Qwt User's Guide 5.2.2
Public Types | Public Member Functions

QwtAlphaColorMap Class Reference

QwtAlphaColorMap variies the alpha value of a color. More...

#include <qwt_color_map.h>

Inheritance diagram for QwtAlphaColorMap:
Inheritance graph
[legend]

List of all members.

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 QwtColorMapcopy () const
Format format () const
QwtAlphaColorMapoperator= (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]
  • 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:
colorColor of the map
QwtAlphaColorMap::QwtAlphaColorMap ( const QwtAlphaColorMap other)

Copy constructor

Parameters:
otherOther 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,
double  value 
) const [inline, inherited]

Map a value into a color

Parameters:
intervalValid interval for values
valueValue
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:
intervalRange 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:
otherOther color map
Returns:
*this
QRgb QwtAlphaColorMap::rgb ( const QwtDoubleInterval interval,
double  value 
) const [virtual]

Map a value of a given interval into a alpha value.

alpha := (value - interval.minValue()) / interval.width();

Parameters:
intervalRange for all values
valueValue 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:
colorColor
See also:
color()