TkGetColormap(3) Tk Library Procedures TkGetColormap(3)

NAME
       TkGetColormap, TkFreeColormap - allocate and free colormaps

SYNOPSIS
       ##iinncclluuddee <>

       Colormap
       TTkkGGeettCCoolloorrmmaapp((interp, tkwin, string))

       TTkkFFrreeeeCCoolloorrmmaapp((display, colormap))

AARRGGUUMMEENNTTSS
       TclInterp *interp    (in)      Interpreter to use for error reporting.

       TkWindow  tkwin      (in)      Token for window in which colormap will
                                       be used.

       CONST char *string    (in)      Selects  a colormap:  either nneeww 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 TTkkGGeett-
                                       CCoolloorrmmaapp or TTkkGGeettVViissuuaall.



DESCRIPTION
       These procedures are used to manage colormaps.  TTkkGGeettCCoolloorrmmaapp  returns
       a  colormap  suitable  for use in tkwin.  If its string argument is nneeww
       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  TTkkGGeettCCoolloorrmmaapp  returns  NNoonnee  and
       leaves an error message in interp->result.

       TTkkFFrreeeeCCoolloorrmmaapp should be called when a colormap returned by TTkkGGeettCCooll-
       oorrmmaapp is no longer needed.  Tk maintains a  reference  count  for  each
       colormap  returned by TTkkGGeettCCoolloorrmmaapp, so there should eventually be one
       call to TTkkFFrreeeeCCoolloorrmmaapp for each call to TTkkGGeettCCoolloorrmmaapp.  When  a  col-
       ormap's reference count becomes zero, Tk releases the X colormap.

       TTkkGGeettVViissuuaall  and  TTkkGGeettCCoolloorrmmaapp work together, in that a new colormap
       created by TTkkGGeettVViissuuaall may later be returned by  TTkkGGeettCCoolloorrmmaapp.   The
       reference counting mechanism for colormaps includes both procedures, so
       callers of TTkkGGeettVViissuuaall must also call TTkkFFrreeeeCCoolloorrmmaapp to  release  the
       colormap.   If TTkkGGeettCCoolloorrmmaapp is called with a string value of nneeww then
       the resulting colormap will never be returned  by  TTkkGGeettVViissuuaall;   how-
       ever,  it  can  be used in other windows by calling TTkkGGeettCCoolloorrmmaapp with
       the original window's name as string.


KKEEYYWWOORRDDSS
       colormap



Tk                                    4.0                    TkGetColormap(3)