xref: /openbsd/usr.bin/mg/window.c (revision 404b540a)
1 /*	$OpenBSD: window.c,v 1.27 2009/06/04 23:39:37 kjell Exp $	*/
2 
3 /* This file is in the public domain. */
4 
5 /*
6  *		Window handling.
7  */
8 
9 #include "def.h"
10 
11 struct mgwin *
12 new_window(struct buffer *bp)
13 {
14 	struct mgwin *wp;
15 
16 	wp = calloc(1, sizeof(struct mgwin));
17 	if (wp == NULL)
18 		return (NULL);
19 
20 	wp->w_bufp = bp;
21 	wp->w_dotp = NULL;
22 	wp->w_doto = 0;
23 	wp->w_markp = NULL;
24 	wp->w_marko = 0;
25 	wp->w_rflag = 0;
26 	wp->w_frame = 0;
27 	wp->w_wrapline = NULL;
28 	wp->w_dotline = wp->w_markline = 1;
29 	if (bp)
30 		bp->b_nwnd++;
31 	return (wp);
32 }
33 
34 /*
35  * Reposition dot in the current window to line "n".  If the argument is
36  * positive, it is that line.  If it is negative it is that line from the
37  * bottom.  If it is 0 the window is centered (this is what the standard
38  * redisplay code does).  If GOSREC is undefined, default is 0, so it acts
39  * like GNU.  If GOSREC is defined, with no argument it defaults to 1 and
40  * works like in Gosling.
41  */
42 /* ARGSUSED */
43 int
44 reposition(int f, int n)
45 {
46 #ifndef GOSREC
47 	curwp->w_frame = (f & FFARG) ? (n >= 0 ? n + 1 : n) : 0;
48 #else /* !GOSREC */
49 	curwp->w_frame = n;
50 #endif /* !GOSREC */
51 	curwp->w_rflag |= WFFRAME;
52 	sgarbf = TRUE;
53 	return (TRUE);
54 }
55 
56 /*
57  * Refresh the display.  A call is made to the "ttresize" entry in the
58  * terminal handler, which tries to reset "nrow" and "ncol".  They will,
59  * however, never be set outside of the NROW or NCOL range.  If the display
60  * changed size, arrange that everything is redone, then call "update" to
61  * fix the display.  We do this so the new size can be displayed.  In the
62  * normal case the call to "update" in "main.c" refreshes the screen, and
63  * all of the windows need not be recomputed. This call includes a
64  * 'force' parameter to ensure that the redraw is done, even after a
65  * a suspend/continue (where the window size parameters will already
66  * be updated). Note that when you get to the "display unusable"
67  * message, the screen will be messed up. If you make the window bigger
68  * again, and send another command, everything will get fixed!
69  */
70 int
71 redraw(int f, int n)
72 {
73 	return (do_redraw(f, n, FALSE));
74 }
75 
76 /* ARGSUSED */
77 int
78 do_redraw(int f, int n, int force)
79 {
80 	struct mgwin	*wp;
81 	int		 oldnrow, oldncol;
82 
83 	oldnrow = nrow;
84 	oldncol = ncol;
85 	ttresize();
86 	if (nrow != oldnrow || ncol != oldncol || force) {
87 
88 		/* find last */
89 		wp = wheadp;
90 		while (wp->w_wndp != NULL)
91 			wp = wp->w_wndp;
92 
93 		/* check if too small */
94 		if (nrow < wp->w_toprow + 3) {
95 			ewprintf("Display unusable");
96 			return (FALSE);
97 		}
98 		wp->w_ntrows = nrow - wp->w_toprow - 2;
99 		sgarbf = TRUE;
100 		update();
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 		}
171 		free(wp);
172 	}
173 	while (curwp->w_wndp != NULL) {
174 		wp = curwp->w_wndp;
175 		curwp->w_wndp = wp->w_wndp;
176 		if (--wp->w_bufp->b_nwnd == 0) {
177 			wp->w_bufp->b_dotp = wp->w_dotp;
178 			wp->w_bufp->b_doto = wp->w_doto;
179 			wp->w_bufp->b_markp = wp->w_markp;
180 			wp->w_bufp->b_marko = wp->w_marko;
181 		}
182 		free(wp);
183 	}
184 	lp = curwp->w_linep;
185 	i = curwp->w_toprow;
186 	while (i != 0 && lback(lp) != curbp->b_headp) {
187 		--i;
188 		lp = lback(lp);
189 	}
190 	curwp->w_toprow = 0;
191 
192 	/* 2 = mode, echo */
193 	curwp->w_ntrows = nrow - 2;
194 	curwp->w_linep = lp;
195 	curwp->w_rflag |= WFMODE | WFFULL;
196 	return (TRUE);
197 }
198 
199 /*
200  * Split the current window.  A window smaller than 3 lines cannot be split.
