text: /****************************************************************************
   * Copyright (c) 1998-2007,2008 Free Software Foundation, Inc.              *
   *                                                                          *
   * Permission is hereby granted, free of charge, to any person obtaining a  *
   * copy of this software and associated documentation files (the            *
   * "Software"), to deal in the Software without restriction, including      *
   * without limitation the rights to use, copy, modify, merge, publish,      *
   * distribute, distribute with modifications, sublicense, and/or sell       *
   * copies of the Software, and to permit persons to whom the Software is    *
   * furnished to do so, subject to the following conditions:                 *
   *                                                                          *
   * The above copyright notice and this permission notice shall be included  *
   * in all copies or substantial portions of the Software.                   *
   *                                                                          *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
   * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
   * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
   * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
   * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
   *                                                                          *
   * Except as contained in this notice, the name(s) of the above copyright   *
   * holders shall not be used in advertising or otherwise to promote the     *
   * sale, use or other dealings in this Software without prior written       *
   * authorization.                                                           *
   ****************************************************************************/
  
  /****************************************************************************
   *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
   *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
   *     and: Thomas E. Dickey                        1996-on                 *
   ****************************************************************************/
  
  /*
   * This module is intended to encapsulate ncurses's interface to pointing
   * devices.
   *
   * The primary method used is xterm's internal mouse-tracking facility.
   * Additional methods depend on the platform:
   *	Alessandro Rubini's GPM server (Linux)
   *	sysmouse (FreeBSD)
   *	special-purpose mouse interface for OS/2 EMX.
   *
   * Notes for implementors of new mouse-interface methods:
   *
   * The code is logically split into a lower level that accepts event reports
   * in a device-dependent format and an upper level that parses mouse gestures
   * and filters events.  The mediating data structure is a circular queue of
   * MEVENT structures.
   *
   * Functionally, the lower level's job is to pick up primitive events and
   * put them on the circular queue.  This can happen in one of two ways:
   * either (a) _nc_mouse_event() detects a series of incoming mouse reports
   * and queues them, or (b) code in lib_getch.c detects the kmous prefix in
   * the keyboard input stream and calls _nc_mouse_inline to queue up a series
   * of adjacent mouse reports.
   *
   * In either case, _nc_mouse_parse() should be called after the series is
   * accepted to parse the digested mouse reports (low-level MEVENTs) into
   * a gesture (a high-level or composite MEVENT).
   *
   * Don't be too shy about adding new event types or modifiers, if you can find
   * room for them in the 32-bit mask.  The API is written so that users get
   * feedback on which theoretical event types they won't see when they call
   * mousemask. There's one bit per button (the RESERVED_EVENT bit) not being
   * used yet, and a couple of bits open at the high end.
   */
  
  #ifdef __EMX__
  #  include <io.h>
  #  define  INCL_DOS
  #  define  INCL_VIO
  #  define  INCL_KBD
  #  define  INCL_MOU
  #  define  INCL_DOSPROCESS
  #  include <os2.h>		/* Need to include before the others */
  #endif
  
  #include <curses.priv.h>
  
  MODULE_ID("$Id: lib_mouse.c,v 1.104 2008/11/30 01:37:27 tom Exp $")
  
  #include <term.h>
  #include <tic.h>
  
  #if USE_GPM_SUPPORT
  #include <linux/keyboard.h>	/* defines KG_* macros */
  
  #ifdef HAVE_LIBDL
  /* use dynamic loader to avoid linkage dependency */
  #include <dlfcn.h>
  
  #ifdef RTLD_NOW
  #define my_RTLD RTLD_NOW
  #else
  #ifdef RTLD_LAZY
  #define my_RTLD RTLD_LAZY
  #else
  make an error
  #endif
  #endif				/* RTLD_NOW */
  #endif				/* HAVE_LIBDL */
  
