xref: /src/usr.bin/menuc/menu_sys.def

/*	$NetBSD: menu_sys.def,v 1.65 2019/02/06 20:08:15 martin Exp $	*/

/*
 * Copyright 1997 Piermont Information Systems Inc.
 * All rights reserved.
 *
 * Written by Philip A. Nelson for Piermont Information Systems Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of Piermont Information Systems Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY PIERMONT INFORMATION SYSTEMS INC. ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL PIERMONT INFORMATION SYSTEMS INC. BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/* menu_sys.defs -- Menu system standard routines. */

#include <string.h>
#include <ctype.h>

#define REQ_EXECUTE    1000
#define REQ_NEXT_ITEM  1001
#define REQ_PREV_ITEM  1002
#define REQ_REDISPLAY  1003
#define REQ_SCROLLDOWN 1004
#define REQ_SCROLLUP   1005
#define REQ_HELP       1006

/* Macros */
#define MAX(x,y) ((x)>(y)?(x):(y))
#define MIN(x,y) ((x)<(y)?(x):(y))

/* Initialization state. */
static int __menu_init = 0;
static int max_lines = 0, max_cols = 0;
#ifndef scrolltext
static const char *scrolltext = " <: page up, >: page down";
#endif

#ifdef DYNAMIC_MENUS
static int num_menus  = 0;
#define DYN_INIT_NUM 32
static menudesc **menu_list;
#define MENUS(n) (*(menu_list[n]))
#else
#define MENUS(n) (menu_def[n])
#endif

/* prototypes for in here! */
static void init_menu(menudesc *m);
static char opt_ch(menudesc *m, int op_no);
static void draw_menu(menudesc *m, void *arg);
static void process_help(menudesc *m);
static void process_req(menudesc *m, void *arg, int req);
static int menucmd(WINDOW *w);

#ifndef NULL
#define NULL 0
#endif

/* menu system processing routines */
#define mbeep() (void)fputc('\a', stderr)

static int
menucmd(WINDOW *w)
{
	int ch;

	while (TRUE) {
		ch = wgetch(w);

		switch (ch) {
		case '\n':
			return REQ_EXECUTE;
		case '\016':  /* Control-P */
		case KEY_DOWN:
			return REQ_NEXT_ITEM;
		case '\020':  /* Control-N */
		case KEY_UP:
			return REQ_PREV_ITEM;
		case '\014':  /* Control-L */
			return REQ_REDISPLAY;
		case '<':
		case '\010':  /* Control-H (backspace) */
		case KEY_PPAGE:
		case KEY_LEFT:
			return REQ_SCROLLUP;
		case '\026':  /* Control-V */
		case '>':
		case ' ':
		case KEY_NPAGE:
		case KEY_RIGHT:
			return REQ_SCROLLDOWN;
		case '?':
			return REQ_HELP;
		case '\033': /* esc-v is scroll down */
			ch = wgetch(w);
			if (ch == 'v')
				return REQ_SCROLLUP;
			else
				ch = 0; /* zap char so we beep */
		}

		if (isalpha(ch))
			return ch;

		mbeep();
		wrefresh(w);
	}
}

static void
init_menu(menudesc *m)
{
	int wmax;
	int hadd, wadd, exithadd;
	int i;
	int x, y, w;
	const char *title, *tp, *ep;

	x = m->x;
	y = m->y;
	w = m->w;
	wmax = 0;
	hadd = ((m->mopt & MC_NOBOX) ? 0 : 2);
	wadd = ((m->mopt & MC_NOBOX) ? 2 : 4);
	if (!(m->mopt & MC_NOSHORTCUT))
		wadd += 3;

	title = m->title;
#ifdef MENU_EXPANDS
	if (m->exp_title)
		title = m->exp_title;
#endif
	if (title)
		title = MSG_XLAT(title);
	if (title && title[0] != 0) {
		/* Allow multiple line titles */
		for (tp = title; (ep = strchr(tp, '\n')); tp = ep + 1) {
			i = ep - tp;
			wmax = MAX(wmax, i);
			hadd++;
		}
		hadd++;
		i = strlen(tp);
		wmax = MAX(wmax, i);
		if (i != 0)
			hadd++;
	} else {
		m->title = NULL;
		title = "untitled";
	}
	exithadd = ((m->mopt & MC_NOEXITOPT) ? 0 : 1);

#ifdef MSG_DEFS_H
	if (y < 0) {
		/* put menu box below message text */
		y = -y;
		i = msg_row();
		if (i > y)
		    y = i;
	}
#endif

	/* Calculate h? h == number of visible options. */
	if (m->h == 0)
		m->h = m->numopts + exithadd;

	if (m->h > max_lines - y - hadd) {
		/* Not enough space for all the options */
		if (m->h <= 4 || !(m->mopt & (MC_SCROLL | MC_ALWAYS_SCROLL))) {
			/* move menu up screen */
			y = max_lines - hadd - m->h;
			if (y < 0)
				y = 0;
		}
		m->h = max_lines - y - hadd;
	}

	if (m->h < m->numopts + exithadd || m->mopt & MC_ALWAYS_SCROLL) {
		/* We need to add the scroll text...
		 * The used to be a check for MC_SCROLL here, but it is
		 * fairly pointless - you just don't want the program
		 * to exit on this sort of error.
		 */
		if (m->h < 3) {
			endwin();
			(void)fprintf(stderr,
				"Window too short (m->h %d, m->numopts %d, exithadd %d, y %d, max_lines %d, hadd %d) for menu \"%.30s\"\n",
				m->h, m->numopts, exithadd, y, max_lines, hadd,
				title);
			exit(1);
		}
		hadd++;
		m->h = MIN(m->h, max_lines - y - hadd);
		i = strlen(scrolltext);
		wmax = MAX(wmax, i);
	}

	/* Calculate w? */
	if (w == 0) {
		int l;
		for (i = 0; i < m->numopts; i++) {
#ifdef MENU_EXPANDS
			tp = m->opts[i].opt_exp_name ?
			    m->opts[i].opt_exp_name :
			    MSG_XLAT(m->opts[i].opt_name);
#else
			tp = MSG_XLAT(m->opts[i].opt_name);
#endif
			if (tp == NULL)
				continue;
			l = strlen(tp);
			wmax = MAX(wmax, l);
		}
		w = wmax;
	}

	/* check and adjust for screen fit */
	if (w + wadd > max_cols) {
		endwin();
		(void)fprintf(stderr,
			"Screen too narrow (%d + %d > %d) for menu \"%s\"\n",
				w, wadd, max_cols, title);
		exit(1);

	}

	if (x == -1)
		x = (max_cols - (w + wadd)) / 2;	/* center */
	else if (x + w + wadd > max_cols)
		x = max_cols - (w + wadd);	/* right align */

	if (y == 0) {
		/* Center - rather than top */
		y = (max_lines - hadd - m->h) / 2;
	}

	/* Get the windows. */
	m->mw = newwin(m->h + hadd, w + wadd, y, x);

	if (m->mw == NULL) {
		endwin();
		(void)fprintf(stderr,
			"Could not create window (%d + %d, %d + %d, %d, %d) for menu \"%s\"\n",
			m->h, hadd, w, wadd, y, x, title);
		exit(1);
	}
	keypad(m->mw, TRUE); /* enable multi-key assembling for win */

	/* XXX is it even worth doing this right? */
	if (has_colors()) {
		wbkgd(m->mw, COLOR_PAIR(1));
		wattrset(m->mw, COLOR_PAIR(1));
	}

	if (m->mopt & MC_SUBMENU) {
		/* Keep a copy of what is on the screen under the window */
		m->sv_mw = newwin(m->h + hadd, w + wadd, y, x);
		/*
		 * cursrc contains post-doupdate() data, not post-refresh()
		 * data so we must call doupdate to ensure we save the
		 * correct data.  Avoids PR 26660.
		 */
		doupdate();
		if (m->sv_mw)
			overwrite(curscr, m->sv_mw);
	}
}

