Qt 4.3: QGraphicsLineItem Class Reference

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# QGraphicsLineItem Class Reference
[QtGui module]

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 )

- 114 public functions inherited from QGraphicsItem

### Additional Inherited Members

- 1 static public member inherited from QGraphicsItem
- 23 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 The 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.

### QLineF QGraphicsLineItem::line () const

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

See also setLine().

### 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 member function, provided for convenience.

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().