QHoverEvent Class | Qt GUI | Qt 6.12.0
Description: The QHoverEvent class contains parameters that describe a mouse event.
Keywords: class

- Qt 6.12
- Qt GUI
- C++ Classes
- QHoverEvent
- Qt 6.12.0 Reference Documentation

# QHoverEvent Class

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

Header: | `#include <QHoverEvent>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS Gui)` `target_link_libraries(mytarget PRIVATE Qt6::Gui)`
qmake: | `QT += gui`
Inherits: | QSinglePointEvent

- List of all members, including inherited members
- Deprecated members
- QHoverEvent is part of Event Classes.

## Public Functions

| QHoverEvent(QEvent::Type type, const QPointF &scenePos, const QPointF &globalPos, const QPointF &oldPos, Qt::KeyboardModifiers modifiers = Qt::NoModifier, const QPointingDevice *device = QPointingDevice::primaryPointingDevice())
QPoint | oldPos() const
QPointF | oldPosF() const

## Protected Functions

| QHoverEvent(QHoverEvent &&)
QHoverEvent & | operator=(QHoverEvent &&)
QHoverEvent & | operator=(const QHoverEvent &other)

## Detailed Description

Mouse events occur when a mouse cursor is moved into, out of, or within a widget, and if the widget has the Qt::WA_Hover attribute.

The function position() gives the current cursor position, while oldPos() gives the old mouse position.

There are a few similarities between the events QEvent::HoverEnter and QEvent::HoverLeave, and the events QEvent::Enter and QEvent::Leave. However, they are slightly different because we do an update() in the event handler of HoverEnter and HoverLeave.

QEvent::HoverMove is also slightly different from QEvent::MouseMove. Let us consider a top-level window A containing a child B which in turn contains a child C (all with mouse tracking enabled):

Now, if you move the cursor from the top to the bottom in the middle of A, you will get the following QEvent::MouseMove events:

1. A::MouseMove
2. B::MouseMove
3. C::MouseMove

You will get the same events for QEvent::HoverMove, except that the event always propagates to the top-level regardless whether the event is accepted or not. It will only stop propagating with the Qt::WA_NoMousePropagation attribute.

In this case the events will occur in the following way:

1. A::HoverMove
2. A::HoverMove, B::HoverMove
3. A::HoverMove, B::HoverMove, C::HoverMove

## Member Function Documentation

### QHoverEvent::QHoverEvent(QEvent::Type type, const QPointF &scenePos, const QPointF &globalPos, const QPointF &oldPos, Qt::KeyboardModifiers modifiers = Qt::NoModifier, const QPointingDevice *device = QPointingDevice::primaryPointingDevice())

Constructs a hover event object originating from device.

The type parameter must be QEvent::HoverEnter, QEvent::HoverLeave, or QEvent::HoverMove.

The scenePos is the current mouse cursor's position relative to the receiving window or scene, oldPos is its previous such position, and globalPos is the mouse position in absolute coordinates. modifiers hold the state of all keyboard modifiers at the time of the event.

### `[protected delete]` QHoverEvent::QHoverEvent(QHoverEvent &&)

Move-constructs an instance of QHoverEvent. This function is deleted.

### QPoint QHoverEvent::oldPos() const

Returns the previous position of the mouse cursor, relative to the widget that received the event. If there is no previous position, oldPos() will return the same position as position().

On QEvent::HoverEnter events, this position will always be QPoint(-1, -1).

See also position().

### QPointF QHoverEvent::oldPosF() const

Returns the previous position of the mouse cursor, relative to the widget that received the event. If there is no previous position, oldPosF() will return the same position as position().

On QEvent::HoverEnter events, this position will always be QPointF(-1, -1).

See also position().

### `[protected delete]` QHoverEvent &QHoverEvent::operator=(QHoverEvent &&)

Move-assigns other to this QHoverEvent instance. This function is deleted.

### `[noexcept protected default]` QHoverEvent &QHoverEvent::operator=(const QHoverEvent &other)

Copy-assigns other to this QHoverEvent instance.