QwtAlphaColorMap man page

QwtAlphaColorMap —

QwtAlphaColorMap variies the alpha value of a color.

Synopsis

#include <qwt_color_map.h>

Inherits QwtColorMap.

Public Types

enum Format { RGB, Indexed }

Public Member Functions

QColor color () const

QColor color (const QwtDoubleInterval &, double value) const

virtual QVector< QRgb > colorTable (const QwtDoubleInterval &) const

virtual QwtColorMap * copy () const

Format format () const

QwtAlphaColorMap & operator= (const QwtAlphaColorMap &)

QwtAlphaColorMap (const QColor &=QColor(Qt::gray))

QwtAlphaColorMap (const QwtAlphaColorMap &)

virtual QRgb rgb (const QwtDoubleInterval &, double value) const

void setColor (const QColor &)

virtual ~QwtAlphaColorMap ()

Detailed Description

QwtAlphaColorMap variies the alpha value of a color.

Member Enumeration Documentation

enum QwtColorMap::Format [inherited] .IP · 2

RGB
The map is intended to map into QRgb values.

·
Indexed
The map is intended to map into 8 bit values, that are indices into the color table.

See also:

rgb(), colorIndex(), colorTable()

Constructor & Destructor Documentation

QwtAlphaColorMap::QwtAlphaColorMap (const QColor &color = QColor(Qt::gray)) Constructor

Parameters:

color Color of the map

QwtAlphaColorMap::QwtAlphaColorMap (const QwtAlphaColorMap &other) Copy constructor

Parameters:

other Other color map

QwtAlphaColorMap::~QwtAlphaColorMap () [virtual]

Destructor.

Member Function Documentation

QColor QwtAlphaColorMap::color () const Returns

the color

See also:

setColor()

QColor QwtColorMap::color (const QwtDoubleInterval &interval, doublevalue) const [inline, inherited] Map a value into a color

Parameters:

interval Valid interval for values
value Value

Returns:

Color corresponding to value

Warning:

This method is slow for Indexed color maps. If it is necessary to map many values, its better to get the color table once and find the color using colorIndex().

QwtColorTable QwtColorMap::colorTable (const QwtDoubleInterval &interval) const [virtual, inherited] Build and return a color map of 256 colors

The color table is needed for rendering indexed images in combination with using colorIndex().

Parameters:

interval Range for the values

Returns:

A color table, that can be used for a QImage

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

Clone the color map.

Implements QwtColorMap.

QwtColorMap::Format QwtColorMap::format () const [inline, inherited] Returns

Intended format of the color map

See also:

Format

QwtAlphaColorMap & QwtAlphaColorMap::operator= (const QwtAlphaColorMap &other) Assignment operator

Parameters:

other Other color map

Returns:

*this

QRgb QwtAlphaColorMap::rgb (const QwtDoubleInterval &interval, doublevalue) const [virtual]

Map a value of a given interval into a alpha value. alpha := (value - interval.minValue()) / interval.width();

Parameters:

interval Range for all values
value Value to map into a rgb value

Returns:

rgb value, with an alpha value

Implements QwtColorMap.

void QwtAlphaColorMap::setColor (const QColor &color) Set the color

Parameters:

color Color

See also:

color()

Author

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

Info

Mon Aug 1 2011 Version 5.2.2 Qwt User's Guide