Tk_GetAnchorFromObj




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 mod-                                           ified    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.


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_CEN-        TER.  Anchor positions are typically used for indicating a point on  an        object that will be used to position the object, e.g. 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 doesn't contain a valid anchor position or an abbre-        viation of one of these names, TCL_ERROR  is  returned,  *anchorPtr  is        unmodified, and an error message is stored in interp's result if interp        isn't 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 caching 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 isn't a legal anchor value,
       then ``unknown anchor position'' is returned.


KEYWORDS
       anchor position



Tk                                    8.1               Tk_GetAnchorFromObj(3)