Tk_GetAnchorFromObj(3)

Tk_GetAnchorFromObj(3)Tk Library ProceduresTk_GetAnchorFromObj(3)

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NAME

     Tk_GetAnchorFromObj,   Tk_GetAnchor,    Tk_NameOfAnchor    -
     translate between strings and anchor positions

SYNOPSIS

     #include <tk.h>

     int
     Tk_GetAnchorFromObj(interp, objPtr, anchorPtr)

     int
     Tk_GetAnchor(interp, string, anchorPtr)

     const char *
     Tk_NameOfAnchor(anchor)

ARGUMENTS

     Tcl_Interp *interp (in)            Interpreter  to  use  for
                                        error reporting, or NULL.

     Tcl_Obj *objPtr (in/out)           String   value   contains
                                        name   of  anchor  point:
                                        "n",  "ne",  "e",   "se",
                                        "s",  "sw", "w", "nw", or
                                        "center";  internal   rep
                                        will be modified to cache
                                        corresponding Tk_Anchor.

     const char *string (in)            Same  as  objPtr   except
                                        description   of   anchor
                                        point  is  passed  as   a
                                        string.

     int *anchorPtr (out)               Pointer  to  location  in
                                        which   to  store  anchor
                                        position corresponding to
                                        objPtr or string.

     Tk_Anchor anchor (in)              Anchor   position,   e.g.
                                        TCL_ANCHOR_CENTER.
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DESCRIPTION

     Tk_GetAnchorFromObj places in *anchorPtr an anchor  position
     (enumerated type Tk_Anchor) corresponding to objPtr's value.
     The  result  will  be  one  of  TK_ANCHOR_N,   TK_ANCHOR_NE,
     TK_ANCHOR_E,    TK_ANCHOR_SE,   TK_ANCHOR_S,   TK_ANCHOR_SW,
     TK_ANCHOR_W,  TK_ANCHOR_NW,  or  TK_ANCHOR_CENTER.    Anchor
     positions  are  typically  used for indicating a point on an
     object that will  be  used  to  position  the  object,  e.g.

Tk                      Last change: 8.1                        1

Tk_GetAnchorFromObj(3)Tk Library ProceduresTk_GetAnchorFromObj(3)

     TK_ANCHOR_N  means  position  the  top  center  point of the
     object at a particular place.

     Under normal circumstances the return value  is  TCL_OK  and
     interp is unused.  If string does not contain a valid anchor
     position or an abbreviation of one of these names, TCL_ERROR
     is  returned, *anchorPtr is unmodified, and an error message
     is  stored  in  interp's  result  if  interp  is  not  NULL.
     Tk_GetAnchorFromObj  caches  information  about  the  return
     value  in  objPtr,  which  speeds   up   future   calls   to
     Tk_GetAnchorFromObj with the same objPtr.

     Tk_GetAnchor is identical to Tk_GetAnchorFromObj except that
     the  description  of  the  anchor is specified with a string
     instead of an object.  This prevents Tk_GetAnchor from cach-
     ing the return value, so Tk_GetAnchor is less efficient than
     Tk_GetAnchorFromObj.

     Tk_NameOfAnchor is  the  logical  inverse  of  Tk_GetAnchor.
     Given  an  anchor  position such as TK_ANCHOR_N it returns a
     statically-allocated string  corresponding  to  anchor.   If
     anchor  is  not  a  legal anchor value, then "unknown anchor
     position" is returned.

KEYWORDS

     anchor position

Tk                      Last change: 8.1                        2