X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_add_wch.3x.html;h=a7dee58c93d89beb36793260b181be5ccb51ef3c;hb=fc11bff62abb32a3e7724180a94c1068c148ea6c;hp=64c645d5ad022464fe8ca6b46cd448f04d758849;hpb=e607aef87171fae9359b0c43a04d8d932719bc71;p=ncurses.git diff --git a/doc/html/man/curs_add_wch.3x.html b/doc/html/man/curs_add_wch.3x.html index 64c645d5..a7dee58c 100644 --- a/doc/html/man/curs_add_wch.3x.html +++ b/doc/html/man/curs_add_wch.3x.html @@ -28,19 +28,19 @@ * sale, use or other dealings in this Software without prior written * * authorization. * **************************************************************************** - * @Id: curs_add_wch.3x,v 1.62 2024/04/20 21:20:07 tom Exp @ + * @Id: curs_add_wch.3x,v 1.63 2024/05/11 21:31:45 tom Exp @ -->
-curs_add_wch(3x) Library calls curs_add_wch(3x) @@ -49,7 +49,7 @@
add_wch, wadd_wch, mvadd_wch, mvwadd_wch, echo_wchar, wecho_wchar - add - a curses complex character to a window and advance the cursor + a curses complex character to a window, possibly advancing the cursor
@@ -66,55 +66,85 @@
-
- The add_wch, wadd_wch, mvadd_wch, and mvwadd_wch functions put the - complex character wch into the given window at its current position, - which is then advanced. These functions perform wrapping and special- - character processing as follows: - - o If wch refers to a spacing character, then any previous character - at that location is removed. A new character specified by wch is - placed at that location with rendition specified by wch. The - cursor then advances after this spacing character, to prepare for - writing the next character on the screen. - - The newly added spacing character is the base of the active complex - character. Subsequent non-spacing characters can be combined with - this base until another spacing character is written to the screen, - or the cursor is moved, e.g., using wmove. - - o If wch refers to a non-spacing character, it is appended to the - active complex character, retaining the previous characters at that - location. The rendition specified by wch is ignored. - - The cursor is not advanced after adding a non-spacing character. - Subsequent calls to add non-spacing characters will update the same - position. +
+ wadd_wch writes the complex character wch to the window win, then may + advance the cursor position, analogously to the standard C library's + putwchar(3). ncurses(3x) describes the variants of this function. + + Much behavior depends on whether the wide characters in wch are spacing + or non-spacing; see subsection "Complex Characters" below. + + o If wch contains a spacing character, then any character at the + cursor is first removed. The complex character wch, with its + attributes and color pair identifier, becomes the base of the + active complex character. + + o If wch contains only non-spacing characters, they are combined with + the active complex character. curses ignores its attributes and + color pair identifier, and does not advance the cursor. + + Further non-spacing characters added with wadd_wch are not written at + the new cursor position but combine with the active complex character + until another spacing character is written to the window or the cursor + is moved. + + If advancement occurs at the right margin, + + o the cursor automatically wraps to the beginning of the next line, + then, + + o if it was at the bottom of the scrolling region, and if + scrollok(3x) is enabled for win, the scrolling region scrolls up + one line. - o If the character part of wch is a tab, newline, backspace or other - control character, the window is updated and the cursor moves as if - addch were called. + If wch is a backspace, carriage return, line feed, or tab, the cursor + moves appropriately within the window. + o Backspace moves the cursor one character left; at the left margin + of a window, it does nothing. -
- The echo_wchar function is functionally equivalent to a call to add_wch - followed by a call to refresh(3x). Similarly, the wecho_wchar is - functionally equivalent to a call to wadd_wch followed by a call to - wrefresh. The knowledge that only a single character is being output - is taken into consideration and, for non-control characters, a - considerable performance gain might be seen by using the *echo* - functions instead of their equivalents. + o Carriage return moves the cursor to the left margin on the current + line of the window. + o Line feed does a clrtoeol(3x), then advances as if from the right + margin. -
- Like addch(3x), addch_wch accepts symbols which make it simple to draw - lines and other frequently used special characters. These symbols - correspond to the same VT100 line-drawing set as addch(3x). + o Tab advances the cursor to the next tab stop (possibly on the next + line); these are placed at every eighth column by default. Alter + the tab interval with the TABSIZE extension; see + curs_variables(3x). - Unicode ASCII acsc + If wch is any other nonprintable character, it is drawn in printable + form using the same convention as wunctrl(3x). + Calling win_wch(3x) on the location of a nonprintable character does + not return the character itself, but its wunctrl(3x) representation. - ACS Name Default Default Char Glyph Name + +
+ echo_wchar and wecho_wchar are equivalent to calling (w)add_wch + followed by (w)refresh. curses interprets these functions as a hint + that only a single (complex) character is being output; for non-control + characters, a considerable performance gain may be enjoyed by employing + them. + + +
+ curses defines macros starting with WACS_ that can be used with + wadd_wch to write line-drawing and other special characters to the + screen. ncurses terms these forms-drawing characters. The ACS default + listed below is used if the acs_chars (acsc) terminfo capability does + not define a terminal-specific replacement for it, or if the terminal + and locale configuration requires Unicode to access these characters + but the library is unable to use Unicode. The "acsc char" column + corresponds to how the characters are specified in the acs_chars (acsc) + string capability, and the characters in it may appear on the screen if + the terminal type's database entry incorrectly advertises ACS support. + The name "ACS" originates in the Alternate Character Set feature of the + DEC VT100 terminal. + + Unicode ACS acsc + Symbol Default Default char Glyph Name ------------------------------------------------------------------------ WACS_BLOCK 0x25ae # 0 solid square block WACS_BOARD 0x2592 # h board of squares @@ -179,7 +209,6 @@ WACS_D_LTEE 0x2560 + F double tee pointing right WACS_D_PLUS 0x256c + E double large plus WACS_D_RTEE 0x2563 + G double tee pointing left - WACS_D_TTEE 0x2566 + I double tee pointing down WACS_D_ULCORNER 0x2554 + C double upper left corner WACS_D_URCORNER 0x2557 + B double upper right corner @@ -198,124 +227,122 @@
