1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  menubox.c -- implements the menu box
4  *
5  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
6  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcapw@cfw.com)
7  */
8 
9 /*
10  *  Changes by Clifford Wolf (god@clifford.at)
11  *
12  *  [ 1998-06-13 ]
13  *
14  *    *)  A bugfix for the Page-Down problem
15  *
16  *    *)  Formerly when I used Page Down and Page Up, the cursor would be set
17  *        to the first position in the menu box.  Now lxdialog is a bit
18  *        smarter and works more like other menu systems (just have a look at
19  *        it).
20  *
21  *    *)  Formerly if I selected something my scrolling would be broken because
22  *        lxdialog is re-invoked by the Menuconfig shell script, can't
23  *        remember the last scrolling position, and just sets it so that the
24  *        cursor is at the bottom of the box.  Now it writes the temporary file
25  *        lxdialog.scrltmp which contains this information. The file is
26  *        deleted by lxdialog if the user leaves a submenu or enters a new
27  *        one, but it would be nice if Menuconfig could make another "rm -f"
28  *        just to be sure.  Just try it out - you will recognise a difference!
29  *
30  *  [ 1998-06-14 ]
31  *
32  *    *)  Now lxdialog is crash-safe against broken "lxdialog.scrltmp" files
33  *        and menus change their size on the fly.
34  *
35  *    *)  If for some reason the last scrolling position is not saved by
36  *        lxdialog, it sets the scrolling so that the selected item is in the
37  *        middle of the menu box, not at the bottom.
38  *
39  * 02 January 1999, Michael Elizabeth Chastain (mec@shout.net)
40  * Reset 'scroll' to 0 if the value from lxdialog.scrltmp is bogus.
41  * This fixes a bug in Menuconfig where using ' ' to descend into menus
42  * would leave mis-synchronized lxdialog.scrltmp files lying around,
43  * fscanf would read in 'scroll', and eventually that value would get used.
44  */
45 
46 #include "dialog.h"
47 
48 static int menu_width, item_x;
49 
50 /*
51  * Print menu item
52  */
53 static void do_print_item(WINDOW * win, const char *item, int line_y,
54 			  int selected, int hotkey)
55 {
56 	int j;
57 	char *menu_item = malloc(menu_width + 1);
58 
59 	strncpy(menu_item, item, menu_width - item_x);
60 	menu_item[menu_width - item_x] = '\0';
61 	j = first_alpha(menu_item, "YyNnMmHh");
62 
63 	/* Clear 'residue' of last item */
64 	wattrset(win, dlg.menubox.atr);
65 	wmove(win, line_y, 0);
66 #if OLD_NCURSES
67 	{
68 		int i;
69 		for (i = 0; i < menu_width; i++)
70 			waddch(win, ' ');
71 	}
72 #else
73 	wclrtoeol(win);
74 #endif
75 	wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
76 	mvwaddstr(win, line_y, item_x, menu_item);
77 	if (hotkey) {
78 		wattrset(win, selected ? dlg.tag_key_selected.atr
79 			 : dlg.tag_key.atr);
80 		mvwaddch(win, line_y, item_x + j, menu_item[j]);
81 	}
82 	if (selected) {
83 		wmove(win, line_y, item_x + 1);
84 	}
85 	free(menu_item);
86 	wrefresh(win);
87 }
88 
89 #define print_item(index, choice, selected)				\
90 do {									\
91 	item_set(index);						\
92 	do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \
93 } while (0)
94 
95 /*
96  * Print the scroll indicators.
97  */
98 static void print_arrows(WINDOW * win, int item_no, int scroll, int y, int x,
99 			 int height)
100 {
101 	int cur_y, cur_x;
102 
103 	getyx(win, cur_y, cur_x);
104 
105 	wmove(win, y, x);
106 
107 	if (scroll > 0) {
108 		wattrset(win, dlg.uarrow.atr);
109 		waddch(win, ACS_UARROW);
110 		waddstr(win, "(-)");
111 	} else {
112 		wattrset(win, dlg.menubox.atr);
113 		waddch(win, ACS_HLINE);
114 		waddch(win, ACS_HLINE);
115 		waddch(win, ACS_HLINE);
116 		waddch(win, ACS_HLINE);
117 	}
118 
119 	y = y + height + 1;
120 	wmove(win, y, x);
121 	wrefresh(win);
122 
123 	if ((height < item_no) && (scroll + height < item_no)) {
124 		wattrset(win, dlg.darrow.atr);
125 		waddch(win, ACS_DARROW);
126 		waddstr(win, "(+)");
127 	} else {
128 		wattrset(win, dlg.menubox_border.atr);
129 		waddch(win, ACS_HLINE);
130 		waddch(win, ACS_HLINE);
131 		waddch(win, ACS_HLINE);
132 		waddch(win, ACS_HLINE);
133 	}
134 
135 	wmove(win, cur_y, cur_x);
136 	wrefresh(win);
137 }
138 
139 /*
140  * Display the termination buttons.
141  */
142 static void print_buttons(WINDOW * win, int height, int width, int selected)
143 {
144 	int x = width / 2 - 28;
145 	int y = height - 2;
146 
147 	print_button(win, gettext("Select"), y, x, selected == 0);
148 	print_button(win, gettext(" Exit "), y, x + 12, selected == 1);
149 	print_button(win, gettext(" Help "), y, x + 24, selected == 2);
150 	print_button(win, gettext(" Save "), y, x + 36, selected == 3);
151 	print_button(win, gettext(" Load "), y, x + 48, selected == 4);
152 
153 	wmove(win, y, x + 1 + 12 * selected);
154 	wrefresh(win);
155 }
156 
157 /* scroll up n lines (n may be negative) */
158 static void do_scroll(WINDOW *win, int *scroll, int n)
159 {
160 	/* Scroll menu up */
161 	scrollok(win, TRUE);
162 	wscrl(win, n);
163 	scrollok(win, FALSE);
164 	*scroll = *scroll + n;
165 	wrefresh(win);
166 }
167 
168 /*
169  * Display a menu for choosing among a number of options
170  */
171 int dialog_menu(const char *title, const char *prompt,
172 		const void *selected, int *s_scroll)
173 {
174 	int i, j, x, y, box_x, box_y;
175 	int height, width, menu_height;
176 	int key = 0, button = 0, scroll = 0, choice = 0;
177 	int first_item =  0, max_choice;
178 	WINDOW *dialog, *menu;
179 
180 do_resize:
181 	height = getmaxy(stdscr);
182 	width = getmaxx(stdscr);
183 	if (height < MENUBOX_HEIGTH_MIN || width < MENUBOX_WIDTH_MIN)
184 		return -ERRDISPLAYTOOSMALL;
185 
186 	height -= 4;
187 	width  -= 5;
188 	menu_height = height - 10;
189 
190 	max_choice = MIN(menu_height, item_count());
191 
192 	/* center dialog box on screen */
193 	x = (getmaxx(stdscr) - width) / 2;
194 	y = (getmaxy(stdscr) - height) / 2;
195 
196 	draw_shadow(stdscr, y, x, height, width);
197 
198 	dialog = newwin(height, width, y, x);
199 	keypad(dialog, TRUE);
200 
201 	draw_box(dialog, 0, 0, height, width,
202 		 dlg.dialog.atr, dlg.border.atr);
203 	wattrset(dialog, dlg.border.atr);
204 	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
205 	for (i = 0; i < width - 2; i++)
206 		waddch(dialog, ACS_HLINE);
207 	wattrset(dialog, dlg.dialog.atr);
208 	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
209 	waddch(dialog, ACS_RTEE);
210 
211 	print_title(dialog, title, width);
212 
213 	wattrset(dialog, dlg.dialog.atr);
214 	print_autowrap(dialog, prompt, width - 2, 1, 3);
215 
216 	menu_width = width - 6;
217 	box_y = height - menu_height - 5;
218 	box_x = (width - menu_width) / 2 - 1;
219 
220 	/* create new window for the menu */
221 	menu = subwin(dialog, menu_height, menu_width,
222 		      y + box_y + 1, x + box_x + 1);
223 	keypad(menu, TRUE);
224 
225 	/* draw a box around the menu items */
226 	draw_box(dialog, box_y, box_x, menu_height + 2, menu_width + 2,
227 		 dlg.menubox_border.atr, dlg.menubox.atr);
228 
229 	if (menu_width >= 80)
230 		item_x = (menu_width - 70) / 2;
231 	else
232 		item_x = 4;
233 
234 	/* Set choice to default item */
235 	item_foreach()
236 		if (selected && (selected == item_data()))
237 			choice = item_n();
238 	/* get the saved scroll info */
239 	scroll = *s_scroll;
240 	if ((scroll <= choice) && (scroll + max_choice > choice) &&
241 	   (scroll >= 0) && (scroll + max_choice <= item_count())) {
242 		first_item = scroll;
243 		choice = choice - scroll;
244 	} else {
245 		scroll = 0;
246 	}
247 	if ((choice >= max_choice)) {
248 		if (choice >= item_count() - max_choice / 2)
249 			scroll = first_item = item_count() - max_choice;
250 		else
251 			scroll = first_item = choice - max_choice / 2;
252 		choice = choice - scroll;
253 	}
254 
255 	/* Print the menu */
256 	for (i = 0; i < max_choice; i++) {
257 		print_item(first_item + i, i, i == choice);
258 	}
259 
260 	wnoutrefresh(menu);
261 
262 	print_arrows(dialog, item_count(), scroll,
263 		     box_y, box_x + item_x + 1, menu_height);
264 
265 	print_buttons(dialog, height, width, 0);
266 	wmove(menu, choice, item_x + 1);
267 	wrefresh(menu);
268 
