/*

 *  menubox.c -- implements the menu box

 *

 *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)

 *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcapw@cfw.com)

 *

 *  This program is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU General Public License

 *  as published by the Free Software Foundation; either version 2

 *  of the License, or (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

/*

 *  Changes by Clifford Wolf (god@clifford.at)

 *

 *  [ 1998-06-13 ]

 *

 *    *)  A bugfix for the Page-Down problem

 *

 *    *)  Formerly when I used Page Down and Page Up, the cursor would be set 

 *        to the first position in the menu box.  Now lxdialog is a bit

 *        smarter and works more like other menu systems (just have a look at

 *        it).

 *

 *    *)  Formerly if I selected something my scrolling would be broken because

 *        lxdialog is re-invoked by the Menuconfig shell script, can't

 *        remember the last scrolling position, and just sets it so that the

 *        cursor is at the bottom of the box.  Now it writes the temporary file

 *        lxdialog.scrltmp which contains this information. The file is

 *        deleted by lxdialog if the user leaves a submenu or enters a new

 *        one, but it would be nice if Menuconfig could make another "rm -f"

 *        just to be sure.  Just try it out - you will recognise a difference!

 *

 *  [ 1998-06-14 ]

 *

 *    *)  Now lxdialog is crash-safe against broken "lxdialog.scrltmp" files

 *        and menus change their size on the fly.

 *

 *    *)  If for some reason the last scrolling position is not saved by

 *        lxdialog, it sets the scrolling so that the selected item is in the

 *        middle of the menu box, not at the bottom.

 *

 * 02 January 1999, Michael Elizabeth Chastain (mec@shout.net)

 * Reset 'scroll' to 0 if the value from lxdialog.scrltmp is bogus.

 * This fixes a bug in Menuconfig where using ' ' to descend into menus

 * would leave mis-synchronized lxdialog.scrltmp files lying around,

 * fscanf would read in 'scroll', and eventually that value would get used.

 */

#include "dialog.h"

static int menu_width, item_x;

/*

 * Print menu item

 */

static void do_print_item(WINDOW * win, const char *item, int line_y,

                          int selected, int hotkey)

{

	int j;

	char *menu_item = malloc(menu_width + 1);

	strncpy(menu_item, item, menu_width - item_x);

	menu_item[menu_width - item_x] = '\0';

	j = first_alpha(menu_item, "YyNnMmHh");

	/* Clear 'residue' of last item */

	wattrset(win, dlg.menubox.atr);

	wmove(win, line_y, 0);

#if OLD_NCURSES

	{

		int i;

		for (i = 0; i < menu_width; i++)

			waddch(win, ' ');

	}

#else

	wclrtoeol(win);

#endif

	wattrset(win, selected ? dlg.item_selected.atr : dlg.item.atr);

	mvwaddstr(win, line_y, item_x, menu_item);

	if (hotkey) {

		wattrset(win, selected ? dlg.tag_key_selected.atr

			 : dlg.tag_key.atr);

		mvwaddch(win, line_y, item_x + j, menu_item[j]);

	}

	if (selected) {

		wmove(win, line_y, item_x + 1);

	}

	free(menu_item);

	wrefresh(win);

}

#define print_item(index, choice, selected)				\

do {									\

	item_set(index);						\

	do_print_item(menu, item_str(), choice, selected, !item_is_tag(':')); \

} while (0)

/*

 * Print the scroll indicators.

 */

static void print_arrows(WINDOW * win, int item_no, int scroll, int y, int x,

			 int height)

{

	int cur_y, cur_x;

	getyx(win, cur_y, cur_x);

	wmove(win, y, x);

	if (scroll > 0) {

		wattrset(win, dlg.uarrow.atr);

		waddch(win, ACS_UARROW);

		waddstr(win, "(-)");

	} else {

		wattrset(win, dlg.menubox.atr);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

	}

	y = y + height + 1;

	wmove(win, y, x);

	wrefresh(win);

	if ((height < item_no) && (scroll + height < item_no)) {

		wattrset(win, dlg.darrow.atr);

		waddch(win, ACS_DARROW);

		waddstr(win, "(+)");

	} else {

		wattrset(win, dlg.menubox_border.atr);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

		waddch(win, ACS_HLINE);

	}

	wmove(win, cur_y, cur_x);

	wrefresh(win);

}

/*

 * Display the termination buttons.

 */

static void print_buttons(WINDOW * win, int height, int width, int selected)

{

	int x = width / 2 - 16;

	int y = height - 2;

	print_button(win, gettext("Select"), y, x, selected == 0);

	print_button(win, gettext(" Exit "), y, x + 12, selected == 1);

	print_button(win, gettext(" Help "), y, x + 24, selected == 2);

	wmove(win, y, x + 1 + 12 * selected);

	wrefresh(win);

}

/* scroll up n lines (n may be negative) */

static void do_scroll(WINDOW *win, int *scroll, int n)

{

	/* Scroll menu up */

	scrollok(win, TRUE);

	wscrl(win, n);

	scrollok(win, FALSE);

	*scroll = *scroll + n;

	wrefresh(win);

}

/*

 * Display a menu for choosing among a number of options

 */

int dialog_menu(const char *title, const char *prompt,

                const void *selected, int *s_scroll)

{

	int i, j, x, y, box_x, box_y;

	int height, width, menu_height;

	int key = 0, button = 0, scroll = 0, choice = 0;

	int first_item =  0, max_choice;

	WINDOW *dialog, *menu;

do_resize:

	height = getmaxy(stdscr);

	width = getmaxx(stdscr);

	if (height < 15 || width < 65)

		return -ERRDISPLAYTOOSMALL;

	height -= 4;

	width  -= 5;

	menu_height = height - 10;

	max_choice = MIN(menu_height, item_count());

	/* center dialog box on screen */

	x = (COLS - width) / 2;

	y = (LINES - height) / 2;

	draw_shadow(stdscr, y, x, height, width);

	dialog = newwin(height, width, y, x);

	keypad(dialog, TRUE);

	draw_box(dialog, 0, 0, height, width,

		 dlg.dialog.atr, dlg.border.atr);

	wattrset(dialog, dlg.border.atr);

	mvwaddch(dialog, height - 3, 0, ACS_LTEE);

	for (i = 0; i < width - 2; i++)

		waddch(dialog, ACS_HLINE);

	wattrset(dialog, dlg.dialog.atr);

	wbkgdset(dialog, dlg.dialog.atr & A_COLOR);

	waddch(dialog, ACS_RTEE);

	print_title(dialog, title, width);

	wattrset(dialog, dlg.dialog.atr);

	print_autowrap(dialog, prompt, width - 2, 1, 3);

	menu_width = width - 6;

	box_y = height - menu_height - 5;

	box_x = (width - menu_width) / 2 - 1;

	/* create new window for the menu */

	menu = subwin(dialog, menu_height, menu_width,

		      y + box_y + 1, x + box_x + 1);

	keypad(menu, TRUE);

	/* draw a box around the menu items */

	draw_box(dialog, box_y, box_x, menu_height + 2, menu_width + 2,

		 dlg.menubox_border.atr, dlg.menubox.atr);

	if (menu_width >= 80)

		item_x = (menu_width - 70) / 2;

	else

		item_x = 4;

	/* Set choice to default item */

	item_foreach()

		if (selected && (selected == item_data()))

			choice = item_n();

	/* get the saved scroll info */

	scroll = *s_scroll;

	if ((scroll <= choice) && (scroll + max_choice > choice) &&

	   (scroll >= 0) && (scroll + max_choice <= item_count())) {

		first_item = scroll;

		choice = choice - scroll;

	} else {

		scroll = 0;

	}

	if ((choice >= max_choice)) {

		if (choice >= item_count() - max_choice / 2)

			scroll = first_item = item_count() - max_choice;

		else

			scroll = first_item = choice - max_choice / 2;

		choice = choice - scroll;

	}

	/* Print the menu */

	for (i = 0; i < max_choice; i++) {

		print_item(first_item + i, i, i == choice);

