/*
* Copyright (C) 1984-2023 Mark Nudelman
*
* You may distribute under the terms of either the GNU General Public
* License or the Less License, as specified in the README file.
*
* For more information, see the README file.
*/
/*
* Routines to manipulate the "line buffer".
* The line buffer holds a line of output as it is being built
* in preparation for output to the screen.
*/
#define MAX_PFX_WIDTH (MAX_LINENUM_WIDTH + MAX_STATUSCOL_WIDTH + 1)
static struct {
char *buf; /* Buffer which holds the current output line */
int *attr; /* Parallel to buf, to hold attributes */
int print; /* Index in buf of first printable char */
int end; /* Number of chars in buf */
char pfx[MAX_PFX_WIDTH]; /* Holds status column and line number */
int pfx_attr[MAX_PFX_WIDTH];
int pfx_end; /* Number of chars in pfx */
} linebuf;
/*
* Buffer of ansi sequences which have been shifted off the left edge
* of the screen.
*/
static struct xbuffer shifted_ansi;
/*
* Ring buffer of last ansi sequences sent.
* While sending a line, these will be resent at the end
* of any highlighted string, to restore text modes.
* {{ Not ideal, since we don't really know how many to resend. }}
*/
#define NUM_LAST_ANSIS 3
static struct xbuffer last_ansi;
static struct xbuffer last_ansis[NUM_LAST_ANSIS];
static int curr_last_ansi;
public int size_linebuf = 0; /* Size of line buffer (and attr buffer) */
static struct ansi_state *line_ansi = NULL;
static int ansi_in_line;
static int hlink_in_line;
static int line_mark_attr;
static int cshift; /* Current left-shift of output line buffer */
public int hshift; /* Desired left-shift of output line buffer */
public int tabstops[TABSTOP_MAX] = { 0 }; /* Custom tabstops */
public int ntabstops = 1; /* Number of tabstops */
public int tabdefault = 8; /* Default repeated tabstops */
public POSITION highest_hilite; /* Pos of last hilite in file found so far */
static POSITION line_pos;
static int end_column; /* Printable length, accounting for backspaces, etc. */
static int right_curr;
static int right_column;
static int overstrike; /* Next char should overstrike previous char */
static int last_overstrike = AT_NORMAL;
static int is_null_line; /* There is no current line */
static LWCHAR pendc;
static POSITION pendpos;
static char *end_ansi_chars;
static char *mid_ansi_chars;
static int in_hilite;
static int attr_swidth(int a);
static int attr_ewidth(int a);
static int do_append(LWCHAR ch, char *rep, POSITION pos);
extern int sigs;
extern int bs_mode;
extern int proc_backspace;
extern int proc_tab;
extern int proc_return;
extern int linenums;
extern int ctldisp;
extern int twiddle;
extern int binattr;
extern int status_col;
extern int status_col_width;
extern int linenum_width;
extern int auto_wrap, ignaw;
extern int bo_s_width, bo_e_width;
extern int ul_s_width, ul_e_width;
extern int bl_s_width, bl_e_width;
extern int so_s_width, so_e_width;
extern int sc_width, sc_height;
extern int utf_mode;
extern POSITION start_attnpos;
extern POSITION end_attnpos;
extern char rscroll_char;
extern int rscroll_attr;
extern int use_color;
extern int status_line;
static char mbc_buf[MAX_UTF_CHAR_LEN];
static int mbc_buf_len = 0;
static int mbc_buf_index = 0;
static POSITION mbc_pos;
static int saved_line_end;
static int saved_end_column;
/* State while processing an ANSI escape sequence */
struct ansi_state {
int hindex; /* Index into hyperlink prefix */
int hlink; /* Processing hyperlink address? */
int prev_esc; /* Prev char was ESC (to detect ESC-\ seq) */
};
/*
* Initialize from environment variables.
*/
public void init_line(void)
{
int ax;
end_ansi_chars = lgetenv("LESSANSIENDCHARS");
if (isnullenv(end_ansi_chars))
end_ansi_chars = "m";
mid_ansi_chars = lgetenv("LESSANSIMIDCHARS");
if (isnullenv(mid_ansi_chars))
mid_ansi_chars = "0123456789:;[?!\"'#%()*+ ";
/*
* Set a character in the line buffer.
*/
static void set_linebuf(int n, char ch, int attr)
{
if (n >= size_linebuf)
{
/*
* Won't fit in line buffer.
