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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
#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 );
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. 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). Name Unicode Default Description ──────────────────────────────────────────────────────────────── WACS_BLOCK 0x25ae # solid square block WACS_BOARD 0x2592 # board of squares WACS_BTEE 0x2534 + bottom tee WACS_BULLET 0x00b7 o bullet WACS_CKBOARD 0x2592 : checker board (stipple) WACS_DARROW 0x2193 v arrow pointing down WACS_DEGREE 0x00b0 ' degree symbol WACS_DIAMOND 0x25c6 + diamond WACS_GEQUAL 0x2265 > greater-than-or-equal-to WACS_HLINE 0x2500 - horizontal line WACS_LANTERN 0x2603 # lantern symbol WACS_LARROW 0x2190 < arrow pointing left WACS_LEQUAL 0x2264 < less-than-or-equal-to WACS_LLCORNER 0x2514 + lower left-hand corner WACS_LRCORNER 0x2518 + lower right-hand corner WACS_LTEE 0x2524 + left tee WACS_NEQUAL 0x2260 ! not-equal WACS_PI 0x03c0 * greek pi WACS_PLMINUS 0x00b1 # plus/minus WACS_PLUS 0x253c + plus WACS_RARROW 0x2192 > arrow pointing right WACS_RTEE 0x251c + right tee WACS_S1 0x23ba - scan line 1 WACS_S3 0x23bb - scan line 3 WACS_S7 0x23bc - scan line 7 WACS_S9 0x23bd _ scan line 9 WACS_STERLING 0x00a3 f pound-sterling symbol WACS_TTEE 0x252c + top tee WACS_UARROW 0x2191 ^ arrow pointing up WACS_ULCORNER 0x250c + upper left-hand corner WACS_URCORNER 0x2510 + upper right-hand corner WACS_VLINE 0x2502 | vertical line The wide-character configuration of ncurses also defines symbols for thick- and double- lines: Name Unicode Default Description ───────────────────────────────────────────────────────────────────── WACS_T_ULCORNER 0x250f + thick upper left corner WACS_T_LLCORNER 0x2517 + thick lower left corner 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 0x254b + thick large plus or crossover WACS_D_ULCORNER 0x2554 + double upper left corner WACS_D_LLCORNER 0x255a + double lower left corner WACS_D_URCORNER 0x2557 + double upper right corner WACS_D_LRCORNER 0x255d + double lower right corner WACS_D_RTEE 0x2563 + double tee pointing left WACS_D_LTEE 0x2560 + double tee pointing right WACS_D_BTEE 0x2569 + double tee pointing up WACS_D_TTEE 0x2566 + double tee pointing down WACS_D_HLINE 0x2550 - double horizontal line WACS_D_VLINE 0x2551 | double vertical line WACS_D_PLUS 0x256c + double large plus or crossover
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.
Note that add_wch, mvadd_wch, mvwadd_wch, and echo_wchar may be macros.
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.