269 	while (key != KEY_ESC) {
270 		key = wgetch(menu);
271 
272 		if (key < 256 && isalpha(key))
273 			key = tolower(key);
274 
275 		if (strchr("ynmh", key))
276 			i = max_choice;
277 		else {
278 			for (i = choice + 1; i < max_choice; i++) {
279 				item_set(scroll + i);
280 				j = first_alpha(item_str(), "YyNnMmHh");
281 				if (key == tolower(item_str()[j]))
282 					break;
283 			}
284 			if (i == max_choice)
285 				for (i = 0; i < max_choice; i++) {
286 					item_set(scroll + i);
287 					j = first_alpha(item_str(), "YyNnMmHh");
288 					if (key == tolower(item_str()[j]))
289 						break;
290 				}
291 		}
292 
293 		if (item_count() != 0 &&
294 		    (i < max_choice ||
295 		     key == KEY_UP || key == KEY_DOWN ||
296 		     key == '-' || key == '+' ||
297 		     key == KEY_PPAGE || key == KEY_NPAGE)) {
298 			/* Remove highligt of current item */
299 			print_item(scroll + choice, choice, FALSE);
300 
301 			if (key == KEY_UP || key == '-') {
302 				if (choice < 2 && scroll) {
303 					/* Scroll menu down */
304 					do_scroll(menu, &scroll, -1);
305 
306 					print_item(scroll, 0, FALSE);
307 				} else
308 					choice = MAX(choice - 1, 0);
309 
310 			} else if (key == KEY_DOWN || key == '+') {
311 				print_item(scroll+choice, choice, FALSE);
312 
313 				if ((choice > max_choice - 3) &&
314 				    (scroll + max_choice < item_count())) {
315 					/* Scroll menu up */
316 					do_scroll(menu, &scroll, 1);
317 
318 					print_item(scroll+max_choice - 1,
319 						   max_choice - 1, FALSE);
320 				} else
321 					choice = MIN(choice + 1, max_choice - 1);
322 
323 			} else if (key == KEY_PPAGE) {
324 				scrollok(menu, TRUE);
325 				for (i = 0; (i < max_choice); i++) {
326 					if (scroll > 0) {
327 						do_scroll(menu, &scroll, -1);
328 						print_item(scroll, 0, FALSE);
329 					} else {
330 						if (choice > 0)
331 							choice--;
332 					}
333 				}
334 
335 			} else if (key == KEY_NPAGE) {
336 				for (i = 0; (i < max_choice); i++) {
337 					if (scroll + max_choice < item_count()) {
338 						do_scroll(menu, &scroll, 1);
339 						print_item(scroll+max_choice-1,
340 							   max_choice - 1, FALSE);
341 					} else {
342 						if (choice + 1 < max_choice)
343 							choice++;
344 					}
345 				}
346 			} else
347 				choice = i;
348 
349 			print_item(scroll + choice, choice, TRUE);
350 
351 			print_arrows(dialog, item_count(), scroll,
352 				     box_y, box_x + item_x + 1, menu_height);
353 
354 			wnoutrefresh(dialog);
355 			wrefresh(menu);
356 
357 			continue;	/* wait for another key press */
358 		}
359 
360 		switch (key) {
361 		case KEY_LEFT:
362 		case TAB:
363 		case KEY_RIGHT:
364 			button = ((key == KEY_LEFT ? --button : ++button) < 0)
365 			    ? 4 : (button > 4 ? 0 : button);
366 
367 			print_buttons(dialog, height, width, button);
368 			wrefresh(menu);
369 			break;
370 		case ' ':
371 		case 's':
372 		case 'y':
373 		case 'n':
374 		case 'm':
375 		case '/':
376 		case 'h':
377 		case '?':
378 		case 'z':
379 		case '\n':
380 			/* save scroll info */
381 			*s_scroll = scroll;
382 			delwin(menu);
383 			delwin(dialog);
384 			item_set(scroll + choice);
385 			item_set_selected(1);
386 			switch (key) {
387 			case 'h':
388 			case '?':
389 				return 2;
390 			case 's':
391 			case 'y':
392 				return 5;
393 			case 'n':
394 				return 6;
395 			case 'm':
396 				return 7;
397 			case ' ':
398 				return 8;
399 			case '/':
400 				return 9;
401 			case 'z':
402 				return 10;
403 			case '\n':
404 				return button;
405 			}
406 			return 0;
407 		case 'e':
408 		case 'x':
409 			key = KEY_ESC;
410 			break;
411 		case KEY_ESC:
412 			key = on_key_esc(menu);
413 			break;
414 		case KEY_RESIZE:
415 			on_key_resize();
416 			delwin(menu);
417 			delwin(dialog);
418 			goto do_resize;
419 		}
420 	}
421 	delwin(menu);
422 	delwin(dialog);
423 	return key;		/* ESC pressed */
424 }
425