* Try to expand it.
*/
if (expand_linebuf())
return;
}
linebuf.buf[n] = ch;
linebuf.attr[n] = attr;
}
/*
* Append a character to the line buffer.
*/
static void add_linebuf(char ch, int attr, int w)
{
set_linebuf(linebuf.end++, ch, attr);
inc_end_column(w);
}
/*
* Append a string to the line buffer.
*/
static void addstr_linebuf(char *s, int attr, int cw)
{
for ( ; *s != '\0'; s++)
add_linebuf(*s, attr, cw);
}
/*
* Set a character in the line prefix buffer.
*/
static void set_pfx(int n, char ch, int attr)
{
linebuf.pfx[n] = ch;
linebuf.pfx_attr[n] = attr;
}
/*
* Append a character to the line prefix buffer.
*/
static void add_pfx(char ch, int attr)
{
set_pfx(linebuf.pfx_end++, ch, attr);
}
/*
* Insert the status column and line number into the line buffer.
*/
public void plinestart(POSITION pos)
{
LINENUM linenum = 0;
int i;
if (linenums == OPT_ONPLUS)
{
/*
* Get the line number and put it in the current line.
* {{ Note: since find_linenum calls forw_raw_line,
* it may seek in the input file, requiring the caller
* of plinestart to re-seek if necessary. }}
* {{ Since forw_raw_line modifies linebuf, we must
* do this first, before storing anything in linebuf. }}
*/
linenum = find_linenum(pos);
}
/*
* Display a status column if the -J option is set.
*/
if (status_col || status_line)
{
char c = posmark(pos);
if (c != 0)
line_mark_attr = AT_HILITE|AT_COLOR_MARK;
else if (start_attnpos != NULL_POSITION &&
pos >= start_attnpos && pos <= end_attnpos)
line_mark_attr = AT_HILITE|AT_COLOR_ATTN;
if (status_col)
{
add_pfx(c ? c : ' ', line_mark_attr); /* column 0: status */
while (linebuf.pfx_end < status_col_width)
add_pfx(' ', AT_NORMAL);
}
}
/*
* Display the line number at the start of each line
* if the -N option is set.
*/
if (linenums == OPT_ONPLUS)
{
char buf[INT_STRLEN_BOUND(linenum) + 2];
int len;
linenum = vlinenum(linenum);
if (linenum == 0)
len = 0;
else
{
linenumtoa(linenum, buf, 10);
len = (int) strlen(buf);
}
for (i = 0; i < linenum_width - len; i++)
add_pfx(' ', AT_NORMAL);
for (i = 0; i < len; i++)
add_pfx(buf[i], AT_BOLD|AT_COLOR_LINENUM);
add_pfx(' ', AT_NORMAL);
}
end_column = linebuf.pfx_end;
}
/*
* Return the width of the line prefix (status column and line number).
* {{ Actual line number can be wider than linenum_width. }}
*/
public int line_pfx_width(void)
{
int width = 0;
if (status_col)
width += status_col_width;
if (linenums == OPT_ONPLUS)
width += linenum_width + 1;
return width;
}
/*
* Shift line left so that the last char is just to the left
* of the first visible column.
*/
public void pshift_all(void)
{
int i;
for (i = linebuf.print; i < linebuf.end; i++)
if (linebuf.attr[i] == AT_ANSI)
xbuf_add_byte(&shifted_ansi, (unsigned char) linebuf.buf[i]);
linebuf.end = linebuf.print;
end_column = linebuf.pfx_end;
}
/*
* Return the printing width of the start (enter) sequence
* for a given character attribute.
*/
static int attr_swidth(int a)
{
int w = 0;
a = apply_at_specials(a);
if (a & AT_UNDERLINE)
w += ul_s_width;
if (a & AT_BOLD)
w += bo_s_width;
if (a & AT_BLINK)
w += bl_s_width;
if (a & AT_STANDOUT)
w += so_s_width;
return w;
}
/*
* Return the printing width of the end (exit) sequence
* for a given character attribute.
*/
static int attr_ewidth(int a)
{
int w = 0;
a = apply_at_specials(a);
if (a & AT_UNDERLINE)
w += ul_e_width;
if (a & AT_BOLD)
w += bo_e_width;
if (a & AT_BLINK)
w += bl_e_width;
if (a & AT_STANDOUT)
w += so_e_width;
return w;
}
/*
* Return the printing width of a given character and attribute,
* if the character were added after prev_ch.