201  * The only other error that is possible is a "malloc" failure allocating the
202  * structure for the new window.
203  * If called with a FFOTHARG, flags on the new window are set to 'n'.
204  */
205 /* ARGSUSED */
206 int
207 splitwind(int f, int n)
208 {
209 	struct mgwin	*wp, *wp1, *wp2;
210 	struct line	*lp;
211 	int		 ntru, ntrd, ntrl;
212 
213 	if (curwp->w_ntrows < 3) {
214 		ewprintf("Cannot split a %d line window", curwp->w_ntrows);
215 		return (FALSE);
216 	}
217 	wp = new_window(curbp);
218 	if (wp == NULL) {
219 		ewprintf("Unable to create a window");
220 		return (FALSE);
221 	}
222 
223 	/* use the current dot and mark */
224 	wp->w_dotp = curwp->w_dotp;
225 	wp->w_doto = curwp->w_doto;
226 	wp->w_markp = curwp->w_markp;
227 	wp->w_marko = curwp->w_marko;
228 	wp->w_dotline = curwp->w_dotline;
229 	wp->w_markline = curwp->w_markline;
230 
231 	/* figure out which half of the screen we're in */
232 	ntru = (curwp->w_ntrows - 1) / 2;	/* Upper size */
233 	ntrl = (curwp->w_ntrows - 1) - ntru;	/* Lower size */
234 
235 	for (lp = curwp->w_linep, ntrd = 0; lp != curwp->w_dotp;
236 	    lp = lforw(lp))
237 		ntrd++;
238 
239 	lp = curwp->w_linep;
240 
241 	/* old is upper window */
242 	if (ntrd <= ntru) {
243 		/* hit mode line */
244 		if (ntrd == ntru)
245 			lp = lforw(lp);
246 		curwp->w_ntrows = ntru;
247 		wp->w_wndp = curwp->w_wndp;
248 		curwp->w_wndp = wp;
249 		wp->w_toprow = curwp->w_toprow + ntru + 1;
250 		wp->w_ntrows = ntrl;
251 	/* old is lower window */
252 	} else {
253 		wp1 = NULL;
254 		wp2 = wheadp;
255 		while (wp2 != curwp) {
256 			wp1 = wp2;
257 			wp2 = wp2->w_wndp;
258 		}
259 		if (wp1 == NULL)
260 			wheadp = wp;
261 		else
262 			wp1->w_wndp = wp;
263 		wp->w_wndp = curwp;
264 		wp->w_toprow = curwp->w_toprow;
265 		wp->w_ntrows = ntru;
266 
267 		/* mode line */
268 		++ntru;
269 		curwp->w_toprow += ntru;
270 		curwp->w_ntrows = ntrl;
271 		while (ntru--)
272 			lp = lforw(lp);
273 	}
274 
275 	/* adjust the top lines if necessary */
276 	curwp->w_linep = lp;
277 	wp->w_linep = lp;
278 
279 	curwp->w_rflag |= WFMODE | WFFULL;
280 	wp->w_rflag |= WFMODE | WFFULL;
281 	/* if FFOTHARG, set flags) */
282 	if (f & FFOTHARG)
283 		wp->w_flag = n;
284 
285 	return (TRUE);
286 }
287 
288 /*
289  * Enlarge the current window.  Find the window that loses space.  Make sure
290  * it is big enough.  If so, hack the window descriptions, and ask redisplay
291  * to do all the hard work.  You don't just set "force reframe" because dot
292  * would move.
