Qt
Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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QQuickTapHandler Class Reference

#include <qquicktaphandler_p.h>

+ Inheritance diagram for QQuickTapHandler:
+ Collaboration diagram for QQuickTapHandler:

Public Types

enum  GesturePolicy { DragThreshold , WithinBounds , ReleaseWithinBounds , DragWithinBounds }
 
enum  ExclusiveSignal { NotExclusive = 0 , SingleTap = 1 << 0 , DoubleTap = 1 << 1 }
 
- Public Types inherited from QQuickPointerHandler
enum  GrabPermission {
  TakeOverForbidden = 0x0 , CanTakeOverFromHandlersOfSameType = 0x01 , CanTakeOverFromHandlersOfDifferentType = 0x02 , CanTakeOverFromItems = 0x04 ,
  CanTakeOverFromAnything = 0x0F , ApprovesTakeOverByHandlersOfSameType = 0x10 , ApprovesTakeOverByHandlersOfDifferentType = 0x20 , ApprovesTakeOverByItems = 0x40 ,
  ApprovesCancellation = 0x80 , ApprovesTakeOverByAnything = 0xF0
}
 

Signals

void pressedChanged ()
 
void tapCountChanged ()
 
void timeHeldChanged ()
 
void longPressThresholdChanged ()
 
void gesturePolicyChanged ()
 
 Q_REVISION (6, 5) void exclusiveSignalsChanged()
 
void tapped (QEventPoint eventPoint, Qt::MouseButton)
 
void singleTapped (QEventPoint eventPoint, Qt::MouseButton)
 
void doubleTapped (QEventPoint eventPoint, Qt::MouseButton)
 
void longPressed ()
 
- Signals inherited from QQuickSinglePointHandler
void pointChanged ()
 
- Signals inherited from QQuickPointerDeviceHandler
void acceptedDevicesChanged ()
 
void acceptedPointerTypesChanged ()
 
void acceptedButtonsChanged ()
 
void acceptedModifiersChanged ()
 
- Signals inherited from QQuickPointerHandler
void enabledChanged ()
 
void activeChanged ()
 
void targetChanged ()
 
void marginChanged ()
 
 Q_REVISION (2, 15) void dragThresholdChanged()
 
void grabChanged (QPointingDevice::GrabTransition transition, QEventPoint point)
 
void grabPermissionChanged ()
 
void canceled (QEventPoint point)
 
 Q_REVISION (6, 3) void parentChanged()
 
- 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

 QQuickTapHandler (QQuickItem *parent=nullptr)
 \qmltype TapHandler \instantiates QQuickTapHandler \inherits SinglePointHandler \inqmlmodule QtQuick
 
bool isPressed () const
 
int tapCount () const
 
qreal timeHeld () const
 
qreal longPressThreshold () const
 \qmlproperty real QtQuick::TapHandler::longPressThreshold
 
void setLongPressThreshold (qreal longPressThreshold)
 
void resetLongPressThreshold ()
 
GesturePolicy gesturePolicy () const
 
void setGesturePolicy (GesturePolicy gesturePolicy)
 \qmlproperty enumeration QtQuick::TapHandler::gesturePolicy
 
QQuickTapHandler::ExclusiveSignals exclusiveSignals () const
 
void setExclusiveSignals (QQuickTapHandler::ExclusiveSignals newexclusiveSignals)
 \qmlproperty enumeration QtQuick::TapHandler::exclusiveSignals
 
- Public Member Functions inherited from QQuickSinglePointHandler
 QQuickSinglePointHandler (QQuickItem *parent=nullptr)
 \qmltype SinglePointHandler \qmlabstract \preliminary \instantiates QQuickSinglePointHandler \inherits PointerDeviceHandler \inqmlmodule QtQuick
 
QQuickHandlerPoint point () const
 
- Public Member Functions inherited from QQuickPointerDeviceHandler
 QQuickPointerDeviceHandler (QQuickItem *parent=nullptr)
 \qmltype PointerDeviceHandler \qmlabstract
 
QInputDevice::DeviceTypes acceptedDevices () const
 
QPointingDevice::PointerTypes acceptedPointerTypes () const
 
Qt::MouseButtons acceptedButtons () const
 \qmlproperty flags QtQuick::PointerDeviceHandler::acceptedButtons
 
