XInstallColormap() XInstallColormap()
Name
XInstallColormap - install a colormap.
Synopsis
XInstallColormap(display, colormap_return)
Display *display;
Colormap colormap_return;
Arguments
display Specifies a connection to an X server; returned from XOpenDisplay().
colormap_return
Specifies the colormap to install.
Description
XInstallColormap() installs a virtual colormap into a hardware colormap. If there is only one hardware colormap, XInstallColormap() loads
a virtual colormap into the hardware colormap. All windows associated with this colormap immediately display with their chosen colors.
Other windows associated with the old colormap will display with false colors. If additional hardware colormaps are possible, XInstallCol-
ormap() loads the new hardware map and keeps the existing ones. Other windows will then remain in their true colors unless the limit for
colormaps has been reached. If the maximum number of allowed hardware colormaps is already installed, an old colormap is swapped out. The
MinCmapsOfScreen(screen) and MaxCmapsOfScreen(screen) macros can be used to determine how many hardware colormaps are supported.
If colormap_return is not already an installed map, a ColormapNotify event is generated on every window having colormap_return as an
attribute. If a colormap is uninstalled as a result of the install, a ColormapNotify event is generated on every window having that col-
ormap as an attribute.
Colormaps are usually installed and uninstalled by the window manager, not by clients. At any time, there is a subset of the installed
colormaps, viewed as an ordered list, called the "required list." The length of the required list is at most the min_maps specified for
each screen in the Display structure. When a colormap is installed with XInstallColormap() it is added to the head of the required list
and the last colormap in the list is removed if necessary to keep the length of the list at min_maps. When a colormap is uninstalled with
XUninstallColormap() and it is in the required list, it is removed from the list. No other actions by the server or the client change the
required list. It is important to realize that on all but high-performance workstations, min_maps is likely to be 1. If the hardware col-
ormap is immutable, and therefore installing any colormap is impossible, XInstallColormap() will work but not do anything.
For more information, see Volume One, Chapter 7, Color.
Errors
BadColor Invalid colormap.
See Also
XDefaultColormap(), XDisplayCells(), XCopyColormapAndFree(), XCreateColormap(), XFreeColormap(), XGetStandardColormap(), XListInstalledCol-
ormaps(), XSetStandardColormap(), XSetWindowColormap(), XUninstallColormap().
Xlib - Colormaps XInstallColormap()
