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1 65d9b3ca 2021-03-14 op /*
2 65d9b3ca 2021-03-14 op * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3 65d9b3ca 2021-03-14 op *
4 65d9b3ca 2021-03-14 op * Permission to use, copy, modify, and distribute this software for any
5 65d9b3ca 2021-03-14 op * purpose with or without fee is hereby granted, provided that the above
6 65d9b3ca 2021-03-14 op * copyright notice and this permission notice appear in all copies.
7 65d9b3ca 2021-03-14 op *
8 65d9b3ca 2021-03-14 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 65d9b3ca 2021-03-14 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 65d9b3ca 2021-03-14 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 65d9b3ca 2021-03-14 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 65d9b3ca 2021-03-14 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 65d9b3ca 2021-03-14 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 65d9b3ca 2021-03-14 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 65d9b3ca 2021-03-14 op */
16 65d9b3ca 2021-03-14 op
17 65d9b3ca 2021-03-14 op #include <stdlib.h>
18 65d9b3ca 2021-03-14 op #include <string.h>
19 65d9b3ca 2021-03-14 op
20 5caf7d67 2021-07-12 op #include "telescope.h"
21 5caf7d67 2021-07-12 op #include "utf8.h"
22 5caf7d67 2021-07-12 op
23 65d9b3ca 2021-03-14 op /*
24 65d9b3ca 2021-03-14 op * Text wrapping
25 65d9b3ca 2021-03-14 op * =============
26 65d9b3ca 2021-03-14 op *
27 65d9b3ca 2021-03-14 op * There's a simple text wrapping algorithm.
28 65d9b3ca 2021-03-14 op *
29 65d9b3ca 2021-03-14 op * 1. if it's a line in a pre-formatted block:
30 65d9b3ca 2021-03-14 op * a. hard wrap.
31 65d9b3ca 2021-03-14 op * b. repeat
32 676fba6f 2021-03-21 op * 2. otherwise advance the line char by char.
33 676fba6f 2021-03-21 op * 3. when ending the space, split the line at the last occurrence of
34 676fba6f 2021-03-21 op * a "word separator" (i.e. " \t-") or at point if none.
35 65d9b3ca 2021-03-14 op * 4. repeat
36 65d9b3ca 2021-03-14 op *
37 65d9b3ca 2021-03-14 op */
38 65d9b3ca 2021-03-14 op
39 ca5da938 2021-04-01 op void
40 bca92a4c 2021-07-01 op erase_buffer(struct buffer *buffer)
41 bca92a4c 2021-07-01 op {
42 bca92a4c 2021-07-01 op empty_vlist(buffer);
43 bca92a4c 2021-07-01 op empty_linelist(buffer);
44 bca92a4c 2021-07-01 op }
45 bca92a4c 2021-07-01 op
46 bca92a4c 2021-07-01 op void
47 46f6e974 2021-05-17 op empty_linelist(struct buffer *buffer)
48 ca5da938 2021-04-01 op {
49 ca5da938 2021-04-01 op struct line *l, *lt;
50 ca5da938 2021-04-01 op
51 46f6e974 2021-05-17 op TAILQ_FOREACH_SAFE(l, &buffer->page.head, lines, lt) {
52 46f6e974 2021-05-17 op TAILQ_REMOVE(&buffer->page.head, l, lines);
53 ca5da938 2021-04-01 op free(l->line);
54 ca5da938 2021-04-01 op free(l->alt);
55 ca5da938 2021-04-01 op free(l);
56 ca5da938 2021-04-01 op }
57 ca5da938 2021-04-01 op }
58 ca5da938 2021-04-01 op
59 ca5da938 2021-04-01 op void
60 46f6e974 2021-05-17 op empty_vlist(struct buffer *buffer)
61 ca5da938 2021-04-01 op {
62 ca5da938 2021-04-01 op struct vline *vl, *t;
63 ca5da938 2021-04-01 op