Qt::KeyboardModifiers acceptedModifiers () const
 
- Public Member Functions inherited from QQuickPointerHandler
 QQuickPointerHandler (QQuickItem *parent=nullptr)
 \qmltype PointerHandler \qmlabstract
 
 ~QQuickPointerHandler ()
 
bool enabled () const
 \qmlproperty bool QtQuick::PointerHandler::enabled
 
void setEnabled (bool enabled)
 
bool active () const
 \readonly \qmlproperty bool QtQuick::PointerHandler::active
 
QQuickItemtarget () const
 \qmlproperty Item QtQuick::PointerHandler::target
 
void setTarget (QQuickItem *target)
 
QQuickItemparentItem () const
 \qmlproperty Item QtQuick::PointerHandler::parent
 
void setParentItem (QQuickItem *p)
 
void handlePointerEvent (QPointerEvent *event)
 
GrabPermissions grabPermissions () const
 \qmlproperty flags QtQuick::PointerHandler::grabPermissions
 
void setGrabPermissions (GrabPermissions grabPermissions)
 
qreal margin () const
 \qmlproperty real PointerHandler::margin
 
void setMargin (qreal pointDistanceThreshold)
 
int dragThreshold () const
 \qmlproperty int PointerHandler::dragThreshold
 
void setDragThreshold (int t)
 
void resetDragThreshold ()
 
- 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 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< QStringbindableObjectName ()
 
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).
 
QThreadthread () 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 >
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 >
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 QObjectListchildren () 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< QByteArraydynamicPropertyNames () const
 
QBindingStoragebindingStorage ()
 
const QBindingStoragebindingStorage () const
 
QObjectparent () 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.
 
- Public Member Functions inherited from QQmlParserStatus
 QQmlParserStatus ()
 
virtual ~QQmlParserStatus ()
 

Protected Member Functions

void onGrabChanged (QQuickPointerHandler *grabber, QPointingDevice::GrabTransition transition, QPointerEvent *ev, QEventPoint &point) override
 Notification that the grab has changed in some way which is relevant to this handler.
 
void timerEvent (QTimerEvent *event) override
 This event handler can be reimplemented in a subclass to receive timer events for the object.
 
bool wantsEventPoint (const QPointerEvent *event, const QEventPoint &point) override
 Returns true if the given point (as part of event) could be relevant at all to this handler, as a preliminary check.
 
void handleEventPoint (QPointerEvent *event, QEventPoint &point) override
 
- Protected Member Functions inherited from QQuickSinglePointHandler
 QQuickSinglePointHandler (QQuickSinglePointHandlerPrivate &dd, QQuickItem *parent)
 
bool wantsPointerEvent (QPointerEvent *event) override
 It is the responsibility of this function to decide whether the event could be relevant at all to this handler, as a preliminary check.
 
void handlePointerEventImpl (QPointerEvent *event) override
 This function can be overridden to implement whatever behavior a specific subclass is intended to have: \list.
 
QEventPointcurrentPoint (QPointerEvent *ev)
 
void setIgnoreAdditionalPoints (bool v=true)
 
void moveTarget (QPointF pos, QEventPoint &point)
 
void setPointId (int id)
 
- Protected Member Functions inherited from QQuickPointerDeviceHandler
 QQuickPointerDeviceHandler (QQuickPointerDeviceHandlerPrivate &dd, QQuickItem *parent=nullptr)
 
- Protected Member Functions inherited from QQuickPointerHandler
 QQuickPointerHandler (QQuickPointerHandlerPrivate &dd, QQuickItem *parent)
 
void classBegin () override
 Overridden only because QQmlParserStatus requires it.
 
void componentComplete () override
 Overridden from QQmlParserStatus to ensure that parentItem() sets its cursor if this handler's \l cursorShape property has been set.
 
bool event (QEvent *) override
 
QPointerEventcurrentEvent ()
 
void setActive (bool active)
 
virtual void onTargetChanged (QQuickItem *oldTarget)
 
virtual void onActiveChanged ()
 
virtual bool canGrab (QPointerEvent *event, const QEventPoint &point)
 Check whether it's OK to take an exclusive grab of the point.
 
virtual bool approveGrabTransition (QPointerEvent *event, const QEventPoint &point, QObject *proposedGrabber)
 Check this handler's rules to see if \l proposedGrabber will be allowed to take the exclusive grab.
 
void setPassiveGrab (QPointerEvent *event, const QEventPoint &point, bool grab=true)
 Acquire or give up a passive grab of the given point, according to the grab state.
 
bool setExclusiveGrab (QPointerEvent *ev, const QEventPoint &point, bool grab=true)
 Acquire or give up the exclusive grab of the given point, according to the grab state, and subject to the rules: canGrab(), and the rule not to relinquish another handler's grab.
 
void cancelAllGrabs (QPointerEvent *event, QEventPoint &point)
 Cancel any existing grab of the given point.
 