* Adding a character with a given attribute may cause an enter or exit
* attribute sequence to be inserted, so this must be taken into account.
*/
public int pwidth(LWCHAR ch, int a, LWCHAR prev_ch, int prev_a)
{
int w;
if (ch == '\b')
{
/*
* Backspace moves backwards one or two positions.
*/
if (prev_a & (AT_ANSI|AT_BINARY))
return strlen(prchar('\b'));
return (utf_mode && is_wide_char(prev_ch)) ? -2 : -1;
}
if (!utf_mode || is_ascii_char(ch))
{
if (control_char((char)ch))
{
/*
* Control characters do unpredictable things,
* so we don't even try to guess; say it doesn't move.
* This can only happen if the -r flag is in effect.
*/
return (0);
}
} else
{
if (is_composing_char(ch) || is_combining_char(prev_ch, ch))
{
/*
* Composing and combining chars take up no space.
*
* Some terminals, upon failure to compose a
* composing character with the character(s) that
* precede(s) it will actually take up one end_column
* for the composing character; there isn't much
* we could do short of testing the (complex)
* composition process ourselves and printing
* a binary representation when it fails.
*/
return (0);
}
}
/*
* Other characters take one or two columns,
* plus the width of any attribute enter/exit sequence.
*/
w = 1;
if (is_wide_char(ch))
w++;
if (linebuf.end > 0 && !is_at_equiv(linebuf.attr[linebuf.end-1], a))
w += attr_ewidth(linebuf.attr[linebuf.end-1]);
if (apply_at_specials(a) != AT_NORMAL &&
(linebuf.end == 0 || !is_at_equiv(linebuf.attr[linebuf.end-1], a)))
w += attr_swidth(a);
return (w);
}
/*
* Delete to the previous base character in the line buffer.
*/
static int backc(void)
{
LWCHAR ch;
char *p;
if (linebuf.end == 0)
return (0);
p = &linebuf.buf[linebuf.end];
ch = step_char(&p, -1, linebuf.buf);
/* Skip back to the next nonzero-width char. */
while (p > linebuf.buf)
{
LWCHAR prev_ch;
int width;
linebuf.end = (int) (p - linebuf.buf);
prev_ch = step_char(&p, -1, linebuf.buf);
width = pwidth(ch, linebuf.attr[linebuf.end], prev_ch, linebuf.attr[linebuf.end-1]);
end_column -= width;
/* {{ right_column? }} */
if (width > 0)
break;
ch = prev_ch;
}
return (1);
}
/*
* Preserve the current position in the line buffer (for word wrapping).
*/
public void savec(void)
{
saved_line_end = linebuf.end;
saved_end_column = end_column;
}
/*
* Restore the position in the line buffer (start of line for word wrapping).
*/
public void loadc(void)
{
linebuf.end = saved_line_end;
end_column = saved_end_column;
}
/*
* Is a character the end of an ANSI escape sequence?
*/
public int is_ansi_end(LWCHAR ch)
{
if (!is_ascii_char(ch))
return (0);
return (strchr(end_ansi_chars, (char) ch) != NULL);
}
/*
* Can a char appear in an ANSI escape sequence, before the end char?
*/
public int is_ansi_middle(LWCHAR ch)
{
if (!is_ascii_char(ch))
return (0);
if (is_ansi_end(ch))
return (0);
return (strchr(mid_ansi_chars, (char) ch) != NULL);
}
/*
* Skip past an ANSI escape sequence.
* pp is initially positioned just after the CSI_START char.
*/
public void skip_ansi(struct ansi_state *pansi, char **pp, constant char *limit)
{
LWCHAR c;
do {
c = step_char(pp, +1, limit);
} while (*pp < limit && ansi_step(pansi, c) == ANSI_MID);
/* Note that we discard final char, for which is_ansi_end is true. */
}
/*
* Determine if a character starts an ANSI escape sequence.
* If so, return an ansi_state struct; otherwise return NULL.
*/
public struct ansi_state * ansi_start(LWCHAR ch)
{
struct ansi_state *pansi;
/*
* Determine whether the next char in an ANSI escape sequence
* ends the sequence.
