Qt 5.13 | Qt GUI | C++ Classes | QMouseEvent

Qt 5.13.2 Reference Documentation

# QMouseEvent Class

The QMouseEvent class contains parameters that describe a mouse event. More...

Header: | #include <QMouseEvent>
qmake: | QT += gui
Inherits: | QInputEvent

- List of all members, including inherited members
- Obsolete members

## Public Functions

| QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &windowPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::MouseEventSource source)
| QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &windowPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)
| QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)
| QMouseEvent(QEvent::Type type, const QPointF &localPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)
Qt::MouseButton | button() const
Qt::MouseButtons | buttons() const
Qt::MouseEventFlags | flags() const
QPoint | globalPos() const
int | globalX() const
int | globalY() const
const QPointF & | localPos() const
QPoint | pos() const
const QPointF & | screenPos() const
Qt::MouseEventSource | source() const
const QPointF & | windowPos() const
int | x() const
int | y() const

## Detailed Description

Mouse events occur when a mouse button is pressed or released inside a widget, or when the mouse cursor is moved.

Mouse move events will occur only when a mouse button is pressed down, unless mouse tracking has been enabled with QWidget::setMouseTracking().

Qt automatically grabs the mouse when a mouse button is pressed inside a widget; the widget will continue to receive mouse events until the last mouse button is released.

A mouse event contains a special accept flag that indicates whether the receiver wants the event. You should call ignore() if the mouse event is not handled by your widget. A mouse event is propagated up the parent widget chain until a widget accepts it with accept(), or an event filter consumes it.

Note: If a mouse event is propagated to a widget for which Qt::WA_NoMousePropagation has been set, that mouse event will not be propagated further up the parent widget chain.

The state of the keyboard modifier keys can be found by calling the modifiers() function, inherited from QInputEvent.

The functions pos(), x(), and y() give the cursor position relative to the widget that receives the mouse event. If you move the widget as a result of the mouse event, use the global position returned by globalPos() to avoid a shaking motion.

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

Reimplement the QWidget event handlers, QWidget::mousePressEvent(), QWidget::mouseReleaseEvent(), QWidget::mouseDoubleClickEvent(), and QWidget::mouseMoveEvent() to receive mouse events in your own widgets.

See also QWidget::setMouseTracking(), QWidget::grabMouse(), and QCursor::pos().

## Member Function Documentation

### QMouseEvent::QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &windowPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers, Qt::MouseEventSource source)

Constructs a mouse event object.

The type parameter must be QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseButtonDblClick, or QEvent::MouseMove.

The points localPos, windowPos and screenPos specify the mouse cursor's position relative to the receiving widget or item, window, and screen, respectively.

The button that caused the event is given as a value from the Qt::MouseButton enum. If the event type is MouseMove, the appropriate button for this event is Qt::NoButton. buttons is the state of all buttons at the time of the event, modifiers is the state of all keyboard modifiers.

The source of the event is specified by source.

This function was introduced in Qt 5.6.

### QMouseEvent::QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &windowPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)

Constructs a mouse event object.

The type parameter must be QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseButtonDblClick, or QEvent::MouseMove.

The points localPos, windowPos and screenPos specify the mouse cursor's position relative to the receiving widget or item, window, and screen, respectively.

The button that caused the event is given as a value from the Qt::MouseButton enum. If the event type is MouseMove, the appropriate button for this event is Qt::NoButton. buttons is the state of all buttons at the time of the event, modifiers the state of all keyboard modifiers.

### QMouseEvent::QMouseEvent(QEvent::Type type, const QPointF &localPos, const QPointF &screenPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)

Constructs a mouse event object.

The type parameter must be QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseButtonDblClick, or QEvent::MouseMove.

