#include <qquickwheelhandler_p.h>

Inheritance diagram for QQuickWheelHandler:

Collaboration diagram for QQuickWheelHandler:

Signals
void	wheel (QQuickWheelEvent *event)
void	orientationChanged ()
void	invertibleChanged ()
void	activeTimeoutChanged ()
void	rotationChanged ()
void	rotationScaleChanged ()
void	propertyChanged ()
void	targetScaleMultiplierChanged ()
void	targetTransformAroundCursorChanged ()
	Q_REVISION (6, 3) void blockingChanged()
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
	QQuickWheelHandler (QQuickItem *parent=nullptr)
	\qmltype WheelHandler \nativetype QQuickWheelHandler \inherits SinglePointHandler \inqmlmodule QtQuick
Qt::Orientation	orientation () const
	\qmlproperty enumeration QtQuick::WheelHandler::orientation
void	setOrientation (Qt::Orientation orientation)
bool	isInvertible () const
	\qmlproperty bool QtQuick::WheelHandler::invertible
void	setInvertible (bool invertible)
qreal	activeTimeout () const
	\qmlproperty real QtQuick::WheelHandler::activeTimeout
void	setActiveTimeout (qreal timeout)
qreal	rotation () const
	\qmlproperty real QtQuick::WheelHandler::rotation
void	setRotation (qreal rotation)
qreal	rotationScale () const
	\qmlproperty real QtQuick::WheelHandler::rotationScale
void	setRotationScale (qreal rotationScale)
QString	property () const
	\qmlproperty string QtQuick::WheelHandler::property
void	setProperty (const QString &name)
qreal	targetScaleMultiplier () const
	\qmlproperty real QtQuick::WheelHandler::targetScaleMultiplier
void	setTargetScaleMultiplier (qreal targetScaleMultiplier)
bool	isTargetTransformAroundCursor () const
	\qmlproperty bool QtQuick::WheelHandler::targetTransformAroundCursor
void	setTargetTransformAroundCursor (bool ttac)
bool	isBlocking () const
	\qmlproperty bool QtQuick::WheelHandler::blocking
void	setBlocking (bool blocking)
Public Member Functions inherited from QQuickSinglePointHandler
	QQuickSinglePointHandler (QQuickItem *parent=nullptr)
	\qmltype SinglePointHandler \qmlabstract \preliminary \nativetype 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
QQuickItem *	target () const
	\qmlproperty Item QtQuick::PointerHandler::target
void	setTarget (QQuickItem *target)
QQuickItem *	parentItem () 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< 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	isQmlObjectType () const
	Returns whether the object has been created by the QML engine or ownership has been explicitly set via QJSEngine::setObjectOwnership().
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`.
Public Member Functions inherited from QQmlParserStatus
	QQmlParserStatus ()
virtual	~QQmlParserStatus ()

Protected Member Functions
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	handleEventPoint (QPointerEvent *event, QEventPoint &point) override
void	onTargetChanged (QQuickItem *oldTarget) override
void	onActiveChanged () override
void	timerEvent (QTimerEvent *event) override
	This event handler can be reimplemented in a subclass to receive timer events for the object.
Protected Member Functions inherited from QQuickSinglePointHandler
	QQuickSinglePointHandler (QQuickSinglePointHandlerPrivate &dd, QQuickItem *parent)
void	handlePointerEventImpl (QPointerEvent *event) override
	This function can be overridden to implement whatever behavior a specific subclass is intended to have: \list.
QEventPoint &	currentPoint (QPointerEvent *ev)
void	onGrabChanged (QQuickPointerHandler grabber, QPointingDevice::GrabTransition transition, QPointerEvent event, QEventPoint &point) override
	Notification that the grab has changed in some way which is relevant to this handler.
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, and that this handler is added to the parent item.
bool	event (QEvent *) override
QPointerEvent *	currentEvent ()
virtual bool	wantsEventPoint (const QPointerEvent *event, const QEventPoint &point)
	Returns `true` if the given point (as part of event) could be relevant at all to this handler, as a preliminary check.
void	setActive (bool active)
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
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	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
Qt::Orientation	orientation
bool	invertible
qreal	activeTimeout
qreal	rotation
qreal	rotationScale
QString	property
qreal	targetScaleMultiplier
bool	targetTransformAroundCursor
bool	blocking
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
QQuickItem *	target
QQuickItem *	parent
GrabPermissions	grabPermissions
qreal	margin
int	dragThreshold
Properties inherited from QObject
QString	objectName
	the name of this object

Additional Inherited Members
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 }
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< QObjectData >	d_ptr
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

Definition at line 29 of file qquickwheelhandler_p.h.

