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 	wclrtoeol(win);
67 	wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
68 	mvwaddstr(win, line_y, item_x, menu_item);
69 	if (hotkey) {
70 		wattrset(win, selected ? dlg.tag_key_selected.atr
71 			 : dlg.tag_key.atr);
72 		mvwaddch(win, line_y, item_x + j, menu_item[j]);
73 	}
74 	if (selected) {
75 		wmove(win, line_y, item_x + 1);
76 	}
77 	free(menu_item);
78 	wrefresh(win);
79 }
80 
81 #define print_item(index, choice, selected)				\
82 do {									\
83 	item_set(index);						\
84 	do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \
85 } while (0)
86 
87 /*
88  * Print the scroll indicators.
89  */
90 static void print_arrows(WINDOW * win, int item_no, int scroll, int y, int x,
91 			 int height)
92 {
93 	int cur_y, cur_x;
94 
95 	getyx(win, cur_y, cur_x);
96 
97 	wmove(win, y, x);
98 
99 	if (scroll > 0) {
100 		wattrset(win, dlg.uarrow.atr);
101 		waddch(win, ACS_UARROW);
102 		waddstr(win, "(-)");
103 	} else {
104 		wattrset(win, dlg.menubox.atr);
105 		waddch(win, ACS_HLINE);
106 		waddch(win, ACS_HLINE);
107 		waddch(win, ACS_HLINE);
108 		waddch(win, ACS_HLINE);
109 	}
110 
111 	y = y + height + 1;
112 	wmove(win, y, x);
113 	wrefresh(win);
114 
115 	if ((height < item_no) && (scroll + height < item_no)) {
116 		wattrset(win, dlg.darrow.atr);
117 		waddch(win, ACS_DARROW);
118 		waddstr(win, "(+)");
119 	} else {
120 		wattrset(win, dlg.menubox_border.atr);
121 		waddch(win, ACS_HLINE);
122 		waddch(win, ACS_HLINE);
123 		waddch(win, ACS_HLINE);
124 		waddch(win, ACS_HLINE);
125 	}
126 
127 	wmove(win, cur_y, cur_x);
128 	wrefresh(win);
129 }
130 
131 /*
132  * Display the termination buttons.
133  */
134 static void print_buttons(WINDOW * win, int height, int width, int selected)
135 {
136 	int x = width / 2 - 28;
137 	int y = height - 2;
138 
139 	print_button(win, "Select", y, x, selected == 0);
140 	print_button(win, " Exit ", y, x + 12, selected == 1);
141 	print_button(win, " Help ", y, x + 24, selected == 2);
142 	print_button(win, " Save ", y, x + 36, selected == 3);
143 	print_button(win, " Load ", y, x + 48, selected == 4);
144 
145 	wmove(win, y, x + 1 + 12 * selected);
146 	wrefresh(win);
147 }
148 
149 /* scroll up n lines (n may be negative) */
150 static void do_scroll(WINDOW *win, int *scroll, int n)
151 {
152 	/* Scroll menu up */
153 	scrollok(win, TRUE);
154 	wscrl(win, n);
155 	scrollok(win, FALSE);
156 	*scroll = *scroll + n;
157 	wrefresh(win);
158 }
159 
160 /*
161  * Display a menu for choosing among a number of options
162  */
163 int dialog_menu(const char *title, const char *prompt,
164 		const void *selected, int *s_scroll)
165 {
166 	int i, j, x, y, box_x, box_y;
167 	int height, width, menu_height;
168 	int key = 0, button = 0, scroll = 0, choice = 0;
169 	int first_item =  0, max_choice;
170 	WINDOW *dialog, *menu;
171 
172 do_resize:
173 	height = getmaxy(stdscr);
174 	width = getmaxx(stdscr);
175 	if (height < MENUBOX_HEIGTH_MIN || width < MENUBOX_WIDTH_MIN)
176 		return -ERRDISPLAYTOOSMALL;
177 
178 	height -= 4;
179 	width  -= 5;
180 	menu_height = height - 10;
181 
182 	max_choice = MIN(menu_height, item_count());
183 
184 	/* center dialog box on screen */
185 	x = (getmaxx(stdscr) - width) / 2;
186 	y = (getmaxy(stdscr) - height) / 2;
187 
188 	draw_shadow(stdscr, y, x, height, width);
189 
190 	dialog = newwin(height, width, y, x);
191 	keypad(dialog, TRUE);
192 
193 	draw_box(dialog, 0, 0, height, width,
194 		 dlg.dialog.atr, dlg.border.atr);
195 	wattrset(dialog, dlg.border.atr);
196 	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
197 	for (i = 0; i < width - 2; i++)
198 		waddch(dialog, ACS_HLINE);
199 	wattrset(dialog, dlg.dialog.atr);
200 	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
201 	waddch(dialog, ACS_RTEE);
202 
203 	print_title(dialog, title, width);
204 
205 	wattrset(dialog, dlg.dialog.atr);
206 	print_autowrap(dialog, prompt, width - 2, 1, 3);
207 
208 	menu_width = width - 6;
209 	box_y = height - menu_height - 5;
210 	box_x = (width - menu_width) / 2 - 1;
211 
212 	/* create new window for the menu */
213 	menu = subwin(dialog, menu_height, menu_width,
214 		      y + box_y + 1, x + box_x + 1);
215 	keypad(menu, TRUE);
216 
217 	/* draw a box around the menu items */
218 	draw_box(dialog, box_y, box_x, menu_height + 2, menu_width + 2,
219 		 dlg.menubox_border.atr, dlg.menubox.atr);
220 
221 	if (menu_width >= 80)
222 		item_x = (menu_width - 70) / 2;
223 	else
224 		item_x = 4;
225 
226 	/* Set choice to default item */
227 	item_foreach()
228 		if (selected && (selected == item_data()))
229 			choice = item_n();
230 	/* get the saved scroll info */
231 	scroll = *s_scroll;
232 	if ((scroll <= choice) && (scroll + max_choice > choice) &&
233 	   (scroll >= 0) && (scroll + max_choice <= item_count())) {
234 		first_item = scroll;
235 		choice = choice - scroll;
236 	} else {
237 		scroll = 0;
238 	}
239 	if ((choice >= max_choice)) {
240 		if (choice >= item_count() - max_choice / 2)
241 			scroll = first_item = item_count() - max_choice;
242 		else
243 			scroll = first_item = choice - max_choice / 2;
244 		choice = choice - scroll;
245 	}
246 
247 	/* Print the menu */
248 	for (i = 0; i < max_choice; i++) {
249 		print_item(first_item + i, i, i == choice);
250 	}
251 
252 	wnoutrefresh(menu);
253 
254 	print_arrows(dialog, item_count(), scroll,
255 		     box_y, box_x + item_x + 1, menu_height);
256 
257 	print_buttons(dialog, height, width, 0);
258 	wmove(menu, choice, item_x + 1);
259 	wrefresh(menu);
260 
261 	while (key != KEY_ESC) {
262 		key = wgetch(menu);
263 
264 		if (key < 256 && isalpha(key))
265 			key = tolower(key);
266 
267 		if (strchr("ynmh", key))
268 			i = max_choice;
269 		else {
270 			for (i = choice + 1; i < max_choice; i++) {
271 				item_set(scroll + i);
272 				j = first_alpha(item_str(), "YyNnMmHh");
273 				if (key == tolower(item_str()[j]))
274 					break;
275 			}
276 			if (i == max_choice)
277 				for (i = 0; i < max_choice; i++) {
278 					item_set(scroll + i);
279 					j = first_alpha(item_str(), "YyNnMmHh");
280 					if (key == tolower(item_str()[j]))
281 						break;
282 				}
283 		}
284 
285 		if (item_count() != 0 &&
286 		    (i < max_choice ||
287 		     key == KEY_UP || key == KEY_DOWN ||