  #endif				/* USE_GPM_SUPPORT */
  
  #if USE_SYSMOUSE
  #undef buttons			/* symbol conflict in consio.h */
  #undef mouse_info		/* symbol conflict in consio.h */
  #include <osreldate.h>
  #if (__FreeBSD_version >= 400017)
  #include <sys/consio.h>
  #include <sys/fbio.h>
  #else
  #include <machine/console.h>
  #endif
  #endif				/* use_SYSMOUSE */
  
  #define MY_TRACE TRACE_ICALLS|TRACE_IEVENT
  
  #define	MASK_RELEASE(x)		NCURSES_MOUSE_MASK(x, 001)
  #define	MASK_PRESS(x)		NCURSES_MOUSE_MASK(x, 002)
  #define	MASK_CLICK(x)		NCURSES_MOUSE_MASK(x, 004)
  #define	MASK_DOUBLE_CLICK(x)	NCURSES_MOUSE_MASK(x, 010)
  #define	MASK_TRIPLE_CLICK(x)	NCURSES_MOUSE_MASK(x, 020)
  #define	MASK_RESERVED_EVENT(x)	NCURSES_MOUSE_MASK(x, 040)
  
  #if NCURSES_MOUSE_VERSION == 1
  #define BUTTON_CLICKED        (BUTTON1_CLICKED        | BUTTON2_CLICKED        | BUTTON3_CLICKED        | BUTTON4_CLICKED)
  #define BUTTON_PRESSED        (BUTTON1_PRESSED        | BUTTON2_PRESSED        | BUTTON3_PRESSED        | BUTTON4_PRESSED)
  #define BUTTON_RELEASED       (BUTTON1_RELEASED       | BUTTON2_RELEASED       | BUTTON3_RELEASED       | BUTTON4_RELEASED)
  #define BUTTON_DOUBLE_CLICKED (BUTTON1_DOUBLE_CLICKED | BUTTON2_DOUBLE_CLICKED | BUTTON3_DOUBLE_CLICKED | BUTTON4_DOUBLE_CLICKED)
  #define BUTTON_TRIPLE_CLICKED (BUTTON1_TRIPLE_CLICKED | BUTTON2_TRIPLE_CLICKED | BUTTON3_TRIPLE_CLICKED | BUTTON4_TRIPLE_CLICKED)
  #define MAX_BUTTONS  4
  #else
  #define BUTTON_CLICKED        (BUTTON1_CLICKED        | BUTTON2_CLICKED        | BUTTON3_CLICKED        | BUTTON4_CLICKED        | BUTTON5_CLICKED)
  #define BUTTON_PRESSED        (BUTTON1_PRESSED        | BUTTON2_PRESSED        | BUTTON3_PRESSED        | BUTTON4_PRESSED        | BUTTON5_PRESSED)
  #define BUTTON_RELEASED       (BUTTON1_RELEASED       | BUTTON2_RELEASED       | BUTTON3_RELEASED       | BUTTON4_RELEASED       | BUTTON5_RELEASED)
  #define BUTTON_DOUBLE_CLICKED (BUTTON1_DOUBLE_CLICKED | BUTTON2_DOUBLE_CLICKED | BUTTON3_DOUBLE_CLICKED | BUTTON4_DOUBLE_CLICKED | BUTTON5_DOUBLE_CLICKED)
  #define BUTTON_TRIPLE_CLICKED (BUTTON1_TRIPLE_CLICKED | BUTTON2_TRIPLE_CLICKED | BUTTON3_TRIPLE_CLICKED | BUTTON4_TRIPLE_CLICKED | BUTTON5_TRIPLE_CLICKED)
  #define MAX_BUTTONS  5
  #endif
  
  #define INVALID_EVENT	-1
  #define NORMAL_EVENT	0
  
  #if USE_GPM_SUPPORT
  
  #ifndef LIBGPM_SONAME
  #define LIBGPM_SONAME "libgpm.so"
  #endif
  
  #define GET_DLSYM(name) (my_##name = (TYPE_##name) dlsym(SP->_dlopen_gpm, #name))
  