64 4ea9160a 2021-07-01 op buffer->top_line = NULL;
65 4ea9160a 2021-07-01 op buffer->line_off = 0;
66 46f6e974 2021-05-17 op buffer->current_line = NULL;
67 46f6e974 2021-05-17 op buffer->line_max = 0;
68 ca5da938 2021-04-01 op
69 46f6e974 2021-05-17 op TAILQ_FOREACH_SAFE(vl, &buffer->head, vlines, t) {
70 46f6e974 2021-05-17 op TAILQ_REMOVE(&buffer->head, vl, vlines);
71 ca5da938 2021-04-01 op free(vl->line);
72 ca5da938 2021-04-01 op free(vl);
73 ca5da938 2021-04-01 op }
74 ca5da938 2021-04-01 op }
75 ca5da938 2021-04-01 op
76 65d9b3ca 2021-03-14 op static int
77 5492b68f 2021-07-05 op push_line(struct buffer *buffer, const struct line *l, const char *buf, size_t len, int flags)
78 65d9b3ca 2021-03-14 op {
79 65d9b3ca 2021-03-14 op struct vline *vl;
80 65d9b3ca 2021-03-14 op
81 46f6e974 2021-05-17 op buffer->line_max++;
82 65d9b3ca 2021-03-14 op
83 65d9b3ca 2021-03-14 op if ((vl = calloc(1, sizeof(*vl))) == NULL)
84 65d9b3ca 2021-03-14 op return 0;
85 65d9b3ca 2021-03-14 op
86 65d9b3ca 2021-03-14 op if (len != 0 && (vl->line = calloc(1, len+1)) == NULL) {
87 65d9b3ca 2021-03-14 op free(vl);
88 65d9b3ca 2021-03-14 op return 0;
89 65d9b3ca 2021-03-14 op }
90 65d9b3ca 2021-03-14 op
91 65d9b3ca 2021-03-14 op vl->parent = l;
92 65d9b3ca 2021-03-14 op if (len != 0)
93 65d9b3ca 2021-03-14 op memcpy(vl->line, buf, len);
94 5492b68f 2021-07-05 op vl->flags = flags;
95 65d9b3ca 2021-03-14 op
96 46f6e974 2021-05-17 op if (TAILQ_EMPTY(&buffer->head))
97 46f6e974 2021-05-17 op TAILQ_INSERT_HEAD(&buffer->head, vl, vlines);
98 65d9b3ca 2021-03-14 op else
99 46f6e974 2021-05-17 op TAILQ_INSERT_TAIL(&buffer->head, vl, vlines);
100 65d9b3ca 2021-03-14 op return 1;
101 65d9b3ca 2021-03-14 op }
102 65d9b3ca 2021-03-14 op
103 65d9b3ca 2021-03-14 op /*
104 e7b982f4 2021-07-14 op * Similar to wrap_text, but emit only o vline.
105 e7b982f4 2021-07-14 op */
106 e7b982f4 2021-07-14 op int
107 e7b982f4 2021-07-14 op wrap_one(struct buffer *buffer, const char *prfx, struct line *l, size_t width)
108 e7b982f4 2021-07-14 op {
109 e7b982f4 2021-07-14 op struct vline *vl, *t;
110 e7b982f4 2021-07-14 op
111 e7b982f4 2021-07-14 op /*
112 e7b982f4 2021-07-14 op * be lazy: call wrap_text and then discard the continuations.
113 e7b982f4 2021-07-14 op */
114 e7b982f4 2021-07-14 op
115 e7b982f4 2021-07-14 op if (!wrap_text(buffer, prfx, l, width))
116 e7b982f4 2021-07-14 op return 0;
117 e7b982f4 2021-07-14 op
118 e7b982f4 2021-07-14 op TAILQ_FOREACH_SAFE(vl, &buffer->head, vlines, t) {
119 e7b982f4 2021-07-14 op if (vl->flags & L_CONTINUATION) {
120 e7b982f4 2021-07-14 op TAILQ_REMOVE(&buffer->head, vl, vlines);
121 e7b982f4 2021-07-14 op free(vl->line);
122 e7b982f4 2021-07-14 op free(vl);
123 e7b982f4 2021-07-14 op }
124 e7b982f4 2021-07-14 op }
125 e7b982f4 2021-07-14 op
126 e7b982f4 2021-07-14 op return 1;
127 e7b982f4 2021-07-14 op }
128 e7b982f4 2021-07-14 op
129 e7b982f4 2021-07-14 op /*
130 65d9b3ca 2021-03-14 op * Build a list of visual line by wrapping the given line, assuming
131 65d9b3ca 2021-03-14 op * that when printed will have a leading prefix prfx.
