Tk\_GetAnchorFromObj(3) Tk Library Procedures Tk\_GetAnchorFromObj(3)

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# [NAME](#NAME)

Tk\_GetAnchorFromObj, Tk\_GetAnchor, Tk\_NameOfAnchor - translate between strings and anchor positions

# [SYNOPSIS](#SYNOPSIS)

```
#include <tk.h>

int
Tk_GetAnchorFromObj(interp, objPtr, anchorPtr)

int
Tk_GetAnchor(interp, string, anchorPtr)

const char *
Tk_NameOfAnchor(anchor)
```

# [ARGUMENTS](#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**.

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# [DESCRIPTION](#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](#KEYWORDS)

anchor position

8.1 Tk

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Document: Tk_GetAnchorFromObj(3) from tk 9.1.0-r0 (Chainguard OS)
Source: https://downloads.sourceforge.net/sourceforge/tcl/tk9.1.0-src.tar.gz