xref: /openbsd-src/usr.bin/tmux/screen.c (revision ac9b4aacc1da35008afea06a5d23c2f2dea9b93e)
1 /* $OpenBSD: screen.c,v 1.23 2012/07/10 11:53:01 nicm 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 <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 
25 #include "tmux.h"
26 
27 void	screen_resize_x(struct screen *, u_int);
28 void	screen_resize_y(struct screen *, u_int);
29 
30 /* Create a new screen. */
31 void
32 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
33 {
34 	char hn[MAXHOSTNAMELEN];
35 
36 	s->grid = grid_create(sx, sy, hlimit);
37 
38 	if (gethostname(hn, MAXHOSTNAMELEN) == 0)
39 		s->title = xstrdup(hn);
40 	else
41 		s->title = xstrdup("");
42 
43 	s->cstyle = 0;
44 	s->ccolour = xstrdup("");
45 	s->tabs = NULL;
46 
47 	screen_reinit(s);
48 }
49 
50 /* Reinitialise screen. */
51 void
52 screen_reinit(struct screen *s)
53 {
54 	s->cx = 0;
55 	s->cy = 0;
56 
57 	s->rupper = 0;
58 	s->rlower = screen_size_y(s) - 1;
59 
60 	s->mode = MODE_CURSOR | MODE_WRAP;
61 
62 	screen_reset_tabs(s);
63 
64 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy);
65 
66 	screen_clear_selection(s);
67 }
68 
69 /* Destroy a screen. */
70 void
71 screen_free(struct screen *s)
72 {
73 	free(s->tabs);
74 	free(s->title);
75 	free(s->ccolour);
76 	grid_destroy(s->grid);
77 }
78 
79 /* Reset tabs to default, eight spaces apart. */
80 void
81 screen_reset_tabs(struct screen *s)
82 {
83 	u_int	i;
84 
85 	free(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 cursor style. */
94 void
95 screen_set_cursor_style(struct screen *s, u_int style)
96 {
97 	if (style <= 6)
98 		s->cstyle = style;
99 }
100 
101 /* Set screen cursor colour. */
102 void
103 screen_set_cursor_colour(struct screen *s, const char *colour_string)
104 {
105 	free(s->ccolour);
106 	s->ccolour = xstrdup(colour_string);
107 }
108 
109 /* Set screen title. */
110 void
111 screen_set_title(struct screen *s, const char *title)
112 {
113 	char	tmp[BUFSIZ];
114 
115 	strlcpy(tmp, title, sizeof tmp);
116 
117 	free(s->title);
118 	s->title = xstrdup(tmp);
119 }
120 
121 /* Resize screen. */
122 void
123 screen_resize(struct screen *s, u_int sx, u_int sy)
124 {
125 	if (sx < 1)
126 		sx = 1;
127 	if (sy < 1)
128 		sy = 1;
129 
130 	if (sx != screen_size_x(s)) {
131 		screen_resize_x(s, sx);
132 
133 		/*
134 		 * It is unclear what should happen to tabs on resize. xterm
135 		 * seems to try and maintain them, rxvt resets them. Resetting
136 		 * is simpler and more reliable so let's do that.
137 		 */
138 		screen_reset_tabs(s);
139 	}
140 
141 	if (sy != screen_size_y(s))
142 		screen_resize_y(s, sy);
143 }
144 
145 void
146 screen_resize_x(struct screen *s, u_int sx)
147 {
148 	struct grid		*gd = s->grid;
149 
150 	if (sx == 0)
151 		fatalx("zero size");
152 
153 	/*
154 	 * Treat resizing horizontally simply: just ensure the cursor is
155 	 * on-screen and change the size. Don't bother to truncate any lines -
156 	 * then the data should be accessible if the size is then incrased.
157 	 *
158 	 * The only potential wrinkle is if UTF-8 double-width characters are
159 	 * left in the last column, but UTF-8 terminals should deal with this
160 	 * sanely.
161 	 */
162 	if (s->cx >= sx)
163 		s->cx = sx - 1;
164 	gd->sx = sx;
165 }
166 
167 void
168 screen_resize_y(struct screen *s, u_int sy)
169 {
170 	struct grid	*gd = s->grid;
171 	u_int		 needed, available, oldy, i;
172 
173 	if (sy == 0)
174 		fatalx("zero size");
175 	oldy = screen_size_y(s);
176 
177 	/*
178 	 * When resizing:
179 	 *
180 	 * If the height is decreasing, delete lines from the bottom until
181 	 * hitting the cursor, then push lines from the top into the history.
182 	 *
183 	 * When increasing, pull as many lines as possible from the history to
184 	 * the top, then fill the remaining with blanks at the bottom.
185 	 */
186 
187 	/* Size decreasing. */
188 	if (sy < oldy) {
189 		needed = oldy - sy;
190 
191 		/* Delete as many lines as possible from the bottom. */
192 		available = oldy - 1 - s->cy;
193 		if (available > 0) {
194 			if (available > needed)
195 				available = needed;
196 			grid_view_delete_lines(gd, oldy - available, available);
197 		}
198 		needed -= available;
199 
200 		/*
201 		 * Now just increase the history size, if possible, to take
202 		 * over the lines which are left. If history is off, delete
203 		 * lines from the top.
