gdk-Colormaps-and-Colors {RGtk2} | R Documentation

## Colormaps and Colors

### Description

Manipulation of colors and colormaps

### Methods and Functions

`gdkColormapNew(visual, allocate)`
`gdkColormapGetSystem()`
`gdkColormapGetSystemSize()`
`gdkColormapAllocColors(colormap, colors, writeable, best.match)`
`gdkColormapAllocColor(object, color, writeable, best.match)`
`gdkColormapFreeColors(object, colors)`
`gdkColormapQueryColor(object, pixel)`
`gdkColormapGetVisual(object)`
`gdkColormapGetScreen(object)`
`gdkColorsStore(object, colors)`
`gdkColorWhite(object)`
`gdkColorBlack(object)`
`gdkColorParse(spec)`
`gdkColorAlloc(object, color)`
`gdkColorChange(object, color)`
`gdkColorToString(object)`
`gdkColormap(visual, allocate)`

### Detailed Description

These functions are used to modify colormaps. A colormap is an object that contains the mapping between the color values stored in memory and the RGB values that are used to display color values. In general, colormaps only contain significant information for pseudo-color visuals, but even for other visual types, a colormap object is required in some circumstances.

There are a couple of special colormaps that can be retrieved. The system colormap (retrieved with `gdkColormapGetSystem`) is the default colormap of the system. If you are using GdkRGB, there is another colormap that is important - the colormap in which GdkRGB works, retrieved with `gdkRgbGetColormap`. However, when using GdkRGB, it is not generally necessary to allocate colors directly.

In previous revisions of this interface, a number of functions that take a `GdkColormap` parameter were replaced with functions whose names began with "gdk_colormap_". This process will probably be extended somewhat in the future - `gdkColorWhite`, `gdkColorBlack`, and `gdkColorChange` will probably become aliases.

### Structures

`GdkColor`

  The `GdkColor` structure is used to describe an allocated or unallocated color. `GdkColor` is a transparent-type.

  `pixel`

    [numeric] For allocated colors, the value used to draw this color on the screen.

  `red`

    [integer] The red component of the color. This is a value between 0 and 65535, with 65535 indicating full intensitiy.

  `green`

    [integer] The blue component of the color.

  `blue`

    [integer] The green component of the color.

`GdkColormap`

  The colormap structure contains the following public fields.

  `size`

    For pseudo-color colormaps, the number of colors in the colormap.

  `colors`

    An list containing the current values in the colormap. This can be used to map from pixel values back to RGB values. This is only meaningful for pseudo-color colormaps.

### Convenient Construction

`gdkColormap` is the equivalent of `gdkColormapNew`.

### Author(s)

Derived by RGtkGen from GTK+ documentation

### References

https://developer.gnome.org/gdk2/stable/gdk2-Colormaps-and-Colors.html

[Package RGtk2 version 2.20.36.3 Index]