xref: /illumos-gate/usr/src/lib/libcurses/screen/mvcur.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 /*LINTLIBRARY*/
41 
42 #include	<sys/types.h>
43 #include	"curses_inc.h"
44 
45 /*
46  * Cursor motion optimization routine.  This routine takes as parameters
47  * the screen positions that the cursor is currently at, and the position
48  * you want it to be at, and it will move the cursor there very
49  * efficiently.  It isn't really optimal, since several approximations
50  * are taken in the interests of efficiency and simplicity.  The code
51  * here considers directly addressing the cursor, and also considers
52  * local motions using left, right, up, down, tabs, backtabs, vertical
53  * and horizontal addressing, and parameterized motions.  It does not
54  * consider using home down, or taking advantage of automatic margins on
55  * any of the four directions.  (Two of these directions, left and right,
56  * are well defined by the am and bw capabilities, but up and down are
57  * not defined, nor are tab or backtab off the ends.)
58  *
59  * General strategies considered:
60  *	CA	Direct Cursor Addressing
61  *	LM	Local Motions from the old position
62  *	HR	Home + Local Motions from upper left corner
63  *	HDR	Home Down + Local Motions from lower left corner
64  *	CR	CR + Local Motions from left margin
65  *
66  * Local Motions can include
67  *	Up	cuu, cuu1, vpa
68  *	Down	cud, cud1, vpa
69  *	Left	cul, cul1, hpa, bs, cbt
70  *	Right	cuf, cuf1, hpa, tab, char moved over
71  */
72 
73 /* This is called _ISMARK2 so it doesn't conflict with _ISMARK1 in wrefresh.c */
74 
75 #define	_ISMARK2(x)	(mks[(x) / BITSPERBYTE] & (1<<((x) % BITSPERBYTE)))
76 
77 #define	H_UP	-1
78 #define	H_DO	1
79 
80 static	int	Newy;
81 static  int	_homefirst(int, int, int, int),
82 		_mvrel(int, int, int, int, int),
83 		_mvvert(int, int, int), _mvhor(int, int, int),
84 		_mvright(int, int, int), _mvleft(int, int, int);
85 
86 int
87 mvcur(int cury, int curx, int newy, int newx)
88 {
89 	int	hu,	/* cost home + relative */
90 		hd,	/* cost home-down + relative */
91 		rl,	/* cost relative */
92 		cm;	/* cost direct cursor motion */
93 
94 	/* obvious case */
95 	if (cury == newy && curx == newx)
96 		return (OK);
97 
98 	/* not in the right mode for cursor movement */
99 	if (SP->fl_endwin)
100 		return (ERR);
101 
102 	if (!move_standout_mode && curscr->_attrs && !SP->_mks)
103 		_VIDS(A_NORMAL, curscr->_attrs);
104 
105 	if (!move_insert_mode && SP->phys_irm)
106 		_OFFINSERT();
107 
108 	Newy = newy;
109 
110 	/* cost of using cm */
111 	cm = _COST(Cursor_address);
112 
113 	rl = hd = hu = LARGECOST;
114 
115 	/* baudrate optimization */
116 	if (cm < LARGECOST && SP->baud >= 2400 &&
117 	    cury >= 0 && cury < curscr->_maxy &&
118 	    curx >= 0 && curx < curscr->_maxx) {
119 		if (cursor_down && (newy == (cury + 1)) &&
120 		    ((newx == curx) || (newx == 0 && carriage_return))) {
121 			if (newx != curx)
122 				_PUTS(carriage_return, 1);
123 			_PUTS(cursor_down, 1);
124 			goto done;
125 		}
126 
127 		/* fast horizontal move */
128 		if (cury == newy && newx < curx - 4 && newx > curx + 4) {
129 			if (newx < curx)
130 				rl = _mvleft(curx, newx, FALSE);
131 			else
132 				rl = _mvright(curx, newx, FALSE);
133 			if (rl < cm) {
134 				if (newx < curx)
135 					rl = _mvleft(curx, newx, TRUE);
136 				else
137 					rl = _mvright(curx, newx, TRUE);
138 				goto done;
139 			}
140 		}
141 	}
142 
143 	/* cost using relative movements */
144 	if (rl >= LARGECOST && cury >= 0 && cury < curscr->_maxy &&
145 	    curx >= 0 && curx < curscr->_maxx)
146 		rl = _mvrel(cury, curx, newy, newx, FALSE);
147 
148 	/* cost of homing to upper-left corner first */
149 	if (cursor_home)
150 		hu = _homefirst(newy, newx, H_UP, FALSE);
151 
152 	/* cost of homing to lower-left corner first */
153 	if (cursor_to_ll)
154 		hd = _homefirst(newy, newx, H_DO, FALSE);
155 
156 	/* can't do any one of them */
157 	if (cm >= LARGECOST && rl >= LARGECOST && hu >= LARGECOST &&
158 	    hd >= LARGECOST)
159 		return (ERR);
160 
161 	/* do the best one */
162 	if (cm <= rl && cm <= hu && cm <= hd)
163 		_PUTS(tparm_p2(cursor_address, newy, newx), 1);
164 	else
165 		if (rl <= hu && rl <= hd)
166 			(void) _mvrel(cury, curx, newy, newx, TRUE);
167 		else
168 			(void) _homefirst(newy, newx, hu <= hd ?
