xref: /netbsd-src/external/bsd/tmux/dist/screen.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /* $Id: screen.c,v 1.2 2011/03/12 03:02:59 christos Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 
21 #include <netdb.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include "tmux.h"
27 
28 void	screen_resize_x(struct screen *, u_int);
29 void	screen_resize_y(struct screen *, u_int);
30 
31 /* Create a new screen. */
32 void
33 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
34 {
35 	char hn[MAXHOSTNAMELEN];
36 
37 	s->grid = grid_create(sx, sy, hlimit);
38 
39 	if (gethostname(hn, MAXHOSTNAMELEN) == 0)
40 		s->title = xstrdup(hn);
41 	else
42 		s->title = xstrdup("");
43 
44 	s->tabs = NULL;
45 
46 	screen_reinit(s);
47 }
48 
49 /* Reinitialise screen. */
50 void
51 screen_reinit(struct screen *s)
52 {
53 	s->cx = 0;
54 	s->cy = 0;
55 
56 	s->rupper = 0;
57 	s->rlower = screen_size_y(s) - 1;
58 
59 	s->mode = MODE_CURSOR | MODE_WRAP;
60 
61 	screen_reset_tabs(s);
62 
63 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy);
64 
65 	screen_clear_selection(s);
66 }
67 
68 /* Destroy a screen. */
69 void
70 screen_free(struct screen *s)
71 {
72 	if (s->tabs != NULL)
73 		xfree(s->tabs);
74 	xfree(s->title);
75 	grid_destroy(s->grid);
76 }
77 
78 /* Reset tabs to default, eight spaces apart. */
79 void
80 screen_reset_tabs(struct screen *s)
81 {
82 	u_int	i;
83 
84 	if (s->tabs != NULL)
85 		xfree(s->tabs);
86 
87 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
88 		fatal("bit_alloc failed");
89 	for (i = 8; i < screen_size_x(s); i += 8)
90 		bit_set(s->tabs, i);
91 }
92 
93 /* Set screen title. */
94 void
95 screen_set_title(struct screen *s, const char *title)
96 {
97 	size_t	slen = strlen(title);
98 	char	tmp[slen * 4 + 1];
99 
100 	strvisx(tmp, title, slen, VIS_OCTAL|VIS_TAB|VIS_NL);
101 
102 	xfree(s->title);
103 	s->title = xstrdup(tmp);
104 }
105 
106 /* Resize screen. */
107 void
108 screen_resize(struct screen *s, u_int sx, u_int sy)
109 {
110 	if (sx < 1)
111 		sx = 1;
112 	if (sy < 1)
113 		sy = 1;
114 
115 	if (sx != screen_size_x(s)) {
116 		screen_resize_x(s, sx);
117 
118 		/*
119 		 * It is unclear what should happen to tabs on resize. xterm
120 		 * seems to try and maintain them, rxvt resets them. Resetting
121 		 * is simpler and more reliable so let's do that.
122 		 */
123 		screen_reset_tabs(s);
124 	}
125 
126 	if (sy != screen_size_y(s))
127 		screen_resize_y(s, sy);
128 }
129 
130 void
131 screen_resize_x(struct screen *s, u_int sx)
132 {
133 	struct grid		*gd = s->grid;
134 
135 	if (sx == 0)
136 		fatalx("zero size");
137 
138 	/*
139 	 * Treat resizing horizontally simply: just ensure the cursor is
140 	 * on-screen and change the size. Don't bother to truncate any lines -
141 	 * then the data should be accessible if the size is then incrased.
142 	 *
143 	 * The only potential wrinkle is if UTF-8 double-width characters are
144 	 * left in the last column, but UTF-8 terminals should deal with this
145 	 * sanely.
146 	 */
147 	if (s->cx >= sx)
148 		s->cx = sx - 1;
149 	gd->sx = sx;
150 }
151 
152 void
153 screen_resize_y(struct screen *s, u_int sy)
154 {
155 	struct grid	*gd = s->grid;
156 	u_int		 needed, available, oldy, i;
157 
158 	if (sy == 0)
159 		fatalx("zero size");
160 	oldy = screen_size_y(s);
161 
162 	/*
163 	 * When resizing:
164 	 *
165 	 * If the height is decreasing, delete lines from the bottom until
166 	 * hitting the cursor, then push lines from the top into the history.
167 	 *
168 	 * When increasing, pull as many lines as possible from the history to
169 	 * the top, then fill the remaining with blanks at the bottom.
170 	 */
171 
172 	/* Size decreasing. */
173 	if (sy < oldy) {
174 		needed = oldy - sy;
175 
176 		/* Delete as many lines as possible from the bottom. */
177 		available = oldy - 1 - s->cy;
178 		if (available > 0) {
179 			if (available > needed)
180 				available = needed;
181 			grid_view_delete_lines(gd, oldy - available, available);
182 		}
183 		needed -= available;
184 
185 		/*
186 		 * Now just increase the history size, if possible, to take
187 		 * over the lines which are left. If history is off, delete
188 		 * lines from the top.
