xref: /openbsd/usr.bin/mg/window.c (revision 3cab2bb3)
1 /*	$OpenBSD: window.c,v 1.36 2015/11/18 18:21:06 jasper Exp $	*/
2 
3 /* This file is in the public domain. */
4 
5 /*
6  *		Window handling.
7  */
8 
9 #include <sys/queue.h>
10 #include <signal.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 
14 #include "def.h"
15 
16 struct mgwin *
17 new_window(struct buffer *bp)
18 {
19 	struct mgwin *wp;
20 
21 	wp = calloc(1, sizeof(struct mgwin));
22 	if (wp == NULL)
23 		return (NULL);
24 
25 	wp->w_bufp = bp;
26 	wp->w_dotp = NULL;
27 	wp->w_doto = 0;
28 	wp->w_markp = NULL;
29 	wp->w_marko = 0;
30 	wp->w_rflag = 0;
31 	wp->w_frame = 0;
32 	wp->w_wrapline = NULL;
33 	wp->w_dotline = wp->w_markline = 1;
34 	if (bp)
35 		bp->b_nwnd++;
36 	return (wp);
37 }
38 
39 /*
40  * Reposition dot in the current window to line "n".  If the argument is
41  * positive, it is that line.  If it is negative it is that line from the
42  * bottom.  If it is 0 the window is centered (this is what the standard
43  * redisplay code does).
44  */
45 /* ARGSUSED */
46 int
47 reposition(int f, int n)
48 {
49 	curwp->w_frame = (f & FFARG) ? (n >= 0 ? n + 1 : n) : 0;
50 	curwp->w_rflag |= WFFRAME;
51 	sgarbf = TRUE;
52 	return (TRUE);
53 }
54 
55 /*
56  * Refresh the display.  A call is made to the "ttresize" entry in the
57  * terminal handler, which tries to reset "nrow" and "ncol".  They will,
58  * however, never be set outside of the NROW or NCOL range.  If the display
59  * changed size, arrange that everything is redone, then call "update" to
60  * fix the display.  We do this so the new size can be displayed.  In the
61  * normal case the call to "update" in "main.c" refreshes the screen, and
62  * all of the windows need not be recomputed. This call includes a
63  * 'force' parameter to ensure that the redraw is done, even after a
64  * a suspend/continue (where the window size parameters will already
65  * be updated). Note that when you get to the "display unusable"
66  * message, the screen will be messed up. If you make the window bigger
67  * again, and send another command, everything will get fixed!
68  */
69 int
70 redraw(int f, int n)
71 {
72 	return (do_redraw(f, n, FALSE));
73 }
74 
75 /* ARGSUSED */
76 int
77 do_redraw(int f, int n, int force)
78 {
79 	struct mgwin	*wp;
80 	int		 oldnrow, oldncol;
81 
82 	oldnrow = nrow;
83 	oldncol = ncol;
84 	ttresize();
85 	if (nrow != oldnrow || ncol != oldncol || force) {
86 
87 		/* find last */
88 		wp = wheadp;
89 		while (wp->w_wndp != NULL)
90 			wp = wp->w_wndp;
91 
92 		/* check if too small */
93 		if (nrow < wp->w_toprow + 3) {
94 			dobeep();
95 			ewprintf("Display unusable");
96 			return (FALSE);
97 		}
98 		wp->w_ntrows = nrow - wp->w_toprow - 2;
99 		sgarbf = TRUE;
100 		update(CMODE);
101 	} else
102 		sgarbf = TRUE;
103 	return (TRUE);
104 }
105 
106 /*
107  * The command to make the next window (next => down the screen) the current
108  * window. There are no real errors, although the command does nothing if
109  * there is only 1 window on the screen.
110  */
111 /* ARGSUSED */
112 int
113 nextwind(int f, int n)
114 {
115 	struct mgwin	*wp;
116 
117 	if ((wp = curwp->w_wndp) == NULL)
118 		wp = wheadp;
119 	curwp = wp;
120 	curbp = wp->w_bufp;
121 	return (TRUE);
122 }
123 
124 /* not in GNU Emacs */
125 /*
126  * This command makes the previous window (previous => up the screen) the
127  * current window. There are no errors, although the command does not do
128  * a lot if there is only 1 window.
