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
48static int menu_width, item_x;
49
50/*
51 * Print menu item
52 */
53static 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)				\
82do {									\
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 */
90static 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 */
134static 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) */
150static 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 */
163int 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
172do_resize:
173	height = getmaxy(stdscr);
174	width = getmaxx(stdscr);
175	if (height < MENUBOX_HEIGHT_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