The QWheelEvent class contains parameters that describe a wheel event. More...

#include <qevent.h>

Inheritance diagram for QWheelEvent:

Public Functions
Qt::MouseButtons	buttons () const
	Returns the mouse state when the event occurred. More...

int	delta () const
	Returns the distance that the wheel is rotated, in eighths of a degree. More...

const QPoint &	globalPos () const
	Returns the global position of the mouse pointer at the time of the event. More...

int	globalX () const
	Returns the global x position of the mouse cursor at the time of the event. More...

int	globalY () const
	Returns the global y position of the mouse cursor at the time of the event. More...

Qt::Orientation	orientation () const
	Returns the wheel's orientation. More...

const QPoint &	pos () const
	Returns the position of the mouse cursor relative to the widget that received the event. More...

	QWheelEvent (const QPoint &pos, int delta, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::Orientation orient=Qt::Vertical)
	Constructs a wheel event object. More...

	QWheelEvent (const QPoint &pos, const QPoint &globalPos, int delta, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::Orientation orient=Qt::Vertical)
	Constructs a wheel event object. More...

int	x () const
	Returns the x position of the mouse cursor, relative to the widget that received the event. More...

int	y () const
	Returns the y position of the mouse cursor, relative to the widget that received the event. More...

	~QWheelEvent ()

Public Functions inherited from QInputEvent
Qt::KeyboardModifiers	modifiers () const
	Returns the keyboard modifier flags that existed immediately before the event occurred. More...

	QInputEvent (Type type, Qt::KeyboardModifiers modifiers=Qt::NoModifier)

void	setModifiers (Qt::KeyboardModifiers amodifiers)
	Sets the keyboard modifiers flags for this event. More...

	~QInputEvent ()

Public Functions inherited from QEvent
void	accept ()
	Sets the accept flag of the event object, the equivalent of calling setAccepted(true). More...

void	ignore ()
	Clears the accept flag parameter of the event object, the equivalent of calling setAccepted(false). More...

bool	isAccepted () const

	QEvent (Type type)
	Contructs an event object of type type. More...

void	setAccepted (bool accepted)

bool	spontaneous () const
	Returns true if the event originated outside the application (a system event); otherwise returns false. More...

Type	type () const
	Returns the event type. More...

virtual	~QEvent ()
	Destroys the event. More...