Constructor & Destructor Documentation

◆ QQuickWheelHandler()

QT_BEGIN_NAMESPACE QQuickWheelHandler::QQuickWheelHandler ( QQuickItem * parent = nullptr )

explicit

\qmltype WheelHandler \nativetype QQuickWheelHandler \inherits SinglePointHandler \inqmlmodule QtQuick

Handler for the mouse wheel.

WheelHandler is a handler that is used to interactively manipulate some numeric property of an Item as the user rotates the mouse wheel. Like other Input Handlers, by default it manipulates its \l {PointerHandler::target} {target}. Declare \l property to control which target property will be manipulated:

import QtQuick
 
Rectangle {
    width: 170; height: 120
    color: "green"; antialiasing: true
 
    WheelHandler {
        property: "rotation"
        onWheel: (event)=> console.log("rotation", event.angleDelta.y,
                                       "scaled", rotation, "@", point.position,
                                       "=>", parent.rotation)
    }
}

\l BoundaryRule is quite useful in combination with WheelHandler (as well as with other Input Handlers) to declare the allowed range of values that the target property can have. For example it is possible to implement scrolling using a combination of WheelHandler and \l DragHandler to manipulate the scrollable Item's \l{QQuickItem::y}{y} property when the user rotates the wheel or drags the item on a touchscreen, and \l BoundaryRule to limit the range of motion from the top to the bottom:

import QtQuick
import Qt.labs.animation
 
Item {
    width: 320; height: 480
    Flow {
        id: content
        width: parent.width
        spacing: 2; padding: 2
 
        WheelHandler {
            orientation: Qt.Vertical
            property: "y"
            rotationScale: 15
            acceptedDevices: PointerDevice.Mouse | PointerDevice.TouchPad
            onActiveChanged: if (!active) ybr.returnToBounds()
        }
 
        DragHandler {
            xAxis.enabled: false
            onActiveChanged: if (!active) ybr.returnToBounds()
        }
 
        BoundaryRule on y {
            id: ybr
            minimum: content.parent.height - content.height
            maximum: 0
            minimumOvershoot: 400; maximumOvershoot: 400
            overshootFilter: BoundaryRule.Peak
        }
 
        Repeater {
            model: 1000
            Rectangle { color: "gray"; width: 10 + Math.random() * 100; height: 15 }
        }
    }
}

Alternatively, if \l property is not set or \l target is null, WheelHandler will not automatically manipulate anything; but the \l rotation property can be used in a binding to manipulate another property, or you can implement onWheel and handle the wheel event directly.

WheelHandler handles only a rotating mouse wheel by default; this can be changed by setting acceptedDevices.

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

Definition at line 53 of file qquickwheelhandler.cpp.

Member Function Documentation

◆ activeTimeout()

qreal QQuickWheelHandler::activeTimeout ( ) const

\qmlproperty real QtQuick::WheelHandler::activeTimeout

The amount of time in seconds after which the \l active property will revert to false if no more wheel events are received. The default is 0.1 (100 ms).

When WheelHandler handles events that contain \l {Qt::ScrollPhase}{scroll phase} information, such as events from some touchpads, the \l active property will become false as soon as an event with phase \l Qt::ScrollEnd is received; in that case the timeout is not necessary. But a conventional mouse with a wheel does not provide a scroll phase: the mouse cannot detect when the user has decided to stop scrolling, so the \l active property transitions to false after this much time has elapsed.

See also: QWheelEvent::phase()

Definition at line 131 of file qquickwheelhandler.cpp.

◆ activeTimeoutChanged

void QQuickWheelHandler::activeTimeoutChanged ( )

signal

◆ handleEventPoint()

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

overrideprotectedvirtual

Reimplemented from QQuickSinglePointHandler.

