Qt 5.6 | Qt Widgets | C++ Classes | QGraphicsLineItem

Qt 5.6.2 Reference Documentation

# QGraphicsLineItem Class

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

Header: | #include <QGraphicsLineItem>
qmake: | QT += widgets
Since: | Qt 4.2
Inherits: | QGraphicsItem

- List of all members, including inherited members

## Public Functions

| QGraphicsLineItem(QGraphicsItem *parent = Q_NULLPTR)
| QGraphicsLineItem(const QLineF &line, QGraphicsItem *parent = Q_NULLPTR)
| QGraphicsLineItem(qreal x1, qreal y1, qreal x2, qreal y2, QGraphicsItem *parent = Q_NULLPTR)
| ~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 = Q_NULLPTR)
virtual QPainterPath | shape() const
virtual int | type() const

- 176 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 = Q_NULLPTR)

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

See also QGraphicsScene::addItem().

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

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 = Q_NULLPTR)

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.

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

Reimplemented from QGraphicsItem::boundingRect().

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

Reimplemented from QGraphicsItem::contains().

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

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().

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

Reimplemented from QGraphicsItem::opaqueArea().

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

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().

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

Reimplemented from QGraphicsItem::shape().

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

Reimplemented from QGraphicsItem::type().