- Qt 6.11
- Qt Widgets
- C++ Classes
- QGraphicsPolygonItem
- Qt 6.11.0 Reference Documentation

# QGraphicsPolygonItem Class

The QGraphicsPolygonItem class provides a polygon item that you can add to a QGraphicsScene. More...

Header: | `#include <QGraphicsPolygonItem>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS Widgets)` `target_link_libraries(mytarget PRIVATE Qt6::Widgets)`
qmake: | `QT += widgets`
Inherits: | QAbstractGraphicsShapeItem

- List of all members, including inherited members

## Public Types

| enum { Type }

## Public Functions

| QGraphicsPolygonItem(QGraphicsItem *parent = nullptr)
| QGraphicsPolygonItem(const QPolygonF &polygon, QGraphicsItem *parent = nullptr)
virtual | ~QGraphicsPolygonItem()
Qt::FillRule | fillRule() const
QPolygonF | polygon() const
void | setFillRule(Qt::FillRule rule)
void | setPolygon(const QPolygonF &polygon)

## Reimplemented Public Functions

virtual QRectF | boundingRect() const override
virtual bool | contains(const QPointF &point) const override
virtual bool | isObscuredBy(const QGraphicsItem *item) const override
virtual QPainterPath | opaqueArea() const override
virtual void | paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override
virtual QPainterPath | shape() const override
virtual int | type() const override

## Reimplemented Protected Functions

virtual QVariant | extension(const QVariant &variant) const override
virtual void | setExtension(QGraphicsItem::Extension extension, const QVariant &variant) override
virtual bool | supportsExtension(QGraphicsItem::Extension extension) const override

## Detailed Description

To set the item's polygon, pass a QPolygonF to QGraphicsPolygonItem's constructor, or call the setPolygon() function. The polygon() function returns the current polygon.

QGraphicsPolygonItem uses the polygon and the pen width to provide a reasonable implementation of boundingRect(), shape(), and contains(). The paint() function draws the polygon using the item's associated pen and brush, which you can set by calling the setPen() and setBrush() functions.

See also QGraphicsPathItem, QGraphicsRectItem, QGraphicsEllipseItem, QGraphicsTextItem, QGraphicsLineItem, QGraphicsPixmapItem, and Graphics View Framework.

## Member Type Documentation

### `[anonymous]` enum

The value returned by the virtual type() function.

Constant | Value | Description
--- | --- | ---
`QGraphicsPolygonItem::Type` | `5` | A graphics polygon item

## Member Function Documentation

### `[explicit]` QGraphicsPolygonItem::QGraphicsPolygonItem(QGraphicsItem *parent = nullptr)

Constructs a QGraphicsPolygonItem. parent is passed to QAbstractGraphicsShapeItem's constructor.

See also QGraphicsScene::addItem().

### `[explicit]` QGraphicsPolygonItem::QGraphicsPolygonItem(const QPolygonF &polygon, QGraphicsItem *parent = nullptr)

Constructs a QGraphicsPolygonItem with polygon as the default polygon. parent is passed to QAbstractGraphicsShapeItem's constructor.

See also QGraphicsScene::addItem().

### `[virtual noexcept]` QGraphicsPolygonItem::~QGraphicsPolygonItem()

Destroys the QGraphicsPolygonItem.

### `[override virtual]` QRectF QGraphicsPolygonItem::boundingRect() const

Reimplements: QGraphicsItem::boundingRect() const.

### `[override virtual]` bool QGraphicsPolygonItem::contains(const QPointF &point) const

Reimplements: QGraphicsItem::contains(const QPointF &point) const.

### Qt::FillRule QGraphicsPolygonItem::fillRule() const

Returns the fill rule of the polygon. The default fill rule is Qt::OddEvenFill.

See also setFillRule(), QPainterPath::fillRule(), and QPainter::drawPolygon().

### `[override virtual]` bool QGraphicsPolygonItem::isObscuredBy(const QGraphicsItem *item) const

Reimplements: QAbstractGraphicsShapeItem::isObscuredBy(const QGraphicsItem *item) const.

### `[override virtual]` QPainterPath QGraphicsPolygonItem::opaqueArea() const

Reimplements: QAbstractGraphicsShapeItem::opaqueArea() const.

### `[override virtual]` void QGraphicsPolygonItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr)

Reimplements: QGraphicsItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget).

### QPolygonF QGraphicsPolygonItem::polygon() const

Returns the item's polygon, or an empty polygon if no polygon has been set.

See also setPolygon().

### void QGraphicsPolygonItem::setFillRule(Qt::FillRule rule)

Sets the fill rule of the polygon to rule. The default fill rule is Qt::OddEvenFill.

See also fillRule(), QPainterPath::fillRule(), and QPainter::drawPolygon().

### void QGraphicsPolygonItem::setPolygon(const QPolygonF &polygon)

Sets the item's polygon to be the given polygon.

See also polygon().

### `[override virtual]` QPainterPath QGraphicsPolygonItem::shape() const

Reimplements: QGraphicsItem::shape() const.

### `[override virtual]` int QGraphicsPolygonItem::type() const

Reimplements: QGraphicsItem::type() const.