QPointF eventPos (const QEventPoint &point) const
 
bool parentContains (const QEventPoint &point) const
 Returns true if margin() > 0 and point is within the margin beyond QQuickItem::boundingRect(), or else returns QQuickItem::contains() QEventPoint::position() effectively (because parentContains(scenePosition) calls QQuickItem::mapFromScene()).
 
bool parentContains (const QPointF &scenePosition) const
 Returns true if scenePosition is within the margin() beyond QQuickItem::boundingRect() (if margin > 0), or parentItem() contains scenePosition according to QQuickItem::contains().
 
- Protected Member Functions inherited from QObject
QObjectsender () 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 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)
 

Properties

bool pressed
 
int tapCount
 
qreal timeHeld
 
qreal longPressThreshold
 
GesturePolicy gesturePolicy
 
QQuickTapHandler::ExclusiveSignals exclusiveSignals
 
- Properties inherited from QQuickSinglePointHandler
QQuickHandlerPoint point
 
- Properties inherited from QQuickPointerDeviceHandler
QInputDevice::DeviceTypes acceptedDevices
 
QPointingDevice::PointerTypes acceptedPointerTypes
 
Qt::MouseButtons acceptedButtons
 
Qt::KeyboardModifiers acceptedModifiers
 
- Properties inherited from QQuickPointerHandler
bool enabled
 
bool active
 
QQuickItemtarget
 
QQuickItemparent
 
GrabPermissions grabPermissions
 
qreal margin
 
int dragThreshold
 
- Properties inherited from QObject
QString objectName
 the name of this object
 

Additional Inherited Members

- Public Slots inherited from QQuickPointerDeviceHandler
void setAcceptedDevices (QInputDevice::DeviceTypes acceptedDevices)
 \qmlproperty flags PointerDeviceHandler::acceptedDevices
 
void setAcceptedPointerTypes (QPointingDevice::PointerTypes acceptedPointerTypes)
 \qmlproperty flags PointerDeviceHandler::acceptedPointerTypes
 
void setAcceptedButtons (Qt::MouseButtons buttons)
 
void setAcceptedModifiers (Qt::KeyboardModifiers acceptedModifiers)
 \qmlproperty flags PointerDeviceHandler::acceptedModifiers
 
- 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< QObjectDatad_ptr
 

Detailed Description

Definition at line 27 of file qquicktaphandler_p.h.

Member Enumeration Documentation

◆ ExclusiveSignal

Enumerator
NotExclusive 
SingleTap 
DoubleTap 

Definition at line 49 of file qquicktaphandler_p.h.

◆ GesturePolicy

Enumerator
DragThreshold 
WithinBounds 
ReleaseWithinBounds 
DragWithinBounds 

Definition at line 41 of file qquicktaphandler_p.h.

Constructor & Destructor Documentation

◆ QQuickTapHandler()

QQuickTapHandler::QQuickTapHandler ( QQuickItem * parent = nullptr)
explicit

\qmltype TapHandler \instantiates QQuickTapHandler \inherits SinglePointHandler \inqmlmodule QtQuick

Handler for taps and clicks.

TapHandler is a handler for taps on a touchscreen or clicks on a mouse.

Detection of a valid tap gesture depends on \l gesturePolicy. The default value is DragThreshold, which requires the press and release to be close together in both space and time. In this case, DragHandler is able to function using only a passive grab, and therefore does not interfere with event delivery to any other Items or Input Handlers. So the default gesturePolicy is useful when you want to modify behavior of an existing control or Item by adding a TapHandler with bindings and/or JavaScript callbacks.

