Qwt Programmer's Manual
QwtGrid
QwtGrid - A class which draws a coordinate grid
#include <qwt_grid.h>
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.
- 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
- gridChanged
- Called when an attribute has changed
Construct a QwtGrid instance
QwtGrid::QwtGrid()
Destroy a QwtGrid instance
QwtGrid::~QwtGrid()
Enable or disable vertical gridlines
void QwtGrid::enableX(bool tf)
- bool tf
- TRUE (enable) or FALSE (disable)
Minor gridlines can be enabled or disabled using
enableXMin
Enable or disable horizontal gridlines
void QwtGrid::enableY(bool tf)
- bool tf
- Enable (TRUE) or disable (FALSE)
Minor gridlines can be enabled or disabled using
enableYMin
Enable or disable minor vertical gridlines.
void QwtGrid::enableXMin(bool tf)
- bool tf
- Enable (TRUE) or disable (FALSE)
enableX
Enable or disable minor horizontal gridlines
void QwtGrid::enableYMin(bool tf)
- bool tf
- Enable (TRUE) or disable (FALSE)
enableY
Assign an x axis scale division
void QwtGrid::setXDiv(const QwtScaleDiv &sx)
- const QwtScaleDiv &sx
- scale division
QwtGrid uses implicit sharing (see Qt Manual) for
the scale divisions.
Assign a y axis division
void QwtGrid::setYDiv(const QwtScaleDiv &sy)
- const QwtScaleDiv &sy
- scale division
QwtGrid uses implicit sharing (see Qt Manual) for
the scale divisions.
Assign a pen for both major and minor gridlines
- const QPen &p
- pen
void QwtGrid::setPen(const QPen &p)
Assign a pen for the major gridlines
void QwtGrid::setMajPen(const QPen &p)
Assign a pen for the minor gridlines
void QwtGrid:.setMinPen(const QPen &p)
Draw the grid
void QwtGrid::draw(QPainter *p, const QRect &r, const QwtDiMap &mx, const QwtDiMap &my)
- QPainter *p
- Qt painter
- const QRect &r
- bounding rectangle
- const QwtDiMap &mx
- x axis map
- const QwtDiMap &my
- y axis map
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.
Assignment operator
const QwtGrid & QwtGrid::operator=(const QwtGrid &g)
- const QwtGrid &g
- Grid to be assigned
Return the pen for the major gridlines
const QPen & QwtGrid::majPen()
setMinPen, QwtGrid:.setPen
Return the pen for the minor gridlines
const QPen & QwtGrid::minPen()
setMinPen, QwtGrid:.setPen
Return TRUE if vertical gridlines are enabled
bool QwtGrid::xEnabled()
enableY
Return TRUE if minor vertical gridlines are enabled
bool QwtGrid::xMinEnabled()
enableXMin
Return TRUE if horizontal gridlines are enabled
bool QwtGrid::yEnabled()
enableY
Return TRUE if minor horizontal gridlines are enabled
bool QwtGrid::yMinEnabled()
enableYMin
Return the scale division of the x axis
const QwtScaleDiv & QwtGrid::xScaleDiv()
QwtScaleDiv
Return the scale division of the y axis
const QwtScaleDiv & QwtGrid::yScaleDiv()
QwtScaleDiv
Notify a change of attributes
void QwtGrid::gridChanged()
protected virtual
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