QGraphicsEllipseItem Class Reference

#include <qgraphicsitem.h>

Inheritance diagram for QGraphicsEllipseItem:

[legend]Collaboration diagram for QGraphicsEllipseItem:

[legend]List of all members.

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Detailed Description

The QGraphicsEllipseItem class provides an ellipse item that you can add to a QGraphicsScene.

Since:

4.2

QGraphicsEllipseItem respresents an ellipse with a fill and an outline, and you can also use it for ellipse segments (see startAngle(), spanAngle()).

graphicsview-ellipseitem.png graphicsview-ellipseitem-pie.png

To set the item's ellipse, pass a QRectF to QGraphicsEllipseItem's constructor, or call setRect(). The rect() function returns the current ellipse geometry.

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

See also:

QGraphicsPathItem, QGraphicsRectItem, QGraphicsPolygonItem, QGraphicsTextItem, QGraphicsLineItem, QGraphicsPixmapItem, {The Graphics View Framework}

Definition at line 404 of file qgraphicsitem.h.

Public Types
enum
Public Member Functions
	QGraphicsEllipseItem (QGraphicsItem *parent=0, QGraphicsScene *scene=0)
	QGraphicsEllipseItem (const QRectF &rect, QGraphicsItem *parent=0, QGraphicsScene *scene=0)
	QGraphicsEllipseItem (qreal x, qreal y, qreal w, qreal h, QGraphicsItem *parent=0, QGraphicsScene *scene=0)
	~QGraphicsEllipseItem ()
QRectF	rect () const
void	setRect (const QRectF &rect)
void	setRect (qreal x, qreal y, qreal w, qreal h)
int	startAngle () const
void	setStartAngle (int angle)
int	spanAngle () const
void	setSpanAngle (int angle)
QRectF	boundingRect () const
QPainterPath	shape () const
bool	contains (const QPointF &point) const
void	paint (QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget=0)
bool	isObscuredBy (const QGraphicsItem *item) const
QPainterPath	opaqueArea () const
int	type () const
Protected Member Functions
bool	supportsExtension (Extension extension) const
void	setExtension (Extension extension, const QVariant &variant)
QVariant	extension (const QVariant &variant) const

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Member Enumeration Documentation

anonymous enum

Definition at line 431 of file qgraphicsitem.h.

{ Type = 4 };

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Constructor & Destructor Documentation

QGraphicsEllipseItem::QGraphicsEllipseItem	(	QGraphicsItem *	parent = 0,
		QGraphicsScene *	scene = 0
	)

Constructs a QGraphicsEllipseItem. The parent and scene parameters are passed to QAbstractGraphicsShapeItem's constructor.

Definition at line 3680 of file qgraphicsitem.cpp.

    : QAbstractGraphicsShapeItem(*new QGraphicsEllipseItemPrivate, parent, scene)
{
}

QGraphicsEllipseItem::QGraphicsEllipseItem	(	const QRectF &	rect,
		QGraphicsItem *	parent = 0,
		QGraphicsScene *	scene = 0
	)

Constructs a QGraphicsEllipseItem using rect as the default rectangle. The parent and scene parameters are passed to QAbstractGraphicsShapeItem's constructor.

Definition at line 3652 of file qgraphicsitem.cpp.

References rect(), and setRect().

    : QAbstractGraphicsShapeItem(*new QGraphicsEllipseItemPrivate, parent, scene)
{
    setRect(rect);
}

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QGraphicsEllipseItem::QGraphicsEllipseItem	(	qreal	x,
		qreal	y,
		qreal	width,
		qreal	height,
		QGraphicsItem *	parent = 0,
		QGraphicsScene *	scene = 0
	)

Constructs a QGraphicsEllipseItem using the rectangle defined by (x, y) and the given width and height, as the default rectangle. The parent and scene parameters are passed to QAbstractGraphicsShapeItem's constructor.

Definition at line 3667 of file qgraphicsitem.cpp.

References setRect().

    : QAbstractGraphicsShapeItem(*new QGraphicsEllipseItemPrivate, parent, scene)
{
    setRect(x,y,w,h);
}

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QGraphicsEllipseItem::~QGraphicsEllipseItem

(

)

Destroys the QGraphicsEllipseItem.