169 			    H_UP : H_DO, TRUE);
170 
171 done:
172 	/* update cursor position */
173 	/*LINTED*/
174 	curscr->_curx = (short) newx;
175 	/*LINTED*/
176 	curscr->_cury = (short) newy;
177 
178 	return (OK);
179 }
180 
181 /* Move by homing first. */
182 
183 static int
184 _homefirst(int ny, int nx, int type, int doit)
185 {
186 	char	*home;
187 	int	cy, cost;
188 
189 	if (type == H_UP) {
190 		home = cursor_home;
191 		cost = _COST(Cursor_home);
192 		cy = 0;
193 	} else {
194 		home = cursor_to_ll;
195 		cost = _COST(Cursor_to_ll);
196 		cy = curscr->_maxy - 1;
197 	}
198 
199 	if (!home)
200 		return (LARGECOST);
201 	if (!doit)
202 		return (cost + _mvrel(cy, 0, ny, nx, FALSE));
203 
204 	_PUTS(home, 1);
205 	return (_mvrel(cy, 0, ny, nx, TRUE));
206 }
207 
208 /* Move relatively */
209 
210 static int
211 _mvrel(int cy, int cx, int ny, int nx, int doit)
212 {
213 	int	cv, ch;
214 
215 	/* do in this order since _mvhor may need the curscr image */
216 	cv = _mvvert(cy, ny, doit);
217 	ch = _mvhor(cx, nx, doit);
218 
219 	return (cv + ch);
220 }
221 
222 /* Move vertically */
223 
224 static int
225 _mvvert(int cy, int ny, int doit)
226 {
227 	char	*ve;
228 	int	dy, st_1, st_n, cv;
229 
230 	if (cy == ny)
231 		goto out;
232 
233 	/* cost of stepwise movement */
234 	if (cy < ny) {
235 		dy = ny-cy;
236 		st_1 = _COST(Cursor_down) * dy;
237 		st_n = _COST(Parm_down_cursor);
238 	} else {
239 		dy = cy-ny;
240 		st_1 = _COST(Cursor_up) * dy;
241 		st_n = _COST(Parm_up_cursor);
242 	}
243 
244 	/* cost of using vertical move */
245 	cv = _COST(Row_address);
246 
247 	/* if calculating cost only */
248 	if (!doit)
249 		return ((cv < st_1 && cv < st_n) ? cv :
250 		    (st_n < st_1) ? st_n : st_1);
251 
252 	/* do it */
253 	if (cv < st_1 && cv < st_n)
254 		_PUTS(tparm_p1(row_address, ny), 1);
255 	else
256 		if (st_n < st_1) {
257 			if (cy < ny)
258 				_PUTS(tparm_p1(parm_down_cursor, dy), 1);
259 			else
260 				_PUTS(tparm_p1(parm_up_cursor, dy), 1);
261 		} else {
262 			if (cy < ny)
263 				ve = cursor_down;
264 			else
265 				ve = cursor_up;
266 			for (; dy > 0; --dy)
267 				_PUTS(ve, 1);
268 		}
269 
270 out:
271 	return (0);
272 }
273 
274 /* Move horizontally */
275 
276 static int
277 _mvhor(int cx, int nx, int doit)
278 {
279 	int	st, ch, hl;
280 
281 	if (cx == nx)
282 		goto out;
283 
284 	/* cost using horizontal move */
285 	ch = _COST(Row_address);
286 
287 	/* cost doing stepwise */
288 	st = cx < nx ? _mvright(cx, nx, FALSE) : _mvleft(cx, nx, FALSE);
289 
290 	/* cost homeleft first */
291 	hl = (_COST(Carriage_return) < LARGECOST) ?