Protected Variables
int	d

QPoint	g

Qt::MouseButtons	mouseState

Qt::Orientation	o

QPoint	p

Protected Variables inherited from QInputEvent
Qt::KeyboardModifiers	modState

Protected Variables inherited from QEvent
QEventPrivate *	d

ushort	t

Additional Inherited Members
Public Types inherited from QEvent
enum	Type { None = 0, Timer = 1, MouseButtonPress = 2, MouseButtonRelease = 3, MouseButtonDblClick = 4, MouseMove = 5, KeyPress = 6, KeyRelease = 7, FocusIn = 8, FocusOut = 9, Enter = 10, Leave = 11, Paint = 12, Move = 13, Resize = 14, Create = 15, Destroy = 16, Show = 17, Hide = 18, Close = 19, Quit = 20, ParentChange = 21, ParentAboutToChange = 131, ThreadChange = 22, WindowActivate = 24, WindowDeactivate = 25, ShowToParent = 26, HideToParent = 27, Wheel = 31, WindowTitleChange = 33, WindowIconChange = 34, ApplicationWindowIconChange = 35, ApplicationFontChange = 36, ApplicationLayoutDirectionChange = 37, ApplicationPaletteChange = 38, PaletteChange = 39, Clipboard = 40, Speech = 42, MetaCall = 43, SockAct = 50, WinEventAct = 132, DeferredDelete = 52, DragEnter = 60, DragMove = 61, DragLeave = 62, Drop = 63, DragResponse = 64, ChildAdded = 68, ChildPolished = 69, ChildRemoved = 71, ShowWindowRequest = 73, PolishRequest = 74, Polish = 75, LayoutRequest = 76, UpdateRequest = 77, UpdateLater = 78, EmbeddingControl = 79, ActivateControl = 80, DeactivateControl = 81, ContextMenu = 82, InputMethod = 83, AccessibilityPrepare = 86, TabletMove = 87, LocaleChange = 88, LanguageChange = 89, LayoutDirectionChange = 90, Style = 91, TabletPress = 92, TabletRelease = 93, OkRequest = 94, HelpRequest = 95, IconDrag = 96, FontChange = 97, EnabledChange = 98, ActivationChange = 99, StyleChange = 100, IconTextChange = 101, ModifiedChange = 102, MouseTrackingChange = 109, WindowBlocked = 103, WindowUnblocked = 104, WindowStateChange = 105, ToolTip = 110, WhatsThis = 111, StatusTip = 112, ActionChanged = 113, ActionAdded = 114, ActionRemoved = 115, FileOpen = 116, Shortcut = 117, ShortcutOverride = 51, WhatsThisClicked = 118, ToolBarChange = 120, ApplicationActivate = 121, ApplicationActivated = ApplicationActivate, ApplicationDeactivate = 122, ApplicationDeactivated = ApplicationDeactivate, QueryWhatsThis = 123, EnterWhatsThisMode = 124, LeaveWhatsThisMode = 125, ZOrderChange = 126, HoverEnter = 127, HoverLeave = 128, HoverMove = 129, AccessibilityHelp = 119, AccessibilityDescription = 130, AcceptDropsChange = 152, MenubarUpdated = 153, ZeroTimerEvent = 154, GraphicsSceneMouseMove = 155, GraphicsSceneMousePress = 156, GraphicsSceneMouseRelease = 157, GraphicsSceneMouseDoubleClick = 158, GraphicsSceneContextMenu = 159, GraphicsSceneHoverEnter = 160, GraphicsSceneHoverMove = 161, GraphicsSceneHoverLeave = 162, GraphicsSceneHelp = 163, GraphicsSceneDragEnter = 164, GraphicsSceneDragMove = 165, GraphicsSceneDragLeave = 166, GraphicsSceneDrop = 167, GraphicsSceneWheel = 168, KeyboardLayoutChange = 169, DynamicPropertyChange = 170, TabletEnterProximity = 171, TabletLeaveProximity = 172, NonClientAreaMouseMove = 173, NonClientAreaMouseButtonPress = 174, NonClientAreaMouseButtonRelease = 175, NonClientAreaMouseButtonDblClick = 176, MacSizeChange = 177, ContentsRectChange = 178, MacGLWindowChange = 179, FutureCallOut = 180, GraphicsSceneResize = 181, GraphicsSceneMove = 182, CursorChange = 183, ToolTipChange = 184, NetworkReplyUpdated = 185, GrabMouse = 186, UngrabMouse = 187, GrabKeyboard = 188, UngrabKeyboard = 189, MacGLClearDrawable = 191, StateMachineSignal = 192, StateMachineWrapped = 193, TouchBegin = 194, TouchUpdate = 195, TouchEnd = 196, NativeGesture = 197, RequestSoftwareInputPanel = 199, CloseSoftwareInputPanel = 200, UpdateSoftKeys = 201, WinIdChange = 203, Gesture = 198, GestureOverride = 202, PlatformPanel = 212, User = 1000, MaxUser = 65535 }
	This enum type defines the valid event types in Qt. More...

Static Public Functions inherited from QEvent
static int	registerEventType (int hint=-1)
	Registers and returns a custom event type. More...

Detailed Description

The QWheelEvent class contains parameters that describe a wheel event.

Wheel events are sent to the widget under the mouse cursor, but if that widget does not handle the event they are sent to the focus widget. The rotation distance is provided by delta(). The functions pos() and globalPos() return the mouse cursor's location at the time of the event.

A wheel event contains a special accept flag that indicates whether the receiver wants the event. You should call ignore() if you do not handle the wheel event; this ensures that it will be sent to the parent widget.

The QWidget::setEnabled() function can be used to enable or disable mouse and keyboard events for a widget.

The event handler QWidget::wheelEvent() receives wheel events.

See also: QMouseEvent QWidget::grabMouse()

Definition at line 139 of file qevent.h.

Constructors and Destructors

◆ QWheelEvent() [1/2]

QWheelEvent::QWheelEvent	(	const QPoint &	pos,
		int	delta,
		Qt::MouseButtons	buttons,
		Qt::KeyboardModifiers	modifiers,
		Qt::Orientation	orient = `Qt::Vertical`
	)

Constructs a wheel event object.

The position, pos, is the location of the mouse cursor within the widget. The globalPos() is initialized to QCursor::pos() which is usually, but not always, correct. Use the other constructor if you need to specify the global position explicitly.

The buttons describe the state of the mouse buttons at the time of the event, delta contains the rotation distance, modifiers holds the keyboard modifier flags at the time of the event, and orient holds the wheel's orientation.

See also: pos() delta() state()

Definition at line 607 of file qevent.cpp.

Referenced by QWheelEvent(), and ~QWheelEvent().

