/*** $Id: vtswitch-lite.c,v 1.9 2003/09/04 03:38:26 weiym Exp $**** vtswitch-lite.c: VT switching.**** Copyright (C) 2003 Feynman Software.** Copyright (C) 2001 ~ 2002 Song Lixin and Wei Yongming**** Created by Song Lixin, 2000/10/17** Clean code for MiniGUI 1.1.x by Wei Yongming, 20001/11/28*//*** 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/#include <stdio.h>#include <unistd.h>#include <fcntl.h>#include <signal.h>#include <sys/ioctl.h>#include <sys/time.h>#include <linux/vt.h>#include "common.h"#include "minigui.h"#ifdef _LITE_VERSION#include "gdi.h"#include "window.h"#include "cliprect.h"#include "gal.h"#include "internals.h"#include "ctrlclass.h"#include "dc.h"#include "ial.h"#include "native.h"static int vtswitch_initialised = 0;static struct vt_mode startup_vtmode;volatile static int console_active = 1;            /* are we active? */volatile static int console_should_be_active = 1;  /* should we be? */static int ttyfd = -1;static int current_vt;static void vt_switch_requested(int signo);static void poll_console_switch (void);static void come_back(void);static void go_away(void);int init_vtswitch (int kbd_fd) {    struct sigaction sa;    struct vt_mode vtm;    struct vt_stat stat;    if (vtswitch_initialised)        return 0;  /* shouldn't happen */    if (kbd_fd >= 0)        ttyfd = kbd_fd;    else {        ttyfd = open("/dev/tty0", O_RDONLY);        if (ttyfd == -1) {            fprintf (stderr, "Error can't open tty: %m.\n");            return -1;        }    }    ioctl (ttyfd, VT_GETSTATE, &stat);    current_vt = stat.v_active;    console_active = console_should_be_active = 1;    /* Hook the signals */    sigemptyset(&sa.sa_mask);    sigaddset(&sa.sa_mask, SIGIO); /* block async IO during the VT switch */    sa.sa_flags = 0;    sa.sa_handler = vt_switch_requested;    if ((sigaction(SIGRELVT, &sa, NULL) < 0) || (sigaction(SIGACQVT, &sa, NULL) < 0)) {        fprintf (stderr, "init_vtswitch: Unable to control VT switch.\n");        return -1;    }    /* Save old mode, take control, and arrange for the signals     * to be raised. */    ioctl(ttyfd, VT_GETMODE, &startup_vtmode);    vtm = startup_vtmode;    vtm.mode = VT_PROCESS;    vtm.relsig = SIGRELVT;    vtm.acqsig = SIGACQVT;    ioctl(ttyfd, VT_SETMODE, &vtm);    vtswitch_initialised = 1;    return 0;}/* vt_switch_requested: *  This is our signal handler; it gets called whenever a switch is *  requested, because either SIGRELVT or SIGACQVT is raised. */static void vt_switch_requested(int signo){    switch (signo) {        case SIGRELVT:            console_should_be_active = 0;            break;        case SIGACQVT:            console_should_be_active = 1;            break;        default:            return;    }    poll_console_switch();}/* poll_console_switch: *  Checks whether a switch is needed and not blocked; if so, *  makes the switch. */static void poll_console_switch (void){    if (console_active == console_should_be_active) return;    if (console_should_be_active)        come_back();    else        go_away();}/* come_back: *  Performs a switch back. */static void come_back (void){    int new_fd;    IAL_ResumeMouse();    if ((new_fd = IAL_ResumeKeyboard()) >= 0)        ttyfd = new_fd;    ioctl (ttyfd, VT_RELDISP, VT_ACKACQ);    console_active = 1;    __mg_switch_away = FALSE;    SendNotifyMessage (HWND_DESKTOP, MSG_PAINT, 0, 0);#ifndef _STAND_ALONE    ClientCanDrawNowEx (TRUE, NULL);#endif}/* go_away: *  Performs a switch away. */static void go_away (void){#ifndef _STAND_ALONE    OnlyMeCanDraw ();#endif    if (ioctl (ttyfd, VT_RELDISP, 1) == -1) {        fprintf (stderr, "Error can't switch away from VT: %m\n");        return;    }    console_active = 0;    __mg_switch_away = TRUE;    IAL_SuspendKeyboard();    IAL_SuspendMouse();}/*  done_vtswitch: *  Undoes the effect of `init_vtswitch'. */int done_vtswitch (int kbd_fd){    struct sigaction sa;    if (!vtswitch_initialised) return 0;  /* shouldn't really happen either */    /* !trout gfoot.  Must turn off the signals before unhooking them... */    ioctl (ttyfd, VT_SETMODE, &startup_vtmode);    sigemptyset (&sa.sa_mask);    sa.sa_handler = SIG_DFL;    sa.sa_flags = SA_RESTART;    sigaction (SIGRELVT, &sa, NULL);    sigaction (SIGACQVT, &sa, NULL);    vtswitch_initialised = 0;    if (ttyfd != kbd_fd)        close (ttyfd);    return 0;}int vtswitch_try(int vt) {    if (!vtswitch_initialised)        return 1;    if(vt == current_vt)         return 1;        ioctl(ttyfd, VT_ACTIVATE, vt);    return 0;}#endif /* _LITE_VERSION */