# QwtLinearColorMap Class Reference

Inheritance diagram for QwtLinearColorMap:

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Collaboration diagram for QwtLinearColorMap:

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List of all members.

## 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.

## 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

## Member Enumeration Documentation

enum QwtLinearColorMap::Mode

Mode of color map

See also:
  setMode(), mode()

Definition at line 118 of file qwt_color_map.h.

## 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 setColorInterval().

Referenced by copy().

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 setColorInterval().

QwtLinearColorMap::QwtLinearColorMap | ( | const QwtLinearColorMap & |  | ) |

| Copy constructor. Definition at line 221 of file qwt_color_map.cpp.

QwtLinearColorMap::~QwtLinearColorMap | ( |  | ) | `[virtual]`

| Destructor. Definition at line 245 of file qwt_color_map.cpp.

## 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.

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.

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.

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 370 of file qwt_color_map.cpp.

References QwtDoubleInterval::isValid(), QwtDoubleInterval::maxValue(), QwtDoubleInterval::minValue(), and QwtDoubleInterval::width().

QwtArray< double > QwtLinearColorMap::colorStops | ( |  | ) | const

| Return all positions of color stops in increasing order Definition at line 328 of file qwt_color_map.cpp.

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

| Clone the color map. Implements QwtColorMap. Definition at line 260 of file qwt_color_map.cpp. References QwtLinearColorMap().

QwtLinearColorMap::Mode QwtLinearColorMap::mode | ( |  | ) | const

Returns:
  Mode of the color map

See also:
  setMode()

Definition at line 286 of file qwt_color_map.cpp.

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

| Assignment operator. Definition at line 251 of file qwt_color_map.cpp. References d_data.

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 QwtDoubleInterval::minValue(), and QwtDoubleInterval::width().

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.

Referenced by QwtLinearColorMap().

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.