diff options
Diffstat (limited to 'line.c')
| -rwxr-xr-x | line.c | 1249 |
1 files changed, 1249 insertions, 0 deletions
@@ -0,0 +1,1249 @@ +/* + * Copyright (C) 1984-2012 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. + */ + +#include "less.h" +#include "charset.h" + +static char *linebuf = NULL; /* Buffer which holds the current output line */ +static char *attr = NULL; /* Extension of linebuf to hold attributes */ +public int size_linebuf = 0; /* Size of line buffer (and attr buffer) */ + +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 int curr; /* Index into linebuf */ +static int column; /* Printable length, accounting for + backspaces, etc. */ +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 int lmargin; /* Left margin */ +static char pendc; +static POSITION pendpos; +static char *end_ansi_chars; +static char *mid_ansi_chars; + +static int attr_swidth(); +static int attr_ewidth(); +static int do_append(); + +extern int sigs; +extern int bs_mode; +extern int linenums; +extern int ctldisp; +extern int twiddle; +extern int binattr; +extern int status_col; +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; + +static char mbc_buf[MAX_UTF_CHAR_LEN]; +static int mbc_buf_len = 0; +static int mbc_buf_index = 0; +static POSITION mbc_pos; + +/* + * Initialize from environment variables. + */ + public void +init_line() +{ + end_ansi_chars = lgetenv("LESSANSIENDCHARS"); + if (end_ansi_chars == NULL || *end_ansi_chars == '\0') + end_ansi_chars = "m"; + + mid_ansi_chars = lgetenv("LESSANSIMIDCHARS"); + if (mid_ansi_chars == NULL || *mid_ansi_chars == '\0') + mid_ansi_chars = "0123456789;[?!\"'#%()*+ "; + + linebuf = (char *) ecalloc(LINEBUF_SIZE, sizeof(char)); + attr = (char *) ecalloc(LINEBUF_SIZE, sizeof(char)); + size_linebuf = LINEBUF_SIZE; +} + +/* + * Expand the line buffer. + */ + static int +expand_linebuf() +{ + /* Double the size of the line buffer. */ + int new_size = size_linebuf * 2; + + /* Just realloc to expand the buffer, if we can. */ +#if HAVE_REALLOC + char *new_buf = (char *) realloc(linebuf, new_size); + char *new_attr = (char *) realloc(attr, new_size); +#else + char *new_buf = (char *) calloc(new_size, sizeof(char)); + char *new_attr = (char *) calloc(new_size, sizeof(char)); +#endif + if (new_buf == NULL || new_attr == NULL) + { + if (new_attr != NULL) + free(new_attr); + if (new_buf != NULL) + free(new_buf); + return 1; + } +#if HAVE_REALLOC + /* + * We realloc'd the buffers; they already have the old contents. + */ + #if 0 + memset(new_buf + size_linebuf, 0, new_size - size_linebuf); + memset(new_attr + size_linebuf, 0, new_size - size_linebuf); + #endif +#else + /* + * We just calloc'd the buffers; copy the old contents. + */ + memcpy(new_buf, linebuf, size_linebuf * sizeof(char)); + memcpy(new_attr, attr, size_linebuf * sizeof(char)); + free(attr); + free(linebuf); +#endif + linebuf = new_buf; + attr = new_attr; + size_linebuf = new_size; + return 0; +} + +/* + * Is a character ASCII? + */ + public int +is_ascii_char(ch) + LWCHAR ch; +{ + return (ch <= 0x7F); +} + +/* + * Rewind the line buffer. + */ + public void +prewind() +{ + curr = 0; + column = 0; + cshift = 0; + overstrike = 0; + last_overstrike = AT_NORMAL; + mbc_buf_len = 0; + is_null_line = 0; + pendc = '\0'; + lmargin = 0; + if (status_col) + lmargin += 1; +} + +/* + * Insert the line number (of the given position) into the line buffer. + */ + public void +plinenum(pos) + POSITION pos; +{ + register LINENUM linenum = 0; + register 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 plinenum 