288 		     key == '-' || key == '+' ||
289 		     key == KEY_PPAGE || key == KEY_NPAGE)) {
290 			/* Remove highligt of current item */
291 			print_item(scroll + choice, choice, FALSE);
292 
293 			if (key == KEY_UP || key == '-') {
294 				if (choice < 2 && scroll) {
295 					/* Scroll menu down */
296 					do_scroll(menu, &scroll, -1);
297 
298 					print_item(scroll, 0, FALSE);
299 				} else
300 					choice = MAX(choice - 1, 0);
301 
302 			} else if (key == KEY_DOWN || key == '+') {
303 				print_item(scroll+choice, choice, FALSE);
304 
305 				if ((choice > max_choice - 3) &&
306 				    (scroll + max_choice < item_count())) {
307 					/* Scroll menu up */
308 					do_scroll(menu, &scroll, 1);
309 
310 					print_item(scroll+max_choice - 1,
311 						   max_choice - 1, FALSE);
312 				} else
313 					choice = MIN(choice + 1, max_choice - 1);
314 
315 			} else if (key == KEY_PPAGE) {
316 				scrollok(menu, TRUE);
317 				for (i = 0; (i < max_choice); i++) {
318 					if (scroll > 0) {
319 						do_scroll(menu, &scroll, -1);
320 						print_item(scroll, 0, FALSE);
321 					} else {
322 						if (choice > 0)
323 							choice--;
324 					}
325 				}
326 
327 			} else if (key == KEY_NPAGE) {
328 				for (i = 0; (i < max_choice); i++) {
329 					if (scroll + max_choice < item_count()) {
330 						do_scroll(menu, &scroll, 1);
331 						print_item(scroll+max_choice-1,
332 							   max_choice - 1, FALSE);
333 					} else {
334 						if (choice + 1 < max_choice)
335 							choice++;
336 					}
337 				}
338 			} else
339 				choice = i;
340 
341 			print_item(scroll + choice, choice, TRUE);
342 
343 			print_arrows(dialog, item_count(), scroll,
344 				     box_y, box_x + item_x + 1, menu_height);
345 
346 			wnoutrefresh(dialog);
347 			wrefresh(menu);
348 
349 			continue;	/* wait for another key press */
350 		}
351 
352 		switch (key) {
353 		case KEY_LEFT:
354 		case TAB:
355 		case KEY_RIGHT:
356 			button = ((key == KEY_LEFT ? --button : ++button) < 0)
357 			    ? 4 : (button > 4 ? 0 : button);
358 
359 			print_buttons(dialog, height, width, button);
360 			wrefresh(menu);
361 			break;
362 		case ' ':
363 		case 's':
364 		case 'y':
365 		case 'n':
366 		case 'm':
367 		case '/':
368 		case 'h':
369 		case '?':
370 		case 'z':
371 		case '\n':
372 			/* save scroll info */
373 			*s_scroll = scroll;
374 			delwin(menu);
375 			delwin(dialog);
376 			item_set(scroll + choice);
377 			item_set_selected(1);
378 			switch (key) {
379 			case 'h':
380 			case '?':
381 				return 2;
382 			case 's':
383 			case 'y':
384 				return 5;
385 			case 'n':
386 				return 6;
387 			case 'm':
388 				return 7;
389 			case ' ':
390 				return 8;
391 			case '/':
392 				return 9;
393 			case 'z':
394 				return 10;
395 			case '\n':
396 				return button;
397 			}
398 			return 0;
399 		case 'e':
400 		case 'x':
401 			key = KEY_ESC;
402 			break;
403 		case KEY_ESC:
404 			key = on_key_esc(menu);
405 			break;
406 		case KEY_RESIZE:
407 			on_key_resize();
408 			delwin(menu);
409 			delwin(dialog);
410 			goto do_resize;
411 		}
412 	}
413 	delwin(menu);
414 	delwin(dialog);
415 	return key;		/* ESC pressed */
416 }
417