1 /*
2  *  menubox.c -- implements the menu box
3  *
4  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
5  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcapw@cfw.com)
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 /*
11  *  Changes by Clifford Wolf (god@clifford.at)
12  *
13  *  [ 1998-06-13 ]
14  *
15  *    *)  A bugfix for the Page-Down problem
16  *
17  *    *)  Formerly when I used Page Down and Page Up, the cursor would be set
18  *        to the first position in the menu box.  Now lxdialog is a bit
19  *        smarter and works more like other menu systems (just have a look at
20  *        it).
21  *
22  *    *)  Formerly if I selected something my scrolling would be broken because
23  *        lxdialog is re-invoked by the Menuconfig shell script, can't
24  *        remember the last scrolling position, and just sets it so that the
25  *        cursor is at the bottom of the box.  Now it writes the temporary file
26  *        lxdialog.scrltmp which contains this information. The file is
27  *        deleted by lxdialog if the user leaves a submenu or enters a new
28  *        one, but it would be nice if Menuconfig could make another "rm -f"
29  *        just to be sure.  Just try it out - you will recognise a difference!
30  *
31  *  [ 1998-06-14 ]
32  *
33  *    *)  Now lxdialog is crash-safe against broken "lxdialog.scrltmp" files
34  *        and menus change their size on the fly.
35  *
36  *    *)  If for some reason the last scrolling position is not saved by
37  *        lxdialog, it sets the scrolling so that the selected item is in the
38  *        middle of the menu box, not at the bottom.
39  *
40  * 02 January 1999, Michael Elizabeth Chastain (mec@shout.net)
41  * Reset 'scroll' to 0 if the value from lxdialog.scrltmp is bogus.
42  * This fixes a bug in Menuconfig where using ' ' to descend into menus
43  * would leave mis-synchronized lxdialog.scrltmp files lying around,
44  * fscanf would read in 'scroll', and eventually that value would get used.
45  */
46 
47 #include "dialog.h"
48 
49 static int menu_width, item_x;
50 
51 /*
52  * Print menu item
53  */
54 static void do_print_item(WINDOW * win, const char *item, int line_y,
55 			  int selected, int hotkey)
56 {
57 	int j;
58 	char *menu_item = malloc(menu_width + 1);
59 
60 	strncpy(menu_item, item, menu_width - item_x);
61 	menu_item[menu_width - item_x] = '\0';
62 	j = first_alpha(menu_item, "YyNnMmHh");
63 
64 	/* Clear 'residue' of last item */
65 	wattrset(win, dlg.menubox.atr);
66 	wmove(win, line_y, 0);
67 #if OLD_NCURSES
68 	{
69 		int i;
70 		for (i = 0; i < menu_width; i++)
71 			waddch(win, ' ');
72 	}
73 #else
74 	wclrtoeol(win);
75 #endif
76 	wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);
77 	mvwaddstr(win, line_y, item_x, menu_item);
78 	if (hotkey) {
79 		wattrset(win, selected ? dlg.tag_key_selected.atr
80 			 : dlg.tag_key.atr);
81 		mvwaddch(win, line_y, item_x + j, menu_item[j]);
82 	}
83 	if (selected) {
84 		wmove(win, line_y, item_x + 1);
85 	}
86 	free(menu_item);
87 	wrefresh(win);
88 }
89 
90 #define print_item(index, choice, selected)				\
91 do {									\
92 	item_set(index);						\
93 	do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \
94 } while (0)
95 
96 /*
97  * Print the scroll indicators.
98  */
99 static void print_arrows(WINDOW * win, int item_no, int scroll, int y, int x,
100 			 int height)
101 {
102 	int cur_y, cur_x;
103 
104 	getyx(win, cur_y, cur_x);
105 
106 	wmove(win, y, x);
107 
108 	if (scroll > 0) {
109 		wattrset(win, dlg.uarrow.atr);
110 		waddch(win, ACS_UARROW);
111 		waddstr(win, "(-)");
112 	} else {
113 		wattrset(win, dlg.menubox.atr);
114 		waddch(win, ACS_HLINE);
115 		waddch(win, ACS_HLINE);
116 		waddch(win, ACS_HLINE);
117 		waddch(win, ACS_HLINE);
118 	}
119 
120 	y = y + height + 1;
121 	wmove(win, y, x);
122 	wrefresh(win);
123 
124 	if ((height < item_no) && (scroll + height < item_no)) {
125 		wattrset(win, dlg.darrow.atr);
126 		waddch(win, ACS_DARROW);
127 		waddstr(win, "(+)");
128 	} else {
129 		wattrset(win, dlg.menubox_border.atr);
130 		waddch(win, ACS_HLINE);
131 		waddch(win, ACS_HLINE);
132 		waddch(win, ACS_HLINE);
133 		waddch(win, ACS_HLINE);
134 	}
135 
136 	wmove(win, cur_y, cur_x);
137 	wrefresh(win);
138 }
139 
140 /*
141  * Display the termination buttons.
142  */
143 static void print_buttons(WINDOW * win, int height, int width, int selected)
144 {
145 	int x = width / 2 - 28;
146 	int y = height - 2;
147 
148 	print_button(win, gettext("Select"), y, x, selected == 0);
149 	print_button(win, gettext(" Exit "), y, x + 12, selected == 1);
150 	print_button(win, gettext(" Help "), y, x + 24, selected == 2);
151 	print_button(win, gettext(" Save "), y, x + 36, selected == 3);
152 	print_button(win, gettext(" Load "), y, x + 48, selected == 4);
153 
154 	wmove(win, y, x + 1 + 12 * selected);
155 	wrefresh(win);
156 }
157 
158 /* scroll up n lines (n may be negative) */
159 static void do_scroll(WINDOW *win, int *scroll, int n)
160 {
161 	/* Scroll menu up */
162 	scrollok(win, TRUE);
163 	wscrl(win, n);
164 	scrollok(win, FALSE);
165 	*scroll = *scroll + n;
166 	wrefresh(win);
167 }
168 
169 /*
170  * Display a menu for choosing among a number of options
171  */
172 int dialog_menu(const char *title, const char *prompt,
173 		const void *selected, int *s_scroll)
174 {
175 	int i, j, x, y, box_x, box_y;
176 	int height, width, menu_height;
177 	int key = 0, button = 0, scroll = 0, choice = 0;
178 	int first_item =  0, max_choice;
179 	WINDOW *dialog, *menu;
180 
181 do_resize:
182 	height = getmaxy(stdscr);
183 	width = getmaxx(stdscr);
184 	if (height < MENUBOX_HEIGTH_MIN || width < MENUBOX_WIDTH_MIN)
185 		return -ERRDISPLAYTOOSMALL;
186 
187 	height -= 4;
188 	width  -= 5;
189 	menu_height = height - 10;
190 
191 	max_choice = MIN(menu_height, item_count());
192 
193 	/* center dialog box on screen */
194 	x = (getmaxx(stdscr) - width) / 2;
195 	y = (getmaxy(stdscr) - height) / 2;
196 
197 	draw_shadow(stdscr, y, x, height, width);
198 
199 	dialog = newwin(height, width, y, x);
200 	keypad(dialog, TRUE);
201 
202 	draw_box(dialog, 0, 0, height, width,
203 		 dlg.dialog.atr, dlg.border.atr);
204 	wattrset(dialog, dlg.border.atr);
205 	mvwaddch(dialog, height - 3, 0, ACS_LTEE);
206 	for (i = 0; i < width - 2; i++)
207 		waddch(dialog, ACS_HLINE);
208 	wattrset(dialog, dlg.dialog.atr);
209 	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);
210 	waddch(dialog, ACS_RTEE);
211 
212 	print_title(dialog, title, width);
213 
214 	wattrset(dialog, dlg.dialog.atr);
215 	print_autowrap(dialog, prompt, width - 2, 1, 3);
216 
217 	menu_width = width - 6;
218 	box_y = height - menu_height - 5;
219 	box_x = (width - menu_width) / 2 - 1;
220 
221 	/* create new window for the menu */
222 	menu = subwin(dialog, menu_height, menu_width,
223 		      y + box_y + 1, x + box_x + 1);
224 	keypad(menu, TRUE);
225 
226 	/* draw a box around the menu items */
227 	draw_box(dialog, box_y, box_x, menu_height + 2, menu_width + 2,
228 		 dlg.menubox_border.atr, dlg.menubox.atr);
229 
230 	if (menu_width >= 80)
231 		item_x = (menu_width - 70) / 2;
232 	else
233 		item_x = 4;
234 
235 	/* Set choice to default item */
236 	item_foreach()
237 		if (selected && (selected == item_data()))
238 			choice = item_n();
239 	/* get the saved scroll info */
240 	scroll = *s_scroll;
241 	if ((scroll <= choice) && (scroll + max_choice > choice) &&
242 	   (scroll >= 0) && (scroll + max_choice <= item_count())) {
243 		first_item = scroll;
244 		choice = choice - scroll;
245 	} else {
246 		scroll = 0;
247 	}
248 	if ((choice >= max_choice)) {
249 		if (choice >= item_count() - max_choice / 2)
250 			scroll = first_item = item_count() - max_choice;
251 		else
252 			scroll = first_item = choice - max_choice / 2;
253 		choice = choice - scroll;
254 	}
255 
256 	/* Print the menu */
257 	for (i = 0; i < max_choice; i++) {
258 		print_item(first_item + i, i, i == choice);
259 	}
260 
261 	wnoutrefresh(menu);
262 
263 	print_arrows(dialog, item_count(), scroll,
264 		     box_y, box_x + item_x + 1, menu_height);
265 
266 	print_buttons(dialog, height, width, 0);
267 	wmove(menu, choice, item_x + 1);
268 	wrefresh(menu);
269 
