Qwt Programmer's Manual

QwtGrid


NAME

QwtGrid - A class which draws a coordinate grid

SYNOPSIS

#include <qwt_grid.h>

DESCRIPTION

The QwtGrid class can be used to draw a coordinate grid. A coordinate grid consists of major and minor vertical and horizontal gridlines. The locations of the gridlines 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.

PUBLIC MEMBERS

QwtGrid (1)
Constructor
QwtGrid (2)
Constructor
~QwtGrid
Destructor
draw
Draw the grid
enableX
Enable vertical gridlines
enableY
Enable horizontal gridlines
enableXMin
Enable minor vertical gridlines
enableYMin
Enable minor horizontal gridlines
setXDiv
Assign a scale division for vertical gridlines
setYDiv
Assign a scale division for horizontal gridlines
setPen
Set a pen for major and minor gridlines
setMajPen
Set a pen for major gridlines
setMinPen
Set a pen for minor gridlines
majPen
Return pen for major gridlines
minPen
Return pen for minor gridlines
xEnabled
Return TRUE if vertical gridlines enabled
xMinEnabled
Return TRUE if minor vertical gridlines enabled
yEnabled
Return TRUE if horizontal gridlines enabled
yMinEnabled
Return TRUE if vertical gridlines enabled
xScaleDiv
Return x scale division
yScaleDiv
Return y scale division

PROTECTED MEMBERS

gridChanged
Called when an attribute has changed

MEMBER FUNCTION DESCRIPTION


QwtGrid::QwtGrid

Construct a QwtGrid instance

Syntax

QwtGrid::QwtGrid()

QwtGrid::~QwtGrid

Destroy a QwtGrid instance

Syntax

QwtGrid::~QwtGrid()

QwtGrid::enableX

Enable or disable vertical gridlines

Syntax

void QwtGrid::enableX(bool tf)

Parameters

bool tf
TRUE (enable) or FALSE (disable)

See also

Minor gridlines can be enabled or disabled using enableXMin

QwtGrid::enableY

Enable or disable horizontal gridlines

Syntax

void QwtGrid::enableY(bool tf)

Parameters

bool tf
Enable (TRUE) or disable (FALSE)

See also

Minor gridlines can be enabled or disabled using enableYMin

QwtGrid::enableXMin

Enable or disable minor vertical gridlines.

Syntax

void QwtGrid::enableXMin(bool tf)

Parameters

bool tf
Enable (TRUE) or disable (FALSE)

See also

enableX

QwtGrid::enableYMin

Enable or disable minor horizontal gridlines

Syntax

void QwtGrid::enableYMin(bool tf)

Parameters

bool tf
Enable (TRUE) or disable (FALSE)

See also

enableY

QwtGrid::setXDiv

Assign an x axis scale division

Syntax

void QwtGrid::setXDiv(const QwtScaleDiv &sx)

Parameters

const QwtScaleDiv &sx
scale division

Note

QwtGrid uses implicit sharing (see Qt Manual) for the scale divisions.

QwtGrid::setYDiv

Assign a y axis division

Syntax

void QwtGrid::setYDiv(const QwtScaleDiv &sy)

Parameters

const QwtScaleDiv &sy
scale division

Note

QwtGrid uses implicit sharing (see Qt Manual) for the scale divisions.

QwtGrid::setPen

Assign a pen for both major and minor gridlines

Parameters

const QPen &p
pen

Syntax

void QwtGrid::setPen(const QPen &p)

QwtGrid::setMajPen

Assign a pen for the major gridlines

Syntax

void QwtGrid::setMajPen(const QPen &p)

QwtGrid:.setMinPen

Assign a pen for the minor gridlines

Syntax

void QwtGrid:.setMinPen(const QPen &p)

QwtGrid::draw

Draw the grid

Syntax

void QwtGrid::draw(QPainter *p, const QRect &r, const QwtDiMap &mx, const QwtDiMap &my)

Parameters

QPainter *p
Qt painter
const QRect &r
bounding rectangle
const QwtDiMap &mx
x axis map
const QwtDiMap &my
y axis map

Description

The grid is drawn into the bounding rectangle such that the gridlines 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.

QwtGrid::operator=

Assignment operator

Syntax

const QwtGrid & QwtGrid::operator=(const QwtGrid &g)

Parameters

const QwtGrid &g
Grid to be assigned

QwtGrid::majPen

Return the pen for the major gridlines

Syntax

const QPen & QwtGrid::majPen()

See Also

setMinPen, QwtGrid:.setPen

QwtGrid::minPen

Return the pen for the minor gridlines

Syntax

const QPen & QwtGrid::minPen()

See Also

setMinPen, QwtGrid:.setPen

QwtGrid::xEnabled

Return TRUE if vertical gridlines are enabled

Syntax

bool QwtGrid::xEnabled()

See Also

enableY

QwtGrid::xMinEnabled

Return TRUE if minor vertical gridlines are enabled

Syntax

bool QwtGrid::xMinEnabled()

See Also

enableXMin

QwtGrid::yEnabled

Return TRUE if horizontal gridlines are enabled

Syntax

bool QwtGrid::yEnabled()

See Also

enableY

QwtGrid::yMinEnabled

Return TRUE if minor horizontal gridlines are enabled

Syntax

bool QwtGrid::yMinEnabled()

See Also

enableYMin

QwtGrid::xScaleDiv

Return the scale division of the x axis

Syntax

const QwtScaleDiv & QwtGrid::xScaleDiv()

Description

See Also

QwtScaleDiv

QwtGrid::yScaleDiv

Return the scale division of the y axis

Syntax

const QwtScaleDiv & QwtGrid::yScaleDiv()

See Also

QwtScaleDiv

QwtGrid::gridChanged

Notify a change of attributes

Syntax

void QwtGrid::gridChanged()

Access

protected virtual

Description

This virtual function is called when an attribute of the grid has changed. It can be redefined by derived classes. The default implementation does nothing.
Qwt Widget Library 01/01/98