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Tk_GetColormap(3)	     Tk	Library	Procedures	     Tk_GetColormap(3)

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NAME
       Tk_GetColormap,	Tk_PreserveColormap,  Tk_FreeColormap  -  allocate and
       free colormaps

SYNOPSIS
       #include	<tk.h>

       Colormap
       Tk_GetColormap(interp, tkwin, string)

       Tk_PreserveColormap(display, colormap)

       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.

       const 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 allo-
				       cated.

       Colormap	colormap (in)	       Colormap	to  free  or  preserve;	  must
				       have  been  returned by a previous call
				       to Tk_GetColormap or Tk_GetVisual.
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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 col-
       ormap from that window is returned.  If string does not 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's result.

       Tk_PreserveColormap  increases  the internal reference count for	a col-
       ormap previously	returned by Tk_GetColormap, which allows the  colormap
       to be stored in several locations without knowing which order they will
       be released.

       Tk_FreeColormap should be called	when a colormap	returned by Tk_GetCol-
       ormap  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 and each call
       to Tk_PreserveColormap.	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;	  how-
       ever,  it  can  be used in other	windows	by calling Tk_GetColormap with
       the original window's name as string.

KEYWORDS
       colormap, visual

Tk				      4.0		     Tk_GetColormap(3)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | KEYWORDS

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