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

# QwtPlotGrid(3)

A class which draws a coordinate grid.

## NAME

QwtPlotGrid - A class which draws a coordinate grid.

## SYNOPSIS

`#include <qwt_plot_grid.h>`

Inherits **QwtPlotItem**.

### Public Member Functions

**QwtPlotGrid** ()\
 Enables major grid, disables minor grid.  virtual **~QwtPlotGrid** ()\
 Destructor.  virtual int **rtti** () const\
 void **enableX** (bool)\
 Enable or disable vertical grid lines.  bool **xEnabled** () const\
 void **enableY** (bool)\
 Enable or disable horizontal grid lines.  bool **yEnabled** () const\
 void **enableXMin** (bool)\
 Enable or disable minor vertical grid lines.  bool **xMinEnabled** () const\
 void **enableYMin** (bool)\
 Enable or disable minor horizontal grid lines.  bool **yMinEnabled** () const\
 void **setXDiv** (const **QwtScaleDiv** &)\
 const **QwtScaleDiv** & **xScaleDiv** () const\
 void **setYDiv** (const **QwtScaleDiv** &)\
 const **QwtScaleDiv** & **yScaleDiv** () const\
 void **setPen** (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)\
 void **setPen** (const QPen &)\
 void **setMajorPen** (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)\
 void **setMajorPen** (const QPen &)\
 const QPen & **majorPen** () const\
 void **setMinorPen** (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)\
 void **setMinorPen** (const QPen &)\
 const QPen & **minorPen** () const\
 virtual void **draw** (QPainter \*, const **QwtScaleMap** &xMap, const **QwtScaleMap** &yMap, const QRectF &canvasRect) const\
 Draw the grid.  virtual void **updateScaleDiv** (const **QwtScaleDiv** &**xScaleDiv**, const **QwtScaleDiv** &**yScaleDiv**)\

### Additional Inherited Members

## Detailed Description

A class which draws a coordinate grid.

The **QwtPlotGrid** class can be used to draw a coordinate grid. A coordinate grid consists of major and minor vertical and horizontal grid lines. The locations of the grid lines are determined by the X and Y scale divisions which can be assigned with **setXDiv()** and **setYDiv()**. The **draw()** member draws the grid within a bounding rectangle.

## Member Function Documentation

### void QwtPlotGrid::draw (QPainter \* painter, const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect) const` [virtual]`

Draw the grid. The grid is drawn into the bounding rectangle such that grid lines begin and end at the rectangle's borders. The X and Y maps are used to map the scale divisions into the drawing region screen.

**Parameters:**

*painter* Painter \
 *xMap* X axis map \
 *yMap* Y axis \
 *canvasRect* Contents rectangle of the plot canvas

Implements **QwtPlotItem**.

### void QwtPlotGrid::enableX (bool on)

Enable or disable vertical grid lines.

**Parameters:**

*on* Enable (true) or disable

**See also:**

Minor grid lines can be enabled or disabled with **enableXMin()**

### void QwtPlotGrid::enableXMin (bool on)

Enable or disable minor vertical grid lines.

**Parameters:**

*on* Enable (true) or disable

**See also:**

**enableX()**

### void QwtPlotGrid::enableY (bool on)

Enable or disable horizontal grid lines.

**Parameters:**

*on* Enable (true) or disable

**See also:**

Minor grid lines can be enabled or disabled with **enableYMin()**

### void QwtPlotGrid::enableYMin (bool on)

Enable or disable minor horizontal grid lines.

**Parameters:**

*on* Enable (true) or disable

**See also:**

**enableY()**

### const QPen & QwtPlotGrid::majorPen () const

**Returns:**

the pen for the major grid lines

**See also:**

**setMajorPen()**, **setMinorPen()**, **setPen()**

### const QPen & QwtPlotGrid::minorPen () const

**Returns:**

the pen for the minor grid lines

**See also:**

**setMinorPen()**, **setMajorPen()**, **setPen()**

### int QwtPlotGrid::rtti () const` [virtual]`

**Returns:**

**QwtPlotItem::Rtti\_PlotGrid**

Reimplemented from **QwtPlotItem**.

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

Build and assign a pen for both major grid lines

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 QwtPlotGrid::setMajorPen (const QPen & pen)

Assign a pen for the major grid lines

**Parameters:**

*pen* Pen

**See also:**

**majorPen()**, **setMinorPen()**, **setPen()**

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

Build and assign a pen for the minor grid lines

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 QwtPlotGrid::setMinorPen (const QPen & pen)

Assign a pen for the minor grid lines

**Parameters:**

*pen* Pen

**See also:**

**minorPen()**, **setMajorPen()**, **setPen()**

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

Build and assign a pen for both major and minor grid lines

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 QwtPlotGrid::setPen (const QPen & pen)

Assign a pen for both major and minor grid lines

**Parameters:**

*pen* Pen

**See also:**

**setMajorPen()**, **setMinorPen()**

### void QwtPlotGrid::setXDiv (const QwtScaleDiv & scaleDiv)

Assign an x axis scale division

**Parameters:**

*scaleDiv* Scale division

### void QwtPlotGrid::setYDiv (const QwtScaleDiv & scaleDiv)

Assign a y axis division

**Parameters:**

*scaleDiv* Scale division

### void QwtPlotGrid::updateScaleDiv (const QwtScaleDiv & xScaleDiv, const QwtScaleDiv & yScaleDiv)` [virtual]`

Update the grid to changes of the axes scale division

**Parameters:**

*xScaleDiv* Scale division of the x-axis \
 *yScaleDiv* Scale division of the y-axis

**See also:**

**QwtPlot::updateAxes()**

Reimplemented from **QwtPlotItem**.

### bool QwtPlotGrid::xEnabled () const

**Returns:**

true if vertical grid lines are enabled

**See also:**

**enableX()**

### bool QwtPlotGrid::xMinEnabled () const

**Returns:**

true if minor vertical grid lines are enabled

**See also:**

**enableXMin()**

### const QwtScaleDiv & QwtPlotGrid::xScaleDiv () const

**Returns:**

the scale division of the x axis

### bool QwtPlotGrid::yEnabled () const

**Returns:**

true if horizontal grid lines are enabled

**See also:**

**enableY()**

### bool QwtPlotGrid::yMinEnabled () const

**Returns:**

true if minor horizontal grid lines are enabled

**See also:**

**enableYMin()**

### const QwtScaleDiv & QwtPlotGrid::yScaleDiv () const

**Returns:**

the scale division of the y axis

## Author

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