Definition at line 376 of file qquickwheelhandler.cpp.

◆ invertibleChanged

void QQuickWheelHandler::invertibleChanged ( )

signal

◆ isBlocking()

bool QQuickWheelHandler::isBlocking ( ) const

\qmlproperty bool QtQuick::WheelHandler::blocking

Since: 6.3

Whether this handler prevents other items or handlers behind it from handling the same wheel event. This property is true by default.

Definition at line 330 of file qquickwheelhandler.cpp.

◆ isInvertible()

bool QQuickWheelHandler::isInvertible ( ) const

\qmlproperty bool QtQuick::WheelHandler::invertible

Whether or not to reverse the direction of property change if \l QWheelEvent::inverted is true. The default is true.

If the operating system has a "natural scrolling" setting that causes scrolling to be in the same direction as the finger movement, then if this property is set to true, and WheelHandler is directly setting a property on \l target, the direction of movement will correspond to the system setting. If this property is set to false, it will invert the \l rotation so that the direction of motion is always the same as the direction of finger movement.

Definition at line 97 of file qquickwheelhandler.cpp.

◆ isTargetTransformAroundCursor()

bool QQuickWheelHandler::isTargetTransformAroundCursor ( ) const

\qmlproperty bool QtQuick::WheelHandler::targetTransformAroundCursor

Whether the \l target should automatically be repositioned in such a way that it is transformed around the mouse cursor position while the \l property is adjusted. The default is true.

If \l property is set to "rotation" and \l targetTransformAroundCursor is true, then as the wheel is rotated, the \l target item will rotate in place around the mouse cursor position. If targetTransformAroundCursor is false, it will rotate around its \l{QQuickItem::transformOrigin}{transformOrigin} instead.

Definition at line 307 of file qquickwheelhandler.cpp.

◆ onActiveChanged()

void QQuickWheelHandler::onActiveChanged ( )

overrideprotectedvirtual

Reimplemented from QQuickPointerHandler.

Definition at line 478 of file qquickwheelhandler.cpp.

◆ onTargetChanged()

void QQuickWheelHandler::onTargetChanged ( QQuickItem * oldTarget )

overrideprotectedvirtual

Reimplemented from QQuickPointerHandler.

Definition at line 471 of file qquickwheelhandler.cpp.

◆ orientation()

Qt::Orientation QQuickWheelHandler::orientation ( ) const

\qmlproperty enumeration QtQuick::WheelHandler::orientation

Which wheel to react to. The default is Qt.Vertical.

Not every mouse has a Horizontal wheel; sometimes it is emulated by tilting the wheel sideways. A touchpad can usually generate both vertical and horizontal wheel events.

Definition at line 68 of file qquickwheelhandler.cpp.

◆ orientationChanged

void QQuickWheelHandler::orientationChanged ( )

signal

◆ property()

QString QQuickWheelHandler::property ( ) const

\qmlproperty string QtQuick::WheelHandler::property

The property to be modified on the \l target when the mouse wheel is rotated.

The default is no property (empty string). When no target property is being automatically modified, you can use bindings to react to mouse wheel rotation in arbitrary ways.

You can use the mouse wheel to adjust any numeric property. For example if property is set to x, the \l target will move horizontally as the wheel is rotated. The following properties have special behavior:

\value scale \l{QQuickItem::scale}{scale} will be modified in a non-linear fashion as described under \l targetScaleMultiplier. If \l targetTransformAroundCursor is true, the \l{QQuickItem::x}{x} and \l{QQuickItem::y}{y} properties will be simultaneously adjusted so that the user will effectively zoom into or out of the point under the mouse cursor. \value rotation \l{QQuickItem::rotation}{rotation} will be set to \l rotation. If \l targetTransformAroundCursor is true, the l{QQuickItem::x}{x} and \l{QQuickItem::y}{y} properties will be simultaneously adjusted so that the user will effectively rotate the item around the point under the mouse cursor.

The adjustment of the given target property is always scaled by \l rotationScale.

Definition at line 243 of file qquickwheelhandler.cpp.