  #endif				/* USE_GPM_SUPPORT */
  
  static bool _nc_mouse_parse(SCREEN *, int);
  static void _nc_mouse_resume(SCREEN *);
  static void _nc_mouse_wrap(SCREEN *);
  
  /* maintain a circular list of mouse events */
  
  #define FirstEV(sp)	((sp)->_mouse_events)
  #define LastEV(sp)	((sp)->_mouse_events + EV_MAX - 1)
  
  #undef  NEXT
  #define NEXT(ep)	((ep >= LastEV(sp)) \
  			 ? FirstEV(sp) \
  			 : ep + 1)
  
  #undef  PREV
  #define PREV(ep)	((ep <= FirstEV(sp)) \
  			 ? LastEV(sp) \
  			 : ep - 1)
  
  #define IndexEV(sp, ep)	(ep - FirstEV(sp))
  
  #define RunParams(sp, eventp, runp) \
  		(long) IndexEV(sp, runp), \
  		(long) (IndexEV(sp, eventp) + (EV_MAX - 1)) % EV_MAX
  
  #ifdef TRACE
  static void
  _trace_slot(SCREEN *sp, const char *tag)
  {
      MEVENT *ep;
  
      _tracef(tag);
  
      for (ep = FirstEV(sp); ep <= LastEV(sp); ep++)
  	_tracef("mouse event queue slot %ld = %s",
  		(long) IndexEV(sp, ep),
  		_nc_tracemouse(sp, ep));
  }
  #endif
  
  #if USE_EMX_MOUSE
  
  #  define TOP_ROW          0
  #  define LEFT_COL         0
  
  #  define M_FD(sp) sp->_mouse_fd
  
  static void
  write_event(SCREEN *sp, int down, int button, int x, int y)
  {
      char buf[6];
      unsigned long ignore;
  
      strncpy(buf, key_mouse, 3);	/* should be "\033[M" */
      buf[3] = ' ' + (button - 1) + (down ? 0 : 0x40);
      buf[4] = ' ' + x - LEFT_COL + 1;
      buf[5] = ' ' + y - TOP_ROW + 1;
      DosWrite(sp->_emxmouse_wfd, buf, 6, &ignore);
  }
  
  static void
  mouse_server(unsigned long param)
  {
      SCREEN *sp = (SCREEN *) param;
      unsigned short fWait = MOU_WAIT;
      /* NOPTRRECT mourt = { 0,0,24,79 }; */
      MOUEVENTINFO mouev;
      HMOU hmou;
      unsigned short mask = MOUSE_BN1_DOWN | MOUSE_BN2_DOWN | MOUSE_BN3_DOWN;
      int nbuttons = 3;
      int oldstate = 0;
      char err[80];
      unsigned long rc;
  
      /* open the handle for the mouse */
      if (MouOpen(NULL, &hmou) == 0) {
  	rc = MouSetEventMask(&mask, hmou);
  	if (rc) {		/* retry with 2 buttons */
  	    mask = MOUSE_BN1_DOWN | MOUSE_BN2_DOWN;
  	    rc = MouSetEventMask(&mask, hmou);
  	    nbuttons = 2;
  	}
  	if (rc == 0 && MouDrawPtr(hmou) == 0) {
  	    for (;;) {
  		/* sit and wait on the event queue */
  		rc = MouReadEventQue(&mouev, &fWait, hmou);
  		if (rc) {
  		    sprintf(err, "Error reading mouse queue, rc=%lu.\r\n", rc);
  		    break;
  		}
  		if (!sp->_emxmouse_activated)
  		    goto finish;
  
