ansi_screen.c

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#include <stdio.h>
#include <curses.h>
#include <ipxe/ansicol.h>
#include <ipxe/console.h>

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

static void ansiscr_reset(struct _curses_screen *scr) __nonnull;
static void ansiscr_movetoyx(struct _curses_screen *scr,
                               unsigned int y, unsigned int x) __nonnull;
static void ansiscr_putc(struct _curses_screen *scr, chtype c) __nonnull;

static unsigned int saved_usage;

static void ansiscr_attrs ( struct _curses_screen *scr, attr_t attrs ) {
        int bold = ( attrs & A_BOLD );
        attr_t cpair = PAIR_NUMBER ( attrs );

        if ( scr->attrs != attrs ) {
                scr->attrs = attrs;
                /* Reset attributes and set/clear bold as appropriate */
                printf ( "\033[0;%dm", ( bold ? 1 : 22 ) );
                /* Set foreground and background colours */
                ansicol_set_pair ( cpair );
        }
}

static void ansiscr_reset ( struct _curses_screen *scr ) {
        /* Reset terminal attributes and clear screen */
        scr->attrs = 0;
        scr->curs_x = 0;
        scr->curs_y = 0;
        printf ( "\0330m" );
        ansicol_set_pair ( CPAIR_DEFAULT );
        printf ( "\033[2J" );
}

static void ansiscr_init ( struct _curses_screen *scr ) {
        saved_usage = console_set_usage ( CONSOLE_USAGE_TUI );
        ansiscr_reset ( scr );
}

static void ansiscr_exit ( struct _curses_screen *scr ) {
        ansiscr_reset ( scr );
        console_set_usage ( saved_usage );
}

static void ansiscr_erase ( struct _curses_screen *scr, attr_t attrs ) {
        ansiscr_attrs ( scr, attrs );
        printf ( "\033[2J" );
}

static void ansiscr_movetoyx ( struct _curses_screen *scr,
                               unsigned int y, unsigned int x ) {
        if ( ( x != scr->curs_x ) || ( y != scr->curs_y ) ) {
                /* ANSI escape sequence to update cursor position */
                printf ( "\033[%d;%dH", ( y + 1 ), ( x + 1 ) );
                scr->curs_x = x;
                scr->curs_y = y;
        }
}

static void ansiscr_putc ( struct _curses_screen *scr, chtype c ) {
        unsigned int character = ( c & A_CHARTEXT );
        attr_t attrs = ( c & ( A_ATTRIBUTES | A_COLOR ) );

        /* Update attributes if changed */
        ansiscr_attrs ( scr, attrs );

        /* Print the actual character */
        putchar ( character );

        /* Update expected cursor position */
        if ( ++(scr->curs_x) == COLS ) {
                scr->curs_x = 0;
                ++scr->curs_y;
        }
}

static int ansiscr_getc ( struct _curses_screen *scr __unused ) {
        return getchar();
}

static bool ansiscr_peek ( struct _curses_screen *scr __unused ) {
        return iskey();
}

static void ansiscr_cursor ( struct _curses_screen *scr __unused,
                             int visibility ) {
        printf ( "\033[?25%c", ( visibility ? 'h' : 'l' ) );
}

SCREEN _ansi_screen = {
        .init           = ansiscr_init,
        .exit           = ansiscr_exit,
        .erase          = ansiscr_erase,
        .movetoyx       = ansiscr_movetoyx,
        .putc           = ansiscr_putc,
        .getc           = ansiscr_getc,
        .peek           = ansiscr_peek,
        .cursor         = ansiscr_cursor,
};