Tk_FreeColormap

Tk_GetColormap(3)            Tk Library Procedures           Tk_GetColormap(3)



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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 allo-
                                       cated.

       Colormap   colormap   (in)      Colormap  to  free;   must  have   been
                                       returned  by a previous call to Tk_Get-
                                       Colormap 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 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_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.  When  a  col-
       ormap'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



Tk                                    4.0                    Tk_GetColormap(3)