270 	while (key != KEY_ESC) {
271 		key = wgetch(menu);
272 
273 		if (key < 256 && isalpha(key))
274 			key = tolower(key);
275 
276 		if (strchr("ynmh", key))
277 			i = max_choice;
278 		else {
279 			for (i = choice + 1; i < max_choice; i++) {
280 				item_set(scroll + i);
281 				j = first_alpha(item_str(), "YyNnMmHh");
282 				if (key == tolower(item_str()[j]))
283 					break;
284 			}
285 			if (i == max_choice)
286 				for (i = 0; i < max_choice; i++) {
287 					item_set(scroll + i);
288 					j = first_alpha(item_str(), "YyNnMmHh");
289 					if (key == tolower(item_str()[j]))
290 						break;
291 				}
292 		}
293 
294 		if (item_count() != 0 &&
295 		    (i < max_choice ||
296 		     key == KEY_UP || key == KEY_DOWN ||
297 		     key == '-' || key == '+' ||
298 		     key == KEY_PPAGE || key == KEY_NPAGE)) {
299 			/* Remove highligt of current item */
300 			print_item(scroll + choice, choice, FALSE);
301 
302 			if (key == KEY_UP || key == '-') {
303 				if (choice < 2 && scroll) {
304 					/* Scroll menu down */
305 					do_scroll(menu, &scroll, -1);
306 
307 					print_item(scroll, 0, FALSE);
308 				} else
309 					choice = MAX(choice - 1, 0);
310 
311 			} else if (key == KEY_DOWN || key == '+') {
312 				print_item(scroll+choice, choice, FALSE);
313 
314 				if ((choice > max_choice - 3) &&
315 				    (scroll + max_choice < item_count())) {
316 					/* Scroll menu up */
317 					do_scroll(menu, &scroll, 1);
318 
319 					print_item(scroll+max_choice - 1,
320 						   max_choice - 1, FALSE);
321 				} else
322 					choice = MIN(choice + 1, max_choice - 1);
323 
324 			} else if (key == KEY_PPAGE) {
325 				scrollok(menu, TRUE);
326 				for (i = 0; (i < max_choice); i++) {
327 					if (scroll > 0) {
328 						do_scroll(menu, &scroll, -1);
329 						print_item(scroll, 0, FALSE);
330 					} else {
331 						if (choice > 0)
332 							choice--;
333 					}
334 				}
335 
336 			} else if (key == KEY_NPAGE) {
337 				for (i = 0; (i < max_choice); i++) {
338 					if (scroll + max_choice < item_count()) {
339 						do_scroll(menu, &scroll, 1);
340 						print_item(scroll+max_choice-1,
341 							   max_choice - 1, FALSE);
342 					} else {
343 						if (choice + 1 < max_choice)
344 							choice++;
345 					}
346 				}
347 			} else
348 				choice = i;
349 
350 			print_item(scroll + choice, choice, TRUE);
351 
352 			print_arrows(dialog, item_count(), scroll,
353 				     box_y, box_x + item_x + 1, menu_height);
354 
355 			wnoutrefresh(dialog);
356 			wrefresh(menu);
357 
358 			continue;	/* wait for another key press */
359 		}
360 
361 		switch (key) {
362 		case KEY_LEFT:
363 		case TAB:
364 		case KEY_RIGHT:
365 			button = ((key == KEY_LEFT ? --button : ++button) < 0)
366 			    ? 4 : (button > 4 ? 0 : button);
367 
368 			print_buttons(dialog, height, width, button);
369 			wrefresh(menu);
370 			break;
371 		case ' ':
372 		case 's':
373 		case 'y':
374 		case 'n':
375 		case 'm':
376 		case '/':
377 		case 'h':
378 		case '?':
379 		case 'z':
380 		case '\n':
381 			/* save scroll info */
382 			*s_scroll = scroll;
383 			delwin(menu);
384 			delwin(dialog);
385 			item_set(scroll + choice);
386 			item_set_selected(1);
387 			switch (key) {
388 			case 'h':
389 			case '?':
390 				return 2;
391 			case 's':
392 			case 'y':
393 				return 5;
394 			case 'n':
395 				return 6;
396 			case 'm':
397 				return 7;
398 			case ' ':
399 				return 8;
400 			case '/':
401 				return 9;
402 			case 'z':
403 				return 10;
404 			case '\n':
405 				return button;
406 			}
407 			return 0;
408 		case 'e':
409 		case 'x':
410 			key = KEY_ESC;
411 			break;
412 		case KEY_ESC:
413 			key = on_key_esc(menu);
414 			break;
415 		case KEY_RESIZE:
416 			on_key_resize();
417 			delwin(menu);
418 			delwin(dialog);
419 			goto do_resize;
420 		}
421 	}
422 	delwin(menu);
423 	delwin(dialog);
424 	return key;		/* ESC pressed */
425 }
426