	}

	wnoutrefresh(menu);

	print_arrows(dialog, item_count(), scroll,

		     box_y, box_x + item_x + 1, menu_height);

	print_buttons(dialog, height, width, 0);

	wmove(menu, choice, item_x + 1);

	wrefresh(menu);

	while (key != KEY_ESC) {

		key = wgetch(menu);

		if (key < 256 && isalpha(key))

			key = tolower(key);

		if (strchr("ynmh", key))

			i = max_choice;

		else {

			for (i = choice + 1; i < max_choice; i++) {

				item_set(scroll + i);

				j = first_alpha(item_str(), "YyNnMmHh");

				if (key == tolower(item_str()[j]))

					break;

			}

			if (i == max_choice)

				for (i = 0; i < max_choice; i++) {

					item_set(scroll + i);

					j = first_alpha(item_str(), "YyNnMmHh");

					if (key == tolower(item_str()[j]))

						break;

				}

		}

		if (i < max_choice ||

		    key == KEY_UP || key == KEY_DOWN ||

		    key == '-' || key == '+' ||

		    key == KEY_PPAGE || key == KEY_NPAGE) {

			/* Remove highligt of current item */

			print_item(scroll + choice, choice, FALSE);

			if (key == KEY_UP || key == '-') {

				if (choice < 2 && scroll) {

					/* Scroll menu down */

					do_scroll(menu, &scroll, -1);

					print_item(scroll, 0, FALSE);

				} else

					choice = MAX(choice - 1, 0);

			} else if (key == KEY_DOWN || key == '+') {

				print_item(scroll+choice, choice, FALSE);

				if ((choice > max_choice - 3) &&

				    (scroll + max_choice < item_count())) {

					/* Scroll menu up */

					do_scroll(menu, &scroll, 1);

					print_item(scroll+max_choice - 1,

						   max_choice - 1, FALSE);

				} else

					choice = MIN(choice + 1, max_choice - 1);

			} else if (key == KEY_PPAGE) {

				scrollok(menu, TRUE);

				for (i = 0; (i < max_choice); i++) {

					if (scroll > 0) {

						do_scroll(menu, &scroll, -1);

						print_item(scroll, 0, FALSE);

					} else {

						if (choice > 0)

							choice--;

					}

				}

			} else if (key == KEY_NPAGE) {

				for (i = 0; (i < max_choice); i++) {

					if (scroll + max_choice < item_count()) {

						do_scroll(menu, &scroll, 1);

						print_item(scroll+max_choice-1,

							   max_choice - 1, FALSE);

					} else {

						if (choice + 1 < max_choice)

							choice++;

					}

				}

			} else

				choice = i;

			print_item(scroll + choice, choice, TRUE);

			print_arrows(dialog, item_count(), scroll,

				     box_y, box_x + item_x + 1, menu_height);

			wnoutrefresh(dialog);

			wrefresh(menu);

			continue;	/* wait for another key press */

		}

		switch (key) {

		case KEY_LEFT:

		case TAB:

		case KEY_RIGHT:

			button = ((key == KEY_LEFT ? --button : ++button) < 0)

			    ? 2 : (button > 2 ? 0 : button);

			print_buttons(dialog, height, width, button);

			wrefresh(menu);

			break;

		case ' ':

		case 's':

		case 'y':

		case 'n':

		case 'm':

		case '/':

		case 'h':

		case '?':

		case 'z':

		case '\n':

			/* save scroll info */

			*s_scroll = scroll;

			delwin(menu);

			delwin(dialog);

			item_set(scroll + choice);

			item_set_selected(1);

			switch (key) {

			case 'h':

			case '?':

				return 2;

			case 's':

			case 'y':

				return 3;

			case 'n':

				return 4;

			case 'm':

				return 5;

			case ' ':

				return 6;

			case '/':

				return 7;

			case 'z':

				return 8;

			case '\n':

				return button;

			}

			return 0;

		case 'e':

		case 'x':

			key = KEY_ESC;

			break;

		case KEY_ESC:

			key = on_key_esc(menu);

			break;

		case KEY_RESIZE:

			on_key_resize();

			delwin(menu);

			delwin(dialog);

			goto do_resize;

		}

	}

	delwin(menu);

	delwin(dialog);

	return key;		/* ESC pressed */

}