libc/xcurses/wget_wch.c

	wget_wch.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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.
 */

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

/*
 * 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 relavent 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);
}