*/
public int ansi_step(struct ansi_state *pansi, LWCHAR ch)
{
if (pansi->hlink)
{
/* Hyperlink ends with \7 or ESC-backslash. */
if (ch == '\7')
return ANSI_END;
if (pansi->prev_esc)
return (ch == '\\') ? ANSI_END : ANSI_ERR;
pansi->prev_esc = (ch == ESC);
return ANSI_MID;
}
if (pansi->hindex >= 0)
{
static char hlink_prefix[] = ESCS "]8;";
if (ch == hlink_prefix[pansi->hindex] ||
(pansi->hindex == 0 && IS_CSI_START(ch)))
{
pansi->hindex++;
if (hlink_prefix[pansi->hindex] == '\0')
pansi->hlink = 1; /* now processing hyperlink addr */
return ANSI_MID;
}
pansi->hindex = -1; /* not a hyperlink */
}
/* Check for SGR sequences */
if (is_ansi_middle(ch))
return ANSI_MID;
if (is_ansi_end(ch))
return ANSI_END;
return ANSI_ERR;
}
/*
* Free an ansi_state structure.
*/
public void ansi_done(struct ansi_state *pansi)
{
free(pansi);
}
/*
* Will w characters in attribute a fit on the screen?
*/
static int fits_on_screen(int w, int a)
{
if (ctldisp == OPT_ON)
/* We're not counting, so say that everything fits. */
return 1;
return (end_column - cshift + w + attr_ewidth(a) <= sc_width);
}
/*
* Append a character and attribute to the line buffer.
*/
#define STORE_CHAR(ch,a,rep,pos) \
do { \
if (store_char((ch),(a),(rep),(pos))) return (1); \
} while (0)
static int store_char(LWCHAR ch, int a, char *rep, POSITION pos)
{
int w;
int i;
int replen;
char cs;
i = (a & (AT_UNDERLINE|AT_BOLD));
if (i != AT_NORMAL)
last_overstrike = i;
#if HILITE_SEARCH
{
int matches;
int resend_last = 0;
int hl_attr = 0;
if (pos == NULL_POSITION)
{
/* Color the prompt unless it has ansi sequences in it. */
hl_attr = ansi_in_line ? 0 : AT_STANDOUT|AT_COLOR_PROMPT;
} else if (a != AT_ANSI)
{
hl_attr = is_hilited_attr(pos, pos+1, 0, &matches);
if (hl_attr == 0 && status_line)
hl_attr = line_mark_attr;
}
if (hl_attr)
{
/*
* This character should be highlighted.
* Override the attribute passed in.
*/
a |= hl_attr;
if (highest_hilite != NULL_POSITION && pos != NULL_POSITION && pos > highest_hilite)
highest_hilite = pos;
in_hilite = 1;
} else
{
if (in_hilite)
{
/*
* This is the first non-hilited char after a hilite.
* Resend the last ANSI seq to restore color.
*/
resend_last = 1;
}
in_hilite = 0;
}
if (resend_last)
{
int ai;
for (ai = 0; ai < NUM_LAST_ANSIS; ai++)
{
int ax = (curr_last_ansi + ai) % NUM_LAST_ANSIS;
for (i = 0; i < last_ansis[ax].end; i++)
STORE_CHAR(last_ansis[ax].data[i], AT_ANSI, NULL, pos);
}
}
}
#endif
if (a == AT_ANSI) {
w = 0;
} else {
char *p = &linebuf.buf[linebuf.end];
LWCHAR prev_ch = (linebuf.end > 0) ? step_char(&p, -1, linebuf.buf) : 0;
int prev_a = (linebuf.end > 0) ? linebuf.attr[linebuf.end-1] : 0;
w = pwidth(ch, a, prev_ch, prev_a);
}
if (cshift == hshift)
{
if (line_pos == NULL_POSITION)
line_pos = pos;
if (shifted_ansi.end > 0)
{
/* Copy shifted ANSI sequences to beginning of line. */
for (i = 0; i < shifted_ansi.end; i++)
add_linebuf(shifted_ansi.data[i], AT_ANSI, 0);
xbuf_reset(&shifted_ansi);
}
}
/* Add the char to the buf, even if we will left-shift it next. */
inc_end_column(w);
for (i = 0; i < replen; i++)
add_linebuf(*rep++, a, 0);
if (cshift < hshift)
{
/* We haven't left-shifted enough yet. */
if (a == AT_ANSI)
xbuf_add_byte(&shifted_ansi, (unsigned char) ch); /* Save ANSI attributes */
if (linebuf.end > linebuf.print)
{
/* Shift left enough to put last byte of this char at print-1. */
int i;
for (i = 0; i < linebuf.print; i++)
{
linebuf.buf[i] = linebuf.buf[i+replen];
linebuf.attr[i] = linebuf.attr[i+replen];
}
linebuf.end -= replen;
cshift += w;
/*
* If the char we just left-shifted was double width,
* the 2 spaces we shifted may be too much.