Note that buttons (such as QPushButton) are often implemented not to care whether the press and release occur close together: if you press the button and then change your mind, you need to drag all the way off the edge of the button in order to cancel the click. For this use case, set the \l gesturePolicy to TapHandler.ReleaseWithinBounds.

import QtQuick
Rectangle {
id: button
signal clicked
property alias text: buttonLabel.text
height: Math.max(Screen.pixelDensity * 7, buttonLabel.implicitHeight * 1.2)
width: Math.max(Screen.pixelDensity * 11, buttonLabel.implicitWidth * 1.3)
radius: 3
property color dark: Qt.darker(palette.button, 1.3)
gradient: Gradient {
GradientStop { position: 0.0; color: tapHandler.pressed ? dark : palette.button }
GradientStop { position: 1.0; color: dark }
}
TapHandler {
id: tapHandler
gesturePolicy: TapHandler.ReleaseWithinBounds
onTapped: button.clicked()
}
Text {
id: buttonLabel
text: "Click Me"
color: palette.buttonText
anchors.centerIn: parent
}
}

For multi-tap gestures (double-tap, triple-tap etc.), the distance moved must not exceed QStyleHints::mouseDoubleClickDistance() with mouse and QStyleHints::touchDoubleTapDistance() with touch, and the time between taps must not exceed QStyleHints::mouseDoubleClickInterval().

See also
MouseArea, {Qt Quick Examples - Pointer Handlers}

Definition at line 56 of file qquicktaphandler.cpp.

References qApp.

Member Function Documentation

◆ doubleTapped

void QQuickTapHandler::doubleTapped ( QEventPoint eventPoint,
Qt::MouseButton  )
signal

Referenced by QQuickTreeView::QQuickTreeView(), QQuickTableViewPrivate::init(), and timerEvent().

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◆ exclusiveSignals()

QQuickTapHandler::ExclusiveSignals QQuickTapHandler::exclusiveSignals ( ) const
inline

Definition at line 71 of file qquicktaphandler_p.h.

◆ gesturePolicy()

GesturePolicy QQuickTapHandler::gesturePolicy ( ) const
inline

Definition at line 68 of file qquicktaphandler_p.h.

◆ gesturePolicyChanged

void QQuickTapHandler::gesturePolicyChanged ( )
signal

Referenced by setGesturePolicy().

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◆ handleEventPoint()

void QQuickTapHandler::handleEventPoint ( QPointerEvent * event,
QEventPoint & point )
overrideprotectedvirtual

Reimplemented from QQuickSinglePointHandler.

Definition at line 124 of file qquicktaphandler.cpp.

References QQuickPointerDeviceHandler::acceptedButtons, DragThreshold, QQuickSinglePointHandler::handleEventPoint(), QQuickDeliveryAgentPrivate::isTouchEvent(), Qt::NoButton, QQuickSinglePointHandler::point, QEventPoint::Pressed, and QEventPoint::Released.

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◆ isPressed()

bool QQuickTapHandler::isPressed ( ) const
inline

Definition at line 59 of file qquicktaphandler_p.h.

Referenced by QQuickSelectionRectanglePrivate::QQuickSelectionRectanglePrivate().

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◆ longPressed

void QQuickTapHandler::longPressed ( )
signal

Referenced by QQuickSelectionRectanglePrivate::QQuickSelectionRectanglePrivate(), and timerEvent().

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◆ longPressThreshold()

qreal QQuickTapHandler::longPressThreshold ( ) const

\qmlproperty real QtQuick::TapHandler::longPressThreshold

The time in seconds that an \l eventPoint must be pressed in order to trigger a long press gesture and emit the \l longPressed() signal, if the value is greater than 0. If the point is released before this time limit, a tap can be detected if the \l gesturePolicy constraint is satisfied. If longPressThreshold is 0, the timer is disabled and the signal will not be emitted. If longPressThreshold is set to undefined, the default value is used instead, and can be read back from this property.

The default value is QStyleHints::mousePressAndHoldInterval() converted to seconds.

Definition at line 162 of file qquicktaphandler.cpp.

◆ longPressThresholdChanged

void QQuickTapHandler::longPressThresholdChanged ( )
signal

Referenced by resetLongPressThreshold(), and setLongPressThreshold().

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◆ onGrabChanged()

void QQuickTapHandler::onGrabChanged ( QQuickPointerHandler * grabber,
QPointingDevice::GrabTransition transition,
QPointerEvent * event,
QEventPoint & point )
overrideprotectedvirtual

Notification that the grab has changed in some way which is relevant to this handler.

