notcurses/doc/man/man3/notcurses_direct.3.md

% notcurses_direct(3) % nick black nickblack@linux.com % v2.1.7

NAME

notcurses_direct - minimal notcurses instances for styling text

SYNOPSIS

#include <notcurses/direct.h>

#define NCDIRECT_OPTION_INHIBIT_SETLOCALE   0x0001ull
#define NCDIRECT_OPTION_INHIBIT_CBREAK      0x0002ull
#define NCDIRECT_OPTION_NO_QUIT_SIGHANDLERS 0x0008ull

struct ncdirect ncdirect_init(const char termtype, FILE* fp, uint64_t flags);**

unsigned ncdirect_palette_size(const struct ncdirect nc);*

int ncdirect_set_bg_rgb8(struct ncdirect nc, unsigned r, unsigned g, unsigned b);*

int ncdirect_set_fg_rgb8(struct ncdirect nc, unsigned r, unsigned g, unsigned b);*

int ncdirect_set_fg_rgb(struct ncdirect nc, unsigned rgb);*

int ncdirect_set_bg_rgb(struct ncdirect nc, unsigned rgb);*

int ncdirect_set_fg_default(struct ncdirect nc);*

int ncdirect_set_bg_default(struct ncdirect nc);*

int ncdirect_set_fg_palindex(struct ncdirect nc, int pidx);*

int ncdirect_set_bg_palindex(struct ncdirect nc, int pidx);*

int ncdirect_dim_x(const struct ncdirect nc);*

int ncdirect_dim_y(const struct ncdirect nc);*

int ncdirect_styles_set(struct ncdirect n, unsigned stylebits);*

int ncdirect_styles_on(struct ncdirect n, unsigned stylebits);*

int ncdirect_styles_off(struct ncdirect n, unsigned stylebits);*

int ncdirect_clear(struct ncdirect nc)*

int ncdirect_stop(struct ncdirect nc);*

int ncdirect_cursor_move_yx(struct ncdirect n, int y, int x);*

int ncdirect_cursor_enable(struct ncdirect nc);*

int ncdirect_cursor_disable(struct ncdirect nc);*

int ncdirect_cursor_up(struct ncdirect nc, int num);*

int ncdirect_cursor_left(struct ncdirect nc, int num);*

int ncdirect_cursor_right(struct ncdirect nc, int num);*

int ncdirect_cursor_down(struct ncdirect nc, int num);*

int ncdirect_putstr(struct ncdirect nc, uint64_t channels, const char utf8);**

int ncdirect_printf_aligned(struct ncdirect n, int y, ncalign_e align, const char fmt, ...);**

bool ncdirect_canopen_images(const struct ncdirect n);*

bool ncdirect_canutf8(const struct ncdirect n);*

int ncdirect_hline_interp(struct ncdirect n, const char egc, int len, uint64_t h1, uint64_t h2);**

int ncdirect_vline_interp(struct ncdirect n, const char egc, int len, uint64_t h1, uint64_t h2);**

int ncdirect_box(struct ncdirect n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, const wchar_t wchars, int ylen, int xlen, unsigned ctlword);**

int ncdirect_rounded_box(struct ncdirect n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, int ylen, int xlen, unsigned ctlword);*

int ncdirect_double_box(struct ncdirect n, uint64_t ul, uint64_t ur, uint64_t ll, uint64_t lr, int ylen, int xlen, unsigned ctlword);*

int ncdirect_render_image(struct ncdirect n, const char filename, ncblitter_e blitter, ncscale_e scale);**

char ncdirect_readline(struct ncdirect n, const char* prompt);**

DESCRIPTION

ncdirect_init prepares the FILE provided as fp for colorizing and styling. On success, a pointer to a valid struct ncdirect is returned. NULL is returned on failure. Before the process exits, ncdirect_stop should be called to reset the terminal and free up resources. ncdirect_init places the terminal into "cbreak" (also known as "rare") mode, disabling line-buffering and echo of input. ncdirect_stop restores the terminal state as it was when the corresponding ncdirect_init call was made.

The following flags are defined:

• NCDIRECT_OPTION_INHIBIT_SETLOCALE: Unless this flag is set, ncdirect_init will call setlocale(LC_ALL, NULL). If the result is either "C" or "POSIX", it will print a diagnostic to stderr, and then call setlocale(LC_ALL, ""). This will attempt to set the locale based off the LANG environment variable. Your program should call setlocale(3) itself, usually as one of the first lines.

• NCDIRECT_OPTION_INHIBIT_CBREAK: Unless this flag is set, ncdirect_init will place the terminal into cbreak mode (i.e. disabling echo and line buffering; see tcgetattr(3)).

• NCDIRECT_OPTION_NO_QUIT_SIGHANDLERS: A signal handler will usually be installed for SIGINT, SIGQUIT, SIGSEGV, SIGTERM, and SIGABRT, cleaning up the terminal on such exceptions. With this flag, the handler will not be installed.

An appropriate terminfo(5) entry must exist for the terminal. This entry is usually selected using the value of the TERM environment variable (see getenv(3)), but a non-NULL value for termtype will override this. An invalid terminfo specification can lead to reduced performance, reduced display capabilities, and/or display errors. notcurses natively targets 24bpp/8bpc RGB color, and it is thus desirable to use a terminal with the rgb capability (e.g. xterm's xterm-direct).

ncdirect_dim_x returns the current number of columns, and ncdirect_dim_y the current number of rows.

ncdirect_clear clears the screen using a control code if one exists in terminfo. Otherwise, it prints successive newlines to scroll everything off.

ncdirect_cursor_move_yx moves the cursor to the specified coordinate. -1 can be specified for either y or x to leave that axis unchanged.

ncdirect_enable_cursor and ncdirect_disable_cursor always flush the output stream, taking effect immediately.

ncdirect_cursor_up and friends all move relative to the current position. Attempting to e.g. move up while on the top row will return 0, but have no effect.

ncdirect_readline uses the Readline library to read a (heap-allocated) line of arbitrary length, supporting line-editing controls. For more information, consult readline(3). If you want input echoed to the terminal while using ncdirect_readline, NCDIRECT_OPTION_INHIBIT_CBREAK must be supplied to ncdirect_init.

RETURN VALUES

ncdirect_init returns NULL on failure. Otherwise, the return value points to a valid struct ncdirect, which can be used until it is provided to ncdirect_stop.

ncdirect_putstr and ncdirect_printf_aligned return the number of bytes written on success. On failure, they return some negative number.

All other functions return 0 on success, and non-zero on error.

SEE ALSO

getenv(3), readline(3) notcurses(3), notcurses_plane(3), terminfo(5), termios(3)