  		/*
  		 * OS/2 numbers a 3-button mouse inconsistently from other
  		 * platforms:
  		 *      1 = left
  		 *      2 = right
  		 *      3 = middle.
  		 */
  		if ((mouev.fs ^ oldstate) & MOUSE_BN1_DOWN)
  		    write_event(sp, mouev.fs & MOUSE_BN1_DOWN,
  				sp->_emxmouse_buttons[1], mouev.col, mouev.row);
  		if ((mouev.fs ^ oldstate) & MOUSE_BN2_DOWN)
  		    write_event(sp, mouev.fs & MOUSE_BN2_DOWN,
  				sp->_emxmouse_buttons[3], mouev.col, mouev.row);
  		if ((mouev.fs ^ oldstate) & MOUSE_BN3_DOWN)
  		    write_event(sp, mouev.fs & MOUSE_BN3_DOWN,
  				sp->_emxmouse_buttons[2], mouev.col, mouev.row);
  
  	      finish:
  		oldstate = mouev.fs;
  	    }
  	} else
  	    sprintf(err, "Error setting event mask, buttons=%d, rc=%lu.\r\n",
  		    nbuttons, rc);
  
  	DosWrite(2, err, strlen(err), &rc);
  	MouClose(hmou);
      }
      DosExit(EXIT_THREAD, 0L);
  }
  
  #endif /* USE_EMX_MOUSE */
  
  #if USE_SYSMOUSE
  static void
  sysmouse_server(SCREEN *sp)
  {
      struct mouse_info the_mouse;
      MEVENT *work;
  
      the_mouse.operation = MOUSE_GETINFO;
      if (sp != 0
  	&& sp->_mouse_fd >= 0
  	&& sp->_sysmouse_tail < FIFO_SIZE
  	&& ioctl(sp->_mouse_fd, CONS_MOUSECTL, &the_mouse) != -1) {
  
  	if (sp->_sysmouse_head > sp->_sysmouse_tail) {
  	    sp->_sysmouse_tail = 0;
  	    sp->_sysmouse_head = 0;
  	}
  	work = &(sp->_sysmouse_fifo[sp->_sysmouse_tail]);
  	memset(work, 0, sizeof(*work));
  	work->id = NORMAL_EVENT;	/* there's only one mouse... */
  
  	sp->_sysmouse_old_buttons = sp->_sysmouse_new_buttons;
  	sp->_sysmouse_new_buttons = the_mouse.u.data.buttons & 0x7;
  
  	if (sp->_sysmouse_new_buttons) {
  	    if (sp->_sysmouse_new_buttons & 1)
  		work->bstate |= BUTTON1_PRESSED;
  	    if (sp->_sysmouse_new_buttons & 2)
  		work->bstate |= BUTTON2_PRESSED;
  	    if (sp->_sysmouse_new_buttons & 4)
  		work->bstate |= BUTTON3_PRESSED;
  	} else {
  	    if (sp->_sysmouse_old_buttons & 1)
  		work->bstate |= BUTTON1_RELEASED;
  	    if (sp->_sysmouse_old_buttons & 2)
  		work->bstate |= BUTTON2_RELEASED;
  	    if (sp->_sysmouse_old_buttons & 4)
  		work->bstate |= BUTTON3_RELEASED;
  	}
  
  	/* for cosmetic bug in syscons.c on FreeBSD 3.[34] */
  	the_mouse.operation = MOUSE_HIDE;
  	ioctl(sp->_mouse_fd, CONS_MOUSECTL, &the_mouse);
  	the_mouse.operation = MOUSE_SHOW;
  	ioctl(sp->_mouse_fd, CONS_MOUSECTL, &the_mouse);
  
  	/*
  	 * We're only interested if the button is pressed or released.
  	 * FIXME: implement continuous event-tracking.
  	 */
  	if (sp->_sysmouse_new_buttons != sp->_sysmouse_old_buttons) {
  	    sp->_sysmouse_tail += 1;
  	}
  	work->x = the_mouse.u.data.x / sp->_sysmouse_char_width;
  	work->y = the_mouse.u.data.y / sp->_sysmouse_char_height;
      }
  }
  
  static void
  handle_sysmouse(int sig GCC_UNUSED)
  {
      sysmouse_server(SP);
  }
  #endif /* USE_SYSMOUSE */
  
  static void
  init_xterm_mouse(SCREEN *sp)
  {
      sp->_mouse_type = M_XTERM;
      sp->_mouse_xtermcap = tigetstr("XM");
      if (!VALID_STRING(sp->_mouse_xtermcap))
  	sp->_mouse_xtermcap = "\033[?1000%?%p1%{1}%=%th%el%;";
  }
  
  static void
  enable_xterm_mouse(SCREEN *sp, int enable)
  {
  #if USE_EMX_MOUSE
      sp->_emxmouse_activated = enable;
  #else
      putp(TPARM_1(sp->_mouse_xtermcap, enable));
  #endif
      sp->_mouse_active = enable;
  }
  