The localPos is the mouse cursor's position relative to the receiving widget or item. The cursor's position in screen coordinates is specified by screenPos. The window position is set to the same value as localPos. The button that caused the event is given as a value from the Qt::MouseButton enum. If the event type is MouseMove, the appropriate button for this event is Qt::NoButton. buttons is the state of all buttons at the time of the event, modifiers the state of all keyboard modifiers.

### QMouseEvent::QMouseEvent(QEvent::Type type, const QPointF &localPos, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)

Constructs a mouse event object.

The type parameter must be one of QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseButtonDblClick, or QEvent::MouseMove.

The localPos is the mouse cursor's position relative to the receiving widget or item. The window position is set to the same value as localPos. The button that caused the event is given as a value from the Qt::MouseButton enum. If the event type is MouseMove, the appropriate button for this event is Qt::NoButton. The mouse and keyboard states at the time of the event are specified by buttons and modifiers.

The screenPos() is initialized to QCursor::pos(), which may not be appropriate. Use the other constructor to specify the global position explicitly.

### Qt::MouseButton QMouseEvent::button() const

Returns the button that caused the event.

Note that the returned value is always Qt::NoButton for mouse move events.

See also buttons() and Qt::MouseButton.

### Qt::MouseButtons QMouseEvent::buttons() const

Returns the button state when the event was generated. The button state is a combination of Qt::LeftButton, Qt::RightButton, Qt::MidButton using the OR operator. For mouse move events, this is all buttons that are pressed down. For mouse press and double click events this includes the button that caused the event. For mouse release events this excludes the button that caused the event.

See also button() and Qt::MouseButton.

### Qt::MouseEventFlags QMouseEvent::flags() const

Returns the mouse event flags.

The mouse event flags provide additional information about a mouse event.

This function was introduced in Qt 5.3.

See also Qt::MouseEventFlag and QGraphicsSceneMouseEvent::flags().

### QPoint QMouseEvent::globalPos() const

Returns the global position of the mouse cursor at the time of the event. This is important on asynchronous window systems like X11. Whenever you move your widgets around in response to mouse events, globalPos() may differ a lot from the current pointer position QCursor::pos(), and from QWidget::mapToGlobal(pos()).

See also globalX() and globalY().

### int QMouseEvent::globalX() const

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

See also globalY() and globalPos().

### int QMouseEvent::globalY() const

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

See also globalX() and globalPos().

### const QPointF &QMouseEvent::localPos() const

Returns the position of the mouse cursor as a QPointF, relative to the widget or item that received the event.

If you move the widget as a result of the mouse event, use the screen position returned by screenPos() to avoid a shaking motion.

This function was introduced in Qt 5.0.

See also x(), y(), windowPos(), and screenPos().

### QPoint QMouseEvent::pos() const

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

If you move the widget as a result of the mouse event, use the global position returned by globalPos() to avoid a shaking motion.

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

### const QPointF &QMouseEvent::screenPos() const

Returns the position of the mouse cursor as a QPointF, relative to the screen that received the event.

This function was introduced in Qt 5.0.

See also x(), y(), pos(), localPos(), and windowPos().

### Qt::MouseEventSource QMouseEvent::source() const

Returns information about the mouse event source.

The mouse event source can be used to distinguish between genuine and artificial mouse events. The latter are events that are synthesized from touch events by the operating system or Qt itself.

Note: Many platforms provide no such information. On such platforms Qt::MouseEventNotSynthesized is returned always.

This function was introduced in Qt 5.3.

See also Qt::MouseEventSource and QGraphicsSceneMouseEvent::source().

### const QPointF &QMouseEvent::windowPos() const

Returns the position of the mouse cursor as a QPointF, relative to the window that received the event.

If you move the widget as a result of the mouse event, use the global position returned by globalPos() to avoid a shaking motion.

This function was introduced in Qt 5.0.

See also x(), y(), pos(), localPos(), and screenPos().

### int QMouseEvent::x() const

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

See also y() and pos().

### int QMouseEvent::y() const

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

See also x() and pos().