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. In the case of “ center” on
input, a non-empty abbreviation of it may also be used on input.
- 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_CENTER. 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 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 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 is not a legal anchor
value, then “unknown anchor position” is returned.
KEYWORDS¶
anchor position