1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * textbox.c -- implements the text box
4 *
5 * ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
6 * MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
7 */
8
9 #include "dialog.h"
10
11 static void back_lines(int n);
12 static void print_page(WINDOW *win, int height, int width, update_text_fn
13 update_text, void *data);
14 static void print_line(WINDOW *win, int row, int width);
15 static char *get_line(void);
16 static void print_position(WINDOW * win);
17
18 static int hscroll;
19 static int begin_reached, end_reached, page_length;
20 static char *buf;
21 static char *page;
22
23 /*
24 * refresh window content
25 */
refresh_text_box(WINDOW * dialog,WINDOW * box,int boxh,int boxw,int cur_y,int cur_x,update_text_fn update_text,void * data)26 static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
27 int cur_y, int cur_x, update_text_fn update_text,
28 void *data)
29 {
30 print_page(box, boxh, boxw, update_text, data);
31 print_position(dialog);
32 wmove(dialog, cur_y, cur_x); /* Restore cursor position */
33 wrefresh(dialog);
34 }
35
36
37 /*
38 * Display text from a file in a dialog box.
39 *
40 * keys is a null-terminated array
41 * update_text() may not add or remove any '\n' or '\0' in tbuf
42 */
dialog_textbox(const char * title,char * tbuf,int initial_height,int initial_width,int * keys,int * _vscroll,int * _hscroll,update_text_fn update_text,void * data)43 int dialog_textbox(const char *title, char *tbuf, int initial_height,
44 int initial_width, int *keys, int *_vscroll, int *_hscroll,
45 update_text_fn update_text, void *data)
46 {
47 int i, x, y, cur_x, cur_y, key = 0;
48 int height, width, boxh, boxw;
49 WINDOW *dialog, *box;
50 bool done = false;
51
52 begin_reached = 1;
53 end_reached = 0;
54 page_length = 0;
55 hscroll = 0;
56 buf = tbuf;
57 page = buf; /* page is pointer to start of page to be displayed */
58
59 if (_vscroll && *_vscroll) {
60 begin_reached = 0;
61
62 for (i = 0; i < *_vscroll; i++)
63 get_line();
64 }
65 if (_hscroll)
66 hscroll = *_hscroll;
67
68 do_resize:
69 getmaxyx(stdscr, height, width);
70 if (height < TEXTBOX_HEIGTH_MIN || width < TEXTBOX_WIDTH_MIN)
71 return -ERRDISPLAYTOOSMALL;
72 if (initial_height != 0)
73 height = initial_height;
74 else
75 if (height > 4)
76 height -= 4;
77 else
78 height = 0;
79 if (initial_width != 0)
80 width = initial_width;
81 else
82 if (width > 5)
83 width -= 5;
84 else
85 width = 0;
86
87 /* center dialog box on screen */
88 x = (getmaxx(stdscr) - width) / 2;
89 y = (getmaxy(stdscr) - height) / 2;
90
91 draw_shadow(stdscr, y, x, height, width);
92
93 dialog = newwin(height, width, y, x);
94 keypad(dialog, TRUE);
95
96 /* Create window for box region, used for scrolling text */
97 boxh = height - 4;
98 boxw = width - 2;
99 box = subwin(dialog, boxh, boxw, y + 1, x + 1);
100 wattrset(box, dlg.dialog.atr);
101 wbkgdset(box, dlg.dialog.atr & A_COLOR);
102
103 keypad(box, TRUE);
104
105 /* register the new window, along with its borders */
106 draw_box(dialog, 0, 0, height, width,
107 dlg.dialog.atr, dlg.border.atr);
108
109 wattrset(dialog, dlg.border.atr);
110 mvwaddch(dialog, height - 3, 0, ACS_LTEE);
111 for (i = 0; i < width - 2; i++)
112 waddch(dialog, ACS_HLINE);
113 wattrset(dialog, dlg.dialog.atr);
114 wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
