1 /* $Id: term.c,v 1.17 2009/10/24 13:13:20 schwarze Exp $ */
3 * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
30 /* FIXME: accomodate non-breaking, non-collapsing white-space. */
31 /* FIXME: accomodate non-breaking, collapsing white-space. */
33 static struct termp *term_alloc(enum termenc);
34 static void term_free(struct termp *);
36 static void do_escaped(struct termp *, const char **);
37 static void do_special(struct termp *,
38 const char *, size_t);
39 static void do_reserved(struct termp *,
40 const char *, size_t);
41 static void buffer(struct termp *, char);
42 static void encode(struct termp *, char);
49 return(term_alloc(TERMENC_ASCII));
54 terminal_free(void *arg)
57 term_free((struct termp *)arg);
62 term_free(struct termp *p)
68 chars_free(p->symtab);
75 term_alloc(enum termenc enc)
79 if (NULL == (p = malloc(sizeof(struct termp))))
81 bzero(p, sizeof(struct termp));
89 * Flush a line of text. A "line" is loosely defined as being something
90 * that should be followed by a newline, regardless of whether it's
91 * broken apart by newlines getting there. A line can also be a
92 * fragment of a columnar list.
94 * Specifically, a line is whatever's in p->buf of length p->col, which
95 * is zeroed after this function returns.
97 * The usage of termp:flags is as follows:
99 * - TERMP_NOLPAD: when beginning to write the line, don't left-pad the
100 * offset value. This is useful when doing columnar lists where the
101 * prior column has right-padded.
103 * - TERMP_NOBREAK: this is the most important and is used when making
104 * columns. In short: don't print a newline and instead pad to the
105 * right margin. Used in conjunction with TERMP_NOLPAD.
107 * - TERMP_TWOSPACE: when padding, make sure there are at least two
108 * space characters of padding. Otherwise, rather break the line.
110 * - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
111 * the line is overrun, and don't pad-right if it's underrun.
113 * - TERMP_HANG: like TERMP_DANGLE, but doesn't newline when
114 * overruning, instead save the position and continue at that point
115 * when the next invocation.
117 * In-line line breaking:
119 * If TERMP_NOBREAK is specified and the line overruns the right
120 * margin, it will break and pad-right to the right margin after
121 * writing. If maxrmargin is violated, it will break and continue
122 * writing from the right-margin, which will lead to the above
123 * scenario upon exit.
125 * Otherwise, the line will break at the right margin. Extremely long
126 * lines will cause the system to emit a warning (TODO: hyphenate, if
130 term_flushln(struct termp *p)
133 size_t vbl, vsz, vis, maxvis, mmax, bp;
134 static int overstep = 0;
137 * First, establish the maximum columns of "visible" content.
138 * This is usually the difference between the right-margin and
139 * an indentation, but can be, for tagged lists or columns, a
140 * small set of values.
143 assert(p->offset < p->rmargin);
144 assert((int)(p->rmargin - p->offset) - overstep > 0);
146 maxvis = /* LINTED */
147 p->rmargin - p->offset - overstep;
149 p->maxrmargin - p->offset - overstep;
151 bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
155 * If in the standard case (left-justified), then begin with our
156 * indentation, otherwise (columns, etc.) just start spitting
160 if ( ! (p->flags & TERMP_NOLPAD))
162 for (j = 0; j < (int)p->offset; j++)
165 for (i = 0; i < (int)p->col; i++) {
167 * Count up visible word characters. Control sequences
168 * (starting with the CSI) aren't counted. A space
169 * generates a non-printing word, which is valid (the
170 * space is printed according to regular spacing rules).
174 for (j = i, vsz = 0; j < (int)p->col; j++) {
175 if (j && ' ' == p->buf[j])
177 else if (8 == p->buf[j])
184 * Choose the number of blanks to prepend: no blank at the
185 * beginning of a line, one between words -- but do not
186 * actually write them yet.
188 vbl = (size_t)(0 == vis ? 0 : 1);
191 * Find out whether we would exceed the right margin.
192 * If so, break to the next line. (TODO: hyphenate)
193 * Otherwise, write the chosen number of blanks now.
195 if (vis && vis + vbl + vsz > bp) {
197 if (TERMP_NOBREAK & p->flags) {
198 for (j = 0; j < (int)p->rmargin; j++)
200 vis = p->rmargin - p->offset;
202 for (j = 0; j < (int)p->offset; j++)
206 /* Remove the overstep width. */
210 for (j = 0; j < (int)vbl; j++)
216 * Finally, write out the word.