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) + { + linebuf[curr] = ' '; + if (start_attnpos != NULL_POSITION && + pos >= start_attnpos && pos < end_attnpos) + attr[curr] = AT_NORMAL|AT_HILITE; + else + attr[curr] = AT_NORMAL; + curr++; + column++; + } + /* + * 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(pos) + 2]; + int n; + + linenumtoa(linenum, buf); + n = strlen(buf); + if (n < MIN_LINENUM_WIDTH) + n = MIN_LINENUM_WIDTH; + sprintf(linebuf+curr, "%*s ", n, buf); + n++; /* One space after the line number. */ + for (i = 0; i < n; i++) + attr[curr+i] = AT_NORMAL; + curr += n; + column += n; + lmargin += n; + } + + /* + * Append enough spaces to bring us to the lmargin. + */ + while (column < lmargin) + { + linebuf[curr] = ' '; + attr[curr++] = AT_NORMAL; + column++; + } +} + +/* + * Shift the input line left. + * This means discarding N printable chars at the start of the buffer. + */ + static void +pshift(shift) + int shift; +{ + LWCHAR prev_ch = 0; + unsigned char c; + int shifted = 0; + int to; + int from; + int len; + int width; + int prev_attr; + int next_attr; + + if (shift > column - lmargin) + shift = column - lmargin; + if (shift > curr - lmargin) + shift = curr - lmargin; + + to = from = lmargin; + /* + * We keep on going when shifted == shift + * to get all combining chars. + */ + while (shifted <= shift && from < curr) + { + c = linebuf[from]; + if (ctldisp == OPT_ONPLUS && IS_CSI_START(c)) + { + /* Keep cumulative effect. */ + linebuf[to] = c; + attr[to++] = attr[from++]; + while (from < curr && linebuf[from]) + { + linebuf[to] = linebuf[from]; + attr[to++] = attr[from]; + if (!is_ansi_middle(linebuf[from++])) + break; + } + continue; + } + + width = 0; + + if (!IS_ASCII_OCTET(c) && utf_mode) + { + /* Assumes well-formedness validation already done. */ + LWCHAR ch; + + len = utf_len(c); + if (from + len > curr) + break; + ch = get_wchar(linebuf + from); + if (!is_composing_char(ch) && !is_combining_char(prev_ch, ch)) + width = is_wide_char(ch) ? 2 : 1; + prev_ch = ch; + } else + { + len = 1; + if (c == '\b') + /* XXX - Incorrect if several '\b' in a row. */ + width = (utf_mode && is_wide_char(prev_ch)) ? -2 : -1; + else if (!control_char(c)) + width = 1; + prev_ch = 0; + } + + if (width == 2 && shift - shifted == 1) { + /* Should never happen when called by pshift_all(). */ + attr[to] = attr[from]; + /* + * Assume a wide_char will never be the first half of a + * combining_char pair, so reset prev_ch in case we're + * followed by a '\b'. + */ + prev_ch = linebuf[to++] = ' '; + from += len; + shifted++; + continue; + } + + /* Adjust width for magic cookies. */ + prev_attr = (to > 0) ? attr[to-1] : AT_NORMAL; + next_attr = (from + len < curr) ? attr[from + len] : prev_attr; + if (!is_at_equiv(attr[from], prev_attr) && + !is_at_equiv(attr[from], next_attr)) + { + width += attr_swidth(attr[from]); + if (from + len < curr) + width += attr_ewidth(attr[from]); + if (is_at_equiv(prev_attr, next_attr)) + { + width += attr_ewidth(prev_attr); + if (from + len < curr) + width += attr_swidth(next_attr); + } + } + + if (shift - shifted < width) + break; + from += len; + shifted += width; + if (shifted < 0) + shifted = 0; + } + while (from < curr) + { + linebuf[to] = linebuf[from]; + attr[to++] = attr[from++]; + } + curr = to; + column -= shifted; + cshift += shifted; +} + +/* + * + */ + public void +pshift_all() +{ + pshift(column); +} + +/* + * Return the printing width of the start (enter) sequence + * for a given character attribute. + */ + static int +attr_swidth(a) + 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(a) + 