     : QInputEvent(Wheel, modifiers), p(pos), d(delta), mouseState(buttons), o(orient)
 {
     g = QCursor::pos();
 }

◆ QWheelEvent() [2/2]

QWheelEvent::QWheelEvent	(	const QPoint &	pos,
		const QPoint &	globalPos,
		int	delta,
		Qt::MouseButtons	buttons,
		Qt::KeyboardModifiers	modifiers,
		Qt::Orientation	orient = `Qt::Vertical`
	)

Constructs a wheel event object.

The pos provides the location of the mouse cursor within the widget. The position in global coordinates is specified by globalPos. delta contains the rotation distance, modifiers holds the keyboard modifier flags at the time of the event, and orient holds the wheel's orientation.

See also: pos() globalPos() delta() state()

Definition at line 646 of file qevent.cpp.

649 : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), d(delta), mouseState(buttons), o(orient)

650 {}

QWheelEvent::d

int d

Definition: qevent.h:172

QWheelEvent::mouseState

Qt::MouseButtons mouseState

Definition: qevent.h:173

QEvent::Wheel

Definition: qcoreevent.h:100

QWheelEvent::o

Qt::Orientation o

Definition: qevent.h:174

QWheelEvent::p

QPoint p

Definition: qevent.h:170

QWheelEvent::delta

int delta() const

Returns the distance that the wheel is rotated, in eighths of a degree.

Definition: qevent.h:150

QWheelEvent::buttons

Qt::MouseButtons buttons() const

Returns the mouse state when the event occurred.

Definition: qevent.h:158

QInputEvent::QInputEvent

QInputEvent(Type type, Qt::KeyboardModifiers modifiers=Qt::NoModifier)

Definition: qevent.cpp:77

QInputEvent::modifiers

Qt::KeyboardModifiers modifiers() const

Returns the keyboard modifier flags that existed immediately before the event occurred.

Definition: qevent.h:79

QWheelEvent::g

QPoint g

Definition: qevent.h:171

◆ ~QWheelEvent()

QWheelEvent::~QWheelEvent ( )

Warning: This function is not part of the public interface.

Definition at line 618 of file qevent.cpp.

619 {

620 }

Functions

◆ buttons()

Qt::MouseButtons QWheelEvent::buttons ( ) const

inline

Returns the mouse state when the event occurred.

Definition at line 158 of file qevent.h.

Referenced by QApplication::notify(), and QGraphicsView::wheelEvent().

158 { return mouseState; }

QWheelEvent::mouseState

Qt::MouseButtons mouseState

Definition: qevent.h:173

◆ delta()

int QWheelEvent::delta ( ) const

inline

Returns the distance that the wheel is rotated, in eighths of a degree.

A positive value indicates that the wheel was rotated forwards away from the user; a negative value indicates that the wheel was rotated backwards toward the user.

Most mouse types work in steps of 15 degrees, in which case the delta value is a multiple of 120; i.e., 120 units * 1/8 = 15 degrees.

However, some mice have finer-resolution wheels and send delta values that are less than 120 units (less than 15 degrees). To support this possibility, you can either cumulatively add the delta values from events until the value of 120 is reached, then scroll the widget, or you can partially scroll the widget in response to each wheel event.

Example:

void MyWidget::wheelEvent(QWheelEvent *event)
{
    int numDegrees = event->delta() / 8;
    int numSteps = numDegrees / 15;
    if (event->orientation() == Qt::Horizontal) {
        scrollHorizontally(numSteps);
    } else {
        scrollVertically(numSteps);
    }
    event->accept();
}

Definition at line 150 of file qevent.h.

Referenced by QScrollBar::event(), QApplication::notify(), QTriangulator< T >::ComplexToSimple::Event::operator<(), QWheelEvent(), QmlJSDebugger::ZoomTool::wheelEvent(), QmlJSDebugger::LiveSelectionTool::wheelEvent(), QAbstractSlider::wheelEvent(), QMenu::wheelEvent(), QComboBox::wheelEvent(), QGraphicsView::wheelEvent(), QTextEdit::wheelEvent(), and ~QWheelEvent().

150 { return d; }

QWheelEvent::d

int d

Definition: qevent.h:172

◆ globalPos()

const QPoint & QWheelEvent::globalPos ( ) const

inline

Returns the global position of the mouse pointer at the time of the event.

This is important on asynchronous window systems such as X11; whenever you move your widgets around in response to mouse events, globalPos() can differ a lot from the current cursor position returned by QCursor::pos().