static char
opt_ch(menudesc *m, int op_no)
{
	char c;

	if (op_no == m->numopts)
		return 'x';

	if (op_no < 25) {
		c = 'a' + op_no;
		if (c >= 'x')
			c++;
	} else
		c = 'A' + op_no - 25;
	return c;
}

static void
draw_menu_line(menudesc *m, int opt, int cury, void *arg, const char *text)
{
	int hasbox = m->mopt & MC_NOBOX ? 0 : 1;
	int noshort = (opt < m->numopts)
	    && (m->opts[opt].opt_flags & OPT_NOSHORT);

	if (m->cursel == opt) {
		mvwaddstr(m->mw, cury, hasbox, ">");
		wstandout(m->mw);
	} else
		mvwaddstr(m->mw, cury, hasbox, " ");
	if (!(m->mopt & MC_NOSHORTCUT) && !noshort)
		wprintw(m->mw, "%c: ", opt_ch(m, opt));
	else if (!(m->mopt & MC_NOSHORTCUT))
		wprintw(m->mw, "   ");

	if (!text && m->draw_line)
		m->draw_line(m, opt, arg);
	else
		waddstr(m->mw, MSG_XLAT(text));
	if (m->cursel == opt)
		wstandend(m->mw);
}

static void
draw_menu(menudesc *m, void *arg)
{
	int opt;
	int hasbox, cury, maxy;
	int tadd;
	int hasexit = (m->mopt & MC_NOEXITOPT ? 0 : 1);
	const char *tp, *ep;
	const char *title;

	hasbox = (m->mopt & MC_NOBOX ? 0 : 1);

	/* Clear the window */
	wclear(m->mw);

	tadd = hasbox;
	title = m->title;
#ifdef MENU_EXPANDS
	if (m->exp_title)
		title = m->exp_title;
#endif
	if (title) {
		for (tp = MSG_XLAT(title); ; tp = ep + 1) {
			ep = strchr(tp , '\n');
			mvwaddnstr(m->mw, tadd++, hasbox + 1, tp,
			    ep ? ep - tp : -1);
			if (ep == NULL || *ep == 0)
				break;
		}
		tadd++;
	}

	cury = tadd;
	maxy = getmaxy(m->mw) - hasbox;
	if (m->numopts + hasexit > m->h)
		/* allow for scroll text */
		maxy--;

	if (m->cursel == -1) {
		m->cursel = m->numopts;
		if (m->h <= m->numopts)
			m->topline = m->numopts + 1 - m->h;
	}

	while (m->cursel >= m->topline + m->h)
		m->topline = MIN(m->topline + m->h,
				 m->numopts + hasexit - m->h);
	while (m->cursel < m->topline)
		m->topline = MAX(0, m->topline - m->h);

	for (opt = m->topline; opt < m->numopts; opt++) {
		if (cury >= maxy)
			break;
		draw_menu_line(m, opt, cury++, arg,
#ifdef MENU_EXPANDS
		    m->opts[opt].opt_exp_name ?
		    	m->opts[opt].opt_exp_name : m->opts[opt].opt_name
#else
		    m->opts[opt].opt_name
#endif
		    );
	}

	/* Add the exit option. */
	if (!(m->mopt & MC_NOEXITOPT)) {
		if (cury < maxy)
			draw_menu_line(m, m->numopts, cury++, arg, m->exitstr);
		else
			opt = 0;
	}

	/* Add the scroll line */
	if (opt != m->numopts || m->topline != 0)
		mvwaddstr(m->mw, cury, hasbox, scrolltext);

	/* Add the box. */
	if (!(m->mopt & MC_NOBOX))
		box(m->mw, 0, 0);

	wmove(m->mw, tadd + m->cursel - m->topline, hasbox);
	wrefresh(m->mw);
}


static void
/*ARGSUSED*/
process_help(menudesc *m)
{
	const char *help = m->helpstr;
	WINDOW *sv_curscr;
	int lineoff = 0;
	int curoff = 0;
	int again;
	int winin;