115 waddch(dialog, ACS_RTEE);
116
117 print_title(dialog, title, width);
118
119 print_button(dialog, " Exit ", height - 2, width / 2 - 4, TRUE);
120 wnoutrefresh(dialog);
121 getyx(dialog, cur_y, cur_x); /* Save cursor position */
122
123 /* Print first page of text */
124 attr_clear(box, boxh, boxw, dlg.dialog.atr);
125 refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x, update_text,
126 data);
127
128 while (!done) {
129 key = wgetch(dialog);
130 switch (key) {
131 case 'E': /* Exit */
132 case 'e':
133 case 'X':
134 case 'x':
135 case 'q':
136 case '\n':
137 done = true;
138 break;
139 case 'g': /* First page */
140 case KEY_HOME:
141 if (!begin_reached) {
142 begin_reached = 1;
143 page = buf;
144 refresh_text_box(dialog, box, boxh, boxw,
145 cur_y, cur_x, update_text,
146 data);
147 }
148 break;
149 case 'G': /* Last page */
150 case KEY_END:
151
152 end_reached = 1;
153 /* point to last char in buf */
154 page = buf + strlen(buf);
155 back_lines(boxh);
156 refresh_text_box(dialog, box, boxh, boxw, cur_y,
157 cur_x, update_text, data);
158 break;
159 case 'K': /* Previous line */
160 case 'k':
161 case KEY_UP:
162 if (begin_reached)
163 break;
164
165 back_lines(page_length + 1);
166 refresh_text_box(dialog, box, boxh, boxw, cur_y,
167 cur_x, update_text, data);
168 break;
169 case 'B': /* Previous page */
170 case 'b':
171 case 'u':
172 case KEY_PPAGE:
173 if (begin_reached)
174 break;
175 back_lines(page_length + boxh);
176 refresh_text_box(dialog, box, boxh, boxw, cur_y,
177 cur_x, update_text, data);
178 break;
179 case 'J': /* Next line */
180 case 'j':
181 case KEY_DOWN:
182 if (end_reached)
183 break;
184
185 back_lines(page_length - 1);
186 refresh_text_box(dialog, box, boxh, boxw, cur_y,
187 cur_x, update_text, data);
188 break;
189 case KEY_NPAGE: /* Next page */
190 case ' ':
191 case 'd':
192 if (end_reached)
193 break;
194
195 begin_reached = 0;
196 refresh_text_box(dialog, box, boxh, boxw, cur_y,
197 cur_x, update_text, data);
198 break;
199 case '0': /* Beginning of line */
200 case 'H': /* Scroll left */
201 case 'h':
202 case KEY_LEFT:
203 if (hscroll <= 0)
204 break;
205
206 if (key == '0')
207 hscroll = 0;
208 else
209 hscroll--;
210 /* Reprint current page to scroll horizontally */
211 back_lines(page_length);
212 refresh_text_box(dialog, box, boxh, boxw, cur_y,
213 cur_x, update_text, data);
214 break;
215 case 'L': /* Scroll right */
216 case 'l':
217 case KEY_RIGHT:
218 if (hscroll >= MAX_LEN)
219 break;
220 hscroll++;
221 /* Reprint current page to scroll horizontally */
222 back_lines(page_length);
223 refresh_text_box(dialog, box, boxh, boxw, cur_y,
224 cur_x, update_text, data);
225 break;
226 case KEY_ESC:
227 if (on_key_esc(dialog) == KEY_ESC)
228 done = true;
229 break;
230 case KEY_RESIZE:
231 back_lines(height);
232 delwin(box);
233 delwin(dialog);
234 on_key_resize();
235 goto do_resize;
236 default:
237 for (i = 0; keys[i]; i++) {
238 if (key == keys[i]) {
239 done = true;
240 break;
241 }
242 }
243 }
244 }
245 delwin(box);
246 delwin(dialog);
247 if (_vscroll) {
248 const char *s;
249
250 s = buf;
251 *_vscroll = 0;
252 back_lines(page_length);
253 while (s < page && (s = strchr(s, '\n'))) {
254 (*_vscroll)++;
255 s++;
256 }
257 }
258 if (_hscroll)
259 *_hscroll = hscroll;
260 return key;
261 }
262
263 /*
264 * Go back 'n' lines in text. Called by dialog_textbox().
