yascreen - Man Page

All of the above can be or'ed into attribute, provided that the bits for foreground/background color are all zeroes.

• Special, generated internally

Previous versions of the library used -1 and 0x100+ for these codes. In order to achieve unicode wide character compatibility and simpler API, the reserved Unicode range 0xf0000-0xffffd is used for the special codes both in narrow and wide character input modes.

There is a macro YAS_IS_CC(code) that will evaluate to non-zero for the special codes and to zero for normal characters. Note that all ASCII control characters in the range 0x00-0x7f are treated as normal ones.

• Normal keys

• Extended keys, parsed from ANSI sequences

• Alt-<letter>

These codes are generated by a helper macro - YAS_K_ALT(keycode).

inline yascreen *yascreen_init(int sx,int sy);

allocate and initialize screen data

output defaults to stdout

in case output is a terminal and initial size is (0,0), the screen size is autodetected

in case of error, returns NULL

inline const char *yascreen_ver(void);

returns a string with the library version

inline int yascreen_setout(yascreen *s,ssize_t (*out)(yascreen *s,const void *data,size_t len));

set callback that handles output

if out=NULL, the output goes to stdout

the callback may implement internal buffering, a flush is signalled by calling out with len=0

inline void yascreen_set_unicode(yascreen *s,int on);

enable (on is non-zero) or disable (on=0) unicode input processing

by default unicode mode is on

changing the unicode input processing will flush all pending input

inline void yascreen_set_telnet(yascreen *s,int on);

enable (on is non-zero) or disable (on=0) telnet sequence processing

by default telnet mode is off

inline void yascreen_init_telnet(yascreen *s);

depending on telnet sequence processing, sends a set of telnet initialization sequences

inline int yascreen_resize(yascreen *s,int sx,int sy);

resize screen

should redraw afterwards

since allocation is involved, this may fail and return -1

inline void yascreen_free(yascreen *s);

finish the lifecycle of struct yascreen - all internally allocated memory is freed

inline void yascreen_term_save(yascreen *s);

save current terminal state on top of state stack

inline void yascreen_term_restore(yascreen *s);

restore previously saved terminal state from top of state stack

inline void yascreen_term_push(yascreen *s);

push current terminal state to state stack

inline void yascreen_term_pop(yascreen *s);

pop and restore previously saved terminal state from state stack

inline void yascreen_term_set(yascreen *s,int mode);

set terminal for proper screen operation

inline int yascreen_printxy(yascreen *s,int x,int y,uint32_t attr,const char *format,...) __attribute__((format(printf,5,6)));

inline int yascreen_putsxy(yascreen *s,int x,int y,uint32_t attr,const char *str);

print at position, if data exceeds buffer, then it gets truncated

inline int yascreen_printxyu(yascreen *s,int x,int y,uint32_t attr,const char *format,...) __attribute__((format(printf,5,6)));

inline int yascreen_putsxyu(yascreen *s,int x,int y,uint32_t attr,const char *str);

print at position, if data exceeds buffer, then it gets truncated

screen is immediately updated

inline int yascreen_update(yascreen *s);

sync memory state to screen

since allocation is involved, this may fail and return -1

inline void yascreen_redraw(yascreen *s);

set next update to be a full redraw

inline void yascreen_clear_mem(yascreen *s,uint32_t attr);

clear memory buffer

all cells in the screen are set to Space, using attr for colors and style

inline void yascreen_cursor(yascreen *s,int on);

hide (on=0) or show (on is non-zero) cusror

screen is updated immediately

inline void yascreen_cursor_xy(yascreen *s,int x,int y);

set cursor position

screen is updated immediately

inline void yascreen_altbuf(yascreen *s,int on);

switch between regular and alternative buffer

screen is updated immediately

inline void yascreen_clear(yascreen *s);

clear real screen, no change to memory buffers

inline void yascreen_clearln(yascreen *s);

clear current line, no change to memory buffers

inline void yascreen_update_attr(yascreen *s,uint32_t oattr,uint32_t nattr);

apply difference between two attrs and output the optimized ANSI sequence to switch from oattr to nattr

if oattr=0xffffffff, the full ANSI sequence will be generated

no change to memory buffers

yascreen_set_attr(s,attr)

reset all attrs and set specific one (attr)

inline int yascreen_print(yascreen *s,const char *format,...) __attribute__((format(printf,2,3)));

inline int yascreen_write(yascreen *s,const char *str,int len);

inline int yascreen_puts(yascreen *s,const char *str);