218 for ( ; i < (int)p->col; i++) {
219 if (' ' == p->buf[i])
227 if ( ! (TERMP_NOBREAK & p->flags)) {
233 if (TERMP_HANG & p->flags) {
234 /* We need one blank after the tag. */
235 overstep = /* LINTED */
239 * Behave exactly the same way as groff:
240 * If we have overstepped the margin, temporarily move
241 * it to the right and flag the rest of the line to be
243 * If we landed right at the margin, be happy.
244 * If we are one step before the margin, temporarily
245 * move it one step LEFT and flag the rest of the line
248 if (overstep >= -1) {
249 assert((int)maxvis + overstep >= 0);
255 } else if (TERMP_DANGLE & p->flags)
259 if (maxvis > vis + /* LINTED */
260 ((TERMP_TWOSPACE & p->flags) ? 1 : 0))
261 for ( ; vis < maxvis; vis++)
263 else { /* ...or newline break. */
265 for (i = 0; i < (int)p->rmargin; i++)
272 * A newline only breaks an existing line; it won't assert vertical
273 * space. All data in the output buffer is flushed prior to the newline
277 term_newln(struct termp *p)
280 p->flags |= TERMP_NOSPACE;
282 p->flags &= ~TERMP_NOLPAD;
286 p->flags &= ~TERMP_NOLPAD;
291 * Asserts a vertical space (a full, empty line-break between lines).
292 * Note that if used twice, this will cause two blank spaces and so on.
293 * All data in the output buffer is flushed prior to the newline
297 term_vspace(struct termp *p)
306 do_special(struct termp *p, const char *word, size_t len)
312 rhs = chars_a2ascii(p->symtab, word, len, &sz);
316 fputs("Unknown special character: ", stderr);
317 for (i = 0; i < (int)len; i++)
318 fputc(word[i], stderr);
323 for (i = 0; i < (int)sz; i++)
329 do_reserved(struct termp *p, const char *word, size_t len)
335 rhs = chars_a2res(p->symtab, word, len, &sz);
339 fputs("Unknown reserved word: ", stderr);
340 for (i = 0; i < (int)len; i++)
341 fputc(word[i], stderr);
346 for (i = 0; i < (int)sz; i++)
352 * Handle an escape sequence: determine its length and pass it to the
353 * escape-symbol look table. Note that we assume mdoc(3) has validated
354 * the escape sequence (we assert upon badly-formed escape sequences).
357 do_escaped(struct termp *p, const char **word)
372 if (0 == *wp || 0 == *(wp + 1)) {
373 *word = 0 == *wp ? wp : wp + 1;
377 do_special(p, wp, 2);
381 } else if ('*' == *wp) {
390 if (0 == *wp || 0 == *(wp + 1)) {
391 *word = 0 == *wp ? wp : wp + 1;
395 do_reserved(p, wp, 2);
402 do_reserved(p, wp, 1);
407 } else if ('f' == *wp) {
423 p->bold = p->under = 0;
432 } else if ('[' != *wp) {
433 do_special(p, wp, 1);
439 for (j = 0; *wp && ']' != *wp; wp++, j++)
448 do_special(p, wp - j, (size_t)j);
450 do_reserved(p, wp - j, (size_t)j);
456 * Handle pwords, partial words, which may be either a single word or a
457 * phrase that cannot be broken down (such as a literal string). This
458 * handles word styling.
461 term_word(struct termp *p, const char *word)
467 if (word[0] && 0 == word[1])
486 if ( ! (TERMP_IGNDELIM & p->flags))
487 p->flags |= TERMP_NOSPACE;
493 if ( ! (TERMP_NOSPACE & p->flags))
496 if ( ! (p->flags & TERMP_NONOSPACE))
497 p->flags &= ~TERMP_NOSPACE;
499 for ( ; *word; word++)
503 do_escaped(p, &word);
505 if (sv[0] && 0 == sv[1])
512 p->flags |= TERMP_NOSPACE;
521 * Insert a single character into the line-buffer. If the buffer's
522 * space is exceeded, then allocate more space by doubling the buffer
526 buffer(struct termp *p, char c)
530 if (p->col + 1 >= p->maxcols) {
534 p->buf = realloc(p->buf, s);
536 err(1, "realloc"); /* FIXME: shouldn't be here! */
539 p->buf[(int)(p->col)++] = c;
544 encode(struct termp *p, char c)
562 term_vspan(const struct roffsu *su)
580 r = su->scale / 1000;
592 return(/* LINTED */(size_t)
598 term_hspan(const struct roffsu *su)
602 /* XXX: CM, IN, and PT are approximations. */
609 /* XXX: this is an approximation. */
613 r = (10 * su->scale) / 6;
616 r = (10 * su->scale) / 72;
619 r = su->scale / 1000; /* FIXME: double-check. */
622 r = su->scale * 2 - 1; /* FIXME: double-check. */
631 return((size_t)/* LINTED */