xref: /openbsd-src/usr.bin/tmux/screen.c (revision c7e8ea31cd41a963f06f0a8ba93948b06aa6b4a4)
1 /* $OpenBSD: screen.c,v 1.47 2017/06/04 09:02:36 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 #include <vis.h>
25 
26 #include "tmux.h"
27 
28 static void	screen_resize_x(struct screen *, u_int);
29 static void	screen_resize_y(struct screen *, u_int);
30 
31 static void	screen_reflow(struct screen *, u_int);
32 
33 /* Create a new screen. */
34 void
35 screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
36 {
37 	s->grid = grid_create(sx, sy, hlimit);
38 	s->title = xstrdup("");
39 
40 	s->cstyle = 0;
41 	s->ccolour = xstrdup("");
42 	s->tabs = NULL;
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, 8);
62 
63 	screen_clear_selection(s);
64 }
65 
66 /* Destroy a screen. */
67 void
68 screen_free(struct screen *s)
69 {
70 	free(s->tabs);
71 	free(s->title);
72 	free(s->ccolour);
73 	grid_destroy(s->grid);
74 }
75 
76 /* Reset tabs to default, eight spaces apart. */
77 void
78 screen_reset_tabs(struct screen *s)
79 {
80 	u_int	i;
81 
82 	free(s->tabs);
83 
84 	if ((s->tabs = bit_alloc(screen_size_x(s))) == NULL)
85 		fatal("bit_alloc failed");
86 	for (i = 8; i < screen_size_x(s); i += 8)
87 		bit_set(s->tabs, i);
88 }
89 
90 /* Set screen cursor style. */
91 void
92 screen_set_cursor_style(struct screen *s, u_int style)
93 {
94 	if (style <= 6)
95 		s->cstyle = style;
96 }
97 
98 /* Set screen cursor colour. */
99 void
100 screen_set_cursor_colour(struct screen *s, const char *colour)
101 {
102 	free(s->ccolour);
103 	s->ccolour = xstrdup(colour);
104 }
105 
106 /* Set screen title. */
107 void
108 screen_set_title(struct screen *s, const char *title)
109 {
110 	free(s->title);
111 	utf8_stravis(&s->title, title, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
112 }
113 
114 /* Resize screen. */
115 void
116 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
117 {
118 	if (sx < 1)
119 		sx = 1;
120 	if (sy < 1)
121 		sy = 1;
122 
123 	if (sx != screen_size_x(s)) {
124 		screen_resize_x(s, sx);
125 
126 		/*
127 		 * It is unclear what should happen to tabs on resize. xterm
128 		 * seems to try and maintain them, rxvt resets them. Resetting
129 		 * is simpler and more reliable so let's do that.
130 		 */
131 		screen_reset_tabs(s);
132 	}
133 
134 	if (sy != screen_size_y(s))
135 		screen_resize_y(s, sy);
136 
137 	if (reflow)
138 		screen_reflow(s, sx);
139 }
140 
141 static void
142 screen_resize_x(struct screen *s, u_int sx)
143 {
144 	struct grid		*gd = s->grid;
145 
146 	if (sx == 0)
147 		fatalx("zero size");
148 
149 	/*
150 	 * Treat resizing horizontally simply: just ensure the cursor is
151 	 * on-screen and change the size. Don't bother to truncate any lines -
152 	 * then the data should be accessible if the size is then increased.
153 	 *
154 	 * The only potential wrinkle is if UTF-8 double-width characters are
155 	 * left in the last column, but UTF-8 terminals should deal with this
156 	 * sanely.
157 	 */
158 	if (s->cx >= sx)
159 		s->cx = sx - 1;
160 	gd->sx = sx;
161 }
162 
163 static void
164 screen_resize_y(struct screen *s, u_int sy)
165 {
166 	struct grid	*gd = s->grid;
167 	u_int		 needed, available, oldy, i;
168 
169 	if (sy == 0)
170 		fatalx("zero size");
171 	oldy = screen_size_y(s);
172 
173 	/*
174 	 * When resizing:
175 	 *
176 	 * If the height is decreasing, delete lines from the bottom until
177 	 * hitting the cursor, then push lines from the top into the history.
178 	 *
179 	 * When increasing, pull as many lines as possible from scrolled
180 	 * history (not explicitly cleared from view) to the top, then fill the
181 	 * remaining with blanks at the bottom.
