Tcl/Tk Applications | Tcl Commands | Tk Commands | Tcl Library | Tk Library
- 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
- DESCRIPTION
- KEYWORDS
NAME
Tk_GetAnchorFromObj, Tk_GetAnchor, Tk_NameOfAnchor - translate between strings and anchor positionsSYNOPSIS
#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.
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.