189 		 *
190 		 * XXX Should apply history limit?
191 		 */
192 		available = s->cy;
193 		if (gd->flags & GRID_HISTORY)
194 			gd->hsize += needed;
195 		else if (needed > 0 && available > 0) {
196 			if (available > needed)
197 				available = needed;
198 			grid_view_delete_lines(gd, 0, available);
199 		}
200 		s->cy -= needed;
201 	}
202 
203 	/* Resize line arrays. */
204 	gd->linedata = xrealloc(
205 	    gd->linedata, gd->hsize + sy, sizeof *gd->linedata);
206 
207 	/* Size increasing. */
208 	if (sy > oldy) {
209 		needed = sy - oldy;
210 
211 		/*
212 		 * Try to pull as much as possible out of the history, if is
213 		 * is enabled.
214 		 */
215 		available = gd->hsize;
216 		if (gd->flags & GRID_HISTORY && available > 0) {
217 			if (available > needed)
218 				available = needed;
219 			gd->hsize -= available;
220 			s->cy += available;
221 		} else
222 			available = 0;
223 		needed -= available;
224 
225 		/* Then fill the rest in with blanks. */
226 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
227 			memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
228 	}
229 
230 	/* Set the new size, and reset the scroll region. */
231 	gd->sy = sy;
232 	s->rupper = 0;
233 	s->rlower = screen_size_y(s) - 1;
234 }
235 
236 /* Set selection. */
237 void
238 screen_set_selection(struct screen *s, u_int sx, u_int sy,
239     u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
240 {
241 	struct screen_sel	*sel = &s->sel;
242 
243 	memcpy(&sel->cell, gc, sizeof sel->cell);
244 	sel->flag = 1;
245 	sel->rectflag = rectflag;
246 
247 	sel->sx = sx; sel->sy = sy;
248 	sel->ex = ex; sel->ey = ey;
249 }
250 
251 /* Clear selection. */
252 void
253 screen_clear_selection(struct screen *s)
254 {
255 	struct screen_sel	*sel = &s->sel;
256 
257 	sel->flag = 0;
258 }
259 
260 /* Check if cell in selection. */
261 int
262 screen_check_selection(struct screen *s, u_int px, u_int py)
263 {
264 	struct screen_sel	*sel = &s->sel;
265 
266 	if (!sel->flag)
267 		return (0);
268 
269 	if (sel->rectflag) {
270 		if (sel->sy < sel->ey) {
271 			/* start line < end line -- downward selection. */
272 			if (py < sel->sy || py > sel->ey)
273 				return (0);
274 		} else if (sel->sy > sel->ey) {
275 			/* start line > end line -- upward selection. */
276 			if (py > sel->sy || py < sel->ey)
277 				return (0);
278 		} else {
279 			/* starting line == ending line. */
280 			if (py != sel->sy)
281 				return (0);
282 		}
283 
284 		/*
285 		 * Need to include the selection start row, but not the cursor
286 		 * row, which means the selection changes depending on which
287 		 * one is on the left.
288 		 */
289 		if (sel->ex < sel->sx) {
290 			/* Cursor (ex) is on the left. */
291 			if (px < sel->ex)
292 				return (0);
293 
294 			if (px > sel->sx)
295 				return (0);
296 		} else {
297 			/* Selection start (sx) is on the left. */
298 			if (px < sel->sx)
299 				return (0);
300 
301 			if (px > sel->ex)
302 				return (0);
303 		}
304 	} else {
305 		/*
306 		 * Like emacs, keep the top-left-most character, and drop the
307 		 * bottom-right-most, regardless of copy direction.
308 		 */
309 		if (sel->sy < sel->ey) {
310 			/* starting line < ending line -- downward selection. */
311 			if (py < sel->sy || py > sel->ey)
312 				return (0);
313 
314 			if ((py == sel->sy && px < sel->sx)
315 			    || (py == sel->ey && px > sel->ex))
316 				return (0);
317 		} else if (sel->sy > sel->ey) {
318 			/* starting line > ending line -- upward selection. */
319 			if (py > sel->sy || py < sel->ey)
320 				return (0);
321 
322 			if ((py == sel->sy && px >= sel->sx)
323 			    || (py == sel->ey && px < sel->ex))
324 				return (0);
325 		} else {
326 			/* starting line == ending line. */
327 			if (py != sel->sy)
328 				return (0);
329 
330 			if (sel->ex < sel->sx) {
331 				/* cursor (ex) is on the left */
332 				if (px > sel->sx || px < sel->ex)
333 					return (0);
334 			} else {
335 				/* selection start (sx) is on the left */
336 				if (px < sel->sx || px > sel->ex)
337 					return (0);
338 			}
339 		}
340 	}
341 
342 	return (1);
343 }
344