Since
5.15 \qmlproperty Qt::CursorShape PointerHandler::cursorShape This property holds the cursor shape that will appear whenever the mouse is hovering over the \l parent item while \l active is true.

The available cursor shapes are: \list

The default value is not set, which allows the \l {QQuickItem::cursor()}{cursor} of \l parent item to appear. This property can be reset to the same initial condition by setting it to undefined.

Note
When this property has not been set, or has been set to undefined, if you read the value it will return Qt.ArrowCursor.
See also
Qt::CursorShape, QQuickItem::cursor(), HoverHandler::cursorShape

The grabber (subject) will be the Input Handler whose state is changing, or null if the state change regards an Item. The transition (verb) tells what happened. The point (object) is the \l eventPoint that was grabbed or ungrabbed. QQuickDeliveryAgent calls this function. The Input Handler must react in whatever way is appropriate, and must emit the relevant signals (for the benefit of QML code). A subclass is allowed to override this virtual function, but must always call its parent class's implementation in addition to (usually after) whatever custom behavior it implements.

Reimplemented from QQuickSinglePointHandler.

Definition at line 453 of file qquicktaphandler.cpp.

References QPointingDevice::CancelGrabExclusive, QPointingDevice::CancelGrabPassive, QQuickSinglePointHandler::onGrabChanged(), QQuickSinglePointHandler::point, and QEventPoint::Released.

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◆ pressedChanged

void QQuickTapHandler::pressedChanged ( )
signal

Referenced by QQuickSelectionRectanglePrivate::QQuickSelectionRectanglePrivate(), QQuickTreeViewDelegate::QQuickTreeViewDelegate(), and QQuickTableViewPrivate::init().

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◆ Q_REVISION

QQuickTapHandler::Q_REVISION ( 6 ,
5  )
signal

◆ resetLongPressThreshold()

void QQuickTapHandler::resetLongPressThreshold ( )

Definition at line 181 of file qquicktaphandler.cpp.

References emit, longPressThresholdChanged(), and QGuiApplication::styleHints().

Referenced by setLongPressThreshold().

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◆ setExclusiveSignals()

void QQuickTapHandler::setExclusiveSignals ( QQuickTapHandler::ExclusiveSignals exc)

\qmlproperty enumeration QtQuick::TapHandler::exclusiveSignals

Since
6.5

Determines the exclusivity of the singleTapped() and doubleTapped() signals.

\value NotExclusive (the default) singleTapped() and doubleTapped() are emitted immediately when the user taps once or twice, respectively.

\value SingleTap singleTapped() is emitted immediately when the user taps once, and doubleTapped() is never emitted.

\value DoubleTap doubleTapped() is emitted immediately when the user taps twice, and singleTapped() is never emitted.

\value (SingleTap | DoubleTap) Both signals are delayed until QStyleHints::mouseDoubleClickInterval(), such that either singleTapped() or doubleTapped() can be emitted, but not both. But if 3 or more taps occur within mouseDoubleClickInterval, neither signal is emitted.

Note
The remaining signals such as tapped() and tapCountChanged() are always emitted immediately, regardless of this property.

Definition at line 344 of file qquicktaphandler.cpp.

References emit.

◆ setGesturePolicy()

void QQuickTapHandler::setGesturePolicy ( QQuickTapHandler::GesturePolicy gesturePolicy)

\qmlproperty enumeration QtQuick::TapHandler::gesturePolicy

The spatial constraint for a tap or long press gesture to be recognized, in addition to the constraint that the release must occur before \l longPressThreshold has elapsed. If these constraints are not satisfied, the \l tapped signal is not emitted, and \l tapCount is not incremented. If the spatial constraint is violated, \l pressed transitions immediately from true to false, regardless of the time held.

The gesturePolicy also affects grab behavior as described below.