182 	 */
183 
184 	/* Size decreasing. */
185 	if (sy < oldy) {
186 		needed = oldy - sy;
187 
188 		/* Delete as many lines as possible from the bottom. */
189 		available = oldy - 1 - s->cy;
190 		if (available > 0) {
191 			if (available > needed)
192 				available = needed;
193 			grid_view_delete_lines(gd, oldy - available, available,
194 			    8);
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, 8);
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
225 		 * is 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->hidden = 0;
259 
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 	sel->hidden = 0;
274 	sel->lineflag = LINE_SEL_NONE;
275 }
276 
277 /* Hide selection. */
278 void
279 screen_hide_selection(struct screen *s)
280 {
281 	struct screen_sel	*sel = &s->sel;
282 
283 	sel->hidden = 1;
284 }
285 
286 /* Check if cell in selection. */
287 int
288 screen_check_selection(struct screen *s, u_int px, u_int py)
289 {
290 	struct screen_sel	*sel = &s->sel;
291 	u_int			 xx;
292 
293 	if (!sel->flag || sel->hidden)
294 		return (0);
295 
296 	if (sel->rectflag) {
297 		if (sel->sy < sel->ey) {
298 			/* start line < end line -- downward selection. */
299 			if (py < sel->sy || py > sel->ey)
300 				return (0);
301 		} else if (sel->sy > sel->ey) {
302 			/* start line > end line -- upward selection. */
303 			if (py > sel->sy || py < sel->ey)
304 				return (0);
305 		} else {
306 			/* starting line == ending line. */
307 			if (py != sel->sy)
308 				return (0);
309 		}
310 
311 		/*
312 		 * Need to include the selection start row, but not the cursor
313 		 * row, which means the selection changes depending on which
314 		 * one is on the left.
315 		 */
316 		if (sel->ex < sel->sx) {
317 			/* Cursor (ex) is on the left. */
318 			if (px < sel->ex)
319 				return (0);
320 
321 			if (px > sel->sx)
322 				return (0);
323 		} else {
324 			/* Selection start (sx) is on the left. */
325 			if (px < sel->sx)
326 				return (0);
327 
328 			if (px > sel->ex)
329 				return (0);
330 		}
331 	} else {
332 		/*
333 		 * Like emacs, keep the top-left-most character, and drop the
334 		 * bottom-right-most, regardless of copy direction.
335 		 */
336 		if (sel->sy < sel->ey) {
337 			/* starting line < ending line -- downward selection. */
338 			if (py < sel->sy || py > sel->ey)
339 				return (0);
340 
341 			if (py == sel->sy && px < sel->sx)
342 				return (0);
343 
344 			if (py == sel->ey && px > sel->ex)
345 				return (0);
346 		} else if (sel->sy > sel->ey) {
347 			/* starting line > ending line -- upward selection. */
348 			if (py > sel->sy || py < sel->ey)
349 				return (0);
350 
351 			if (py == sel->ey && px < sel->ex)
352 				return (0);
353 
354 			if (sel->modekeys == MODEKEY_EMACS)
355 				xx = sel->sx - 1;
356 			else
357 				xx = sel->sx;
358 			if (py == sel->sy && (sel->sx == 0 || px > xx))
359 				return (0);
360 		} else {
361 			/* starting line == ending line. */
362 			if (py != sel->sy)
363 				return (0);
364 
365 			if (sel->ex < sel->sx) {
366 				/* cursor (ex) is on the left */
367 				if (sel->modekeys == MODEKEY_EMACS)
368 					xx = sel->sx - 1;
369 				else
370 					xx = sel->sx;
371 				if (px > xx || px < sel->ex)
372 					return (0);
373 			} else {
374 				/* selection start (sx) is on the left */
375 				if (px < sel->sx || px > sel->ex)
376 					return (0);
377 			}
378 		}
379 	}
380 
381 	return (1);
382 }
383 
384 /* Get selected grid cell. */
385 void
386 screen_select_cell(struct screen *s, struct grid_cell *dst,
387     const struct grid_cell *src)
388 {
389 	if (!s->sel.flag || s->sel.hidden)
390 		return;
391 
392 	memcpy(dst, &s->sel.cell, sizeof *dst);
393 
394 	utf8_copy(&dst->data, &src->data);
395 	dst->attr = dst->attr & ~GRID_ATTR_CHARSET;
396 	dst->attr |= src->attr & GRID_ATTR_CHARSET;
397 	dst->flags = src->flags;
398 }
399 
400 /* Reflow wrapped lines. */
401 static void
402 screen_reflow(struct screen *s, u_int new_x)
403 {
404 	struct grid	*old = s->grid;
405 	u_int		 change;
406 
407 	s->grid = grid_create(old->sx, old->sy, old->hlimit);
408 
409 	change = grid_reflow(s->grid, old, new_x);
410 	if (change < s->cy)
411 		s->cy -= change;
412 	else
413 		s->cy = 0;
414 }
415