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

#include <qwt_color_map.h>

Inheritance diagram for QwtLinearColorMap:

Collaboration diagram for QwtLinearColorMap:

Classes
class	ColorStops
class	PrivateData
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 &)
	Copy constructor.
virtual	~QwtLinearColorMap ()
	Destructor.
QwtLinearColorMap &	operator= (const QwtLinearColorMap &)
	Assignment operator.
virtual QwtColorMap *	copy () const
	Clone the color map.
void	setMode (Mode)
	Set the mode of the color map.
Mode	mode () const
void	setColorInterval (const QColor &color1, const QColor &color2)
void	addColorStop (double value, const QColor &)
QMemArray< 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.

Definition at line 111 of file qwt_color_map.h.

Member Enumeration Documentation

enum QwtLinearColorMap::Mode

Mode of color map

See also:: setMode(), mode()

Enumerator:

FixedColors
ScaledColors

Definition at line 118 of file qwt_color_map.h.

    {
        FixedColors,
        ScaledColors
    };

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

Definition at line 211 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::mode, ScaledColors, and setColorInterval().

Referenced by copy().

                                                            :
    QwtColorMap(format)
{
    d_data = new PrivateData;
    d_data->mode = ScaledColors;

    setColorInterval( Qt::blue, Qt::yellow);
}

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

Definition at line 235 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::mode, ScaledColors, and setColorInterval().

                                                       :
    QwtColorMap(format)
{
    d_data = new PrivateData;
    d_data->mode = ScaledColors;
    setColorInterval(color1, color2); 
}

QwtLinearColorMap::QwtLinearColorMap ( const QwtLinearColorMap & other )

Copy constructor.

Definition at line 221 of file qwt_color_map.cpp.

                                                                  :
    QwtColorMap(other)
{
    d_data = new PrivateData;
    *this = other;
}

QwtLinearColorMap::~QwtLinearColorMap ( ) [virtual]

Destructor.

Definition at line 245 of file qwt_color_map.cpp.

{
    delete d_data;
}

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

Definition at line 319 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, and QwtLinearColorMap::ColorStops::insert().

{
    if ( value >= 0.0 && value <= 1.0 )
        d_data->colorStops.insert(value, color);
}

QColor QwtLinearColorMap::color1 ( ) const

Returns:: the first color of the color range

See also:: setColorInterval()

Definition at line 337 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, QwtLinearColorMap::PrivateData::mode, and QwtLinearColorMap::ColorStops::rgb().

{
    return QColor(d_data->colorStops.rgb(d_data->mode, 0.0));
}

QColor QwtLinearColorMap::color2 ( ) const

Returns:: the second color of the color range

See also:: setColorInterval()

Definition at line 346 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, QwtLinearColorMap::PrivateData::mode, and QwtLinearColorMap::ColorStops::rgb().

{
    return QColor(d_data->colorStops.rgb(d_data->mode, 1.0));
}

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.

Definition at line 375 of file qwt_color_map.cpp.

References FixedColors, QwtDoubleInterval::maxValue(), QwtDoubleInterval::minValue(), QwtLinearColorMap::PrivateData::mode, and QwtDoubleInterval::width().

{
    const double width = interval.width();

    if ( width <= 0.0 || value <= interval.minValue() )
        return 0;

    if ( value >= interval.maxValue() )
        return (unsigned char)255;

    const double ratio = (value - interval.minValue()) / width;
    
    unsigned char index;
    if ( d_data->mode == FixedColors )
        index = (unsigned char)(ratio * 255); // always floor
    else
        index = (unsigned char)qRound(ratio * 255);

    return index;
}

QMemArray< double > QwtLinearColorMap::colorStops ( ) const

Return all positions of color stops in increasing order

Definition at line 328 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, and QwtLinearColorMap::ColorStops::stops().

{
    return d_data->colorStops.stops();
}

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

Clone the color map.

Implements QwtColorMap.

Definition at line 260 of file qwt_color_map.cpp.

References QwtLinearColorMap().

{
    QwtLinearColorMap* map = new QwtLinearColorMap();
    *map = *this;

    return map;
}

QwtLinearColorMap::Mode QwtLinearColorMap::mode ( ) const

Returns:: Mode of the color map

See also:: setMode()

Definition at line 286 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::mode.

Referenced by setMode().

{
    return d_data->mode;
}

QwtLinearColorMap & QwtLinearColorMap::operator= ( const QwtLinearColorMap & other )

Assignment operator.

Definition at line 251 of file qwt_color_map.cpp.

{
    QwtColorMap::operator=(other);
    *d_data = *other.d_data;
    return *this;
}

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.

Definition at line 357 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, QwtDoubleInterval::minValue(), QwtLinearColorMap::PrivateData::mode, QwtLinearColorMap::ColorStops::rgb(), and QwtDoubleInterval::width().

Referenced by QwtLinearColorMap::ColorStops::rgb().

{
    const double width = interval.width();

    double ratio = 0.0;
    if ( width > 0.0 )
        ratio = (value - interval.minValue()) / width;

    return d_data->colorStops.rgb(d_data->mode, ratio);
}

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()

Definition at line 301 of file qwt_color_map.cpp.

References QwtLinearColorMap::PrivateData::colorStops, and QwtLinearColorMap::ColorStops::insert().

Referenced by QwtLinearColorMap().

{
    d_data->colorStops = ColorStops();
    d_data->colorStops.insert(0.0, color1);
    d_data->colorStops.insert(1.0, 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()

Definition at line 277 of file qwt_color_map.cpp.

References mode(), and QwtLinearColorMap::PrivateData::mode.

{
    d_data->mode = mode;
}

The documentation for this class was generated from the following files:

QwtLinearColorMap Class Reference

Classes

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation