Qwt User's Guide  5.2.3
Public Types | Public Member Functions
QwtLinearColorMap Class Reference

#include <qwt_color_map.h>

Inheritance diagram for QwtLinearColorMap:
Inheritance graph
[legend]

List of all members.

Public Types

enum  Mode {
  FixedColors,
  ScaledColors
}
- Public Types inherited from QwtColorMap
enum  Format {
  RGB,
  Indexed
}

Public Member Functions

 QwtLinearColorMap (QwtColorMap::Format=QwtColorMap::RGB)
 QwtLinearColorMap (const QColor &from, const QColor &to, QwtColorMap::Format=QwtColorMap::RGB)
 QwtLinearColorMap (const QwtLinearColorMap &)
virtual ~QwtLinearColorMap ()
void addColorStop (double value, const QColor &)
QColor color1 () const
QColor color2 () const
virtual unsigned char colorIndex (const QwtDoubleInterval &, double value) const
QwtArray< double > colorStops () const
virtual QwtColorMapcopy () const
Mode mode () const
QwtLinearColorMapoperator= (const QwtLinearColorMap &)
virtual QRgb rgb (const QwtDoubleInterval &, double value) const
void setColorInterval (const QColor &color1, const QColor &color2)
void setMode (Mode)
- Public Member Functions inherited from QwtColorMap
 QwtColorMap (Format=QwtColorMap::RGB)
virtual ~QwtColorMap ()
QColor color (const QwtDoubleInterval &, double value) const
virtual QVector< QRgb > colorTable (const QwtDoubleInterval &) const
Format format () const

Detailed Description

QwtLinearColorMap builds a color map from color stops.

A color stop is a color at a specific position. The valid range for the positions is [0.0, 1.0]. When mapping a value into a color it is translated into this interval. If mode() == FixedColors the color is calculated from the next lower color stop. If mode() == ScaledColors the color is calculated by interpolating the colors of the adjacent stops.


Member Enumeration Documentation

Mode of color map

See also:
setMode(), mode()

Constructor & Destructor Documentation

QwtLinearColorMap::QwtLinearColorMap ( QwtColorMap::Format  format = QwtColorMap::RGB)

Build a color map with two stops at 0.0 and 1.0. The color at 0.0 is Qt::blue, at 1.0 it is Qt::yellow.

Parameters:
formatPreferred format of the color map
QwtLinearColorMap::QwtLinearColorMap ( const QColor &  color1,
const QColor &  color2,
QwtColorMap::Format  format = QwtColorMap::RGB 
)

Build a color map with two stops at 0.0 and 1.0.

Parameters:
color1Color used for the minimum value of the value interval
color2Color used for the maximum value of the value interval
formatPreferred format of the coor map

Member Function Documentation

void QwtLinearColorMap::addColorStop ( double  value,
const QColor &  color 
)

Add a color stop

The value has to be in the range [0.0, 1.0]. F.e. a stop at position 17.0 for a range [10.0,20.0] must be passed as: (17.0 - 10.0) / (20.0 - 10.0)

Parameters:
valueValue between [0.0, 1.0]
colorColor stop
QColor QwtLinearColorMap::color1 ( ) const
Returns:
the first color of the color range
See also:
setColorInterval()
QColor QwtLinearColorMap::color2 ( ) const
Returns:
the second color of the color range
See also:
setColorInterval()
unsigned char QwtLinearColorMap::colorIndex ( const QwtDoubleInterval interval,
double  value 
) const
virtual

Map a value of a given interval into a color index, between 0 and 255

Parameters:
intervalRange for all values
valueValue to map into a color index

Implements QwtColorMap.

QwtArray< double > QwtLinearColorMap::colorStops ( ) const

Return all positions of color stops in increasing order

QwtLinearColorMap::Mode QwtLinearColorMap::mode ( ) const
Returns:
Mode of the color map
See also:
setMode()
QRgb QwtLinearColorMap::rgb ( const QwtDoubleInterval interval,
double  value 
) const
virtual

Map a value of a given interval into a rgb value

Parameters:
intervalRange for all values
valueValue to map into a rgb value

Implements QwtColorMap.

void QwtLinearColorMap::setColorInterval ( const QColor &  color1,
const QColor &  color2 
)

Set the color range

Add stops at 0.0 and 1.0.

Parameters:
color1Color used for the minimum value of the value interval
color2Color used for the maximum value of the value interval
See also:
color1(), color2()
void QwtLinearColorMap::setMode ( Mode  mode)

Set the mode of the color map.

FixedColors means the color is calculated from the next lower color stop. ScaledColors means the color is calculated by interpolating the colors of the adjacent stops.

See also:
mode()