xref: /openbsd-src/usr.bin/tmux/screen.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /* $OpenBSD: screen.c,v 1.40 2016/09/02 20:57:20 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
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 	s->grid = grid_create(sx, sy, hlimit);
35 	s->title = xstrdup("");
36 
37 	s->cstyle = 0;
38 	s->ccolour = xstrdup("");
39 	s->tabs = NULL;
40 
41 	s->dirty = NULL;
42 	s->dirtysize = 0;
43 
44 	screen_reinit(s);
45 }
46 
47 /* Reinitialise screen. */
48 void
49 screen_reinit(struct screen *s)
50 {
51 	s->cx = 0;
52 	s->cy = 0;
53 
54 	s->rupper = 0;
55 	s->rlower = screen_size_y(s) - 1;
56 
57 	s->mode = MODE_CURSOR | MODE_WRAP;
58 
59 	screen_reset_tabs(s);
60 
61 	grid_clear_lines(s->grid, s->grid->hsize, s->grid->sy);
62 
63 	screen_clear_selection(s);
64 }
65 
66 /* Destroy a screen. */
67 void
68 screen_free(struct screen *s)
69 {
70 	free(s->dirty);
71 	free(s->tabs);
72 	free(s->title);
73 	free(s->ccolour);
74 	grid_destroy(s->grid);
75 }
76 
77 /* Reset tabs to default, eight spaces apart. */
78 void
79 screen_reset_tabs(struct screen *s)
80 {
81 	u_int	i;
82 
83 	free(s->tabs);
84 
85 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
86 		fatal("bit_alloc failed");
87 	for (i = 8; i < screen_size_x(s); i += 8)
88 		bit_set(s->tabs, i);
89 }
90 
91 /* Set screen cursor style. */
92 void
93 screen_set_cursor_style(struct screen *s, u_int style)
94 {
95 	if (style <= 6)
96 		s->cstyle = style;
97 }
98 
99 /* Set screen cursor colour. */
100 void
101 screen_set_cursor_colour(struct screen *s, const char *colour)
102 {
103 	free(s->ccolour);
104 	s->ccolour = xstrdup(colour);
105 }
106 
107 /* Set screen title. */
108 void
109 screen_set_title(struct screen *s, const char *title)
110 {
111 	free(s->title);
112 	s->title = xstrdup(title);
113 }
114 
115 /* Resize screen. */
116 void
117 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
118 {
119 	if (sx < 1)
120 		sx = 1;
121 	if (sy < 1)
122 		sy = 1;
123 
124 	if (sx != screen_size_x(s)) {
125 		screen_resize_x(s, sx);
126 
127 		/*
128 		 * It is unclear what should happen to tabs on resize. xterm
129 		 * seems to try and maintain them, rxvt resets them. Resetting
130 		 * is simpler and more reliable so let's do that.
131 		 */
132 		screen_reset_tabs(s);
133 	}
134 
135 	if (sy != screen_size_y(s))
136 		screen_resize_y(s, sy);
137 
138 	if (reflow)
139 		screen_reflow(s, sx);
140 }
141 
142 void
143 screen_resize_x(struct screen *s, u_int sx)
144 {
145 	struct grid		*gd = s->grid;
146 
147 	if (sx == 0)
148 		fatalx("zero size");
149 
150 	/*
151 	 * Treat resizing horizontally simply: just ensure the cursor is
152 	 * on-screen and change the size. Don't bother to truncate any lines -
153 	 * then the data should be accessible if the size is then increased.
154 	 *
155 	 * The only potential wrinkle is if UTF-8 double-width characters are
156 	 * left in the last column, but UTF-8 terminals should deal with this
157 	 * sanely.
158 	 */
159 	if (s->cx >= sx)
160 		s->cx = sx - 1;
161 	gd->sx = sx;
162 }
163 
164 void
165 screen_resize_y(struct screen *s, u_int sy)
166 {
167 	struct grid	*gd = s->grid;
168 	u_int		 needed, available, oldy, i;
169 
170 	if (sy == 0)
171 		fatalx("zero size");
172 	oldy = screen_size_y(s);
173 
174 	/*
175 	 * When resizing:
176 	 *
177 	 * If the height is decreasing, delete lines from the bottom until
178 	 * hitting the cursor, then push lines from the top into the history.
179 	 *
180 	 * When increasing, pull as many lines as possible from scrolled
181 	 * history (not explicitly cleared from view) to the top, then fill the
182 	 * remaining with blanks at the bottom.
