Qwt User's Guide: QwtLinearColorMap Class Reference

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QwtLinearColorMap Class Reference

QwtLinearColorMap builds a color map from color stops. More...

#include <qwt_color_map.h>

Inheritance diagram for QwtLinearColorMap:
[legend]

List of all members.

Public Types

enum  Mode {
  FixedColors,
  ScaledColors
}

Public Member Functions

 QwtLinearColorMap (QwtColorMap::Format=QwtColorMap::RGB)
 QwtLinearColorMap (const QColor &from, const QColor &to, QwtColorMap::Format=QwtColorMap::RGB)
 QwtLinearColorMap (const QwtLinearColorMap &)
virtual ~QwtLinearColorMap ()
QwtLinearColorMap & operator= (const QwtLinearColorMap &)
virtual QwtColorMap * copy () const
void setMode (Mode)
Mode mode () const
void setColorInterval (const QColor &color1, const QColor &color2)
void addColorStop (double value, const QColor &)
QwtArray< double > colorStops () const
QColor color1 () const
QColor color2 () const
virtual QRgb rgb (const QwtDoubleInterval &, double value) const
virtual unsigned char colorIndex (const QwtDoubleInterval &, double value) 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

enum QwtLinearColorMap::Mode

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:
format Preferred 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:
color1 Color used for the minimum value of the value interval
color2 Color used for the maximum value of the value interval
format Preferred format of the coor map
QwtLinearColorMap::QwtLinearColorMap ( const QwtLinearColorMap &  other  ) 

Copy constructor.

QwtLinearColorMap::~QwtLinearColorMap (  )  [virtual]

Destructor.

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:
value Value between [0.0, 1.0]
color Color 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:
interval Range for all values
value Value to map into a color index

Implements QwtColorMap.

QwtArray< double > QwtLinearColorMap::colorStops (  )  const

Return all positions of color stops in increasing order

QwtColorMap * QwtLinearColorMap::copy (  )  const [virtual]

Clone the color map.

Implements QwtColorMap.

QwtLinearColorMap::Mode QwtLinearColorMap::mode (  )  const
Returns:
Mode of the color map
See also:
setMode()
QwtLinearColorMap & QwtLinearColorMap::operator= ( const QwtLinearColorMap &  other  ) 

Assignment operator.

QRgb QwtLinearColorMap::rgb ( const QwtDoubleInterval &  interval,
double  value 
) const [virtual]

Map a value of a given interval into a rgb value

Parameters:
interval Range for all values
value Value 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:
color1 Color used for the minimum value of the value interval
color2 Color 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()
Generated on Wed Sep 2 18:37:24 2009 for Qwt User's Guide by  doxygen 1.6.1
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