- 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
- DESCRIPTION
- KEYWORDS
Tk_GetColormap, Tk_PreserveColormap, Tk_FreeColormap — allocate and
free colormaps
#include <tk.h>
Colormap
Tk_GetColormap(interp, tkwin, string)
Tk_PreserveColormap(display, colormap)
Tk_FreeColormap(display, colormap)
- 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 allocated.
- Colormap colormap (in)
- Colormap to free or preserve; must have been returned by a
previous call to Tk_GetColormap or Tk_GetVisual.
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
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 colormap 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_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 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; however,
it can be used in other windows by calling Tk_GetColormap
with the original window's name as string.
colormap, visual
Copyright © 1994 The Regents of the University of
California.
Copyright © 1994-1996 Sun Microsystems, Inc.