183 	 */
184 
185 	/* Size decreasing. */
186 	if (sy < oldy) {
187 		needed = oldy - sy;
188 
189 		/* Delete as many lines as possible from the bottom. */
190 		available = oldy - 1 - s->cy;
191 		if (available > 0) {
192 			if (available > needed)
193 				available = needed;
194 			grid_view_delete_lines(gd, oldy - available, available);
195 		}
196 		needed -= available;
197 
198 		/*
199 		 * Now just increase the history size, if possible, to take
200 		 * over the lines which are left. If history is off, delete
201 		 * lines from the top.
202 		 */
203 		available = s->cy;
204 		if (gd->flags & GRID_HISTORY) {
205 			gd->hscrolled += needed;
206 			gd->hsize += needed;
207 		} else if (needed > 0 && available > 0) {
208 			if (available > needed)
209 				available = needed;
210 			grid_view_delete_lines(gd, 0, available);
211 		}
212 		s->cy -= needed;
213 	}
214 
215 	/* Resize line arrays. */
216 	gd->linedata = xreallocarray(gd->linedata, gd->hsize + sy,
217 	    sizeof *gd->linedata);
218 
219 	/* Size increasing. */
220 	if (sy > oldy) {
221 		needed = sy - oldy;
222 
223 		/*
224 		 * Try to pull as much as possible out of scrolled history, if is
225 		 * is enabled.
226 		 */
227 		available = gd->hscrolled;
228 		if (gd->flags & GRID_HISTORY && available > 0) {
229 			if (available > needed)
230 				available = needed;
231 			gd->hscrolled -= available;
232 			gd->hsize -= available;
233 			s->cy += available;
234 		} else
235 			available = 0;
236 		needed -= available;
237 
238 		/* Then fill the rest in with blanks. */
239 		for (i = gd->hsize + sy - needed; i < gd->hsize + sy; i++)
240 			memset(&gd->linedata[i], 0, sizeof gd->linedata[i]);
241 	}
242 
243 	/* Set the new size, and reset the scroll region. */
244 	gd->sy = sy;
245 	s->rupper = 0;
246 	s->rlower = screen_size_y(s) - 1;
247 }
248 
249 /* Set selection. */
250 void
251 screen_set_selection(struct screen *s, u_int sx, u_int sy,
252     u_int ex, u_int ey, u_int rectflag, struct grid_cell *gc)
253 {
254 	struct screen_sel	*sel = &s->sel;
255 
256 	memcpy(&sel->cell, gc, sizeof sel->cell);
257 	sel->flag = 1;
258 	sel->rectflag = rectflag;
259 
260 	sel->sx = sx; sel->sy = sy;
261 	sel->ex = ex; sel->ey = ey;
262 }
263 
264 /* Clear selection. */
265 void
266 screen_clear_selection(struct screen *s)
267 {
268 	struct screen_sel	*sel = &s->sel;
269 
270 	sel->flag = 0;
271 	sel->lineflag = LINE_SEL_NONE;
272 }
273 
274 /* Check if cell in selection. */
275 int
276 screen_check_selection(struct screen *s, u_int px, u_int py)
277 {
278 	struct screen_sel	*sel = &s->sel;
279 	u_int			 xx;
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 				return (0);
331 
332 			if (py == sel->ey && px > sel->ex)
333 				return (0);
334 		} else if (sel->sy > sel->ey) {
335 			/* starting line > ending line -- upward selection. */
336 			if (py > sel->sy || py < sel->ey)
337 				return (0);
338 
339 			if (py == sel->ey && px < sel->ex)
340 				return (0);
341 
342 			if (sel->modekeys == MODEKEY_EMACS)
343 				xx = sel->sx - 1;
344 			else
345 				xx = sel->sx;
346 			if (py == sel->sy && px > xx)
347 				return (0);
348 		} else {
349 			/* starting line == ending line. */
350 			if (py != sel->sy)
351 				return (0);
352 
353 			if (sel->ex < sel->sx) {
354 				/* cursor (ex) is on the left */
355 				if (sel->modekeys == MODEKEY_EMACS)
356 					xx = sel->sx - 1;
357 				else
358 					xx = sel->sx;
359 				if (px > xx || px < sel->ex)
360 					return (0);
361 			} else {
362 				/* selection start (sx) is on the left */
363 				if (px < sel->sx || px > sel->ex)
364 					return (0);
365 			}
366 		}
367 	}
368 
369 	return (1);
370 }
371 
372 /* Reflow wrapped lines. */
373 void
374 screen_reflow(struct screen *s, u_int new_x)
375 {
376 	struct grid	*old = s->grid;
377 	u_int		 change;
378 
379 	s->grid = grid_create(old->sx, old->sy, old->hlimit);
380 
381 	change = grid_reflow(s->grid, old, new_x);
382 	if (change < s->cy)
383 		s->cy -= change;
384 	else
385 		s->cy = 0;
386 }
387