◆ propertyChanged

void QQuickWheelHandler::propertyChanged ( )

signal

◆ Q_REVISION

QQuickWheelHandler::Q_REVISION	(	6	,
		3	)

signal

◆ rotation()

qreal QQuickWheelHandler::rotation ( ) const

\qmlproperty real QtQuick::WheelHandler::rotation

The angle through which the mouse wheel has been rotated since the last time this property was set, in wheel degrees.

A positive value indicates that the wheel was rotated up/right; a negative value indicates that the wheel was rotated down/left.

A basic mouse click-wheel works in steps of 15 degrees.

The default is 0 at startup. It can be programmatically set to any value at any time. The value will be adjusted from there as the user rotates the mouse wheel.

See also: orientation

Definition at line 169 of file qquickwheelhandler.cpp.

◆ rotationChanged

void QQuickWheelHandler::rotationChanged ( )

signal

◆ rotationScale()

qreal QQuickWheelHandler::rotationScale ( ) const

\qmlproperty real QtQuick::WheelHandler::rotationScale

The scaling to be applied to the \l rotation property, and to the \l property on the \l target item, if any. The default is 1, such that \l rotation will be in units of degrees of rotation. It can be set to a negative number to invert the effect of the direction of mouse wheel rotation.

Definition at line 194 of file qquickwheelhandler.cpp.

◆ rotationScaleChanged

void QQuickWheelHandler::rotationScaleChanged ( )

signal

◆ setActiveTimeout()

void QQuickWheelHandler::setActiveTimeout ( qreal timeout )

Definition at line 137 of file qquickwheelhandler.cpp.

◆ setBlocking()

void QQuickWheelHandler::setBlocking ( bool blocking )

Definition at line 336 of file qquickwheelhandler.cpp.

◆ setInvertible()

void QQuickWheelHandler::setInvertible ( bool invertible )

Definition at line 103 of file qquickwheelhandler.cpp.

◆ setOrientation()

void QQuickWheelHandler::setOrientation ( Qt::Orientation orientation )

Definition at line 74 of file qquickwheelhandler.cpp.

◆ setProperty()

void QQuickWheelHandler::setProperty ( const QString & name )

Definition at line 249 of file qquickwheelhandler.cpp.

◆ setRotation()

void QQuickWheelHandler::setRotation ( qreal rotation )

Definition at line 175 of file qquickwheelhandler.cpp.

◆ setRotationScale()

void QQuickWheelHandler::setRotationScale ( qreal rotationScale )

Definition at line 200 of file qquickwheelhandler.cpp.

◆ setTargetScaleMultiplier()

void QQuickWheelHandler::setTargetScaleMultiplier ( qreal targetScaleMultiplier )

Definition at line 284 of file qquickwheelhandler.cpp.

◆ setTargetTransformAroundCursor()

void QQuickWheelHandler::setTargetTransformAroundCursor ( bool ttac )

Definition at line 313 of file qquickwheelhandler.cpp.

◆ targetScaleMultiplier()

qreal QQuickWheelHandler::targetScaleMultiplier ( ) const

\qmlproperty real QtQuick::WheelHandler::targetScaleMultiplier

The amount by which the \l target \l{QQuickItem::scale}{scale} is to be multiplied whenever the \l rotation changes by 15 degrees. This is relevant only when \l property is "scale".

The scale will be multiplied by targetScaleMultiplier \sup {angleDelta * rotationScale / 15}. The default is 2 \sup {1/3}, which means that if \l rotationScale is left at its default value, and the mouse wheel is rotated by one "click" (15 degrees), the \l target will be scaled by approximately 1.25; after three "clicks" its size will be doubled or halved, depending on the direction that the wheel is rotated. If you want to make it double or halve with every 2 clicks of the wheel, set this to 2 \sup {1/2} (1.4142). If you want to make it scale the opposite way as the wheel is rotated, set rotationScale to a negative value.

Definition at line 278 of file qquickwheelhandler.cpp.

◆ targetScaleMultiplierChanged

void QQuickWheelHandler::targetScaleMultiplierChanged ( )

signal

◆ targetTransformAroundCursorChanged

void QQuickWheelHandler::targetTransformAroundCursorChanged ( )

signal

◆ timerEvent()

void QQuickWheelHandler::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 485 of file qquickwheelhandler.cpp.