inline const char *yascreen_clearln_s(yascreen *s);

print in line mode

inline int yascreen_sx(yascreen *s);

get current x size

inline int yascreen_sy(yascreen *s);

get current y size

inline int yascreen_x(yascreen *s);

get current x

inline int yascreen_y(yascreen *s);

get current y

inline void yascreen_esc_to(yascreen *s,int timeout);

set timeout for single ESC key press

inline void yascreen_ckto(yascreen *s);

in case of external event loop, this call will check for single ESC key

should be called regularly enough so that the above specified timeout is not extended too much

if not called often enough then single ESC will be yielded after longer timeout

if not called at all then single ESC will be yielded with next key press

inline int yascreen_getch_to(yascreen *s,int timeout);

wait for a key, return ASCII or extended keycode, wait no more than timeout in milliseconds

yascreen_getch(s)

get a key without timeout

this macro expands to yascreen_getch_to(s,0)

zero timeout=wait forever

yascreen_getch_nowait(s)

get a key, if available, return immediately

this macro expands to yascreen_getch_to(s,-1)

negative timeout=do not wait

inline void yascreen_ungetch(yascreen *s,int key);

put back key value in key buffer

the internal key buffer is dynamically allocated, hence there is no limit of how many key codes may be put back, but in case of memory allocation failure, the error will not be reported and the key will not be put into the buffer

inline void yascreen_pushch(yascreen *s,int key);

push key value at end of key buffer

similar to yascreen_ungetch but the key code will be returned after all other key codes currently in the buffer

the internal key buffer is dynamically allocated, hence there is no limit of how many key codes may be put back, but in case of memory allocation failure, the error will not be reported and the key will not be put into the buffer

inline void yascreen_feed(yascreen *s,unsigned char c);

feed key sequence state machine with byte stream

this is useful to implement external event loop and read key codes by yascreen_getch_nowait until it returns -1

inline int yascreen_peekch(yascreen *s);

peek for key without removing it from input queue

inline void yascreen_getsize(yascreen *s,int *sx,int *sy);

get last reported screen size

set both to 0 if there is none

this will yield valid result after YAS_SCREEN_SIZE is returned as keypress

inline void yascreen_reqsize(yascreen *s);

request terminal to report its size via ANSI sequence

inline void yascreen_set_hint_i(yascreen *s,int hint);

inline int yascreen_get_hint_i(yascreen *s);

inline void yascreen_set_hint_p(yascreen *s,void *hint);

inline void *yascreen_get_hint_p(yascreen *s);

get/set opaque hint values

integer and pointer hints are stored separately and both can be used at the same time

these are useful to link the yascreen instance to user program data

for example a single output callback may output to socket or a terminal, depending on the hint values

inline void yascreen_line_flush(yascreen *s,int on);

enable/disable auto flush for line and direct screen oriented operations

yascreen versions before 1.77 didn't use buffered output and would immediately send the output to the screen

disabling internal flush can help an application optimize the number of write calls at the cost of performing explicit flush after each group of operations

explicit flush example:

yascreen_write(s,"",0);

inline wchar_t yascreen_getwch_to(yascreen *s,int timeout);

wait for a key, return wide character or extended keycode, wait no more than timeout in milliseconds

yascreen_getwch_to does not work in non-unicode mode and will always return YAS_K_NONE

mixing the utf8 and wide character input modes will break on multibyte utf8 sequences and is not supported

yascreen_getwch(s)

get a key as wide character without timeout

this macro expands to yascreen_getwch_to(s,0)

zero timeout=wait forever

yascreen_getwch does not work in non-unicode mode and will always return YAS_K_NONE

yascreen_getwch_nowait(s)

get a key as a wide character, if available, return immediately

this macro expands to yascreen_getwch_to(s,-1)

negative timeout=do not wait

yascreen_getwch_nowait does not work in non-unicode mode and will always return YAS_K_NONE

inline void yascreen_ungetwch(yascreen *s,wchar_t key);

put back wide character key value in key buffer

the internal key buffer is dynamically allocated, hence there is no limit of how many key codes may be put back, but in case of memory allocation failure, the error will not be reported and the key will not be put into the buffer

the internal key buffer contains utf8 and the wide character will be expanded to the appropriate utf8 sequence

yascreen_ungetwch does not do anything in non-unicode mode

inline wchar_t yascreen_peekwch(yascreen *s);

peek for key without removing it from input queue

yascreen_peekwch does not work in non-unicode mode and will always return YAS_K_NONE