X-Git-Url: http://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_add_wch.3x.html;h=52bed5a853511aefce9f26c2ff080738c49a973e;hb=89730563d0a660d4ddd83d28660dc23c6d3f0bed;hp=3891f83ccf57bd19f2d46f89baa68eba8f9f7049;hpb=47d2fb4537d9ad5bb14f4810561a327930ca4280;p=ncurses.git diff --git a/doc/html/man/curs_add_wch.3x.html b/doc/html/man/curs_add_wch.3x.html index 3891f83c..52bed5a8 100644 --- a/doc/html/man/curs_add_wch.3x.html +++ b/doc/html/man/curs_add_wch.3x.html @@ -27,7 +27,7 @@ * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** - * @Id: curs_add_wch.3x,v 1.26 2020/02/02 23:34:34 tom Exp @ + * @Id: curs_add_wch.3x,v 1.27 2020/03/22 00:25:15 tom Exp @ --> @@ -188,7 +188,24 @@
All routines return the integer ERR upon failure and OK on success. - Functions with a "mv" prefix first perform a cursor movement using + X/Open does not define any error conditions. This implementation + returns an error + + o if the window pointer is null or + + o if it is not possible to add a complete character in the window. + + The latter may be due to different causes: + + o If scrollok 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 + + o 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. + + Functions with a "mv" prefix first perform a cursor movement using wmove, and return an error if the position is outside the window, or if the window pointer is null. @@ -198,71 +215,71 @@
- All of these functions are described in the XSI Curses standard, Issue - 4. The defaults specified for line-drawing characters apply in the + All of these functions are described in the XSI Curses standard, Issue + 4. The defaults specified for line-drawing characters apply in the POSIX locale. - X/Open Curses makes it clear that the WACS_ symbols should be defined + X/Open Curses makes it clear that the WACS_ symbols should be defined as a pointer to cchar_t data, e.g., in the discussion of border_set. A few implementations are problematic: o NetBSD curses defines the symbols as a wchar_t within a cchar_t. o HPUX curses equates some of the ACS_ symbols to the analogous WACS_ - symbols as if the ACS_ symbols were wide characters. The misde- - fined symbols are the arrows and other symbols which are not used + symbols as if the ACS_ symbols were wide characters. The misde- + fined symbols are the arrows and other symbols which are not used for line-drawing. X/Open Curses does not define symbols for thick- or double-lines. SVr4 - curses implementations defined their line-drawing symbols in terms of - intermediate symbols. This implementation extends those symbols, pro- + curses implementations defined their line-drawing symbols in terms of + intermediate symbols. This implementation extends those symbols, pro- viding new definitions which are not in the SVr4 implementations. - Not all Unicode-capable terminals provide support for VT100-style + Not all Unicode-capable terminals provide support for VT100-style alternate character sets (i.e., the acsc capability), with their corre- - sponding line-drawing characters. X/Open Curses did not address the - aspect of integrating Unicode with line-drawing characters. Existing - implementations of Unix curses (AIX, HPUX, Solaris) use only the acsc - character-mapping to provide this feature. As a result, those imple- - mentations can only use single-byte line-drawing characters. Ncurses - 5.3 (2002) provided a table of Unicode values to solve these problems. + sponding line-drawing characters. X/Open Curses did not address the + aspect of integrating Unicode with line-drawing characters. Existing + implementations of Unix curses (AIX, HPUX, Solaris) use only the acsc + character-mapping to provide this feature. As a result, those imple- + mentations can only use single-byte line-drawing characters. Ncurses + 5.3 (2002) provided a table of Unicode values to solve these problems. NetBSD curses incorporated that table in 2010. In this implementation, the Unicode values are used instead of the ter- - minal description's acsc mapping as discussed in ncurses(3x) for the - environment variable NCURSES_NO_UTF8_ACS. In contrast, for the same + minal description's acsc mapping as discussed in ncurses(3x) for the + environment variable NCURSES_NO_UTF8_ACS. In contrast, for the same cases, the line-drawing characters described in curs_addch(3x) will use only the ASCII default values. - Having Unicode available does not solve all of the problems with line- + Having Unicode available does not solve all of the problems with line- drawing for curses: - o The closest Unicode equivalents to the VT100 graphics S1, S3, S7 - and S9 frequently are not displayed at the regular intervals which + o The closest Unicode equivalents to the VT100 graphics S1, S3, S7 + and S9 frequently are not displayed at the regular intervals which the terminal used. - o The lantern is a special case. It originated with the AT&T 4410 - terminal in the early 1980s. There is no accessible documentation + o The lantern is a special case. It originated with the AT&T 4410 + terminal in the early 1980s. There is no accessible documentation depicting the lantern symbol on the AT&T terminal. Lacking documentation, most readers assume that a storm lantern was intended. But there are several possibilities, all with problems. - Unicode 6.0 (2010) does provide two lantern symbols: U+1F383 and - U+1F3EE. Those were not available in 2002, and are irrelevant - since they lie outside the BMP and as a result are not generally + Unicode 6.0 (2010) does provide two lantern symbols: U+1F383 and + U+1F3EE. Those were not available in 2002, and are irrelevant + since they lie outside the BMP and as a result are not generally available in terminals. They are not storm lanterns, in any case. Most storm lanterns have a tapering glass chimney (to guard against tipping); some have a wire grid protecting the chimney. - For the tapering appearance, U+2603 was adequate. In use on a + For the tapering appearance, U+2603 was adequate. In use on a terminal, no one can tell what the image represents. Unicode calls it a snowman. - Others have suggested these alternatives: S U+00A7 (section mark), + Others have suggested these alternatives: S U+00A7 (section mark), O U+0398 (theta), O U+03A6 (phi), d U+03B4 (delta), U+2327 (x in a - rectangle), U+256C (forms double vertical and horizontal), and + rectangle), U+256C (forms double vertical and horizontal), and U+2612 (ballot box with x).