.\"***************************************************************************
-.\" Copyright (c) 2001-2015,2017 Free Software Foundation, Inc. *
+.\" Copyright 2019-2020,2021 Thomas E. Dickey *
+.\" Copyright 2001-2015,2017 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: curs_add_wch.3x,v 1.23 2017/05/20 14:45:24 Sven.Joachim Exp $
+.\" $Id: curs_add_wch.3x,v 1.31 2021/12/25 21:37:49 tom Exp $
.TH curs_add_wch 3X ""
.ie \n(.g .ds `` \(lq
.el .ds `` ``
.ie \n(.g .ds '' \(rq
.el .ds '' ''
.de bP
-.IP \(bu 4
+.ie n .IP \(bu 4
+.el .IP \(bu 2
..
.SH NAME
\fBadd_wch\fP,
\fBmvadd_wch\fP,
\fBmvwadd_wch\fP,
\fBecho_wchar\fP,
-\fBwecho_wchar\fP \- add a complex character and rendition to a \fBcurses\fR window, then advance the cursor
+\fBwecho_wchar\fP \- add a complex character and rendition to a \fBcurses\fP window, then advance the cursor
.SH SYNOPSIS
.PP
\fB#include <curses.h>\fP
.B "int mvadd_wch( int \fIy\fP, int \fIx\fP, const cchar_t *\fIwch\fB );"
.br
.B "int mvwadd_wch( WINDOW *\fIwin\fP, int \fIy\fP, int \fIx\fP, const cchar_t *\fIwch\fB );"
-.br
+.sp
.B "int echo_wchar( const cchar_t *\fIwch\fB );"
.br
.B "int wecho_wchar( WINDOW *\fIwin\fP, const cchar_t *\fIwch\fB );"
.bP
If the character part of \fIwch\fP is
a tab, newline, backspace or other control character,
-the window is updated and the cursor moves as if \fBaddch\fR were called.
+the window is updated and the cursor moves as if \fBaddch\fP were called.
.SS echo_wchar
.PP
The \fBecho_wchar\fP
l l l l l
_ _ _ _ _
lw(1.5i) lw5 lw5 lw5 lw20.
-\fBACS\fR \fBUnicode\fP \fBASCII\fR \fBacsc\fP \fBGlyph\fR
-\fBName\fR \fBDefault\fP \fBDefault\fR \fBchar\fP \fBName\fR
+\fBACS\fP \fBUnicode\fP \fBASCII\fP \fBacsc\fP \fBGlyph\fP
+\fBName\fP \fBDefault\fP \fBDefault\fP \fBchar\fP \fBName\fP
WACS_BLOCK 0x25ae # 0 solid square block
WACS_BOARD 0x2592 # h board of squares
WACS_BTEE 0x2534 + v bottom tee
.TE
.PP
The wide-character configuration of ncurses also defines symbols
-for double-lines:
+for thick lines (\fBacsc\fP \*(``J\*('' to \*(``V\*(''):
+.TS
+l l l l l
+l l l l l
+_ _ _ _ _
+lw(1.5i) lw5 lw5 lw5 lw20.
+\fBACS\fP \fBUnicode\fP \fBASCII\fP \fBacsc\fP \fBGlyph\fP
+\fBName\fP \fBDefault\fP \fBDefault\fP \fBchar\fP \fBName\fP
+WACS_T_BTEE 0x253b + V thick tee pointing up
+WACS_T_HLINE 0x2501 - Q thick horizontal line
+WACS_T_LLCORNER 0x2517 + M thick lower left corner
+WACS_T_LRCORNER 0x251b + J thick lower right corner
+WACS_T_LTEE 0x252b + T thick tee pointing right
+WACS_T_PLUS 0x254b + N thick large plus
+WACS_T_RTEE 0x2523 + U thick tee pointing left
+WACS_T_TTEE 0x2533 + W thick tee pointing down
+WACS_T_ULCORNER 0x250f + L thick upper left corner
+WACS_T_URCORNER 0x2513 + K thick upper right corner
+WACS_T_VLINE 0x2503 | X thick vertical line
+.TE
+.PP
+and for double-lines (\fBacsc\fP \*(``A\*('' to \*(``I\*(''):
.PP
.TS
l l l l l
l l l l l
_ _ _ _ _
lw(1.5i) lw5 lw5 lw5 lw20.