\table \header

  • Constant
  • Description \row
  • TapHandler.DragThreshold Grab on press: passive
  • (the default value) The \l eventPoint must not move significantly. If the mouse, finger or stylus moves past the system-wide drag threshold (QStyleHints::startDragDistance), the tap gesture is canceled, even if the device or finger is still pressed. This policy can be useful whenever TapHandler needs to cooperate with other input handlers (for example \l DragHandler) or event-handling Items (for example \l {Qt Quick Controls}), because in this case TapHandler will not take the exclusive grab, but merely a \l {QPointerEvent::addPassiveGrabber()}{passive grab}. That is, DragThreshold is especially useful to augment existing behavior: it reacts to tap/click/long-press even when another item or handler is already reacting, perhaps even in a different layer of the UI. The following snippet shows one TapHandler as used in one component; but if we stack up two instances of the component, you will see the handlers in both of them react simultaneously when a press occurs over both of them, because the passive grab does not stop event propagation: \quotefromfile pointerHandlers/tapHandlerOverlappingButtons.qml \skipto Item \printuntil component Button \skipto TapHandler \printuntil } \skipuntil Text { \skipuntil } \printuntil Button \printuntil Button \printuntil }

\row

  • TapHandler.WithinBounds Grab on press: exclusive
  • If the \l eventPoint leaves the bounds of the parent Item, the tap gesture is canceled. The TapHandler will take the \l {QPointerEvent::setExclusiveGrabber}{exclusive grab} on press, but will release the grab as soon as the boundary constraint is no longer satisfied.
    TapHandler {
    id: tapHandler
    gesturePolicy: TapHandler.WithinBounds
    onTapped: tapFlash.start()
    }

\row

  • TapHandler.ReleaseWithinBounds Grab on press: exclusive
  • At the time of release (the mouse button is released or the finger is lifted), if the \l eventPoint is outside the bounds of the parent Item, a tap gesture is not recognized. This corresponds to typical behavior for button widgets: you can cancel a click by dragging outside the button, and you can also change your mind by dragging back inside the button before release. Note that it's necessary for TapHandler to take the \l {QPointerEvent::setExclusiveGrabber}{exclusive grab} on press and retain it until release in order to detect this gesture.
    TapHandler {
    id: tapHandler
    gesturePolicy: TapHandler.ReleaseWithinBounds
    onTapped: tapFlash.start()
    }

\row

  • TapHandler.DragWithinBounds Grab on press: exclusive
  • On press, TapHandler takes the \l {QPointerEvent::setExclusiveGrabber}{exclusive grab}; after that, the \l eventPoint can be dragged within the bounds of the parent item, while the \l timeHeld property keeps counting, and the \l longPressed() signal will be emitted regardless of drag distance. However, like WithinBounds, if the point leaves the bounds, the tap gesture is \l {PointerHandler::}{canceled()}, \l active() becomes false, and \l timeHeld stops counting. This is suitable for implementing press-drag-release components, such as menus, in which a single TapHandler detects press, timeHeld drives an "opening" animation, and then the user can drag to a menu item and release, while never leaving the bounds of the parent scene containing the menu. This value was added in Qt 6.3.
    TapHandler {
    id: menuPopupHandler
    gesturePolicy: TapHandler.DragWithinBounds
    onPressedChanged:
    if (pressed) {
    menu.x = point.position.x - menu.width / 2
    menu.y = point.position.y - menu.height / 2
    } else {
    feedback.text = menu.highlightedMenuItem
    selectFlash.start()
    }
    onCanceled: feedback.text = "canceled"
    }
    \endtable

The \l {Qt Quick Examples - Pointer Handlers} demonstrates some use cases for these.

Note
If you find that TapHandler is reacting in cases that conflict with some other behavior, the first thing you should try is to think about which gesturePolicy is appropriate. If you cannot fix it by changing gesturePolicy, some cases are better served by adjusting \l {PointerHandler::}{grabPermissions}, either in this handler, or in another handler that should prevent TapHandler from reacting.

Definition at line 312 of file qquicktaphandler.cpp.

References emit, gesturePolicy, and gesturePolicyChanged().

Referenced by QQuickTreeViewDelegatePrivate::updateIndicatorPointerHandlers().

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◆ setLongPressThreshold()

void QQuickTapHandler::setLongPressThreshold ( qreal longPressThreshold)

Definition at line 167 of file qquicktaphandler.cpp.

References emit, longPressThreshold, longPressThresholdChanged(), qRound(), and resetLongPressThreshold().

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◆ singleTapped

void QQuickTapHandler::singleTapped ( QEventPoint eventPoint,
Qt::MouseButton  )
signal

Referenced by QQuickTableViewPrivate::init(), and timerEvent().

