Tk_GetColormap(3Tk)Tk_GetColormap(3Tk)NAME
Tk_GetColormap, Tk_FreeColormap - allocate and free colormaps
SYNOPSIS
#include <tk.h>
Colormap
Tk_GetColormap(interp, tkwin, string)
Tk_FreeColormap(display, colormap)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter to use for error reporting.
Tk_Window tkwin (in) Token for window in which colormap will
be used.
char *string (in) Selects a colormap: either new or the
name of a window with the same screen and
visual as tkwin.
Display *display (in) Display for which colormap was allocated.
Colormap colormap (in) Colormap to free; must have been
returned by a previous call to
Tk_GetColormap or Tk_GetVisual.
DESCRIPTION
These procedures are used to manage colormaps. Tk_GetColormap returns a
colormap suitable for use in tkwin. If its string argument is new then a
new colormap is created; otherwise string must be the name of another
window with the same screen and visual as tkwin, and the colormap from
that window is returned. If string doesn't make sense, or if it refers
to a window on a different screen from tkwin or with a different visual
than tkwin, then Tk_GetColormap returns None and leaves an error message
in interp->result.
Tk_FreeColormap should be called when a colormap returned by
Tk_GetColormap is no longer needed. Tk maintains a reference count for
each colormap returned by Tk_GetColormap, so there should eventually be
one call to Tk_FreeColormap for each call to Tk_GetColormap. When a
colormap's reference count becomes zero, Tk releases the X colormap.
Tk_GetVisual and Tk_GetColormap work together, in that a new colormap
created by Tk_GetVisual may later be returned by Tk_GetColormap. The
reference counting mechanism for colormaps includes both procedures, so
callers of Tk_GetVisual must also call Tk_FreeColormap to release the
colormap. If Tk_GetColormap is called with a string value of new then
the resulting colormap will never be returned by Tk_GetVisual; however,
it can be used in other windows by calling Tk_GetColormap with the
original window's name as string.
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Tk_GetColormap(3Tk)Tk_GetColormap(3Tk)KEYWORDS
colormap
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