204 		 *
205 		 * XXX Should apply history limit?
206 		 */
207 		available = s->cy;
208 		if (gd->flags & GRID_HISTORY)
209 			gd->hsize += needed;
210 		else if (needed > 0 && available > 0) {
211 			if (available > needed)
212 				available = needed;
213 			grid_view_delete_lines(gd, 0, available);
214 		}
215 		s->cy -= needed;
216 	}
217 
218 	/* Resize line arrays. */
219 	gd->linedata = xrealloc(
220 	    gd->linedata, gd->hsize + sy, sizeof *gd->linedata);
221 
222 	/* Size increasing. */
223 	if (sy > oldy) {
224 		needed = sy - oldy;
225 
226 		/*
227 		 * Try to pull as much as possible out of the history, if is
228 		 * is enabled.
229 		 */
230 		available = gd->hsize;
231 		if (gd->flags & GRID_HISTORY && available > 0) {
232 			if (available > needed)
233 				available = needed;
234 			gd->hsize -= available;
235 			s->cy += available;
236 		} else
237 			available = 0;
238 		needed -= available;
239 
240 		/* Then fill the rest in with blanks. */
241 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
242 			memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
243 	}
244 
245 	/* Set the new size, and reset the scroll region. */
246 	gd->sy = sy;
247 	s->rupper = 0;
248 	s->rlower = screen_size_y(s) - 1;
249 }
250 
251 /* Set selection. */
252 void
253 screen_set_selection(struct screen *s, u_int sx, u_int sy,
254     u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
255 {
256 	struct screen_sel	*sel = &s->sel;
257 
258 	memcpy(&sel->cell, gc, sizeof sel->cell);
259 	sel->flag = 1;
260 	sel->rectflag = rectflag;
261 
262 	sel->sx = sx; sel->sy = sy;
263 	sel->ex = ex; sel->ey = ey;
264 }
265 
266 /* Clear selection. */
267 void
268 screen_clear_selection(struct screen *s)
269 {
270 	struct screen_sel	*sel = &s->sel;
271 
272 	sel->flag = 0;
273 }
274 
275 /* Check if cell in selection. */
276 int
277 screen_check_selection(struct screen *s, u_int px, u_int py)
278 {
279 	struct screen_sel	*sel = &s->sel;
280 
281 	if (!sel->flag)
282 		return (0);
283 
284 	if (sel->rectflag) {
285 		if (sel->sy < sel->ey) {
286 			/* start line < end line -- downward selection. */
287 			if (py < sel->sy || py > sel->ey)
288 				return (0);
289 		} else if (sel->sy > sel->ey) {
290 			/* start line > end line -- upward selection. */
291 			if (py > sel->sy || py < sel->ey)
292 				return (0);
293 		} else {
294 			/* starting line == ending line. */
295 			if (py != sel->sy)
296 				return (0);
297 		}
298 
299 		/*
300 		 * Need to include the selection start row, but not the cursor
301 		 * row, which means the selection changes depending on which
302 		 * one is on the left.
303 		 */
304 		if (sel->ex < sel->sx) {
305 			/* Cursor (ex) is on the left. */
306 			if (px < sel->ex)
307 				return (0);
308 
309 			if (px > sel->sx)
310 				return (0);
311 		} else {
312 			/* Selection start (sx) is on the left. */
313 			if (px < sel->sx)
314 				return (0);
315 
316 			if (px > sel->ex)
317 				return (0);
318 		}
319 	} else {
320 		/*
321 		 * Like emacs, keep the top-left-most character, and drop the
322 		 * bottom-right-most, regardless of copy direction.
323 		 */
324 		if (sel->sy < sel->ey) {
325 			/* starting line < ending line -- downward selection. */
326 			if (py < sel->sy || py > sel->ey)
327 				return (0);
328 
329 			if ((py == sel->sy && px < sel->sx)
330 			    || (py == sel->ey && px > sel->ex))
331 				return (0);
332 		} else if (sel->sy > sel->ey) {
333 			/* starting line > ending line -- upward selection. */
334 			if (py > sel->sy || py < sel->ey)
335 				return (0);
336 
337 			if ((py == sel->sy && px >= sel->sx)
338 			    || (py == sel->ey && px < sel->ex))
339 				return (0);
340 		} else {
341 			/* starting line == ending line. */
342 			if (py != sel->sy)
343 				return (0);
344 
345 			if (sel->ex < sel->sx) {
346 				/* cursor (ex) is on the left */
347 				if (px > sel->sx || px < sel->ex)
348 					return (0);
349 			} else {
350 				/* selection start (sx) is on the left */
351 				if (px < sel->sx || px > sel->ex)
352 					return (0);
353 			}
354 		}
355 	}
356 
357 	return (1);
358 }
359