* Represent the "half char" at start of line with a highlighted space.
*/
while (cshift > hshift)
{
add_linebuf(' ', rscroll_attr, 0);
cshift--;
}
}
}
return (0);
}
#define STORE_STRING(s,a,pos) \
do { if (store_string((s),(a),(pos))) return (1); } while (0)
static int store_string(char *s, int a, POSITION pos)
{
if (!fits_on_screen(strlen(s), a))
return 1;
for ( ; *s != 0; s++)
STORE_CHAR(*s, a, NULL, pos);
return 0;
}
/*
* Append a tab to the line buffer.
* Store spaces to represent the tab.
*/
#define STORE_TAB(a,pos) \
do { if (store_tab((a),(pos))) return (1); } while (0)
static int store_tab(int attr, POSITION pos)
{
int to_tab = end_column - linebuf.pfx_end;
if (ntabstops < 2 || to_tab >= tabstops[ntabstops-1])
to_tab = tabdefault -
((to_tab - tabstops[ntabstops-1]) % tabdefault);
else
{
int i;
for (i = ntabstops - 2; i >= 0; i--)
if (to_tab >= tabstops[i])
break;
to_tab = tabstops[i+1] - to_tab;
}
do {
STORE_CHAR(' ', attr, " ", pos);
} while (--to_tab > 0);
return 0;
}
#define STORE_PRCHAR(c, pos) \
do { if (store_prchar((c), (pos))) return 1; } while (0)
static int store_prchar(LWCHAR c, POSITION pos)
{
/*
* Convert to printable representation.
*/
STORE_STRING(prchar(c), AT_BINARY|AT_COLOR_CTRL, pos);
return 0;
}
static int flush_mbc_buf(POSITION pos)
{
int i;
for (i = 0; i < mbc_buf_index; i++)
if (store_prchar(mbc_buf[i], pos))
return mbc_buf_index - i;
return 0;
}
/*
* Append a character to the line buffer.
* Expand tabs into spaces, handle underlining, boldfacing, etc.
* Returns 0 if ok, 1 if couldn't fit in buffer.
*/
public int pappend(int c, POSITION pos)
{
int r;
if (pendc)
{
if (c == '\r' && pendc == '\r')
return (0);
if (do_append(pendc, NULL, pendpos))
/*
* Oops. We've probably lost the char which
* was in pendc, since caller won't back up.
*/
return (1);
pendc = '\0';
}
if (c == '\r' && (proc_return == OPT_ON || (bs_mode == BS_SPECIAL && proc_return == OPT_OFF)))
{
if (mbc_buf_len > 0) /* utf_mode must be on. */
{
/* Flush incomplete (truncated) sequence. */
r = flush_mbc_buf(mbc_pos);
mbc_buf_index = r + 1;
mbc_buf_len = 0;
if (r)
return (mbc_buf_index);
}
/*
* Don't put the CR into the buffer until we see
* the next char. If the next char is a newline,
* discard the CR.
