notcurses_output(3)

NAME

notcurses_output - output to ncplanes

SYNOPSIS

#include <notcurses/notcurses.h>

static inline int ncplane_putc(struct ncplane* n, const nccell* c);

int ncplane_putc_yx(struct ncplane* n, int y, int x, const nccell* c);

static inline int ncplane_putchar(struct ncplane* n, char c);

static inline int ncplane_putchar_yx(struct ncplane* n, int y, int x, char c);

int ncplane_putchar_stained(struct ncplane* n, char c);

static inline int ncplane_putwc(struct ncplane* n, wchar_t w);

int ncplane_putwc_yx(struct ncplane* n, int y, int x, wchar_t w);

static inline int ncplane_putwc_stained(struct ncplane* n, wchar_t w);

static inline int ncplane_putegc(struct ncplane* n, const char* gclust, int* sbytes);

int ncplane_putegc_yx(struct ncplane* n, int y, int x, const char* gclust, int* sbytes);

int ncplane_putegc_stained(struct ncplane* n, const char* gclust, int* sbytes);

static inline int ncplane_putwegc(struct ncplane* n, const wchar_t* gclust, int* sbytes);

static inline int ncplane_putwegc_yx(struct ncplane* n, int y, int x, const wchar_t* gclust, int* sbytes);

int ncplane_putwegc_stained(struct ncplane* n, const wchar_t* gclust, int* sbytes);

int ncplane_putstr_yx(struct ncplane* n, int y, int x, const char* gclustarr);

static inline int ncplane_putstr(struct ncplane* n, const char* gclustarr);

int ncplane_putstr_aligned(struct ncplane* n, int y, ncalign_e align, const char* s);

int ncplane_putstr_stained(struct ncplane* n, const char* s);

static inline int ncplane_putwstr(struct ncplane* n, const wchar_t* gclustarr);

int ncplane_putwstr_yx(struct ncplane* n, int y, int x, const wchar_t* gclustarr);

static inline int ncplane_putwstr_aligned(struct ncplane* n, int y, ncalign_e align, const wchar_t* gclustarr);

int ncplane_putwstr_stained(struct ncplane* n, const wchar_t* gclustarr);

static inline int ncplane_putnstr(struct ncplane* n, size_t s, const char* gclustarr);

int ncplane_putnstr_yx(struct ncplane* n, int y, int x, size_t s, const char* gclusters);

int ncplane_putnstr_aligned(struct ncplane* n, int y, ncalign_e align, size_t s, const char* s);

int ncplane_vprintf_aligned(struct ncplane* n, int y, ncalign_e align, const char* format, va_list ap);

int ncplane_vprintf_yx(struct ncplane* n, int y, int x, const char* format, va_list ap);

static inline int ncplane_vprintf(struct ncplane* n, const char* format, va_list ap);

static inline int ncplane_printf(struct ncplane* n, const char* format, ...);

static inline int ncplane_printf_yx(struct ncplane* n, int y, int x, const char* format, ...);

static inline int ncplane_printf_aligned(struct ncplane* n, int y, ncalign_e align, const char* format, ...);

int ncplane_cursor_move_yx(struct ncplane* n, int y, int x);

int ncplane_puttext(struct ncplane* n, int y, ncalign_e align, const char* text, size_t* bytes);

DESCRIPTION

These functions write EGCs (Extended Grapheme Clusters) to the specified struct ncplanes. The following inputs are supported:

•   ncplane_putc(): writes a single nccell (see notcurses_cell(3))

•   ncplane_putchar(): writes a single 7-bit ASCII character

•   ncplane_putwc(): writes a single wchar_t (following UTF-8 conversion)

•   ncplane_putwegc(): writes a single EGC from an array of wchar_t

•   ncplane_putegc(): writes a single EGC from an array of UTF-8

•   ncplane_putstr(): writes a set of EGCs from an array of UTF-8

•   ncplane_putwstr(): writes a set of EGCs from an array of wchar_t

•   ncplane_vprintf(): formatted output using va_list

•   ncplane_printf(): formatted output using variadic arguments

•   ncplane_puttext(): multi-line, line-broken, aligned text

All of these use the ncplane's active styling, save notcurses_putc(), which uses the nccell's styling. Functions accepting a single EGC expect a series of wchar_t terminated by L'\0' or a series of UTF-8 char terminated by '\0'. The EGC must be well-formed, and must not contain any cluster breaks. For more information, consult Unicode® Standard Annex #29 (https://unicode.org/reports/tr29/). Functions accepting a set of EGCs must consist of a series of well-formed EGCs, broken by cluster breaks, terminated by the appropriate NUL terminator.

Control characters are rejected, aside from two exceptions: a horizontal tab (', 0x09), and a newline ('', 0x0a) when the output plane is in scrolling mode. A newline outside of scrolling mode will be rejected. A tab will advance to the next tab stop, filling the space between with spaces. Tab stops are separated by eight columns, and the first character of each line is a tab stop.

These functions output to the ncplane's current cursor location. Aside from ncplane_puttext(), they do not move to the next line upon reaching the right extreme of the containing plane. If the entirety of the content cannot be output, they will output as much as possible.

Each of these base functions has two additional forms:

•   ncplane_putc_aligned(), etc.: accepts a row and an alignment type

•   ncplane_putc_yx(), etc.: accepts a row and column

If a positional parameter is -1, no movement will be made along that axis. Passing -1, -1 to e.g. ncplane_putc_yx() is equivalent to calling the base form. These functions are implemented by moving the cursor, and then performing the output. The two steps are atomic on success (it is not possible for another caller to move the cursor between when it is positioned, and when output begins), and thus these functions ought generally be preferred to an explicit ncplane_cursor_move_yx().

Upon successful return, the cursor will follow the last cell output.

RETURN VALUES

ncplane_cursor_move_yx() returns -1 on error (invalid coordinate), or 0 on success.

For output functions, a negative return indicates an error with the inputs. Otherwise, the number of screen columns output is returned. It is entirely possible to get a short return, if there was insufficient room to output all EGCs.

SEE ALSO

fprintf(3) notcurses(3), notcurses_cell(3), notcurses_plane(3), stdarg(3), ascii(7), unicode(7), utf-8(7)

AUTHORS
nick black <nickblack@linux.com>.