curs_add_wch

Section: Miscellaneous Library Functions (3X)
Updated:
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NAME

add_wch, wadd_wch, mvadd_wch, mvwadd_wch, echo_wchar, wecho_wchar - add a complex character and rendition to a curses window, then advance the cursor  

SYNOPSIS

#include <curses.h>

int add_wch( const cchar_t *wch );
int wadd_wch( WINDOW *win, const cchar_t *wch );
int mvadd_wch( int y, int x, const cchar_t *wch );
int mvwadd_wch( WINDOW *win, int y, int x, const cchar_t *wch );
int echo_wchar( const cchar_t *wch );
int wecho_wchar( WINDOW *win, const cchar_t *wch );
 

DESCRIPTION

 

add_wch

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:

*

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 to the next spacing character on the screen.

*

If wch refers to a non-spacing character, all previous characters at that location are preserved. The non-spacing characters of wch are added to the spacing complex character, and the rendition specified by wch is ignored.

*

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.

 

echo_wchar

The echo_wchar function is functionally equivalent to a call to add_wch followed by a call to refresh. 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.  

Line Graphics

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).

The wide-character configuration of ncurses also defines symbols
l l l l
_ _ _ _
lw(1.5i) lw7 lw7 lw20.
Name	Unicode	Default	Description
WACS_T_ULCORNER
WACS_T_LLCORNER	0x2517
WACS_T_URCORNER	0x2513	+	thick upper right corner
WACS_T_LRCORNER	0x251b	+	thick lower right corner
WACS_T_LTEE	0x252b	+	thick tee pointing right
WACS_T_RTEE	0x2523	+	thick tee pointing left
WACS_T_BTEE	0x253b	+	thick tee pointing up
WACS_T_TTEE			0x2533	+	thick tee pointing down
WACS_T_HLINE	0x2501	-	thick horizontal line
WACS_T_VLINE	0x2503	|	thick vertical line
WACS_T_PLUS
WACS_D_ULCORNER	0x2554	+
WACS_D_LLCORNER	0x255a
WACS_D_URCORNER		0x2557
WACS_D_LRCORNER	0x255d
WACS_D_RTEE	0x2563	+	double tee pointing left
WACS_D_LTEE	0x2560
WACS_D_BTEE		0x2569	+	double tee pointing up
0x2566	+	double tee pointing down
WACS_D_HLINE		0x2550	-	double horizontal line
		0x2551	|	double vertical line
WACS_D_PLUS	0x256c		+	double large plus or crossover

 

RETURN VALUE

All routines return the integer ERR upon failure and OK on success.

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.  

NOTES

Note that add_wch, mvadd_wch, mvwadd_wch, and echo_wchar may be macros.  

PORTABILITY

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 as a pointer to cchar_t data, e.g., in the discussion of border_set. A few implementations are problematic:

*

NetBSD curses defines the symbols as a wchar_t within a cchar_t.

*

HPUX 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 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, providing new definitions which are not in the SVr4 implementations.  

SEE ALSO

curses(3X), curs_addch(3X), curs_attr(3X), curs_clear(3X), curs_outopts(3X), curs_refresh(3X), putwc(3)

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Index

NAME

SYNOPSIS

DESCRIPTION

add_wch

echo_wchar

Line Graphics

RETURN VALUE

NOTES

PORTABILITY

SEE ALSO