292 	    _COST(Carriage_return) + _mvright(0, nx, FALSE) : LARGECOST;
293 
294 	if (!doit)
295 		return ((ch < st && ch < hl) ? ch : (hl < st ? hl : st));
296 
297 	if (ch < st && ch < hl)
298 		_PUTS(tparm_p1(column_address, nx), 1);
299 	else
300 		if (hl < st) {
301 			_PUTS(carriage_return, 1);
302 			(void) _mvright(0, nx, TRUE);
303 		} else {
304 			if (cx < nx)
305 				(void) _mvright(cx, nx, TRUE);
306 			else
307 				(void) _mvleft(cx, nx, TRUE);
308 	}
309 out:
310 	return (0);
311 }
312 
313 /* Move right. */
314 
315 static int
316 _mvright(int cx, int nx, int doit)
317 {
318 	chtype	*scp;
319 	char	*mks;
320 	int	nt, tx, x, stcost, iscont;
321 
322 	if (!cursor_right && !parm_right_cursor)
323 		return (LARGECOST);
324 
325 	scp = curscr->_y[Newy];
326 	mks = magic_cookie_glitch >= 0 ? SP->_mks[Newy] : NULL;
327 
328 	if (cursor_right) {
329 		/* number of tabs used in stepwise movement */
330 		nt = tab ? (nx / TABSIZE - cx / TABSIZE) : 0;
331 		tx = (nt > 0) ? (cx / TABSIZE + nt) * TABSIZE : cx;
332 
333 		/* calculate stepwise cost */
334 		stcost = nt * _COST(Tab);
335 		iscont = 0;
336 		for (x = tx; x < nx; ++x) {
337 			if (iscont == 0 && !ISCBIT(scp[x]))
338 				iscont = 1;
339 			if ((!ceol_standout_glitch && !mks &&
340 			    _ATTR(scp[x]) == curscr->_attrs) ||
341 			    ceol_standout_glitch || (mks && !_ISMARK2(x))) {
342 				if (!ISMBIT(scp[x]))
343 					stcost += 1;
344 				else if (iscont && !(nx - x == 1 && nx <
345 				    curscr->_maxx && ISCBIT(scp[nx])))
346 					stcost += 1;
347 				else
348 					stcost += _COST(Cursor_right);
349 			} else
350 				stcost += _COST(Cursor_right);
351 		}
352 	} else
353 		stcost = LARGECOST;
354 
355 	if (!doit)
356 		return ((_COST(Parm_right_cursor) < stcost) ?
357 		    _COST(Parm_right_cursor) : stcost);
358 
359 	/* actually move */
360 	if (_COST(Parm_right_cursor) < stcost)
361 		_PUTS(tparm_p1(parm_right_cursor, nx-cx), 1);
362 	else {
363 		if (SP->phys_irm)
364 			_OFFINSERT();
365 		for (; nt > 0; --nt)
366 			_PUTS(tab, 1);
367 		iscont = 0;
368 		for (x = tx; x < nx; ++x) {
369 			if (iscont == 0 && !ISCBIT(scp[x]))
370 				iscont = 1;
371 			if ((!ceol_standout_glitch && !mks &&
372 			    _ATTR(scp[x]) == curscr->_attrs) ||
373 			    ceol_standout_glitch || (mks && !_ISMARK2(x))) {
374 				if (!ISMBIT(scp[x]))
375 					(void) _outwch(_CHAR(scp[x]));
376 				else if (iscont && !(nx - x == 1 &&
377 				    nx < curscr->_maxx && ISCBIT(scp[nx])))
378 					(void) _outwch(_CHAR(scp[x]));
379 				else
380 					_PUTS(cursor_right, 1);
381 			} else
382 				_PUTS(cursor_right, 1);
383 		}
384 	}
385 
386 	return (0);
387 }
388 
389 /* Move left */
390 
391 static int
392 _mvleft(int cx, int nx, int doit)
393 {
394 	int	tx, nt, x, stcost;
395 
396 	if (!cursor_left && !parm_left_cursor)
397 		return (LARGECOST);
398 
399 	if (cursor_left) {
400 		/* stepwise cost */
401 		tx = cx;
402 		nt = 0;
403 		if (back_tab) {
404 			/* the TAB position >= nx */
405 			x = (nx % TABSIZE) ? (nx / TABSIZE + 1) * TABSIZE : nx;
406 
407 			/* # of tabs used and position after using them */
408 			if (x < cx) {
409 				nt = (cx / TABSIZE - x / TABSIZE) +
410 				    ((cx % TABSIZE) ? 1 : 0);
411 				tx = x;
412 			}
413 		}
414 		stcost = nt * _COST(Back_tab) + (tx-nx) * _COST(Cursor_left);
415 	} else
416 		stcost = LARGECOST;
417 
418 	/* get cost only */
419 	if (!doit)
420 		return ((_COST(Parm_left_cursor) < stcost) ?
421 		    _COST(Parm_left_cursor) : stcost);
422 
423 	/* doit */
424 	if (_COST(Parm_left_cursor) < stcost)
425 		_PUTS(tparm_p1(parm_left_cursor, cx - nx), 1);
426 	else {
427 		for (; nt > 0; --nt)
428 		    _PUTS(back_tab, 1);
429 		for (; tx > nx; --tx)
430 		    _PUTS(cursor_left, 1);
431 	}
432 
433 	return (0);
434 }
435