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# QWheelEvent Class Reference

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

    #include <QWheelEvent>

Inherits QInputEvent.

- List of all members, including inherited members

### Public Functions

- QWheelEvent ( const QPoint & pos, int delta, int state, Qt::Orientation orient = Qt::Vertical )
- QWheelEvent ( const QPoint & position, const QPoint & globalPos, int delta, int state, Qt::Orientation orient = Qt::Vertical )
- int delta () const
- const QPoint & globalPos () const
- int globalX () const
- int globalY () const
- Qt::Orientation orientation () const
- const QPoint & pos () const
- Qt::ButtonState state () const
- int x () const
- int y () const

- 3 public functions inherited from QInputEvent
- 2 public functions inherited from QEvent

## 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::setEnable() 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 and QWidget::grabMouse().

## Member Function Documentation

### QWheelEvent::QWheelEvent ( const QPoint & pos, int delta, int state, 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. delta contains the rotation distance, state holds the keyboard modifier flags at the time of the event, and orient holds the wheel's orientation.

See also pos(), delta(), and state().

### QWheelEvent::QWheelEvent ( const QPoint & position, const QPoint & globalPos, int delta, int state, Qt::Orientation orient = Qt::Vertical )

Constructs a wheel event object.

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

See also pos(), globalPos(), delta(), and state().

### int QWheelEvent::delta () const

Returns the distance that the wheel is rotated, given in multiples or divisions of `WHEEL_DELTA`. 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.

The `WHEEL_DELTA` constant was defined to be 120 by the wheel mouse vendors to allow finer-resolution wheels to be built in the future, such as a freely rotating wheel with no notches. The expectation is that such a device would send more messages per rotation, but with a smaller value in each message.

### const QPoint & QWheelEvent::globalPos () const

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().

See also globalX() and globalY().

### int QWheelEvent::globalX () const

Returns the global x position of the mouse cursor at the time of the event.

See also globalY() and globalPos().

### int QWheelEvent::globalY () const

Returns the global y position of the mouse cursor at the time of the event.

See also globalX() and globalPos().

### Qt::Orientation QWheelEvent::orientation () const

Returns the wheel's orientation.

### const QPoint & QWheelEvent::pos () const

Returns the position of the mouse cursor relative to the widget that received the event.

If you move your widgets around in response to mouse events, use globalPos() instead of this function.

See also x(), y(), and globalPos().

### Qt::ButtonState QWheelEvent::state () const

Returns the keyboard modifier flags at the time of the event.

The returned value is a selection of the following values, combined using the OR operator: `Qt::ShiftButton`, `Qt::ControlButton`, and `Qt::AltButton`.

### int QWheelEvent::x () const

Returns the x position of the mouse cursor, relative to the widget that received the event.

See also y() and pos().

### int QWheelEvent::y () const

Returns the y position of the mouse cursor, relative to the widget that received the event.

See also x() and pos().