Definition at line 3688 of file qgraphicsitem.cpp.

{
}

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Member Function Documentation

QRectF QGraphicsEllipseItem::rect

(

)

const

Returns the item's ellipse geometry as a QRectF.

See also:

setRect(), QPainter::drawEllipse()

Definition at line 3697 of file qgraphicsitem.cpp.

References d.

Referenced by QGraphicsEllipseItem(), and setRect().

{
    Q_D(const QGraphicsEllipseItem);
    return d->rect;
}

void QGraphicsEllipseItem::setRect

(

const QRectF &

rect

)

Sets the item's ellipse geometry to rect. The rectangle's left edge defines the left edge of the ellipse, and the rectangle's top edge describes the top of the ellipse. The height and width of the rectangle describe the height and width of the ellipse.

See also:

rect(), QPainter::drawEllipse()

Definition at line 3711 of file qgraphicsitem.cpp.

References QGraphicsItem::addToIndex(), d, rect(), and QGraphicsItem::removeFromIndex().

Referenced by QGraphicsEllipseItem(), and setRect().

{
    Q_D(QGraphicsEllipseItem);
    removeFromIndex();
    d->rect = rect;
    addToIndex();
}

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void QGraphicsEllipseItem::setRect	(	qreal	x,
		qreal	y,
		qreal	width,
		qreal	height
	)			[inline]

Sets the item's rectangle to the rectangle defined by (x, y) and the given width and height.

This convenience function is equivalent to calling {setRect(QRectF(x, y, width, height))}

See also:

rect()

Definition at line 444 of file qgraphicsitem.h.

References setRect().

{ setRect(QRectF(ax, ay, w, h)); }

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int QGraphicsEllipseItem::startAngle

(

)

const

Returns the start angle for an ellipse segment in 16ths of a degree. This angle is used together with spanAngle() for representing an ellipse segment (a pie). By default, the start angle is 0.

See also:

setStartAngle(), spanAngle()

Definition at line 3726 of file qgraphicsitem.cpp.

References d.

{
    Q_D(const QGraphicsEllipseItem);
    return d->startAngle;
}

void QGraphicsEllipseItem::setStartAngle

(

int

angle

)

Sets the start angle for an ellipse segment to angle, which is in 16ths of a degree. This angle is used together with spanAngle() for representing an ellipse segment (a pie). By default, the start angle is 0.

See also:

startAngle(), setSpanAngle(), QPainter::drawPie()

Definition at line 3739 of file qgraphicsitem.cpp.

References d, and QGraphicsItem::update().

{
    Q_D(QGraphicsEllipseItem);
    if (angle != d->startAngle) {
        d->startAngle = angle;
        update();
    }
}

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int QGraphicsEllipseItem::spanAngle

(

)

const

Returns the span angle of an ellipse segment in 16ths of a degree. This angle is used together with startAngle() for representing an ellipse segment (a pie). By default, this function returns 5760 (360 * 16, a full ellipse).

See also:

setSpanAngle(), startAngle()

Definition at line 3756 of file qgraphicsitem.cpp.

References d.

{
    Q_D(const QGraphicsEllipseItem);
    return d->spanAngle;
}

void QGraphicsEllipseItem::setSpanAngle

(

int

angle

)

Sets the span angle for an ellipse segment to angle, which is in 16ths of a degree. This angle is used together with startAngle() to represent an ellipse segment (a pie). By default, the span angle is 5760 (360 * 16, a full ellipse).

See also:

spanAngle(), setStartAngle(), QPainter::drawPie()

Definition at line 3770 of file qgraphicsitem.cpp.

References d, and QGraphicsItem::update().

{
    Q_D(QGraphicsEllipseItem);
    if (angle != d->spanAngle) {
        d->spanAngle = angle;
        update();
    }
}

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QRectF QGraphicsEllipseItem::boundingRect

(

)

const [virtual]

Implements QGraphicsItem.

Definition at line 3782 of file qgraphicsitem.cpp.

References d.

Referenced by paint().

{
    Q_D(const QGraphicsEllipseItem);
    qreal penWidth = d->pen.widthF() / 2.0;
    return d->rect.adjusted(-penWidth, -penWidth,
                            penWidth, penWidth);
}

QPainterPath QGraphicsEllipseItem::shape

(

)

const [virtual]

Reimplemented from QGraphicsItem.

