/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1995, by Sun Microsystems, Inc.
 * All rights reserved.
 */

/*
 * wget_wch.c
 *
 * XCurses Library
 *
 * Copyright 1990, 1995 by Mortice Kern Systems Inc.  All rights reserved.
 *
 */

#ifdef M_RCSID
#ifndef lint
static char rcsID[] = "$Header: /rd/src/libc/xcurses/rcs/wget_wch.c 1.2 1995/06/08 19:00:47 ant Exp $";
#endif
#endif

#include <private.h>
#include <m_wio.h>
#include <stdlib.h>

/*
 * Push a wide character back onto the input queue.
 *
 * XPG4 is silent as to whether wget_wch() and wgetch()
 * can both be used in an applicaton.  Assume they can,
 * in which case we have to push the multibyte equivalent
 * back onto the input queue.
 */
int
unget_wch(const wchar_t wc)
{
        int i, len;
        char mb[MB_LEN_MAX];

#ifdef M_CURSES_TRACE
        __m_trace("unget_wch(%ld)", (long) wc);
#endif

        if (!ISEMPTY() || (len = wctomb(mb, wc)) < 0)
                return __m_return_code("unget_wch", ERR);

        for (i = 0; i < len; ++i)
                PUSH(mb[i]);

        return __m_return_code("unget_wch", OK);
}

int
wget_wch(w, wcp)
WINDOW *w;
wint_t *wcp;
{
        cchar_t cc;
        int ch, oecho;
        t_wide_io *wio;

#ifdef M_CURSES_TRACE
        __m_trace("wget_wch(%p, %p)", w, wcp);
#endif

        /* Disable echo temporarily, because we're using
         * wgetch() to read in individual bytes and only
         * want echo the resulting character, not the
         * individual bytes composing the character.
         */
        oecho = __m_set_echo(0);

        /* Input function is wgetch(), which takes a WINDOW * for
         * a parameter.  The WINDOW * is used to set the "focus" by
         * updatng and position the cursor in the relevant window and
         * provide window specific settings.  Input for all windows
         * comes from one stream (__m_screen->_if), which is normally
         * the terminal, but can be redirected.
         */
        wio = (t_wide_io *) __m_screen->_in;
        wio->object = w;

        /* Get the first byte or KEY_ value. */
        if ((ch = wgetch(w)) < __KEY_BASE) {
                *wcp = ch;
                (void) __m_set_echo(oecho);
                return __m_return_code("wget_wch", KEY_CODE_YES);
        }

        /* Push the byte back onto the input stream so that
         * it can be processed by __m_wio_get().
         */
        (void) ungetc(ch, __m_screen->_if);

        /* Fetch a wide character from a narrow input stream.
         * Invalid sequences are preserved as individual bytes.
         * Handles insignificant and redundant shifts in the input
         * stream.
         */
        *wcp = m_wio_get(wio);

        /* Restore echo. */
        (void) __m_set_echo(oecho);

        /* Push any invalid multibyte sequence back onto the
         * input stack, so that no data is lost, just in case
         * the application mixes wide (wget_wch()) and narrow
         * (wgetch()) input methods.
         */
        while (wio->_next < wio->_size)
                PUSH(wio->_mb[--wio->_size]);

        /* Now echo wide character if necessary. */
        if ((__m_screen->_flags & S_ECHO) && *wcp != WEOF) {
                (void) __m_wc_cc(*wcp, &cc);
                (void) wadd_wch(w, &cc);
                (void) wrefresh(w);
        }

        return __m_return_code("wget_wch", OK);
}