◆ wantsPointerEvent()

bool QQuickWheelHandler::wantsPointerEvent ( QPointerEvent * event )

overrideprotectedvirtual

It is the responsibility of this function to decide whether the event could be relevant at all to this handler, as a preliminary check.

Returns true if this handler would like handlePointerEventImpl() to be called. If it returns false, the handler will be deactivated: setActive(false) will be called, and any remaining exclusive grab will be relinquished, as a fail-safe.

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. QQuickSinglePointHandler::wantsPointerEvent() and QQuickMultiPointHandler::wantsPointerEvent() call wantsEventPoint(), which is also virtual. You usually can get the behavior you want by subclassing the appropriate handler type, overriding QQuickSinglePointHandler::handleEventPoint() or handlePointerEventImpl(), and perhaps overriding wantsEventPoint() if needed.

See also: wantsEventPoint(), QQuickPointerDeviceHandler::wantsPointerEvent(), QQuickMultiPointHandler::wantsPointerEvent(), QQuickSinglePointHandler::wantsPointerEvent()

Reimplemented from QQuickSinglePointHandler.

Definition at line 346 of file qquickwheelhandler.cpp.

◆ wheel

void QQuickWheelHandler::wheel ( QQuickWheelEvent * event )

signal

Property Documentation

◆ activeTimeout

qreal QQuickWheelHandler::activeTimeout

readwrite

Definition at line 34 of file qquickwheelhandler_p.h.

◆ blocking

bool QQuickWheelHandler::blocking

readwrite

Definition at line 40 of file qquickwheelhandler_p.h.

◆ invertible

bool QQuickWheelHandler::invertible

readwrite

Definition at line 33 of file qquickwheelhandler_p.h.

◆ orientation

Qt::Orientation QQuickWheelHandler::orientation

readwrite

Definition at line 32 of file qquickwheelhandler_p.h.

◆ property

QString QQuickWheelHandler::property

readwrite

Definition at line 37 of file qquickwheelhandler_p.h.

◆ rotation

qreal QQuickWheelHandler::rotation

readwrite

Definition at line 35 of file qquickwheelhandler_p.h.

◆ rotationScale

qreal QQuickWheelHandler::rotationScale

readwrite

Definition at line 36 of file qquickwheelhandler_p.h.

◆ targetScaleMultiplier

qreal QQuickWheelHandler::targetScaleMultiplier

readwrite

Definition at line 38 of file qquickwheelhandler_p.h.

◆ targetTransformAroundCursor

bool QQuickWheelHandler::targetTransformAroundCursor

readwrite

Definition at line 39 of file qquickwheelhandler_p.h.

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

qtdeclarative/src/quick/handlers/qquickwheelhandler_p.h (01cd43d30e3ca2c4dd94a4a4711604adb9417517)
qtdeclarative/src/quick/handlers/qquickwheelhandler.cpp (01cd43d30e3ca2c4dd94a4a4711604adb9417517)

Signals

Public Member Functions

Protected Member Functions

Properties

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QQuickWheelHandler()

Member Function Documentation

◆ activeTimeout()

◆ activeTimeoutChanged

◆ handleEventPoint()

◆ invertibleChanged

◆ isBlocking()

◆ isInvertible()

◆ isTargetTransformAroundCursor()

◆ onActiveChanged()

◆ onTargetChanged()

◆ orientation()

◆ orientationChanged

◆ property()

◆ propertyChanged

◆ Q_REVISION

◆ rotation()

◆ rotationChanged

◆ rotationScale()

◆ rotationScaleChanged

◆ setActiveTimeout()

◆ setBlocking()

◆ setInvertible()

◆ setOrientation()

◆ setProperty()

◆ setRotation()

◆ setRotationScale()

◆ setTargetScaleMultiplier()

◆ setTargetTransformAroundCursor()

◆ targetScaleMultiplier()

◆ targetScaleMultiplierChanged

◆ targetTransformAroundCursorChanged

◆ timerEvent()

◆ wantsPointerEvent()

◆ wheel

Property Documentation

◆ activeTimeout

◆ blocking

◆ invertible

◆ orientation

◆ property

◆ rotation

◆ rotationScale

◆ targetScaleMultiplier

◆ targetTransformAroundCursor