tk_getcolormap(3)
NAME
Tk_GetColormap, Tk_FreeColormap - allocate and free col
ormaps
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.
- 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; must
- have been returned by a
previous call to Tk_Get
Colormap or Tk_GetVisual.
DESCRIPTION
These procedures are used to manage colormaps. Tk_GetCol
ormap 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_GetCol
ormap, so there should eventually be one call to Tk_Free
Colormap 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; however, it can be used in other windows
by calling Tk_GetColormap with the original window's name
as string.
KEYWORDS
- colormap