- All routines return the integer ERR upon failure and OK on success. + These functions return OK on success and ERR on failure. In ncurses, + wadd_wch returns ERR if - X/Open Curses does not specify any error conditions. This - implementation returns an error + o win is NULL, - o if the window pointer is null or + o wrapping to a new line is impossible because scrollok(3x) has not + been called on win when writing to its bottom right location is + attempted, or - o if it is not possible to add a complete character in the window. + o it is not possible to add a complete character at the cursor + position. - The latter may be due to different causes: + Functions prefixed with "mv" first perform cursor movement and fail if + the position (y, x) is outside the window boundaries. - o If scrollok(3x) 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. +
+ add_wch, mvadd_wch, mvwadd_wch, and echo_wchar may be implemented as + macros. - Functions prefixed with "mv" first perform cursor movement and fail if - the position (y, x) is outside the window boundaries. +
-
- Note that add_wch, mvadd_wch, mvwadd_wch, and echo_wchar may be macros. +
+ The TABSIZE variable is implemented in SVr4 and other versions of + curses, but is not specified by X/Open Curses (see curs_variables(3x)).
- These functions are described in X/Open Curses, Issue 4. The defaults - specified for line-drawing characters apply in the POSIX locale. + These functions are described in X/Open Curses, Issue 4. It specifies + no error conditions for them. + SVr4 curses describes a successful return value only as "an integer + value other than ERR". -
- 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: + The defaults specified for forms-drawing characters apply in the POSIX + locale. 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 HP-UX curses equates some of the ACS_ symbols to the analogous - WACS_ symbols as if the ACS_ symbols were wide characters. The - misdefined symbols are the arrows and other symbols which are not + o HP-UX curses equates some of the ACS_ symbols to the analogous + WACS_ symbols as if the ACS_ symbols were wide characters. The + misdefined symbols are the arrows and other symbols which are not used for line-drawing. - X/Open Curses does not specify symbols for thick- or double-lines. + X/Open Curses does not specify symbols for thick- or double-lines. SVr4 curses implementations defined their line-drawing symbols in terms - of intermediate symbols. This implementation extends those symbols, + of intermediate symbols. This implementation extends those symbols, providing new definitions which are not in the SVr4 implementations. - Not all Unicode-capable terminals provide support for VT100-style - alternate character sets (i.e., the acsc capability), with their - corresponding line-drawing characters. X/Open Curses did not address - the aspect of integrating Unicode with line-drawing characters. - Existing implementations of Unix curses (AIX, HP-UX, Solaris) use only + Not all Unicode-capable terminals provide support for VT100-style + alternate character sets (i.e., the acsc capability), with their + corresponding line-drawing characters. X/Open Curses did not address + the aspect of integrating Unicode with line-drawing characters. + Existing implementations of Unix curses (AIX, HP-UX, Solaris) use only the acsc character-mapping to provide this feature. As a result, those implementations can only use single-byte line-drawing characters. - ncurses 5.3 (2002) provided a table of Unicode values to solve these + 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 + In this implementation, the Unicode values are used instead of the terminal description's acsc mapping as discussed in ncurses(3x) for the - environment variable NCURSES_NO_UTF8_ACS. In contrast, for the same + environment variable NCURSES_NO_UTF8_ACS. In contrast, for the same cases, the line-drawing characters described in 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: <section> U+00A7 (section - mark), <Theta> U+0398 (theta), <Phi> U+03A6 (phi), <delta> U+03B4 + mark), <Theta> U+0398 (theta), <Phi> U+03A6 (phi), <delta> U+03B4 (delta), U+2327 (x in a rectangle), U+256C (forms double vertical and horizontal), and U+2612 (ballot box with x).
- The complex character type cchar_t can store more than one wide - character (wchar_t). The X/Open Curses description does not mention - this possibility, describing only the cases where wch is a spacing - character or a non-spacing character. + The complex character type cchar_t can store more than one wide + character (wchar_t). X/Open Curses does not mention this possibility, + specifying behavior only where wch is a single character, either + spacing or non-spacing. - This implementation assumes that wch is constructed using setcchar(3x), - and in turn that the result + ncurses assumes that wch is constructed using setcchar(3x), and in turn + that the result - o contains at most one spacing character in the beginning of its list - of wide characters, and zero or more non-spacing characters or + o contains at most one spacing character at the beginning of its list + of wide characters, and zero or more non-spacing characters, or - o may hold one non-spacing character. + o holds one non-spacing character. - In the latter case, ncurses adds the non-spacing character to the - active (base) spacing character. - - -
- The TABSIZE variable is implemented in SVr4 and other versions of - curses, but is not specified by X/Open Curses (see curs_variables(3x)). + In the latter case, ncurses adds the non-spacing character to the + active complex character.
@@ -328,7 +355,7 @@ -ncurses 6.5 2024-04-20 curs_add_wch(3x) +ncurses 6.5 2024-05-11 curs_add_wch(3x)