-\fBACS\fR \fBUnicode\fP \fBASCII\fR \fBacsc\fP \fBGlyph\fR
-\fBName\fR \fBDefault\fP \fBDefault\fR \fBchar\fP \fBName\fR
+\fBACS\fP \fBUnicode\fP \fBASCII\fP \fBacsc\fP \fBGlyph\fP
+\fBName\fP \fBDefault\fP \fBDefault\fP \fBchar\fP \fBName\fP
WACS_D_BTEE 0x2569 + H double tee pointing up
WACS_D_HLINE 0x2550 - R double horizontal line
WACS_D_LLCORNER 0x255a + D double lower left corner
WACS_D_VLINE 0x2551 | Y double vertical line
.TE
.PP
-and for thick lines:
-.TS
-l l l l l
-l l l l l
-_ _ _ _ _
-lw(1.5i) lw5 lw5 lw5 lw20.
-\fBACS\fR \fBUnicode\fP \fBASCII\fR \fBacsc\fP \fBGlyph\fR
-\fBName\fR \fBDefault\fP \fBDefault\fR \fBchar\fP \fBName\fR
-WACS_T_BTEE 0x253b + V thick tee pointing up
-WACS_T_HLINE 0x2501 - Q thick horizontal line
-WACS_T_LLCORNER 0x2517 + M thick lower left corner
-WACS_T_LRCORNER 0x251b + J thick lower right corner
-WACS_T_LTEE 0x252b + T thick tee pointing right
-WACS_T_PLUS 0x254b + N thick large plus
-WACS_T_RTEE 0x2523 + U thick tee pointing left
-WACS_T_TTEE 0x2533 + W thick tee pointing down
-WACS_T_ULCORNER 0x250f + L thick upper left corner
-WACS_T_URCORNER 0x2513 + K thick upper right corner
-WACS_T_VLINE 0x2503 | X thick vertical line
-.TE
+Unicode's descriptions for these characters differs slightly from ncurses,
+by introducing the term \*(``light\*('' (along with less important details).
+Here are its descriptions for the normal, thick, and double horizontal lines:
+.bP
+U+2500 BOX DRAWINGS LIGHT HORIZONTAL
+.bP
+U+2501 BOX DRAWINGS HEAVY HORIZONTAL
+.bP
+U+2550 BOX DRAWINGS DOUBLE HORIZONTAL
.SH RETURN VALUE
.PP
-All routines return the integer \fBERR\fR upon failure and \fBOK\fR on success.
+All routines return the integer \fBERR\fP upon failure and \fBOK\fP on success.
+.PP
+X/Open does not define any error conditions.
+This implementation returns an error
+.bP
+if the window pointer is null or
+.bP
+if it is not possible to add a complete character in the window.
+.PP
+The latter may be due to different causes:
+.bP
+If \fBscrollok\fP is not enabled,
+writing a character at the lower right margin succeeds.
+However, an error is returned because
+it is not possible to wrap to a new line
+.bP
+If an error is detected when converting a multibyte character to a sequence
+of bytes,
+or if it is not possible to add all of the resulting bytes in the window,
+an error is returned.
.PP
Functions with a \*(``mv\*('' prefix first perform a cursor movement using
\fBwmove\fP, and return an error if the position is outside the window,
The defaults specified for line-drawing characters apply in the POSIX locale.
.PP
X/Open Curses makes it clear that the WACS_ symbols should be defined as
-a pointer to \fBcchar_t\fP data, e.g., in the discussion of \fBborder_set\fR.
+a pointer to \fBcchar_t\fP data, e.g., in the discussion of \fBborder_set\fP.
A few implementations are problematic:
.bP
NetBSD curses defines the symbols as a \fBwchar_t\fP within a \fBcchar_t\fP.
.bP
-HPUX curses equates some of the \fIACS_\fP symbols
-to the analogous \fIWACS_\fP symbols as if the \fIACS_\fP symbols were
+HPUX curses equates some of the \fBACS_\fP symbols
+to the analogous \fBWACS_\fP symbols as if the \fBACS_\fP symbols were
wide characters.
The misdefined symbols are the arrows
and other symbols which are not used for line-drawing.
.SH SEE ALSO
.na
.PP
-\fBcurses\fR(3X),
-\fBcurs_addch\fR(3X),
-\fBcurs_attr\fR(3X),
-\fBcurs_clear\fR(3X),
-\fBcurs_outopts\fR(3X),
-\fBcurs_refresh\fR(3X),
-\fBputwc\fR(3)
+\fBcurses\fP(3X),
+\fBcurs_addch\fP(3X),
+\fBcurs_attr\fP(3X),
+\fBcurs_clear\fP(3X),
+\fBcurs_outopts\fP(3X),
+\fBcurs_refresh\fP(3X),
+\fBputwc\fP(3)