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 to the current position in the line buffer. + * 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. + */ + static int +pwidth(ch, a, prev_ch) + LWCHAR ch; + int a; + LWCHAR prev_ch; +{ + int w; + + if (ch == '\b') + /* + * Backspace moves backwards one or two positions. + * XXX - Incorrect if several '\b' in a row. + */ + 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 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 (curr > 0 && !is_at_equiv(attr[curr-1], a)) + w += attr_ewidth(attr[curr-1]); + if ((apply_at_specials(a) != AT_NORMAL) && + (curr == 0 || !is_at_equiv(attr[curr-1], a))) + w += attr_swidth(a); + return (w); +} + +/* + * Delete to the previous base character in the line buffer. + * Return 1 if one is found. + */ + static int +backc() +{ + LWCHAR prev_ch; + char *p = linebuf + curr; + LWCHAR ch = step_char(&p, -1, linebuf + lmargin); + int width; + + /* This assumes that there is no '\b' in linebuf. */ + while ( curr > lmargin + && column > lmargin + && (!(attr[curr - 1] & (AT_ANSI|AT_BINARY)))) + { + curr = p - linebuf; + prev_ch = step_char(&p, -1, linebuf + lmargin); + width = pwidth(ch, attr[curr], prev_ch); + column -= width; + if (width > 0) + return 1; + ch = prev_ch; + } + + return 0; +} + +/* + * Are we currently within a recognized ANSI escape sequence? + */ + static int +in_ansi_esc_seq() +{ + char *p; + + /* + * Search backwards for either an ESC (which means we ARE in a seq); + * or an end char (which means we're NOT in a seq). + */ + for (p = &linebuf[curr]; p > linebuf; ) + { + LWCHAR ch = step_char(&p, -1, linebuf); + if (IS_CSI_START(ch)) + return (1); + if (!is_ansi_middle(ch)) + return (0); + } + return (0); +} + +/* + * Is a character the end of an ANSI escape sequence? + */ + public int +is_ansi_end(ch) + LWCHAR ch; +{ + if (!is_ascii_char(ch)) + return (0); + return (strchr(end_ansi_chars, (char) ch) != NULL); +} + +/* + * + */ + public int +is_ansi_middle(ch) + LWCHAR ch; +{ + if (!is_ascii_char(ch)) + return (0); + if (is_ansi_end(ch)) + return (0); + return (strchr(mid_ansi_chars, (char) ch) != NULL); +} + +/* + * 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(ch, a, rep, pos) + LWCHAR ch; + int a; + char *rep; + POSITION pos; +{ + int w; + int replen; + char cs; + + w = (a & (AT_UNDERLINE|AT_BOLD)); /* Pre-use w. */ + if (w != AT_NORMAL) + last_overstrike = w; + +#if HILITE_SEARCH + { + int matches; + if (is_hilited(pos, pos+1, 0, &matches)) + { + /* + * This character should be highlighted. + * Override the attribute passed in. + */ + if (a != AT_ANSI) + { + if (highest_hilite != NULL_POSITION && + pos > highest_hilite) + highest_hilite = pos; + a |= AT_HILITE; + } + } + } +#endif + + if (ctldisp == OPT_ONPLUS && in_ansi_esc_seq()) + { + if (!is_ansi_end(ch) && !is_ansi_middle(ch)) { + /* Remove whole unrecognized sequence. */ + char *p = &linebuf[curr]; + LWCHAR bch; + do { + bch = step_char(&p, -1, linebuf); + } while (p > linebuf && !IS_CSI_START(bch)); + curr = p - linebuf; + return 0; + } + a = AT_ANSI; /* Will force re-AT_'ing around it. */ + w = 0; + } + else if (ctldisp == OPT_ONPLUS && IS_CSI_START(ch)) + { + a = AT_ANSI; /* Will force re-AT_'ing around it. */ + w = 0; + } + else + { + char *p = &linebuf[curr]; + LWCHAR prev_ch = step_char(&p, -1, linebuf); + w = pwidth(ch, a, prev_ch); + } + + if (ctldisp != OPT_ON && column + w + attr_ewidth(a) > sc_width) + /* + * Won't fit on screen. + */ + return (1); + + if (rep == NULL) + { + cs = (char) ch; + rep = &cs; + replen = 1; + } else + { + replen = utf_len(rep[0]); + } + if (curr + replen >= size_linebuf-6) + { + /* + * Won't fit in line buffer. + * Try to expand it. + */ + if (expand_linebuf()) + return (1); + } + + while (replen-- > 0) + { + linebuf[curr] = *rep++; + attr[curr] = a; + curr++; + } + column += w; + 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(attr, pos) + int attr; + POSITION pos; +{ + int to_tab = column + cshift - lmargin; + int i; + + if (ntabstops < 2 || to_tab >= tabstops[ntabstops-1]) + to_tab = tabdefault - + ((to_tab - tabstops[ntabstops-1]) % tabdefault); + else + { + for (i = ntabstops - 2; i >= 0; i--) + if (to_tab >= tabstops[i]) + break; + to_tab = tabstops[i+1] - to_tab; + } + + if (column + to_tab - 1 + pwidth(' ', attr, 0) + attr_ewidth(attr) > sc_width) + return 1; + + 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(c, pos) + char c; + POSITION pos; +{ + char *s; + + /* + * Convert to printable representation. + */ + s = prchar(c); + + /* + * Make sure we can get the entire representation + * of the character on this line. + */ + if (column + (int) strlen(s) - 1 + + pwidth(' ', binattr, 0) + attr_ewidth(binattr) > sc_width) + return 1; + + for ( ; *s != 0; s++) + STORE_CHAR(*s, AT_BINARY, NULL, pos); + + return 0; +} + + static int +flush_mbc_buf(pos) + 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(c, pos) + char c; + POSITION pos; +{ + int r; + + if (pendc) + { + 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' && bs_mode == BS_SPECIAL) + { + 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((LWCHAR) 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((LWCHAR) 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)) + 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 we need to shift the line, do it. + * But wait until we get to at least the middle of the screen, + * so shifting it doesn't affect the chars we're currently + * pappending. (Bold & underline can get messed up otherwise.) + */ + if (cshift < hshift && column > sc_width / 2) + { + linebuf[curr] = '\0'; + pshift(hshift - cshift); + } + if (r) + { + /* How many chars should caller back up? */ + r = (!utf_mode) ? 1 : mbc_buf_index; + } + return (r); +} + + static int +do_append(ch, rep, pos) + LWCHAR ch; + char *rep; + POSITION pos; +{ + register int a; + LWCHAR prev_ch; + + a = AT_NORMAL; + + if (ch == '\b') + { + if (bs_mode == BS_CONTROL) + goto do_control_char; + + /* + * A better test is needed here so we don't + * backspace over part of the printed + * representation of a binary character. + */ + if ( curr <= lmargin + || column <= lmargin + || (attr[curr - 1] & (AT_ANSI|AT_BINARY))) + STORE_PRCHAR('\b', pos); + else if (bs_mode == BS_NORMAL) + STORE_CHAR(ch, AT_NORMAL, NULL, pos); + else if (bs_mode == BS_SPECIAL) + overstrike = backc(); + + return 0; + } + + if (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 deletion of the character in the buffer. + */ + overstrike = utf_mode ? -1 : 0; + /* To be correct, this must be a base character. */ + prev_ch = get_wchar(linebuf + curr); + a = attr[curr]; + 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 + curr; + } else if (prev_ch == '_') + { + a |= AT_UNDERLINE; + } + /* Else we replace prev_ch, but we keep its attributes. */ + } else if (overstrike < 0) + { + if ( is_composing_char(ch) + || is_combining_char(get_wchar(linebuf + curr), ch)) + /* Continuation of the same overstrike. */ + a = last_overstrike; + else + overstrike = 0; + } + + if (ch == '\t') + { + /* + * Expand a tab into spaces. + */ + switch (bs_mode) + { + case BS_CONTROL: + goto