QColormap Class | Qt Widgets 5.6

Qt 5.6 | Qt Widgets | C++ Classes | QColormap

Qt 5.6.2 Reference Documentation

# QColormap Class

The QColormap class maps device independent QColors to device dependent pixel values. More...

Header: | #include <QColormap>
qmake: | QT += widgets

- List of all members, including inherited members

## Public Types

enum | Mode { Direct, Indexed, Gray }

## Public Functions

| QColormap(const QColormap &colormap)
| ~QColormap()
const QColor | colorAt(uint pixel) const
const QVector<QColor> | colormap() const
int | depth() const
Mode | mode() const
uint | pixel(const QColor &color) const
int | size() const
QColormap & | operator=(const QColormap &colormap)

## Static Public Members

QColormap | instance(int screen = -1)

## Detailed Description

The QColormap class maps device independent QColors to device dependent pixel values.

## Member Type Documentation

### enum QColormap::Mode

This enum describes how QColormap maps device independent RGB values to device dependent pixel values.

Constant | Value | Description
--- | --- | ---
`QColormap::Direct` | `0` | Pixel values are derived directly from the RGB values, also known as "True Color."
`QColormap::Indexed` | `1` | Pixel values represent indexes into a vector of available colors, i.e. QColormap uses the index of the color that most closely matches an RGB value.
`QColormap::Gray` | `2` | Similar to `Indexed`, pixel values represent a vector of available gray tones. QColormap uses the index of the gray tone that most closely matches the computed gray tone of an RGB value.

## Member Function Documentation

### QColormap::QColormap(const QColormap &colormap)

Constructs a copy of another colormap.

### QColormap::~QColormap()

Destroys the colormap.

### const QColor QColormap::colorAt(uint pixel) const

Returns a QColor for the pixel.

See also pixel().

### const QVector<QColor> QColormap::colormap() const

Returns a vector of colors which represents the devices colormap for `Indexed` and `Gray` modes. This function returns an empty vector for `Direct` mode.

See also size().

### int QColormap::depth() const

Returns the depth of the device.

See also size().

### `[static]` QColormap QColormap::instance(int screen = -1)

Returns the colormap for the specified screen. If screen is -1, this function returns the colormap for the default screen.

### Mode QColormap::mode() const

Returns the mode of this colormap.

See also QColormap::Mode.

### uint QColormap::pixel(const QColor &color) const

Returns a device dependent pixel value for the color.

See also colorAt().

### int QColormap::size() const

Returns the size of the colormap for `Indexed` and `Gray` modes; Returns -1 for `Direct` mode.

See also colormap().

### QColormap &QColormap::operator=(const QColormap &colormap)

Assigns the given colormap to this color map and returns a reference to this color map.

This function was introduced in Qt 4.2.