QGraphicsPolygonItem Class

The QGraphicsPolygonItem class provides a polygon item that you can add to a QGraphicsScene. \since 4.2 \ingroup graphicsview-api \inmodule QtWidgets. More...

Header: #include <QGraphicsPolygonItem>
Inherits: QAbstractGraphicsShapeItem

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(Extension extension, const QVariant &variant) override
virtual bool supportsExtension(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 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.

[override virtual protected] QVariant QGraphicsPolygonItem::extension(const QVariant &variant) const

Reimplements: QGraphicsItem::extension(const QVariant &variant) const.

\internal

See also setExtension().

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().

[override virtual protected] void QGraphicsPolygonItem::setExtension(Extension extension, const QVariant &variant)

Reimplements: QGraphicsItem::setExtension(Extension extension, const QVariant &variant).

\internal

See also extension().

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 protected] bool QGraphicsPolygonItem::supportsExtension(Extension extension) const

Reimplements: QGraphicsItem::supportsExtension(Extension extension) const.

\internal

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

Reimplements: QGraphicsItem::type() const.