*/
pendc = c;
pendpos = pos;
return (0);
}
if (!utf_mode)
{
r = do_append(c, NULL, pos);
} else
{
/* Perform strict validation in all possible cases. */
if (mbc_buf_len == 0)
{
retry:
mbc_buf_index = 1;
*mbc_buf = c;
if (IS_ASCII_OCTET(c))
r = do_append(c, NULL, pos);
else if (IS_UTF8_LEAD(c))
{
mbc_buf_len = utf_len(c);
mbc_pos = pos;
return (0);
} else
/* UTF8_INVALID or stray UTF8_TRAIL */
r = flush_mbc_buf(pos);
} else if (IS_UTF8_TRAIL(c))
{
mbc_buf[mbc_buf_index++] = c;
if (mbc_buf_index < mbc_buf_len)
return (0);
if (is_utf8_well_formed(mbc_buf, mbc_buf_index))
r = do_append(get_wchar(mbc_buf), mbc_buf, mbc_pos);
else
/* Complete, but not shortest form, sequence. */
mbc_buf_index = r = flush_mbc_buf(mbc_pos);
mbc_buf_len = 0;
} else
{
/* Flush incomplete (truncated) sequence. */
r = flush_mbc_buf(mbc_pos);
mbc_buf_index = r + 1;
mbc_buf_len = 0;
/* Handle new char. */
if (!r)
goto retry;
}
}
if (r)
{
/* How many chars should caller back up? */
r = (!utf_mode) ? 1 : mbc_buf_index;
}
return (r);
}
static int store_control_char(LWCHAR ch, char *rep, POSITION pos)
{
if (ctldisp == OPT_ON)
{
/* Output the character itself. */
STORE_CHAR(ch, AT_NORMAL, rep, pos);
} else
{
/* Output a printable representation of the character. */
STORE_PRCHAR((char) ch, pos);
}
return (0);
}
if (in_overstrike > 0)
{
/*
* Overstrike the character at the current position
* in the line buffer. This will cause either
* underline (if a "_" is overstruck),
* bold (if an identical character is overstruck),
* or just replacing the character in the buffer.
*/
LWCHAR prev_ch;
overstrike = utf_mode ? -1 : 0;
if (utf_mode)
{
/* To be correct, this must be a base character. */
prev_ch = get_wchar(&linebuf.buf[linebuf.end]);
} else
{
prev_ch = (unsigned char) linebuf.buf[linebuf.end];
}
a = linebuf.attr[linebuf.end];
if (ch == prev_ch)
{
/*
* Overstriking a char with itself means make it bold.
* But overstriking an underscore with itself is
* ambiguous. It could mean make it bold, or
* it could mean make it underlined.
* Use the previous overstrike to resolve it.
*/
if (ch == '_')
{
if ((a & (AT_BOLD|AT_UNDERLINE)) != AT_NORMAL)
a |= (AT_BOLD|AT_UNDERLINE);
else if (last_overstrike != AT_NORMAL)
a |= last_overstrike;
else
a |= AT_BOLD;
} else
a |= AT_BOLD;
} else if (ch == '_')
{
a |= AT_UNDERLINE;
ch = prev_ch;
rep = &linebuf.buf[linebuf.end];
} else if (prev_ch == '_')
{
a |= AT_UNDERLINE;
}
/* Else we replace prev_ch, but we keep its attributes. */
} else if (in_overstrike < 0)
{
if ( is_composing_char(ch)
|| is_combining_char(get_wchar(&linebuf.buf[linebuf.end]), ch))
/* Continuation of the same overstrike. */
a = last_overstrike;
else
overstrike = 0;
}
if (ch == '\t')
{
/*
* Expand a tab into spaces.
*/
if (proc_tab == OPT_ONPLUS || (bs_mode == BS_CONTROL && proc_tab == OPT_OFF))
return store_control_char(ch, rep, pos);
STORE_TAB(a, pos);
return (0);
}
if ((!utf_mode || is_ascii_char(ch)) && control_char((char)ch))
{
return store_control_char(ch, rep, pos);
} else if (utf_mode && ctldisp != OPT_ON && is_ubin_char(ch))
{
STORE_STRING(prutfchar(ch), AT_BINARY, pos);
} else
{
STORE_CHAR(ch, a, rep, pos);
}
return (0);
}
/*
* Switch to normal attribute at end of line.
*/
static void add_attr_normal(void)
{
if (ctldisp != OPT_ONPLUS || !is_ansi_end('m'))
return;
addstr_linebuf("\033[m", AT_ANSI, 0);
if (hlink_in_line) /* Don't send hyperlink clear if we know we don't need to. */
addstr_linebuf("\033]8;;\033\\", AT_ANSI, 0);
}
/*
* Terminate the line in the line buffer.
*/
public void pdone(int endline, int chopped, int forw)
{
(void) pflushmbc();
if (pendc && (pendc != '\r' || !endline))
/*
* If we had a pending character, put it in the buffer.
* But discard a pending CR if we are at end of line
* (that is, discard the CR in a CR/LF sequence).
*/
(void) do_append(pendc, NULL, pendpos);
if (chopped && rscroll_char)
{
/*
* Display the right scrolling char.
* If we've already filled the rightmost screen char
* (in the buffer), overwrite it.