129  */
130 /* ARGSUSED */
131 int
132 prevwind(int f, int n)
133 {
134 	struct mgwin	*wp1, *wp2;
135 
136 	wp1 = wheadp;
137 	wp2 = curwp;
138 	if (wp1 == wp2)
139 		wp2 = NULL;
140 	while (wp1->w_wndp != wp2)
141 		wp1 = wp1->w_wndp;
142 	curwp = wp1;
143 	curbp = wp1->w_bufp;
144 	return (TRUE);
145 }
146 
147 /*
148  * This command makes the current window the only window on the screen.  Try
149  * to set the framing so that "." does not have to move on the display.  Some
150  * care has to be taken to keep the values of dot and mark in the buffer
151  * structures right if the destruction of a window makes a buffer become
152  * undisplayed.
153  */
154 /* ARGSUSED */
155 int
156 onlywind(int f, int n)
157 {
158 	struct mgwin	*wp;
159 	struct line	*lp;
160 	int		 i;
161 
162 	while (wheadp != curwp) {
163 		wp = wheadp;
164 		wheadp = wp->w_wndp;
165 		if (--wp->w_bufp->b_nwnd == 0) {
166 			wp->w_bufp->b_dotp = wp->w_dotp;
167 			wp->w_bufp->b_doto = wp->w_doto;
168 			wp->w_bufp->b_markp = wp->w_markp;
169 			wp->w_bufp->b_marko = wp->w_marko;
170 			wp->w_bufp->b_dotline = wp->w_dotline;
171 			wp->w_bufp->b_markline = wp->w_markline;
172 		}
173 		free(wp);
174 	}
175 	while (curwp->w_wndp != NULL) {
176 		wp = curwp->w_wndp;
177 		curwp->w_wndp = wp->w_wndp;
178 		if (--wp->w_bufp->b_nwnd == 0) {
179 			wp->w_bufp->b_dotp = wp->w_dotp;
180 			wp->w_bufp->b_doto = wp->w_doto;
181 			wp->w_bufp->b_markp = wp->w_markp;
182 			wp->w_bufp->b_marko = wp->w_marko;
183 			wp->w_bufp->b_dotline = wp->w_dotline;
184 			wp->w_bufp->b_markline = wp->w_markline;
185 		}
186 		free(wp);
187 	}
188 	lp = curwp->w_linep;
189 	i = curwp->w_toprow;
190 	while (i != 0 && lback(lp) != curbp->b_headp) {
191 		--i;
192 		lp = lback(lp);
193 	}
194 	curwp->w_toprow = 0;
195 
196 	/* 2 = mode, echo */
197 	curwp->w_ntrows = nrow - 2;
198 	curwp->w_linep = lp;
199 	curwp->w_rflag |= WFMODE | WFFULL;
200 	return (TRUE);
201 }
202 
203 /*
204  * Split the current window.  A window smaller than 3 lines cannot be split.
205  * The only other error that is possible is a "malloc" failure allocating the
206  * structure for the new window.
207  * If called with a FFOTHARG, flags on the new window are set to 'n'.