do_control_char; + case BS_NORMAL: + case BS_SPECIAL: + STORE_TAB(a, pos); + break; + } + } else if ((!utf_mode || is_ascii_char(ch)) && control_char((char)ch)) + { + do_control_char: + if (ctldisp == OPT_ON || (ctldisp == OPT_ONPLUS && IS_CSI_START(ch))) + { + /* + * Output as a normal character. + */ + STORE_CHAR(ch, AT_NORMAL, rep, pos); + } else + { + STORE_PRCHAR((char) ch, pos); + } + } else if (utf_mode && ctldisp != OPT_ON && is_ubin_char(ch)) + { + char *s; + + s = prutfchar(ch); + + if (column + (int) strlen(s) - 1 + + pwidth(' ', binattr, 0) + attr_ewidth(binattr) > sc_width) + return (1); + + for ( ; *s != 0; s++) + STORE_CHAR(*s, AT_BINARY, NULL, pos); + } else + { + STORE_CHAR(ch, a, rep, pos); + } + return (0); +} + +/* + * + */ + public int +pflushmbc() +{ + int r = 0; + + if (mbc_buf_len > 0) + { + /* Flush incomplete (truncated) sequence. */ + r = flush_mbc_buf(mbc_pos); + mbc_buf_len = 0; + } + return r; +} + +/* + * Terminate the line in the line buffer. + */ + public void +pdone(endline, forw) + int endline; + 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); + + /* + * Make sure we've shifted the line, if we need to. + */ + if (cshift < hshift) + pshift(hshift - cshift); + + if (ctldisp == OPT_ONPLUS && is_ansi_end('m')) + { + /* Switch to normal attribute at end of line. */ + char *p = "\033[m"; + for ( ; *p != '\0'; p++) + { + linebuf[curr] = *p; + attr[curr++] = AT_ANSI; + } + } + + /* + * 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 (column < sc_width || !auto_wrap || (endline && ignaw) || ctldisp == OPT_ON) + { + linebuf[curr] = '\n'; + attr[curr] = AT_NORMAL; + curr++; + } + else if (ignaw && column >= sc_width && 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. + */ + linebuf[curr] = ' '; + attr[curr++] = AT_NORMAL; + linebuf[curr] = '\b'; + attr[curr++] = AT_NORMAL; + } + linebuf[curr] = '\0'; + attr[curr] = AT_NORMAL; +} + +/* + * + */ + public void +set_status_col(c) + char c; +{ + linebuf[0] = c; + attr[0] = AT_NORMAL|AT_HILITE; +} + +/* + * Get a character from the current line. + * Return the character as the function return value, + * and the character attribute in *ap. + */ + public int +gline(i, ap) + register int i; + register 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'; + } + + *ap = attr[i]; + return (linebuf[i] & 0xFF); +} + +/* + * Indicate that there is no current line. + */ + public void +null_line() +{ + 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(curr_pos, linep, line_lenp) + POSITION curr_pos; + char **linep; + int *line_lenp; +{ + register int n; + register int c; + POSITION new_pos; + + if (curr_pos == NULL_POSITION || ch_seek(curr_pos) || + (c = ch_forw_get()) == EOI) + return (NULL_POSITION); + + 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[n++] = c; + c = ch_forw_get(); + } + linebuf[n] = '\0'; + if (linep != NULL) + *linep = linebuf; + 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(curr_pos, linep, line_lenp) + POSITION curr_pos; + char **linep; + int *line_lenp; +{ + register int n; + register int c; + POSITION new_pos; + + if (curr_pos == NULL_POSITION || curr_pos <= ch_zero() || + ch_seek(curr_pos-1)) + return (NULL_POSITION); + + n = size_linebuf; + linebuf[--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 + old_size_linebuf - 1, + to = linebuf + size_linebuf - 1; + fm >= linebuf; fm--, to--) + *to = *fm; + n = size_linebuf - old_size_linebuf; + } + linebuf[--n] = c; + } + if (linep != NULL) + *linep = &linebuf[n]; + if (line_lenp != NULL) + *line_lenp = size_linebuf - 1 - n; + return (new_pos); +} |