---
name: "QwtIntervalSymbol"
section: "3"
platform: "linux"
package: "libqwt-doc"
version: "6.1.4-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/QwtIntervalSymbol"
---

# QwtIntervalSymbol(3)

A drawing primitive for displaying an interval like an error bar.

## NAME

QwtIntervalSymbol - A drawing primitive for displaying an interval like an error bar.

## SYNOPSIS

`#include <qwt_interval_symbol.h>`

### Public Types

enum **Style** { **NoSymbol** = -1, **Bar**, **Box**, **UserSymbol** = 1000 }\
 Symbol style.

### Public Member Functions

**QwtIntervalSymbol** (**Style**=**NoSymbol**)\
 **QwtIntervalSymbol** (const **QwtIntervalSymbol** &)\
 Copy constructor.  virtual **~QwtIntervalSymbol** ()\
 Destructor.  **QwtIntervalSymbol** & **operator=** (const **QwtIntervalSymbol** &)\
 Assignment operator.  bool **operator==** (const **QwtIntervalSymbol** &) const\
 Compare two symbols.  bool **operator!=** (const **QwtIntervalSymbol** &) const\
 Compare two symbols.  void **setWidth** (int)\
 int **width** () const\
 void **setBrush** (const QBrush &)\
 Assign a brush.  const QBrush & **brush** () const\
 void **setPen** (const QColor &, qreal **width**=0.0, Qt::PenStyle=Qt::SolidLine)\
 void **setPen** (const QPen &)\
 const QPen & **pen** () const\
 void **setStyle** (**Style**)\
 **Style** **style** () const\
 virtual void **draw** (QPainter \*, Qt::Orientation, const QPointF &from, const QPointF &to) const\

## Detailed Description

A drawing primitive for displaying an interval like an error bar.

**See also:**

**QwtPlotIntervalCurve**

## Member Enumeration Documentation

### enum QwtIntervalSymbol::Style

Symbol style.

**Enumerator**

- *NoSymbol*

  *No Style. The symbol cannot be drawn.*

- *Bar*

  *The symbol displays a line with caps at the beginning/end. The size of the caps depends on the symbol* **width()***.*

- *Box*

  *The symbol displays a plain rectangle using* **pen()** *and* **brush()***. The size of the rectangle depends on the translated interval and the* **width()***,*

- *UserSymbol*

  *Styles \>= UserSymbol are reserved for derived classes of* **QwtIntervalSymbol** *that overload* **draw()** *with additional application specific symbol types.*

## Constructor & Destructor Documentation

### QwtIntervalSymbol::QwtIntervalSymbol (Style style = NoSymbol)

*Constructor*

**Parameters:**

*style Style of the symbol*

**See also:**

**setStyle()***,* **style()***,* **Style**

## Member Function Documentation

### const QBrush & QwtIntervalSymbol::brush () const

**Returns:**

*Brush*

**See also:**

**setBrush()**

### void QwtIntervalSymbol::draw (QPainter \* painter, Qt::Orientation orientation, const QPointF & from, const QPointF & to) const` [virtual]`

*Draw a symbol depending on its style*

**Parameters:**

*painter Painter* \
 *orientation Orientation* \
 *from Start point of the interval in target device coordinates* \
 *to End point of the interval in target device coordinates*

**See also:**

**setStyle()**

### const QPen & QwtIntervalSymbol::pen () const

**Returns:**

*Pen*

**See also:**

**setPen()***,* **brush()**

### void QwtIntervalSymbol::setBrush (const QBrush & brush)

*Assign a brush. The brush is used for the Box style.*

**Parameters:**

*brush Brush*

**See also:**

**brush()**

### void QwtIntervalSymbol::setPen (const QColor & color, qreal width = `0.0`, Qt::PenStyle style = `Qt::SolidLine`)

*Build and assign a pen*

*In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.*

**Parameters:**

*color Pen color* \
 *width Pen width* \
 *style Pen style*

**See also:**

**pen()***,* **brush()**

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

*Assign a pen*

**Parameters:**

*pen Pen*

**See also:**

**pen()***,* **setBrush()**

### void QwtIntervalSymbol::setStyle (Style style)

*Specify the symbol style*

**Parameters:**

*style Style*

**See also:**

**style()***,* **Style**

### void QwtIntervalSymbol::setWidth (int width)

*Specify the width of the symbol It is used depending on the style.*

**Parameters:**

*width Width*

**See also:**

**width()***,* **setStyle()**

### QwtIntervalSymbol::Style QwtIntervalSymbol::style () const

**Returns:**

*Current symbol style*

**See also:**

**setStyle()**

### int QwtIntervalSymbol::width () const

**Returns:**

*Width of the symbol.*

**See also:**

**setWidth()***,* **setStyle()**

## Author

*Generated automatically by Doxygen for Qwt User's Guide from the source code.*