208  */
209 /* ARGSUSED */
210 int
211 splitwind(int f, int n)
212 {
213 	struct mgwin	*wp, *wp1, *wp2;
214 	struct line	*lp;
215 	int		 ntru, ntrd, ntrl;
216 
217 	if (curwp->w_ntrows < 3) {
218 		dobeep();
219 		ewprintf("Cannot split a %d line window", curwp->w_ntrows);
220 		return (FALSE);
221 	}
222 	wp = new_window(curbp);
223 	if (wp == NULL) {
224 		dobeep();
225 		ewprintf("Unable to create a window");
226 		return (FALSE);
227 	}
228 
229 	/* use the current dot and mark */
230 	wp->w_dotp = curwp->w_dotp;
231 	wp->w_doto = curwp->w_doto;
232 	wp->w_markp = curwp->w_markp;
233 	wp->w_marko = curwp->w_marko;
234 	wp->w_dotline = curwp->w_dotline;
235 	wp->w_markline = curwp->w_markline;
236 
237 	/* figure out which half of the screen we're in */
238 	ntru = (curwp->w_ntrows - 1) / 2;	/* Upper size */
239 	ntrl = (curwp->w_ntrows - 1) - ntru;	/* Lower size */
240 
241 	for (lp = curwp->w_linep, ntrd = 0; lp != curwp->w_dotp;
242 	    lp = lforw(lp))
243 		ntrd++;
244 
245 	lp = curwp->w_linep;
246 
247 	/* old is upper window */
248 	if (ntrd <= ntru) {
249 		/* hit mode line */
250 		if (ntrd == ntru)
251 			lp = lforw(lp);
252 		curwp->w_ntrows = ntru;
253 		wp->w_wndp = curwp->w_wndp;
254 		curwp->w_wndp = wp;
255 		wp->w_toprow = curwp->w_toprow + ntru + 1;
256 		wp->w_ntrows = ntrl;
257 	/* old is lower window */
258 	} else {
259 		wp1 = NULL;
260 		wp2 = wheadp;
261 		while (wp2 != curwp) {
262 			wp1 = wp2;
263 			wp2 = wp2->w_wndp;
264 		}
265 		if (wp1 == NULL)
266 			wheadp = wp;
267 		else
268 			wp1->w_wndp = wp;
269 		wp->w_wndp = curwp;
270 		wp->w_toprow = curwp->w_toprow;
271 		wp->w_ntrows = ntru;
272 
273 		/* mode line */
274 		++ntru;
275 		curwp->w_toprow += ntru;
276 		curwp->w_ntrows = ntrl;
277 		while (ntru--)
278 			lp = lforw(lp);
279 	}
280 
281 	/* adjust the top lines if necessary */
282 	curwp->w_linep = lp;
283 	wp->w_linep = lp;
284 
285 	curwp->w_rflag |= WFMODE | WFFULL;
286 	wp->w_rflag |= WFMODE | WFFULL;
287 	/* if FFOTHARG, set flags) */
288 	if (f & FFOTHARG)
289 		wp->w_flag = n;
290 
291 	return (TRUE);
292 }
293 
294 /*
295  * Enlarge the current window.  Find the window that loses space.  Make sure
296  * it is big enough.  If so, hack the window descriptions, and ask redisplay
297  * to do all the hard work.  You don't just set "force reframe" because dot
298  * would move.
299  */
300 /* ARGSUSED */
301 int
302 enlargewind(int f, int n)
303 {
304 	struct mgwin	*adjwp;
305 	struct line	*lp;
306 	int		 i;
307 
308 	if (n < 0)
309 		return (shrinkwind(f, -n));
310 	if (wheadp->w_wndp == NULL) {
311 		dobeep();
312 		ewprintf("Only one window");
313 		return (FALSE);
314 	}
315 	if ((adjwp = curwp->w_wndp) == NULL) {
316 		adjwp = wheadp;
317 		while (adjwp->w_wndp != curwp)
318 			adjwp = adjwp->w_wndp;
319 	}
320 	if (adjwp->w_ntrows <= n) {
321 		dobeep();
322 		ewprintf("Impossible change");
323 		return (FALSE);
324 	}
325 
326 	/* shrink below */
327 	if (curwp->w_wndp == adjwp) {
328 		lp = adjwp->w_linep;
329 		for (i = 0; i < n && lp != adjwp->w_bufp->b_headp; ++i)
330 			lp = lforw(lp);
331 		adjwp->w_linep = lp;
332 		adjwp->w_toprow += n;
333 	/* shrink above */
334 	} else {
335 		lp = curwp->w_linep;
336 		for (i = 0; i < n && lback(lp) != curbp->b_headp; ++i)
337 			lp = lback(lp);
338 		curwp->w_linep = lp;
339 		curwp->w_toprow -= n;
340 	}
341 	curwp->w_ntrows += n;
342 	adjwp->w_ntrows -= n;
343 	curwp->w_rflag |= WFMODE | WFFULL;
344 	adjwp->w_rflag |= WFMODE | WFFULL;
345 	return (TRUE);
346 }
347 
348 /*
349  * Shrink the current window.  Find the window that gains space.  Hack at the
350  * window descriptions. Ask the redisplay to do all the hard work.
