Qt 4.7: QGraphicsLineItem Class Reference

Qt Reference Documentation

# QGraphicsLineItem Class Reference

The QGraphicsLineItem class provides a line item that you can add to a QGraphicsScene. More...

     #include <QGraphicsLineItem>

Inherits: QGraphicsItem.

This class was introduced in Qt 4.2.

- List of all members, including inherited members

## Public Functions

| QGraphicsLineItem ( QGraphicsItem * parent = 0 )
| QGraphicsLineItem ( const QLineF & line, QGraphicsItem * parent = 0 )
| QGraphicsLineItem ( qreal x1, qreal y1, qreal x2, qreal y2, QGraphicsItem * parent = 0 )
| ~QGraphicsLineItem ()
QLineF | line () const
QPen | pen () const
void | setLine ( const QLineF & line )
void | setLine ( qreal x1, qreal y1, qreal x2, qreal y2 )
void | setPen ( const QPen & pen )

## Reimplemented Public Functions

virtual QRectF | boundingRect () const
virtual bool | contains ( const QPointF & point ) const
virtual bool | isObscuredBy ( const QGraphicsItem * item ) const
virtual QPainterPath | opaqueArea () const
virtual void | paint ( QPainter * painter, const QStyleOptionGraphicsItem * option, QWidget * widget = 0 )
virtual QPainterPath | shape () const
virtual int | type () const

- 177 public functions inherited from QGraphicsItem

### Additional Inherited Members

- 2 static public members inherited from QGraphicsItem
- 24 protected functions inherited from QGraphicsItem

## Detailed Description

The QGraphicsLineItem class provides a line item that you can add to a QGraphicsScene.

To set the item's line, pass a QLineF to QGraphicsLineItem's constructor, or call the setLine() function. The line() function returns the current line. By default the line is black with a width of 0, but you can change this by calling setPen().

QGraphicsLineItem uses the line and the pen width to provide a reasonable implementation of boundingRect(), shape(), and contains(). The paint() function draws the line using the item's associated pen.

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

## Member Function Documentation

### QGraphicsLineItem::QGraphicsLineItem ( QGraphicsItem * parent = 0 )

Constructs a QGraphicsLineItem. parent is passed to QGraphicsItem's constructor.

See also QGraphicsScene::addItem().

### QGraphicsLineItem::QGraphicsLineItem ( const QLineF & line, QGraphicsItem * parent = 0 )

Constructs a QGraphicsLineItem, using line as the default line. parent is passed to QGraphicsItem's constructor.

See also QGraphicsScene::addItem().

### QGraphicsLineItem::QGraphicsLineItem ( qreal x1, qreal y1, qreal x2, qreal y2, QGraphicsItem * parent = 0 )

Constructs a QGraphicsLineItem, using the line between (x1, y1) and (x2, y2) as the default line. parent is passed to QGraphicsItem's constructor.

See also QGraphicsScene::addItem().

### QGraphicsLineItem::~QGraphicsLineItem ()

Destroys the QGraphicsLineItem.

### QRectF QGraphicsLineItem::boundingRect () const`[virtual]`

Reimplemented from QGraphicsItem::boundingRect().

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

Reimplemented from QGraphicsItem::contains().

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

Reimplemented from QGraphicsItem::isObscuredBy().

### QLineF QGraphicsLineItem::line () const

Returns the item's line, or a null line if no line has been set.

See also setLine().

### QPainterPath QGraphicsLineItem::opaqueArea () const`[virtual]`

Reimplemented from QGraphicsItem::opaqueArea().

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

Reimplemented from QGraphicsItem::paint().

### QPen QGraphicsLineItem::pen () const

Returns the item's pen, or a black solid 0-width pen if no pen has been set.

See also setPen().

### void QGraphicsLineItem::setLine ( const QLineF & line )

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

See also line().

### void QGraphicsLineItem::setLine ( qreal x1, qreal y1, qreal x2, qreal y2 )

This is an overloaded function.

Sets the item's line to be the line between (x1, y1) and (x2, y2).

This is the same as calling `setLine(QLineF(x1, y1, x2, y2))`.

### void QGraphicsLineItem::setPen ( const QPen & pen )

Sets the item's pen to pen. If no pen is set, the line will be painted using a black solid 0-width pen.

See also pen().

### QPainterPath QGraphicsLineItem::shape () const`[virtual]`

Reimplemented from QGraphicsItem::shape().

### int QGraphicsLineItem::type () const`[virtual]`

Reimplemented from QGraphicsItem::type().