*/
if (end_column >= sc_width + cshift)
{
/* We've already written in the rightmost char. */
end_column = right_column;
linebuf.end = right_curr;
}
add_attr_normal();
while (end_column < sc_width-1 + cshift)
{
/*
* Space to last (rightmost) char on screen.
* This may be necessary if the char we overwrote
* was double-width.
*/
add_linebuf(' ', rscroll_attr, 1);
}
/* Print rscroll char. It must be single-width. */
add_linebuf(rscroll_char, rscroll_attr, 1);
} else
{
add_attr_normal();
}
/*
* If we're coloring a status line, fill out the line with spaces.
*/
if (status_line && line_mark_attr != 0) {
while (end_column +1 < sc_width + cshift)
add_linebuf(' ', line_mark_attr, 1);
}
/*
* Add a newline if necessary,
* and append a '\0' to the end of the line.
* We output a newline if we're not at the right edge of the screen,
* or if the terminal doesn't auto wrap,
* or if this is really the end of the line AND the terminal ignores
* a newline at the right edge.
* (In the last case we don't want to output a newline if the terminal
* doesn't ignore it since that would produce an extra blank line.
* But we do want to output a newline if the terminal ignores it in case
* the next line is blank. In that case the single newline output for
* that blank line would be ignored!)
*/
if (end_column < sc_width + cshift || !auto_wrap || (endline && ignaw) || ctldisp == OPT_ON)
{
add_linebuf('\n', AT_NORMAL, 0);
}
else if (ignaw && end_column >= sc_width + cshift && forw)
{
/*
* Terminals with "ignaw" don't wrap until they *really* need
* to, i.e. when the character *after* the last one to fit on a
* line is output. But they are too hard to deal with when they
* get in the state where a full screen width of characters
* have been output but the cursor is sitting on the right edge
* instead of at the start of the next line.
* So we nudge them into wrapping by outputting a space
* character plus a backspace. But do this only if moving
* forward; if we're moving backward and drawing this line at
* the top of the screen, the space would overwrite the first
* char on the next line. We don't need to do this "nudge"
* at the top of the screen anyway.
*/
add_linebuf(' ', AT_NORMAL, 1);
add_linebuf('\b', AT_NORMAL, -1);
}
set_linebuf(linebuf.end, '\0', AT_NORMAL);
}
/*
* Set an attribute on each char of the line in the line buffer.
*/
public void set_attr_line(int a)
{
int i;
for (i = linebuf.print; i < linebuf.end; i++)
if ((linebuf.attr[i] & AT_COLOR) == 0 || (a & AT_COLOR) == 0)
linebuf.attr[i] |= a;
}
/*
* Set the char to be displayed in the status column.
*/
public void set_status_col(char c, int attr)
{
set_pfx(0, c, attr);
}
/*
* Get a character from the current line.
* Return the character as the function return value,
* and the character attribute in *ap.
*/
public int gline(int i, int *ap)
{
if (is_null_line)
{
/*
* If there is no current line, we pretend the line is
* either "~" or "", depending on the "twiddle" flag.
*/
if (twiddle)
{
if (i == 0)
{
*ap = AT_BOLD;
return '~';
}
--i;
}
/* Make sure we're back to AT_NORMAL before the '\n'. */
*ap = AT_NORMAL;
return i ? '\0' : '\n';
}
if (i < linebuf.pfx_end)
{
*ap = linebuf.pfx_attr[i];
return linebuf.pfx[i];
}
i += linebuf.print - linebuf.pfx_end;
*ap = linebuf.attr[i];
return (linebuf.buf[i] & 0xFF);
}
/*
* Indicate that there is no current line.
*/
public void null_line(void)
{
is_null_line = 1;
cshift = 0;
}
/*
* Analogous to forw_line(), but deals with "raw lines":
* lines which are not split for screen width.
* {{ This is supposed to be more efficient than forw_line(). }}
*/
public POSITION forw_raw_line(POSITION curr_pos, char **linep, int *line_lenp)
{
int n;
int c;
POSITION new_pos;
n = 0;
for (;;)
{
if (c == '\n' || c == EOI || ABORT_SIGS())
{
new_pos = ch_tell();
break;
}
if (n >= size_linebuf-1)
{
if (expand_linebuf())
{
/*
* Overflowed the input buffer.
* Pretend the line ended here.