351  */
352 int
353 shrinkwind(int f, int n)
354 {
355 	struct mgwin	*adjwp;
356 	struct line	*lp;
357 	int		 i;
358 
359 	if (n < 0)
360 		return (enlargewind(f, -n));
361 	if (wheadp->w_wndp == NULL) {
362 		dobeep();
363 		ewprintf("Only one window");
364 		return (FALSE);
365 	}
366 	/*
367 	 * Bit of flakiness - FFRAND means it was an internal call, and
368 	 * to be trusted implicitly about sizes.
369 	 */
370 	if (!(f & FFRAND) && curwp->w_ntrows <= n) {
371 		dobeep();
372 		ewprintf("Impossible change");
373 		return (FALSE);
374 	}
375 	if ((adjwp = curwp->w_wndp) == NULL) {
376 		adjwp = wheadp;
377 		while (adjwp->w_wndp != curwp)
378 			adjwp = adjwp->w_wndp;
379 	}
380 
381 	/* grow below */
382 	if (curwp->w_wndp == adjwp) {
383 		lp = adjwp->w_linep;
384 		for (i = 0; i < n && lback(lp) != adjwp->w_bufp->b_headp; ++i)
385 			lp = lback(lp);
386 		adjwp->w_linep = lp;
387 		adjwp->w_toprow -= n;
388 	/* grow above */
389 	} else {
390 		lp = curwp->w_linep;
391 		for (i = 0; i < n && lp != curbp->b_headp; ++i)
392 			lp = lforw(lp);
393 		curwp->w_linep = lp;
394 		curwp->w_toprow += n;
395 	}
396 	curwp->w_ntrows -= n;
397 	adjwp->w_ntrows += n;
398 	curwp->w_rflag |= WFMODE | WFFULL;
399 	adjwp->w_rflag |= WFMODE | WFFULL;
400 	return (TRUE);
401 }
402 
403 /*
404  * Delete current window. Call shrink-window to do the screen updating, then
405  * throw away the window.
406  */
407 /* ARGSUSED */
408 int
409 delwind(int f, int n)
410 {
411 	struct mgwin	*wp, *nwp;
412 
413 	wp = curwp;		/* Cheap...		 */
414 
415 	/* shrinkwind returning false means only one window... */
416 	if (shrinkwind(FFRAND, wp->w_ntrows + 1) == FALSE)
417 		return (FALSE);
418 	if (--wp->w_bufp->b_nwnd == 0) {
419 		wp->w_bufp->b_dotp = wp->w_dotp;
420 		wp->w_bufp->b_doto = wp->w_doto;
421 		wp->w_bufp->b_markp = wp->w_markp;
422 		wp->w_bufp->b_marko = wp->w_marko;
423 		wp->w_bufp->b_dotline = wp->w_dotline;
424 		wp->w_bufp->b_markline = wp->w_markline;
425 	}
426 
427 	/* since shrinkwind did't crap out, we know we have a second window */
428 	if (wp == wheadp)
429 		wheadp = curwp = wp->w_wndp;
430 	else if ((curwp = wp->w_wndp) == NULL)
431 		curwp = wheadp;
432 	curbp = curwp->w_bufp;
433 	for (nwp = wheadp; nwp != NULL; nwp = nwp->w_wndp)
434 		if (nwp->w_wndp == wp) {
435 			nwp->w_wndp = wp->w_wndp;
436 			break;
437 		}
438 	free(wp);
439 	return (TRUE);
440 }
441