QwtAlphaColorMap Class Reference

#include <qwt_color_map.h>

Inherits QwtColorMap.

List of all members.

Public Types
enum	Format {   RGB,   Indexed }
Public Member Functions
QColor	color (const QwtInterval &, double value) const
QColor	color () const
virtual QVector< QRgb >	colorTable (const QwtInterval &) const
Format	format () const
	QwtAlphaColorMap (const QColor &=QColor(Qt::gray))
virtual QRgb	rgb (const QwtInterval &, double value) const
void	setColor (const QColor &)
virtual	~QwtAlphaColorMap ()

---

Detailed Description

QwtAlphaColorMap variies the alpha value of a color.

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Member Enumeration Documentation

enum QwtColorMap::Format [inherited]

Format for color mapping

See also:

rgb(), colorIndex(), colorTable()

Enumerator:

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.

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Constructor & Destructor Documentation

QwtAlphaColorMap::QwtAlphaColorMap

(

const QColor &

color = QColor( Qt::gray )

)

Constructor

Parameters:

color

Color of the map

QwtAlphaColorMap::~QwtAlphaColorMap

(

)

[virtual]

Destructor.

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Member Function Documentation

QColor QwtColorMap::color	(	const QwtInterval &	interval,
		double	value
	)		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().

QColor QwtAlphaColorMap::color

(

)

const

Returns:

the color

See also:

setColor()

QVector< QRgb > QwtColorMap::colorTable

(

const QwtInterval &

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::Format QwtColorMap::format

(

)

const [inline, inherited]

Returns:

Intended format of the color map

See also:

Format

QRgb QwtAlphaColorMap::rgb	(	const QwtInterval &	interval,
		double	value
	)		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()