emitted when a target device enters communications range. Communications can be initiated from the slot connected to this signal.

NFC Forum devices generally operate as the master in master/slave communications. Some devices are also capable of operating as the slave, so called Card Emulation mode. In this mode the local NFC device emulates a NFC Forum Tag or Contactless Card.

Applications can connect to the targetDetected() and targetLost() signals to get notified when an NFC Forum Tag enters or leaves proximity. Before these signals are emitted target detection must be started with the startTargetDetection() function. Target detection can be stopped with the stopTargetDetection() function. When the target is no longer required the target should be deleted as other applications may be blocked from accessing the target.

Definition at line 16 of file qnearfieldmanager.h.

Member Enumeration Documentation

◆ AdapterState

enum class QNearFieldManager::AdapterState
strong
Since
5.12

This enum describes the different states a NFC adapter can have.

\value Offline The nfc adapter is offline. \value TurningOn The nfc adapter is turning on. \value Online The nfc adapter is online. \value TurningOff The nfc adapter is turning off.

Enumerator
Offline 
TurningOn 
Online 
TurningOff 

Definition at line 23 of file qnearfieldmanager.h.

Constructor & Destructor Documentation

◆ QNearFieldManager() [1/2]

QNearFieldManager::QNearFieldManager ( QObject * parent = nullptr)
explicit

Constructs a new near field manager with parent.

Definition at line 129 of file qnearfieldmanager.cpp.

◆ QNearFieldManager() [2/2]

QNearFieldManager::QNearFieldManager ( QNearFieldManagerPrivate * backend,
QObject * parent = nullptr )
explicit

Constructs a new near field manager with the specified backend and with parent.

Note
: This constructor is only enable for internal builds and is used for testing the simulator backend.

Definition at line 152 of file qnearfieldmanager.cpp.

◆ ~QNearFieldManager()

QNearFieldManager::~QNearFieldManager ( )

Destroys the near field manager.

Definition at line 170 of file qnearfieldmanager.cpp.

Member Function Documentation

◆ adapterStateChanged

void QNearFieldManager::adapterStateChanged ( QNearFieldManager::AdapterState state)
signal
Since
5.12

This signal is emitted whenever the state of the NFC adapter changed.

Note
Currently, this signal is only emitted on Android.

◆ isEnabled()

bool QNearFieldManager::isEnabled ( ) const
Since
6.2

Returns true if the device has a NFC adapter and it is turned on; otherwise returns false.

See also
isSupported()

Definition at line 183 of file qnearfieldmanager.cpp.

◆ isSupported()

bool QNearFieldManager::isSupported ( QNearFieldTarget::AccessMethod accessMethod = QNearFieldTarget::AnyAccess) const
Since
5.12

Returns true if the underlying device has a NFC adapter; otherwise returns false. If an accessMethod is given, the function returns true only if the NFC adapter supports the given accessMethod.

See also
isEnabled()

Definition at line 199 of file qnearfieldmanager.cpp.

◆ setUserInformation()

void QNearFieldManager::setUserInformation ( const QString & message)
Since
6.2

Sets the message that the system shows to the user. If target detection is running, the message will be updated immediately and can be used as a progress message. The last message set before a call to \l startTargetDetection() without an error message is used as a success message. If target detection is not running, the message will be used as the initial message when the next detection is started. By default, no message is shown to the user.

Note
Currently, this function only has an effect on iOS because the system shows a popup during the scan. On iOS, this message is mapped to the alert message which is shown upon successful completion of the scan. Other platforms will ignore message.
See also
startTargetDetection(), stopTargetDetection()

Definition at line 270 of file qnearfieldmanager.cpp.

◆ startTargetDetection()

bool QNearFieldManager::startTargetDetection ( QNearFieldTarget::AccessMethod accessMethod)

Starts detecting targets and returns true if target detection started successfully; otherwise returns false.

Causes the targetDetected() signal to be emitted when a target is within proximity. Only tags with the given accessMethod will be reported. Target detection continues until \l stopTargetDetection() is called.

To detect targets with a different accessMethod, stopTargetDetection() must be called first.

Note
On iOS, it is impossible to start target detection for both NdefAccess and TagTypeSpecificAccess at the same time. So if AnyAccess is selected, NdefAccess will be used instead.
On platforms using neard, target detection will stop as soon as a tag has been detected.
See also
stopTargetDetection()

Definition at line 223 of file qnearfieldmanager.cpp.

◆ stopTargetDetection()

void QNearFieldManager::stopTargetDetection ( const QString & errorMessage = QString())

Stops detecting targets.

The \l targetDetected() signal will no longer be emitted until another call to \l startTargetDetection() is made. Targets detected before are still valid.

Note
On iOS, detected targets become invalid after this call (e.g. an attempt to write or read NDEF messages will result in an error).

If an errorMessage is provided, it is a hint to the system that the application's goal was not achieved. The errorMessage and a matching error icon are shown to the user. Calling this function with an empty errorMessage implies a successful end of operation; otherwise, an errorMessage should be passed to this function.

Note
Currently, errorMessage only has an effect on iOS because the system shows a popup during the scan where the errorMessage is visible. Other platforms will ignore this parameter.
See also
setUserInformation()

Definition at line 248 of file qnearfieldmanager.cpp.

◆ targetDetected

void QNearFieldManager::targetDetected ( QNearFieldTarget * target)
signal

This signal is emitted whenever a target is detected.

The target parameter represents the detected target.

This signal will be emitted for all detected targets.

QNearFieldManager maintains ownership of target, however, it will not be destroyed until the QNearFieldManager destructor is called. Ownership may be transferred by calling setParent().

Do not delete target from the slot connected to this signal, instead call deleteLater().

Note
that if target is deleted before it moves out of proximity the targetLost() signal will not be emitted.
See also
targetLost()

◆ targetDetectionStopped

void QNearFieldManager::targetDetectionStopped ( )
signal
Since
6.2

This signal is emitted whenever the target detection is stopped.

Note
Mostly this signal is emitted when \l stopTargetDetection() has been called. Additionally the user is able to stop the detection on iOS within a popup shown by the system during the scan, which also leads to emitting this signal.

◆ targetLost

void QNearFieldManager::targetLost ( QNearFieldTarget * target)
signal

This signal is emitted whenever a target moves out of proximity.

The target parameter represents the lost target.

Do not delete target from the slot connected to this signal, instead use deleteLater().

See also
QNearFieldTarget::disconnected()
The documentation for this class was generated from the following files: