freebsd-dev/contrib/mdocml/term.c
2016-01-15 23:28:12 +00:00

830 lines
18 KiB
C

/* $Id: term.c,v 1.256 2016/01/07 21:03:54 schwarze Exp $ */
/*
* Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
* Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include <sys/types.h>
#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mandoc.h"
#include "mandoc_aux.h"
#include "out.h"
#include "term.h"
#include "main.h"
static size_t cond_width(const struct termp *, int, int *);
static void adjbuf(struct termp *p, size_t);
static void bufferc(struct termp *, char);
static void encode(struct termp *, const char *, size_t);
static void encode1(struct termp *, int);
void
term_free(struct termp *p)
{
free(p->buf);
free(p->fontq);
free(p);
}
void
term_begin(struct termp *p, term_margin head,
term_margin foot, const struct roff_meta *arg)
{
p->headf = head;
p->footf = foot;
p->argf = arg;
(*p->begin)(p);
}
void
term_end(struct termp *p)
{
(*p->end)(p);
}
/*
* Flush a chunk of text. By default, break the output line each time
* the right margin is reached, and continue output on the next line
* at the same offset as the chunk itself. By default, also break the
* output line at the end of the chunk.
* The following flags may be specified:
*
* - TERMP_NOBREAK: Do not break the output line at the right margin,
* but only at the max right margin. Also, do not break the output
* line at the end of the chunk, such that the next call can pad to
* the next column. However, if less than p->trailspace blanks,
* which can be 0, 1, or 2, remain to the right margin, the line
* will be broken.
* - TERMP_BRTRSP: Consider trailing whitespace significant
* when deciding whether the chunk fits or not.
* - TERMP_BRIND: If the chunk does not fit and the output line has
* to be broken, start the next line at the right margin instead
* of at the offset. Used together with TERMP_NOBREAK for the tags
* in various kinds of tagged lists.
* - TERMP_DANGLE: Do not break the output line at the right margin,
* append the next chunk after it even if this one is too long.
* To be used together with TERMP_NOBREAK.
* - TERMP_HANG: Like TERMP_DANGLE, and also suppress padding before
* the next chunk if this column is not full.
*/
void
term_flushln(struct termp *p)
{
size_t i; /* current input position in p->buf */
int ntab; /* number of tabs to prepend */
size_t vis; /* current visual position on output */
size_t vbl; /* number of blanks to prepend to output */
size_t vend; /* end of word visual position on output */
size_t bp; /* visual right border position */
size_t dv; /* temporary for visual pos calculations */
size_t j; /* temporary loop index for p->buf */
size_t jhy; /* last hyph before overflow w/r/t j */
size_t maxvis; /* output position of visible boundary */
/*
* First, establish the maximum columns of "visible" content.
* This is usually the difference between the right-margin and
* an indentation, but can be, for tagged lists or columns, a
* small set of values.
*
* The following unsigned-signed subtractions look strange,
* but they are actually correct. If the int p->overstep
* is negative, it gets sign extended. Subtracting that
* very large size_t effectively adds a small number to dv.
*/
dv = p->rmargin > p->offset ? p->rmargin - p->offset : 0;
maxvis = (int)dv > p->overstep ? dv - (size_t)p->overstep : 0;
if (p->flags & TERMP_NOBREAK) {
dv = p->maxrmargin > p->offset ?
p->maxrmargin - p->offset : 0;
bp = (int)dv > p->overstep ?
dv - (size_t)p->overstep : 0;
} else
bp = maxvis;
/*
* Calculate the required amount of padding.
*/
vbl = p->offset + p->overstep > p->viscol ?
p->offset + p->overstep - p->viscol : 0;
vis = vend = 0;
i = 0;
while (i < p->col) {
/*
* Handle literal tab characters: collapse all
* subsequent tabs into a single huge set of spaces.
*/
ntab = 0;
while (i < p->col && '\t' == p->buf[i]) {
vend = (vis / p->tabwidth + 1) * p->tabwidth;
vbl += vend - vis;
vis = vend;
ntab++;
i++;
}
/*
* Count up visible word characters. Control sequences
* (starting with the CSI) aren't counted. A space
* generates a non-printing word, which is valid (the
* space is printed according to regular spacing rules).
*/
for (j = i, jhy = 0; j < p->col; j++) {
if (' ' == p->buf[j] || '\t' == p->buf[j])
break;
/* Back over the the last printed character. */
if (8 == p->buf[j]) {
assert(j);
vend -= (*p->width)(p, p->buf[j - 1]);
continue;
}
/* Regular word. */
/* Break at the hyphen point if we overrun. */
if (vend > vis && vend < bp &&
(ASCII_HYPH == p->buf[j] ||
ASCII_BREAK == p->buf[j]))
jhy = j;
/*
* Hyphenation now decided, put back a real
* hyphen such that we get the correct width.
*/
if (ASCII_HYPH == p->buf[j])
p->buf[j] = '-';
vend += (*p->width)(p, p->buf[j]);
}
/*
* Find out whether we would exceed the right margin.
* If so, break to the next line.
*/
if (vend > bp && 0 == jhy && vis > 0) {
vend -= vis;
(*p->endline)(p);
p->viscol = 0;
if (TERMP_BRIND & p->flags) {
vbl = p->rmargin;
vend += p->rmargin;
vend -= p->offset;
} else
vbl = p->offset;
/* use pending tabs on the new line */
if (0 < ntab)
vbl += ntab * p->tabwidth;
/*
* Remove the p->overstep width.
* Again, if p->overstep is negative,
* sign extension does the right thing.
*/
bp += (size_t)p->overstep;
p->overstep = 0;
}
/* Write out the [remaining] word. */
for ( ; i < p->col; i++) {
if (vend > bp && jhy > 0 && i > jhy)
break;
if ('\t' == p->buf[i])
break;
if (' ' == p->buf[i]) {
j = i;
while (i < p->col && ' ' == p->buf[i])
i++;
dv = (i - j) * (*p->width)(p, ' ');
vbl += dv;
vend += dv;
break;
}
if (ASCII_NBRSP == p->buf[i]) {
vbl += (*p->width)(p, ' ');
continue;
}
if (ASCII_BREAK == p->buf[i])
continue;
/*
* Now we definitely know there will be
* printable characters to output,
* so write preceding white space now.
*/
if (vbl) {
(*p->advance)(p, vbl);
p->viscol += vbl;
vbl = 0;
}
(*p->letter)(p, p->buf[i]);
if (8 == p->buf[i])
p->viscol -= (*p->width)(p, p->buf[i-1]);
else
p->viscol += (*p->width)(p, p->buf[i]);
}
vis = vend;
}
/*
* If there was trailing white space, it was not printed;
* so reset the cursor position accordingly.
*/
if (vis > vbl)
vis -= vbl;
else
vis = 0;
p->col = 0;
p->overstep = 0;
p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE);
if ( ! (TERMP_NOBREAK & p->flags)) {
p->viscol = 0;
(*p->endline)(p);
return;
}
if (TERMP_HANG & p->flags) {
p->overstep += (int)(p->offset + vis - p->rmargin +
p->trailspace * (*p->width)(p, ' '));
/*
* If we have overstepped the margin, temporarily move
* it to the right and flag the rest of the line to be
* shorter.
* If there is a request to keep the columns together,
* allow negative overstep when the column is not full.
*/
if (p->trailspace && p->overstep < 0)
p->overstep = 0;
return;
} else if (TERMP_DANGLE & p->flags)
return;
/* Trailing whitespace is significant in some columns. */
if (vis && vbl && (TERMP_BRTRSP & p->flags))
vis += vbl;
/* If the column was overrun, break the line. */
if (maxvis < vis + p->trailspace * (*p->width)(p, ' ')) {
(*p->endline)(p);
p->viscol = 0;
}
}
/*
* A newline only breaks an existing line; it won't assert vertical
* space. All data in the output buffer is flushed prior to the newline
* assertion.
*/
void
term_newln(struct termp *p)
{
p->flags |= TERMP_NOSPACE;
if (p->col || p->viscol)
term_flushln(p);
}
/*
* Asserts a vertical space (a full, empty line-break between lines).
* Note that if used twice, this will cause two blank spaces and so on.
* All data in the output buffer is flushed prior to the newline
* assertion.
*/
void
term_vspace(struct termp *p)
{
term_newln(p);
p->viscol = 0;
if (0 < p->skipvsp)
p->skipvsp--;
else
(*p->endline)(p);
}
/* Swap current and previous font; for \fP and .ft P */
void
term_fontlast(struct termp *p)
{
enum termfont f;
f = p->fontl;
p->fontl = p->fontq[p->fonti];
p->fontq[p->fonti] = f;
}
/* Set font, save current, discard previous; for \f, .ft, .B etc. */
void
term_fontrepl(struct termp *p, enum termfont f)
{
p->fontl = p->fontq[p->fonti];
p->fontq[p->fonti] = f;
}
/* Set font, save previous. */
void
term_fontpush(struct termp *p, enum termfont f)
{
p->fontl = p->fontq[p->fonti];
if (++p->fonti == p->fontsz) {
p->fontsz += 8;
p->fontq = mandoc_reallocarray(p->fontq,
p->fontsz, sizeof(*p->fontq));
}
p->fontq[p->fonti] = f;
}
/* Flush to make the saved pointer current again. */
void
term_fontpopq(struct termp *p, int i)
{
assert(i >= 0);
if (p->fonti > i)
p->fonti = i;
}
/* Pop one font off the stack. */
void
term_fontpop(struct termp *p)
{
assert(p->fonti);
p->fonti--;
}
/*
* Handle pwords, partial words, which may be either a single word or a
* phrase that cannot be broken down (such as a literal string). This
* handles word styling.
*/
void
term_word(struct termp *p, const char *word)
{
const char nbrsp[2] = { ASCII_NBRSP, 0 };
const char *seq, *cp;
int sz, uc;
size_t ssz;
enum mandoc_esc esc;
if ( ! (TERMP_NOSPACE & p->flags)) {
if ( ! (TERMP_KEEP & p->flags)) {
bufferc(p, ' ');
if (TERMP_SENTENCE & p->flags)
bufferc(p, ' ');
} else
bufferc(p, ASCII_NBRSP);
}
if (TERMP_PREKEEP & p->flags)
p->flags |= TERMP_KEEP;
if ( ! (p->flags & TERMP_NONOSPACE))
p->flags &= ~TERMP_NOSPACE;
else
p->flags |= TERMP_NOSPACE;
p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
p->skipvsp = 0;
while ('\0' != *word) {
if ('\\' != *word) {
if (TERMP_NBRWORD & p->flags) {
if (' ' == *word) {
encode(p, nbrsp, 1);
word++;
continue;
}
ssz = strcspn(word, "\\ ");
} else
ssz = strcspn(word, "\\");
encode(p, word, ssz);
word += (int)ssz;
continue;
}
word++;
esc = mandoc_escape(&word, &seq, &sz);
if (ESCAPE_ERROR == esc)
continue;
switch (esc) {
case ESCAPE_UNICODE:
uc = mchars_num2uc(seq + 1, sz - 1);
break;
case ESCAPE_NUMBERED:
uc = mchars_num2char(seq, sz);
if (uc < 0)
continue;
break;
case ESCAPE_SPECIAL:
if (p->enc == TERMENC_ASCII) {
cp = mchars_spec2str(seq, sz, &ssz);
if (cp != NULL)
encode(p, cp, ssz);
} else {
uc = mchars_spec2cp(seq, sz);
if (uc > 0)
encode1(p, uc);
}
continue;
case ESCAPE_FONTBOLD:
term_fontrepl(p, TERMFONT_BOLD);
continue;
case ESCAPE_FONTITALIC:
term_fontrepl(p, TERMFONT_UNDER);
continue;
case ESCAPE_FONTBI:
term_fontrepl(p, TERMFONT_BI);
continue;
case ESCAPE_FONT:
case ESCAPE_FONTROMAN:
term_fontrepl(p, TERMFONT_NONE);
continue;
case ESCAPE_FONTPREV:
term_fontlast(p);
continue;
case ESCAPE_NOSPACE:
if (p->flags & TERMP_BACKAFTER)
p->flags &= ~TERMP_BACKAFTER;
else if (*word == '\0')
p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
continue;
case ESCAPE_SKIPCHAR:
p->flags |= TERMP_BACKAFTER;
continue;
case ESCAPE_OVERSTRIKE:
cp = seq + sz;
while (seq < cp) {
if (*seq == '\\') {
mandoc_escape(&seq, NULL, NULL);
continue;
}
encode1(p, *seq++);
if (seq < cp) {
if (p->flags & TERMP_BACKBEFORE)
p->flags |= TERMP_BACKAFTER;
else
p->flags |= TERMP_BACKBEFORE;
}
}
/* Trim trailing backspace/blank pair. */
if (p->col > 2 && p->buf[p->col - 1] == ' ')
p->col -= 2;
continue;
default:
continue;
}
/*
* Common handling for Unicode and numbered
* character escape sequences.
*/
if (p->enc == TERMENC_ASCII) {
cp = ascii_uc2str(uc);
encode(p, cp, strlen(cp));
} else {
if ((uc < 0x20 && uc != 0x09) ||
(uc > 0x7E && uc < 0xA0))
uc = 0xFFFD;
encode1(p, uc);
}
}
p->flags &= ~TERMP_NBRWORD;
}
static void
adjbuf(struct termp *p, size_t sz)
{
if (0 == p->maxcols)
p->maxcols = 1024;
while (sz >= p->maxcols)
p->maxcols <<= 2;
p->buf = mandoc_reallocarray(p->buf, p->maxcols, sizeof(int));
}
static void
bufferc(struct termp *p, char c)
{
if (p->col + 1 >= p->maxcols)
adjbuf(p, p->col + 1);
p->buf[p->col++] = c;
}
/*
* See encode().
* Do this for a single (probably unicode) value.
* Does not check for non-decorated glyphs.
*/
static void
encode1(struct termp *p, int c)
{
enum termfont f;
if (p->col + 7 >= p->maxcols)
adjbuf(p, p->col + 7);
f = (c == ASCII_HYPH || c > 127 || isgraph(c)) ?
p->fontq[p->fonti] : TERMFONT_NONE;
if (p->flags & TERMP_BACKBEFORE) {
if (p->buf[p->col - 1] == ' ')
p->col--;
else
p->buf[p->col++] = 8;
p->flags &= ~TERMP_BACKBEFORE;
}
if (TERMFONT_UNDER == f || TERMFONT_BI == f) {
p->buf[p->col++] = '_';
p->buf[p->col++] = 8;
}
if (TERMFONT_BOLD == f || TERMFONT_BI == f) {
if (ASCII_HYPH == c)
p->buf[p->col++] = '-';
else
p->buf[p->col++] = c;
p->buf[p->col++] = 8;
}
p->buf[p->col++] = c;
if (p->flags & TERMP_BACKAFTER) {
p->flags |= TERMP_BACKBEFORE;
p->flags &= ~TERMP_BACKAFTER;
}
}
static void
encode(struct termp *p, const char *word, size_t sz)
{
size_t i;
if (p->col + 2 + (sz * 5) >= p->maxcols)
adjbuf(p, p->col + 2 + (sz * 5));
for (i = 0; i < sz; i++) {
if (ASCII_HYPH == word[i] ||
isgraph((unsigned char)word[i]))
encode1(p, word[i]);
else
p->buf[p->col++] = word[i];
}
}
void
term_setwidth(struct termp *p, const char *wstr)
{
struct roffsu su;
int iop, width;
iop = 0;
width = 0;
if (NULL != wstr) {
switch (*wstr) {
case '+':
iop = 1;
wstr++;
break;
case '-':
iop = -1;
wstr++;
break;
default:
break;
}
if (a2roffsu(wstr, &su, SCALE_MAX))
width = term_hspan(p, &su);
else
iop = 0;
}
(*p->setwidth)(p, iop, width);
}
size_t
term_len(const struct termp *p, size_t sz)
{
return (*p->width)(p, ' ') * sz;
}
static size_t
cond_width(const struct termp *p, int c, int *skip)
{
if (*skip) {
(*skip) = 0;
return 0;
} else
return (*p->width)(p, c);
}
size_t
term_strlen(const struct termp *p, const char *cp)
{
size_t sz, rsz, i;
int ssz, skip, uc;
const char *seq, *rhs;
enum mandoc_esc esc;
static const char rej[] = { '\\', ASCII_NBRSP, ASCII_HYPH,
ASCII_BREAK, '\0' };
/*
* Account for escaped sequences within string length
* calculations. This follows the logic in term_word() as we
* must calculate the width of produced strings.
*/
sz = 0;
skip = 0;
while ('\0' != *cp) {
rsz = strcspn(cp, rej);
for (i = 0; i < rsz; i++)
sz += cond_width(p, *cp++, &skip);
switch (*cp) {
case '\\':
cp++;
esc = mandoc_escape(&cp, &seq, &ssz);
if (ESCAPE_ERROR == esc)
continue;
rhs = NULL;
switch (esc) {
case ESCAPE_UNICODE:
uc = mchars_num2uc(seq + 1, ssz - 1);
break;
case ESCAPE_NUMBERED:
uc = mchars_num2char(seq, ssz);
if (uc < 0)
continue;
break;
case ESCAPE_SPECIAL:
if (p->enc == TERMENC_ASCII) {
rhs = mchars_spec2str(seq, ssz, &rsz);
if (rhs != NULL)
break;
} else {
uc = mchars_spec2cp(seq, ssz);
if (uc > 0)
sz += cond_width(p, uc, &skip);
}
continue;
case ESCAPE_SKIPCHAR:
skip = 1;
continue;
case ESCAPE_OVERSTRIKE:
rsz = 0;
rhs = seq + ssz;
while (seq < rhs) {
if (*seq == '\\') {
mandoc_escape(&seq, NULL, NULL);
continue;
}
i = (*p->width)(p, *seq++);
if (rsz < i)
rsz = i;
}
sz += rsz;
continue;
default:
continue;
}
/*
* Common handling for Unicode and numbered
* character escape sequences.
*/
if (rhs == NULL) {
if (p->enc == TERMENC_ASCII) {
rhs = ascii_uc2str(uc);
rsz = strlen(rhs);
} else {
if ((uc < 0x20 && uc != 0x09) ||
(uc > 0x7E && uc < 0xA0))
uc = 0xFFFD;
sz += cond_width(p, uc, &skip);
continue;
}
}
if (skip) {
skip = 0;
break;
}
/*
* Common handling for all escape sequences
* printing more than one character.
*/
for (i = 0; i < rsz; i++)
sz += (*p->width)(p, *rhs++);
break;
case ASCII_NBRSP:
sz += cond_width(p, ' ', &skip);
cp++;
break;
case ASCII_HYPH:
sz += cond_width(p, '-', &skip);
cp++;
break;
default:
break;
}
}
return sz;
}
int
term_vspan(const struct termp *p, const struct roffsu *su)
{
double r;
int ri;
switch (su->unit) {
case SCALE_BU:
r = su->scale / 40.0;
break;
case SCALE_CM:
r = su->scale * 6.0 / 2.54;
break;
case SCALE_FS:
r = su->scale * 65536.0 / 40.0;
break;
case SCALE_IN:
r = su->scale * 6.0;
break;
case SCALE_MM:
r = su->scale * 0.006;
break;
case SCALE_PC:
r = su->scale;
break;
case SCALE_PT:
r = su->scale / 12.0;
break;
case SCALE_EN:
case SCALE_EM:
r = su->scale * 0.6;
break;
case SCALE_VS:
r = su->scale;
break;
default:
abort();
}
ri = r > 0.0 ? r + 0.4995 : r - 0.4995;
return ri < 66 ? ri : 1;
}
/*
* Convert a scaling width to basic units, rounding down.
*/
int
term_hspan(const struct termp *p, const struct roffsu *su)
{
return (*p->hspan)(p, su);
}