	/* Is there help? */
	if (!help) {
		mbeep();
		return;
	}
	sv_curscr = newwin(getmaxy(curscr), getmaxx(curscr), 0, 0);
	if (!sv_curscr) {
		mbeep();
		return;
	}
	/*
	 * Save screen contents so we can restore before returning.
	 * cursrc contains post-doupdate() data, not post-refresh()
	 * data so we must call doupdate to ensure we save the
	 * correct data.  Avoids PR 26660.
	 */
	doupdate();
	overwrite(curscr, sv_curscr);
	touchwin(stdscr);

	help = MSG_XLAT(help);
	/* Display the help information. */
	do {
		if (lineoff < curoff) {
			help = MSG_XLAT(m->helpstr);
			curoff = 0;
		}
		while (*help && curoff < lineoff) {
			if (*help == '\n')
				curoff++;
			help++;
		}

		wclear(stdscr);
		mvwaddstr(stdscr, 0, 0,
			"Help: exit: x,  page up: u <, page down: d >");
		mvwaddstr(stdscr, 2, 0, help);
		wmove(stdscr, 1, 0);
		wrefresh(stdscr);

		do {
			winin = wgetch(stdscr);
			if (winin < KEY_MIN)
				winin = tolower(winin);
			again = 0;
			switch (winin) {
				case '<':
				case 'u':
				case KEY_UP:
				case KEY_LEFT:
				case KEY_PPAGE:
					if (lineoff)
						lineoff -= max_lines - 2;
					else
						again = 1;
					break;
				case '>':
				case 'd':
				case KEY_DOWN:
				case KEY_RIGHT:
				case KEY_NPAGE:
					if (*help)
						lineoff += max_lines - 2;
					else
						again = 1;
					break;
				case 'q':
					break;
				case 'x':
					winin = 'q';
					break;
				default:
					again = 1;
			}
			if (again)
				mbeep();
		} while (again);
	} while (winin != 'q');

	/* Restore the original screen contents */
	touchwin(sv_curscr);
	wnoutrefresh(sv_curscr);
	delwin(sv_curscr);

	/* Some code thinks that wrefresh(stdout) is a good idea... */
	wclear(stdscr);
}

#ifdef MENU_EXPANDS
static void
free_exp_menu_items(menudesc *m)
{
	int i;

	if (m->exp_title != NULL) {
		free(__UNCONST(m->exp_title));
		m->exp_title = NULL;
	}
	for (i = 0; i < m->numopts; i++) {
		if (m->opts[i].opt_exp_name != NULL) {
			free(__UNCONST(m->opts[i].opt_exp_name));
			m->opts[i].opt_exp_name = NULL;
		}
	}
}
#endif

static void
process_req(menudesc *m, void *arg, int req)
{
	int ch;
	int hasexit = (m->mopt & MC_NOEXITOPT ? 0 : 1);

	switch(req) {

	case REQ_EXECUTE:
		return;

	case REQ_NEXT_ITEM:
		ch = m->cursel;
		for (;;) {
			ch++;
			if (ch >= m->numopts + hasexit) {
				mbeep();
				return;
			}
			if (hasexit && ch == m->numopts)
				break;
			if (!(m->opts[ch].opt_flags & OPT_IGNORE))
				break;
		}
		m->cursel = ch;
		if (m->cursel >= m->topline + m->h)
			m->topline = m->cursel - m->h + 1;
		break;

	case REQ_PREV_ITEM:
		ch = m->cursel;
		for (;;) {
			if (ch <= 0) {
				mbeep();
				return;
			}
			ch--;
			if (!(m->opts[ch].opt_flags & OPT_IGNORE))
				break;
		}
		m->cursel = ch;
		if (m->cursel < m->topline)
			m->topline = m->cursel;
		break;

	case REQ_HELP:
		process_help(m);
		break;

	case REQ_REDISPLAY:
		endwin();
		doupdate();
		break;

	case REQ_SCROLLUP:
		if (m->cursel == 0) {
			mbeep();
			return;
		}
		m->topline = MAX(0, m->topline - m->h);
		m->cursel = MAX(0, m->cursel - m->h);
		wclear(m->mw);
		break;

