libc/xcurses/wget_wch.c

	wget_wch.c revision 63360950109af2ce85a962ca61f40b8782f11100
/*
 * 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) 1995-1998 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/* LINTLIBRARY */

/*
 * 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: /team/ps/sun_xcurses/archive/local_changes/xcurses/src/lib/"
"libxcurses/src/libc/xcurses/rcs/wget_wch.c 1.7 1998/05/22 17:57:03 "
"cbates 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];

    if (!iqIsEmpty() || (len = wctomb(mb, wc)) < 0)
        return (ERR);

    for (i = 0; i < len; ++i) {
        iqAdd((unsigned char)mb[i]);
    }

    return (OK);
}

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


    /*
     * 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)) == ERR) {
        (void) __m_set_echo(oecho);
        return (ERR);
    }
    if (ch < __KEY_BASE) {
        (void) __m_set_echo(oecho);
        if (oecho) {
            (void) beep();
            return (ERR);
        } else {
            *wcp = ch;
            return (KEY_CODE_YES);
        }
    }

    /*
     * Push the byte back onto the input stream so that
     * it can be processed by __m_wio_get().
     */
    iqPush(ch);

    /*
     * 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)
        iqPush(wio->_mb[--wio->_size]);

    /* Now echo wide character if necessary. */
    if ((__m_screen->_flags & S_ECHO) && *wcp != WEOF) {
        if (*wcp == L'\b') {
            if (w->_curx <= 0) {
                (void) beep();
                return (ch);
            }
            w->_curx--;
            (void) wdelch(w);
        } else {
            (void) __m_wc_cc(*wcp, &cc);
            (void) wadd_wch(w, &cc);
        }
        (void) wrefresh(w);
    }

    return (OK);
}