132 65d9b3ca 2021-03-14 op */
133 676fba6f 2021-03-21 op int
134 46f6e974 2021-05-17 op wrap_text(struct buffer *buffer, const char *prfx, struct line *l, size_t width)
135 65d9b3ca 2021-03-14 op {
136 676fba6f 2021-03-21 op const char *separators = " \t-";
137 676fba6f 2021-03-21 op const char *start, *end, *line, *lastsep, *lastchar;
138 676fba6f 2021-03-21 op uint32_t cp = 0, state = 0;
139 676fba6f 2021-03-21 op size_t cur, prfxwidth, w;
140 5492b68f 2021-07-05 op int flags;
141 65d9b3ca 2021-03-14 op
142 676fba6f 2021-03-21 op if ((line = l->line) == NULL)
143 46f6e974 2021-05-17 op return push_line(buffer, l, NULL, 0, 0);
144 65d9b3ca 2021-03-14 op
145 676fba6f 2021-03-21 op prfxwidth = utf8_swidth(prfx);
146 676fba6f 2021-03-21 op cur = prfxwidth;
147 676fba6f 2021-03-21 op start = line;
148 676fba6f 2021-03-21 op lastsep = NULL;
149 676fba6f 2021-03-21 op lastchar = line;
150 5492b68f 2021-07-05 op flags = 0;
151 676fba6f 2021-03-21 op for (; *line; line++) {
152 676fba6f 2021-03-21 op if (utf8_decode(&state, &cp, *line))
153 676fba6f 2021-03-21 op continue;
154 676fba6f 2021-03-21 op w = utf8_chwidth(cp);
155 676fba6f 2021-03-21 op if (cur + w >= width -1) {
156 676fba6f 2021-03-21 op end = lastsep == NULL
157 676fba6f 2021-03-21 op ? utf8_next_cp((char*)lastchar)
158 676fba6f 2021-03-21 op : utf8_next_cp((char*)lastsep);
159 5492b68f 2021-07-05 op if (!push_line(buffer, l, start, end - start, flags))
160 676fba6f 2021-03-21 op return 0;
161 963c680c 2021-07-05 op flags = L_CONTINUATION;
162 676fba6f 2021-03-21 op start = end;
163 676fba6f 2021-03-21 op cur = prfxwidth + utf8_swidth_between(start, lastchar);
164 5b010818 2021-07-05 op } else if (strchr(separators, *line) != NULL) {
165 5b010818 2021-07-05 op lastsep = line;
166 65d9b3ca 2021-03-14 op }
167 65d9b3ca 2021-03-14 op
168 676fba6f 2021-03-21 op lastchar = utf8_prev_cp(line, l->line);
169 676fba6f 2021-03-21 op cur += w;
170 65d9b3ca 2021-03-14 op }
171 65d9b3ca 2021-03-14 op
172 5492b68f 2021-07-05 op return push_line(buffer, l, start, line - start, flags);
173 65d9b3ca 2021-03-14 op }
174 65d9b3ca 2021-03-14 op
175 65d9b3ca 2021-03-14 op int
176 46f6e974 2021-05-17 op hardwrap_text(struct buffer *buffer, struct line *l, size_t width)
177 65d9b3ca 2021-03-14 op {
178 676fba6f 2021-03-21 op const char *line, *start, *lastchar;
179 65d9b3ca 2021-03-14 op int cont;
180 676fba6f 2021-03-21 op uint32_t state = 0, cp = 0;
181 676fba6f 2021-03-21 op size_t cur, w;
182 65d9b3ca 2021-03-14 op
183 676fba6f 2021-03-21 op if ((line = l->line) == NULL)
184 46f6e974 2021-05-17 op return push_line(buffer, l, NULL, 0, 0);
185 166712b4 2021-03-14 op
186 676fba6f 2021-03-21 op start = line;
187 676fba6f 2021-03-21 op lastchar = line;
188 676fba6f 2021-03-21 op cont = 0;
189 676fba6f 2021-03-21 op cur = 0;
190 676fba6f 2021-03-21 op for (; *line; line++) {
191 676fba6f 2021-03-21 op if (utf8_decode(&state, &cp, *line))
192 676fba6f 2021-03-21 op continue;
193 676fba6f 2021-03-21 op w = utf8_chwidth(cp);
194 676fba6f 2021-03-21 op if (cur + w >= width) {
195 46f6e974 2021-05-17 op if (!push_line(buffer, l, start, lastchar - start, cont))
196 676fba6f 2021-03-21 op return 0;
197 676fba6f 2021-03-21 op cont = 1;
198 676fba6f 2021-03-21 op cur = 0;
199 676fba6f 2021-03-21 op start = lastchar;
200 676fba6f 2021-03-21 op }
201 65d9b3ca 2021-03-14 op
202 676fba6f 2021-03-21 op lastchar = utf8_prev_cp(line, l->line);
203 676fba6f 2021-03-21 op cur += w;
204 65d9b3ca 2021-03-14 op }
205 65d9b3ca 2021-03-14 op
206 46f6e974 2021-05-17 op return push_line(buffer, l, start, line - start, cont);
207 65d9b3ca 2021-03-14 op }