	case REQ_SCROLLDOWN:
		if (m->cursel >= m->numopts + hasexit - 1) {
			mbeep();
			return;
		}
		m->topline = MIN(m->topline + m->h,
				 MAX(m->numopts + hasexit - m->h, 0));
		m->cursel = MIN(m->numopts + hasexit - 1, m->cursel + m->h);
		wclear(m->mw);
		break;

	default:
		ch = req;
		if (ch == 'x' && hasexit) {
			m->cursel = m->numopts;
			break;
		}
		if (m->mopt & MC_NOSHORTCUT) {
			mbeep();
			return;
		}
		if (ch > 'z')
			ch = 255;
		if (ch >= 'a') {
			if (ch > 'x')
				ch--;
			ch = ch - 'a';
		} else
			ch = 25 + ch - 'A';
		if (ch < 0 || ch >= m->numopts) {
			mbeep();
			return;
		}
		if (m->opts[ch].opt_flags & OPT_IGNORE) {
			mbeep();
			return;
		}
		m->cursel = ch;
	}

	draw_menu(m, arg);
}

int
menu_init(void)
{
	int i;

	if (__menu_init)
		return 0;

#ifdef	USER_MENU_INIT
	if (USER_MENU_INIT)
		return 1;
#endif

	if (initscr() == NULL)
		return 1;

	cbreak();
	noecho();

	/* XXX Should be configurable but it almost isn't worth it. */
	if (has_colors()) {
		start_color();
		init_pair(1, COLOR_WHITE, COLOR_BLUE);
		bkgd(COLOR_PAIR(1));
		attrset(COLOR_PAIR(1));
	}

	max_lines = getmaxy(stdscr);
	max_cols = getmaxx(stdscr);
	keypad(stdscr, TRUE);
#ifdef DYNAMIC_MENUS
	num_menus = DYN_INIT_NUM;
	while (num_menus < DYN_MENU_START)
		num_menus *= 2;
	menu_list = malloc(sizeof *menu_list * num_menus);
	if (menu_list == NULL)
		return 2;
	(void)memset(menu_list, 0, sizeof *menu_list * num_menus);
	for (i = 0; i < DYN_MENU_START; i++)
		menu_list[i] = &menu_def[i];
#endif

	__menu_init = 1;
	return 0;
}

void
process_menu(int num, void *arg)
{
	int sel = 0;
	int req;
	menu_ent *opt;

	menudesc *m;

	/* Initialize? */
	if (menu_init()) {
		__menu_initerror();
		return;
	}

	if (num < 0 || num >= num_menus)
		return;
	m = &MENUS(num);
	if (m == NULL)
		return;

	/* Default to select option 0 and display from 0, skip any
	 * disabled options at the top of the menu. */
	m->topline = 0;
	if ((m->mopt & (MC_DFLTEXIT | MC_NOEXITOPT)) == MC_DFLTEXIT) {
		m->cursel = -1;
	} else if (m->opts != NULL) {
		for (m->cursel = 0; m->cursel < m->numopts; m->cursel++)
			if ((m->opts[m->cursel].opt_flags & OPT_IGNORE) == 0)
				break;
	}

	for (;;) {
		if (isendwin())
			/* I'm not sure this is needed with netbsd's curses */
			doupdate();
#ifdef MENU_EXPANDS
		/* Expand the menu items, if needed */
		if (m->expand_act && m->mw == NULL)
			(*m->expand_act)(m, arg);
#endif

		/* Process the display action */
		if (m->post_act)
			(*m->post_act)(m, arg);
		if (m->mw == NULL)
			init_menu(m);
		draw_menu(m, arg);

		while ((req = menucmd(m->mw)) != REQ_EXECUTE)
			process_req(m, arg, req);

		sel = m->cursel;
		if (!(m->mopt & MC_NOCLEAR)) {
			wclear(m->mw);
			if (m->sv_mw)
				overwrite(m->sv_mw, m->mw);
			wnoutrefresh(m->mw);
		}