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◆ tapCount()

int QQuickTapHandler::tapCount ( ) const
inline

Definition at line 61 of file qquicktaphandler_p.h.

◆ tapCountChanged

void QQuickTapHandler::tapCountChanged ( )
signal

◆ tapped

void QQuickTapHandler::tapped ( QEventPoint eventPoint,
Qt::MouseButton  )
signal

Referenced by QQuickTreeViewDelegatePrivate::updateIndicatorPointerHandlers().

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◆ timeHeld()

qreal QQuickTapHandler::timeHeld ( ) const
inline

Definition at line 62 of file qquicktaphandler_p.h.

◆ timeHeldChanged

void QQuickTapHandler::timeHeldChanged ( )
signal

◆ timerEvent()

void QQuickTapHandler::timerEvent ( QTimerEvent * event)
overrideprotectedvirtual

This event handler can be reimplemented in a subclass to receive timer events for the object.

QChronoTimer provides higher-level interfaces to the timer functionality, and also more general information about timers. The timer event is passed in the event parameter.

See also
startTimer(), killTimer(), event()

Reimplemented from QObject.

Definition at line 191 of file qquicktaphandler.cpp.

References DoubleTap, doubleTapped(), emit, longPressed(), QObject::objectName, Q_ASSERT, qCDebug, SingleTap, singleTapped(), QBasicTimer::stop(), and QBasicTimer::timerId().

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◆ wantsEventPoint()

bool QQuickTapHandler::wantsEventPoint ( const QPointerEvent * event,
const QEventPoint & point )
overrideprotectedvirtual

Returns true if the given point (as part of event) could be relevant at all to this handler, as a preliminary check.

If you override this function, you should call the immediate parent class implementation (and return false if it returns false); that in turn calls its parent class implementation, and so on.

In particular, the bounds checking is done here: the base class QQuickPointerHandler::wantsEventPoint() calls parentContains(point) (which allows the flexibility promised by margin(), QQuickItem::contains() and QQuickItem::containmentMask()). Pointer Handlers can receive QEventPoints that are outside the parent item's bounds: this allows some flexibility for dealing with multi-point gestures in which one or more fingers have strayed outside the bounds, and yet the gesture is still unambiguously intended for the target() item.

You should not generally react to the event or point here, but it's ok to set state to remember what needs to be done in your overridden handlePointerEventImpl() or QQuickSinglePointHandler::handleEventPoint().

Reimplemented from QQuickPointerHandler.

Definition at line 69 of file qquicktaphandler.cpp.

References DragThreshold, DragWithinBounds, QQuickHandlerPoint::id, QElapsedTimer::invalidate(), QBasicTimer::isActive(), QQuickDeliveryAgentPrivate::isMouseEvent(), QQuickDeliveryAgentPrivate::isTabletEvent(), QQuickDeliveryAgentPrivate::isTouchEvent(), QObject::objectName, QQuickPointerHandler::parentContains(), QQuickSinglePointHandler::point, QEventPoint::Pressed, qCDebug, QEventPoint::Released, ReleaseWithinBounds, ret, QEventPoint::Stationary, QBasicTimer::stop(), this, QEventPoint::Unknown, QEventPoint::Updated, and WithinBounds.

Referenced by QQuickTableViewTapHandler::wantsEventPoint().

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Property Documentation

◆ exclusiveSignals

QQuickTapHandler::ExclusiveSignals QQuickTapHandler::exclusiveSignals
readwrite

Definition at line 35 of file qquicktaphandler_p.h.

◆ gesturePolicy

GesturePolicy QQuickTapHandler::gesturePolicy
readwrite

Definition at line 34 of file qquicktaphandler_p.h.

Referenced by setGesturePolicy().

◆ longPressThreshold

qreal QQuickTapHandler::longPressThreshold
readwrite

Definition at line 33 of file qquicktaphandler_p.h.

Referenced by setLongPressThreshold().

◆ pressed

bool QQuickTapHandler::pressed
read

Definition at line 30 of file qquicktaphandler_p.h.

◆ tapCount

int QQuickTapHandler::tapCount
read

Definition at line 31 of file qquicktaphandler_p.h.

◆ timeHeld

qreal QQuickTapHandler::timeHeld
read

Definition at line 32 of file qquicktaphandler_p.h.


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