1Tk_GetAnchorFromObj(3)       Tk Library Procedures      Tk_GetAnchorFromObj(3)
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NAME

8       Tk_GetAnchorFromObj,  Tk_GetAnchor, Tk_NameOfAnchor - translate between
9       strings and anchor positions
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SYNOPSIS

12       #include <tk.h>
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14       int                                                                     │
15       Tk_GetAnchorFromObj(interp, objPtr, anchorPtr)                          │
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17       int
18       Tk_GetAnchor(interp, string, anchorPtr)
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20       CONST char *
21       Tk_NameOfAnchor(anchor)
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ARGUMENTS

24       Tcl_Interp  *interp      (in)      Interpreter to use for error report‐
25                                          ing, or NULL.
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27       Tcl_Obj     *objPtr      (in/out)                                       │
28                                          String value contains name of anchor │
29                                          point: n, ne, e, se, s, sw,  w,  nw, │
30                                          or center; internal rep will be mod‐ │
31                                          ified   to    cache    corresponding │
32                                          Tk_Anchor.                           │
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34       CONST char  *string      (in)                                           │
35                                          Same as objPtr except description of │
36                                          anchor point is passed as a string.
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38       int         *anchorPtr   (out)     Pointer  to  location  in  which  to
39                                          store  anchor position corresponding
40                                          to objPtr or string.
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42       Tk_Anchor   anchor       (in)      Anchor        position,         e.g.
43                                          TCL_ANCHOR_CENTER.
44_________________________________________________________________
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DESCRIPTION

48       Tk_GetAnchorFromObj places in *anchorPtr an anchor position (enumerated │
49       type Tk_Anchor) corresponding to objPtr's value.  The  result  will  be │
50       one    of   TK_ANCHOR_N,   TK_ANCHOR_NE,   TK_ANCHOR_E,   TK_ANCHOR_SE, │
51       TK_ANCHOR_S, TK_ANCHOR_SW, TK_ANCHOR_W, TK_ANCHOR_NW, or TK_ANCHOR_CEN‐ │
52       TER.   Anchor positions are typically used for indicating a point on an │
53       object that will be used to position the object, e.g. TK_ANCHOR_N means │
54       position the top center point of the object at a particular place.      │
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56       Under  normal  circumstances  the  return value is TCL_OK and interp is │
57       unused.  If string doesn't contain a valid anchor position or an abbre‐ │
58       viation  of  one  of  these names, TCL_ERROR is returned, *anchorPtr is │
59       unmodified, and an error message is stored in interp's result if interp │
60       isn't  NULL.   Tk_GetAnchorFromObj  caches information about the return │
61       value in objPtr, which speeds up future  calls  to  Tk_GetAnchorFromObj │
62       with the same objPtr.                                                   │
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64       Tk_GetAnchor  is  identical  to  Tk_GetAnchorFromObj  except  that  the │
65       description of the anchor is specified with  a  string  instead  of  an │
66       object.   This  prevents Tk_GetAnchor from caching the return value, so │
67       Tk_GetAnchor is less efficient than Tk_GetAnchorFromObj.
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69       Tk_NameOfAnchor is the  logical  inverse  of  Tk_GetAnchor.   Given  an
70       anchor  position  such as TK_ANCHOR_N it returns a statically-allocated
71       string corresponding to anchor.  If anchor isn't a legal anchor  value,
72       then ``unknown anchor position'' is returned.
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KEYWORDS

76       anchor position
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80Tk                                    8.1               Tk_GetAnchorFromObj(3)