293  */
294 /* ARGSUSED */
295 int
296 enlargewind(int f, int n)
297 {
298 	struct mgwin	*adjwp;
299 	struct line	*lp;
300 	int		 i;
301 
302 	if (n < 0)
303 		return (shrinkwind(f, -n));
304 	if (wheadp->w_wndp == NULL) {
305 		ewprintf("Only one window");
306 		return (FALSE);
307 	}
308 	if ((adjwp = curwp->w_wndp) == NULL) {
309 		adjwp = wheadp;
310 		while (adjwp->w_wndp != curwp)
311 			adjwp = adjwp->w_wndp;
312 	}
313 	if (adjwp->w_ntrows <= n) {
314 		ewprintf("Impossible change");
315 		return (FALSE);
316 	}
317 
318 	/* shrink below */
319 	if (curwp->w_wndp == adjwp) {
320 		lp = adjwp->w_linep;
321 		for (i = 0; i < n && lp != adjwp->w_bufp->b_headp; ++i)
322 			lp = lforw(lp);
323 		adjwp->w_linep = lp;
324 		adjwp->w_toprow += n;
325 	/* shrink above */
326 	} else {
327 		lp = curwp->w_linep;
328 		for (i = 0; i < n && lback(lp) != curbp->b_headp; ++i)
329 			lp = lback(lp);
330 		curwp->w_linep = lp;
331 		curwp->w_toprow -= n;
332 	}
333 	curwp->w_ntrows += n;
334 	adjwp->w_ntrows -= n;
335 	curwp->w_rflag |= WFMODE | WFFULL;
336 	adjwp->w_rflag |= WFMODE | WFFULL;
337 	return (TRUE);
338 }
339 
340 /*
341  * Shrink the current window.  Find the window that gains space.  Hack at the
342  * window descriptions. Ask the redisplay to do all the hard work.
343  */
344 int
345 shrinkwind(int f, int n)
346 {
347 	struct mgwin	*adjwp;
348 	struct line	*lp;
349 	int		 i;
350 
351 	if (n < 0)
352 		return (enlargewind(f, -n));
353 	if (wheadp->w_wndp == NULL) {
354 		ewprintf("Only one window");
355 		return (FALSE);
356 	}
357 	/*
358 	 * Bit of flakiness - KRANDOM means it was an internal call, and
359 	 * to be trusted implicitly about sizes.
360 	 */
361 	if (!(f & FFRAND) && curwp->w_ntrows <= n) {
362 		ewprintf("Impossible change");
363 		return (FALSE);
364 	}
365 	if ((adjwp = curwp->w_wndp) == NULL) {
366 		adjwp = wheadp;
367 		while (adjwp->w_wndp != curwp)
368 			adjwp = adjwp->w_wndp;
369 	}
370 
371 	/* grow below */
372 	if (curwp->w_wndp == adjwp) {
373 		lp = adjwp->w_linep;
374 		for (i = 0; i < n && lback(lp) != adjwp->w_bufp->b_headp; ++i)
375 			lp = lback(lp);
376 		adjwp->w_linep = lp;
377 		adjwp->w_toprow -= n;
378 	/* grow above */
379 	} else {
380 		lp = curwp->w_linep;
381 		for (i = 0; i < n && lp != curbp->b_headp; ++i)
382 			lp = lforw(lp);
383 		curwp->w_linep = lp;
384 		curwp->w_toprow += n;
385 	}
386 	curwp->w_ntrows -= n;
387 	adjwp->w_ntrows += n;
388 	curwp->w_rflag |= WFMODE | WFFULL;
389 	adjwp->w_rflag |= WFMODE | WFFULL;
390 	return (TRUE);
391 }
392 
393 /*
394  * Delete current window. Call shrink-window to do the screen updating, then
395  * throw away the window.
396  */
397 /* ARGSUSED */
398 int
399 delwind(int f, int n)
400 {
401 	struct mgwin	*wp, *nwp;
402 
403 	wp = curwp;		/* Cheap...		 */
404 
405 	/* shrinkwind returning false means only one window... */
406 	if (shrinkwind(FFRAND, wp->w_ntrows + 1) == FALSE)
407 		return (FALSE);
408 	if (--wp->w_bufp->b_nwnd == 0) {
409 		wp->w_bufp->b_dotp = wp->w_dotp;
410 		wp->w_bufp->b_doto = wp->w_doto;
411 		wp->w_bufp->b_markp = wp->w_markp;
412 		wp->w_bufp->b_marko = wp->w_marko;
413 	}
414 
415 	/* since shrinkwind did't crap out, we know we have a second window */
416 	if (wp == wheadp)
417 		wheadp = curwp = wp->w_wndp;
418 	else if ((curwp = wp->w_wndp) == NULL)
419 		curwp = wheadp;
420 	curbp = curwp->w_bufp;
421 	for (nwp = wheadp; nwp != NULL; nwp = nwp->w_wndp)
422 		if (nwp->w_wndp == wp) {
423 			nwp->w_wndp = wp->w_wndp;
424 			break;
425 		}
426 	free(wp);
427 	return (TRUE);
428 }
429