		/* Process the items */
		if (sel >= m->numopts)
			/* exit option */
			break;

		opt = &m->opts[sel];
		if (opt->opt_flags & OPT_IGNORE)
			continue;
		if (opt->opt_flags & OPT_ENDWIN)
			endwin();
		if (opt->opt_action && (*opt->opt_action)(m, arg))
			break;

		if (opt->opt_menu != -1) {
			if (!(opt->opt_flags & OPT_SUB)) {
				num = opt->opt_menu;
				wclear(m->mw);
				if (m->sv_mw) {
					overwrite(m->sv_mw, m->mw);
					delwin(m->sv_mw);
					m->sv_mw = NULL;
				}
				wnoutrefresh(m->mw);
				delwin(m->mw);
				m->mw = NULL;
				m = &MENUS(num);
				continue;
			}
			process_menu(opt->opt_menu, arg);
		}
		if (opt->opt_flags & OPT_EXIT)
			break;
	}

	if (m->mopt & MC_NOCLEAR) {
		wclear(m->mw);
		if (m->sv_mw)
			overwrite(m->sv_mw, m->mw);
		wnoutrefresh(m->mw);
	}

#ifdef MENU_EXPANDS
	/* Free expanded menu items, if any */
	free_exp_menu_items(m);
#endif

	/* Process the exit action */
	if (m->exit_act)
		(*m->exit_act)(m, arg);
	delwin(m->mw);
	m->mw = NULL;
	if (m->sv_mw) {
		delwin(m->sv_mw);
		m->sv_mw = NULL;
	}
}


void
set_menu_numopts(int menu, int numopts)
{

	MENUS(menu).numopts = numopts;
}

menudesc *
get_menudesc(int menu)
{
	if (menu < 0 || menu >= num_menus)
		return NULL;

	return &MENUS(menu);
}

/* Control L is end of standard routines, remaining only for dynamic. */

/* Beginning of routines for dynamic menus. */

static int
double_menus(void)
{
	menudesc **temp;
	int sz = sizeof *menu_list * num_menus;

	temp  = realloc(menu_list, sz * 2);
	if (temp == NULL)
		return 0;
	(void)memset(temp + num_menus, 0, sz);
	menu_list = temp;
	num_menus *= 2;

	return 1;
}

int
new_menu(const char *title, menu_ent *opts, int numopts,
	int x, int y, int h, int w, int mopt,
	void (*post_act)(menudesc *, void *),
	void (*draw_line)(menudesc *, int, void *),
	void (*exit_act)(menudesc *, void *),
	const char *help, const char *exit_str)
{
	int ix;
	menudesc *m;

	/* Find free menu entry. */
	for (ix = DYN_MENU_START; ; ix++) {
		if (ix >= num_menus && !double_menus())
			return -1;
		m = menu_list[ix];
		if (m == NULL) {
			m = calloc(sizeof *m, 1);
			if (m == NULL)
				return -1;
			menu_list[ix] = m;
			break;
		}
		if (!(m->mopt & MC_VALID))
			break;
	}

	/* Set Entries */
	m->title = title;
#ifdef MENU_EXPANDS
	m->exp_title = NULL;
#endif
	m->opts = opts;
	m->numopts = numopts;
	m->x = x;
	m->y = y;
	m->h = h;
	m->w = w;
	m->mopt = mopt | MC_VALID;
#ifdef MENU_EXPANDS
	m->expand_act = NULL;
#endif
	m->post_act = post_act;
	m->draw_line = draw_line;
	m->exit_act = exit_act;
	m->helpstr  = help;
	m->exitstr  = exit_str ? exit_str : "Exit";

	return ix;
}

void
free_menu(int menu_no)
{
	menudesc *m;

	if (menu_no < 0 || menu_no >= num_menus)
		return;

	m = menu_list[menu_no];
	if (!(m->mopt & MC_VALID))
		return;
	if (m->mw != NULL)
		delwin(m->mw);
	memset(m, 0, sizeof *m);
}