*/
new_pos = ch_tell() - 1;
break;
}
}
linebuf.buf[n++] = c;
c = ch_forw_get();
}
linebuf.buf[n] = '\0';
if (linep != NULL)
*linep = linebuf.buf;
if (line_lenp != NULL)
*line_lenp = n;
return (new_pos);
}
/*
* Analogous to back_line(), but deals with "raw lines".
* {{ This is supposed to be more efficient than back_line(). }}
*/
public POSITION back_raw_line(POSITION curr_pos, char **linep, int *line_lenp)
{
int n;
int c;
POSITION new_pos;
n = size_linebuf;
linebuf.buf[--n] = '\0';
for (;;)
{
c = ch_back_get();
if (c == '\n' || ABORT_SIGS())
{
/*
* This is the newline ending the previous line.
* We have hit the beginning of the line.
*/
new_pos = ch_tell() + 1;
break;
}
if (c == EOI)
{
/*
* We have hit the beginning of the file.
* This must be the first line in the file.
* This must, of course, be the beginning of the line.
*/
new_pos = ch_zero();
break;
}
if (n <= 0)
{
int old_size_linebuf = size_linebuf;
char *fm;
char *to;
if (expand_linebuf())
{
/*
* Overflowed the input buffer.
* Pretend the line ended here.
*/
new_pos = ch_tell() + 1;
break;
}
/*
* Shift the data to the end of the new linebuf.
*/
for (fm = linebuf.buf + old_size_linebuf - 1,
to = linebuf.buf + size_linebuf - 1;
fm >= linebuf.buf; fm--, to--)
*to = *fm;
n = size_linebuf - old_size_linebuf;
}
linebuf.buf[--n] = c;
}
if (linep != NULL)
*linep = &linebuf.buf[n];
if (line_lenp != NULL)
*line_lenp = size_linebuf - 1 - n;
return (new_pos);
}
/*
* Skip cols printable columns at the start of line.
* Return number of bytes skipped.
*/
public int skip_columns(int cols, char **linep, int *line_lenp)
{
char *line = *linep;
char *eline = line + *line_lenp;
LWCHAR pch = 0;
int bytes;
/*
* Append a string to the line buffer.
*/
static int pappstr(constant char *str)
{
while (*str != '\0')
{
if (pappend(*str++, NULL_POSITION))
/* Doesn't fit on screen. */
return 1;
}
return 0;
}
/*
* Load a string into the line buffer.
* If the string is too long to fit on the screen,
* truncate the beginning of the string to fit.
*/
public void load_line(constant char *str)
{
int save_hshift = hshift;
hshift = 0;
for (;;)
{
prewind();
if (pappstr(str) == 0)
break;
/*
* Didn't fit on screen; increase left shift by one.
* {{ This gets very inefficient if the string
* is much longer than the screen width. }}
*/
hshift += 1;
}
set_linebuf(linebuf.end, '\0', AT_NORMAL);
hshift = save_hshift;
}
/*
* Find the shift necessary to show the end of the longest displayed line.
*/
public int rrshift(void)
{
POSITION pos;
int save_width;
int line;
int longest = 0;
/*
* Get the color_map index associated with a given attribute.
*/
static int lookup_color_index(int attr)
{
int cx;
for (cx = 0; cx < sizeof(color_map)/sizeof(*color_map); cx++)
if (color_map[cx].attr == attr)
return cx;
return -1;
}
static int color_index(int attr)
{
if (use_color && (attr & AT_COLOR))
return lookup_color_index(attr & AT_COLOR);
if (attr & AT_UNDERLINE)
return lookup_color_index(AT_UNDERLINE);
if (attr & AT_BOLD)
return lookup_color_index(AT_BOLD);
if (attr & AT_BLINK)
return lookup_color_index(AT_BLINK);
if (attr & AT_STANDOUT)
return lookup_color_index(AT_STANDOUT);
return -1;
}
/*
* Set the color string to use for a given attribute.
*/
public int set_color_map(int attr, char *colorstr)
{
int cx = color_index(attr);
if (cx < 0)
return -1;
if (strlen(colorstr)+1 > sizeof(color_map[cx].color))
return -1;
if (*colorstr != '\0' && parse_color(colorstr, NULL, NULL) == CT_NULL)
return -1;
strcpy(color_map[cx].color, colorstr);
return 0;
}
/*
* Get the color string to use for a given attribute.
*/
public char * get_color_map(int attr)
{
int cx = color_index(attr);
if (cx < 0)
return NULL;
return color_map[cx].color;
}