Definition at line 3793 of file qgraphicsitem.cpp.

References d, path, and qt_graphicsItem_shapeFromPath().

{
    Q_D(const QGraphicsEllipseItem);
    QPainterPath path;
    if (d->rect.isNull())
        return path;
    if (d->spanAngle != 360 * 16) {
        path.moveTo(d->rect.center());
        path.arcTo(d->rect, d->startAngle / 16.0, d->spanAngle / 16.0);
    } else {
        path.addEllipse(d->rect);
    }

    return qt_graphicsItem_shapeFromPath(path, d->pen);
}

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bool QGraphicsEllipseItem::contains

(

const QPointF &

point

)

const [virtual]

Reimplemented from QGraphicsItem.

Definition at line 3812 of file qgraphicsitem.cpp.

References QGraphicsItem::contains().

{
    return QAbstractGraphicsShapeItem::contains(point);
}

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void QGraphicsEllipseItem::paint	(	QPainter *	painter,
		const QStyleOptionGraphicsItem *	option,
		QWidget *	widget = 0
	)			[virtual]

Implements QGraphicsItem.

Definition at line 3820 of file qgraphicsitem.cpp.

References boundingRect(), d, Qt::DashLine, QPainter::drawEllipse(), QPainter::drawPie(), QPainter::drawRect(), Qt::NoBrush, QStyleOption::palette, QPainter::setBrush(), QPainter::setPen(), QStyleOption::state, QStyle::State_Selected, and QPalette::text().

{
    Q_D(QGraphicsEllipseItem);
    Q_UNUSED(widget);
    painter->setPen(d->pen);
    painter->setBrush(d->brush);
    if ((d->spanAngle != 0) && (qAbs(d->spanAngle) % (360 * 16) == 0))
        painter->drawEllipse(d->rect);
    else
        painter->drawPie(d->rect, d->startAngle, d->spanAngle);

    if (option->state & QStyle::State_Selected) {
        painter->setPen(QPen(option->palette.text(), 1.0, Qt::DashLine));
        painter->setBrush(Qt::NoBrush);
        painter->drawRect(boundingRect().adjusted(2, 2, -2, -2));
    }
}

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bool QGraphicsEllipseItem::isObscuredBy

(

const QGraphicsItem *

item

)

const [virtual]

Reimplemented from QAbstractGraphicsShapeItem.

Definition at line 3842 of file qgraphicsitem.cpp.

References QAbstractGraphicsShapeItem::isObscuredBy().

{
    return QAbstractGraphicsShapeItem::isObscuredBy(item);
}

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QPainterPath QGraphicsEllipseItem::opaqueArea

(

)

const [virtual]

Reimplemented from QAbstractGraphicsShapeItem.

Definition at line 3850 of file qgraphicsitem.cpp.

References QAbstractGraphicsShapeItem::opaqueArea().

{
    return QAbstractGraphicsShapeItem::opaqueArea();
}

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int QGraphicsEllipseItem::type

(

)

const [virtual]

Reimplemented from QGraphicsItem.

Definition at line 3858 of file qgraphicsitem.cpp.

{
    return Type;
}

bool QGraphicsEllipseItem::supportsExtension

(

Extension

extension

)

const [protected, virtual]

Reimplemented from QGraphicsItem.

Definition at line 3867 of file qgraphicsitem.cpp.

{
    Q_UNUSED(extension);
    return false;
}

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

Reimplemented from QGraphicsItem.

Definition at line 3876 of file qgraphicsitem.cpp.

References variant.

{
    Q_UNUSED(extension);
    Q_UNUSED(variant);
}

QVariant QGraphicsEllipseItem::extension

(

const QVariant &

variant

)

const [protected, virtual]

Reimplemented from QGraphicsItem.

Definition at line 3885 of file qgraphicsitem.cpp.

References variant.

{
    Q_UNUSED(variant);
    return QVariant();
}

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The documentation for this class was generated from the following files:

• src/gui/graphicsview/qgraphicsitem.h
• src/gui/graphicsview/qgraphicsitem.cpp

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