Tk_GetJustifyFromObj

Section: Tk Library Procedures (3)
Updated: 8.1
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NAME

Tk_GetJustifyFromObj, Tk_GetJustify, Tk_NameOfJustify - translate between strings and justification styles

SYNOPSIS

#include <tk.h>

int
Tk_GetJustifyFromObj(interp, objPtr, justifyPtr)

int
Tk_GetJustify(interp, string, justifyPtr)

const char *
Tk_NameOfJustify(justify)

ARGUMENTS

Tcl_Interp *interp (in) Interpreter to use for error reporting, or NULL.

Tcl_Obj *objPtr (in/out) String value contains name of justification style - one of ``left'', ``right'', or ``center'' - or a unique abbreviation of one. The internal rep will be modified to cache corresponding justify value.

const char *string (in) Same as objPtr except description of justification style is passed as a string.

int *justifyPtr (out) Pointer to location in which to store justify value corresponding to objPtr or string.

Tk_Justify justify (in) Justification style (one of the values listed below).

DESCRIPTION

Tk_GetJustifyFromObj places in *justifyPtr the justify value corresponding to objPtr's value. This value will be one of the following:

TK_JUSTIFY_LEFT: Means that the text on each line should start at the left edge of the line; as a result, the right edges of lines may be ragged.
TK_JUSTIFY_RIGHT: Means that the text on each line should end at the right edge of the line; as a result, the left edges of lines may be ragged.
TK_JUSTIFY_CENTER: Means that the text on each line should be centered; as a result, both the left and right edges of lines may be ragged.

Under normal circumstances the return value is TCL_OK and interp is unused. If objPtr does not contain a valid justification style or an abbreviation of one of these names, TCL_ERROR is returned, *justifyPtr is unmodified, and an error message is stored in interp's result if interp is not NULL. Tk_GetJustifyFromObj caches information about the return value in objPtr, which speeds up future calls to Tk_GetJustifyFromObj with the same objPtr.

Tk_GetJustify is identical to Tk_GetJustifyFromObj except that the description of the justification is specified with a string instead of an object. This prevents Tk_GetJustify from caching the return value, so Tk_GetJustify is less efficient than Tk_GetJustifyFromObj.

Tk_NameOfJustify is the logical inverse of Tk_GetJustify. Given a justify value it returns a statically-allocated string corresponding to justify. If justify is not a legal justify value, then ``unknown justification style'' is returned.

KEYWORDS

center, fill, justification, string