265 * 'page' will be updated to point to the desired line in 'buf'.
266 */
back_lines(int n)267 static void back_lines(int n)
268 {
269 int i;
270
271 begin_reached = 0;
272 /* Go back 'n' lines */
273 for (i = 0; i < n; i++) {
274 if (*page == '\0') {
275 if (end_reached) {
276 end_reached = 0;
277 continue;
278 }
279 }
280 if (page == buf) {
281 begin_reached = 1;
282 return;
283 }
284 page--;
285 do {
286 if (page == buf) {
287 begin_reached = 1;
288 return;
289 }
290 page--;
291 } while (*page != '\n');
292 page++;
293 }
294 }
295
296 /*
297 * Print a new page of text.
298 */
print_page(WINDOW * win,int height,int width,update_text_fn update_text,void * data)299 static void print_page(WINDOW *win, int height, int width, update_text_fn
300 update_text, void *data)
301 {
302 int i, passed_end = 0;
303
304 if (update_text) {
305 char *end;
306
307 for (i = 0; i < height; i++)
308 get_line();
309 end = page;
310 back_lines(height);
311 update_text(buf, page - buf, end - buf, data);
312 }
313
314 page_length = 0;
315 for (i = 0; i < height; i++) {
316 print_line(win, i, width);
317 if (!passed_end)
318 page_length++;
319 if (end_reached && !passed_end)
320 passed_end = 1;
321 }
322 wnoutrefresh(win);
323 }
324
325 /*
326 * Print a new line of text.
327 */
print_line(WINDOW * win,int row,int width)328 static void print_line(WINDOW * win, int row, int width)
329 {
330 char *line;
331
332 line = get_line();
333 line += MIN(strlen(line), hscroll); /* Scroll horizontally */
334 wmove(win, row, 0); /* move cursor to correct line */
335 waddch(win, ' ');
336 waddnstr(win, line, MIN(strlen(line), width - 2));
337
338 /* Clear 'residue' of previous line */
339 #if OLD_NCURSES
340 {
341 int x = getcurx(win);
342 int i;
343 for (i = 0; i < width - x; i++)
344 waddch(win, ' ');
345 }
346 #else
347 wclrtoeol(win);
348 #endif
349 }
350
351 /*
352 * Return current line of text. Called by dialog_textbox() and print_line().
353 * 'page' should point to start of current line before calling, and will be
354 * updated to point to start of next line.
355 */
get_line(void)356 static char *get_line(void)
357 {
358 int i = 0;
359 static char line[MAX_LEN + 1];
360
361 end_reached = 0;
362 while (*page != '\n') {
363 if (*page == '\0') {
364 end_reached = 1;
365 break;
366 } else if (i < MAX_LEN)
367 line[i++] = *(page++);
368 else {
369 /* Truncate lines longer than MAX_LEN characters */
370 if (i == MAX_LEN)
371 line[i++] = '\0';
372 page++;
373 }
374 }
375 if (i <= MAX_LEN)
376 line[i] = '\0';
377 if (!end_reached)
378 page++; /* move past '\n' */
379
380 return line;
381 }
382
383 /*
384 * Print current position
385 */
print_position(WINDOW * win)386 static void print_position(WINDOW * win)
387 {
388 int percent;
389
390 wattrset(win, dlg.position_indicator.atr);
391 wbkgdset(win, dlg.position_indicator.atr & A_COLOR);
392 percent = (page - buf) * 100 / strlen(buf);
393 wmove(win, getmaxy(win) - 3, getmaxx(win) - 9);
394 wprintw(win, "(%3d%%)", percent);
395 }
396