  #if USE_GPM_SUPPORT
  static bool
  allow_gpm_mouse(void)
  {
      bool result = FALSE;
  
      /* GPM does printf's without checking if stdout is a terminal */
      if (isatty(fileno(stdout))) {
  	char *list = getenv("NCURSES_GPM_TERMS");
  	char *env = getenv("TERM");
  	if (list != 0) {
  	    if (env != 0) {
  		result = _nc_name_match(list, env, "|:");
  	    }
  	} else {
  	    /* GPM checks the beginning of the $TERM variable to decide if it
  	     * should pass xterm events through.  There is no real advantage in
  	     * allowing GPM to do this.  Recent versions relax that check, and
  	     * pretend that GPM can work with any terminal having the kmous
  	     * capability.  Perhaps that works for someone.  If so, they can
  	     * set the environment variable (above).
  	     */
  	    if (env != 0 && strstr(env, "linux") != 0) {
  		result = TRUE;
  	    }
  	}
      }
      return result;
  }
  
  #ifdef HAVE_LIBDL
  static void
  unload_gpm_library(SCREEN *sp)
  {
      if (SP->_dlopen_gpm != 0) {
  	T(("unload GPM library"));
  	sp->_mouse_gpm_loaded = FALSE;
  	sp->_mouse_fd = -1;
  	dlclose(sp->_dlopen_gpm);
  	sp->_dlopen_gpm = 0;
      }
  }
  
  static void
  load_gpm_library(SCREEN *sp)
  {
      sp->_mouse_gpm_found = FALSE;
      if ((sp->_dlopen_gpm = dlopen(LIBGPM_SONAME, my_RTLD)) != 0) {
  	if (GET_DLSYM(gpm_fd) == 0 ||
  	    GET_DLSYM(Gpm_Open) == 0 ||
  	    GET_DLSYM(Gpm_Close) == 0 ||
  	    GET_DLSYM(Gpm_GetEvent) == 0) {
  	    T(("GPM initialization failed: %s", dlerror()));
  	    unload_gpm_library(sp);
  	} else {
  	    sp->_mouse_gpm_found = TRUE;
  	    sp->_mouse_gpm_loaded = TRUE;
  	}
      }
  }
  #endif
  
  static bool
  enable_gpm_mouse(SCREEN *sp, bool enable)
  {
      bool result;
  
      T((T_CALLED("enable_gpm_mouse(%d)"), enable));
  
      if (enable && !sp->_mouse_active) {
  #ifdef HAVE_LIBDL
  	if (sp->_mouse_gpm_found && !sp->_mouse_gpm_loaded) {
  	    load_gpm_library(sp);
  	}
  #endif
  	if (sp->_mouse_gpm_loaded) {
  	    /* GPM: initialize connection to gpm server */
  	    sp->_mouse_gpm_connect.eventMask = GPM_DOWN | GPM_UP;
  	    sp->_mouse_gpm_connect.defaultMask =
  		(unsigned short) (~(sp->_mouse_gpm_connect.eventMask | GPM_HARD));
  	    sp->_mouse_gpm_connect.minMod = 0;
  	    sp->_mouse_gpm_connect.maxMod =
  		(unsigned short) (~((1 << KG_SHIFT) |
  				    (1 << KG_SHIFTL) |
  				    (1 << KG_SHIFTR)));
  	    /*
  	     * Note: GPM hardcodes \E[?1001s and \E[?1000h during its open.
  	     * The former is recognized by wscons (SunOS), and the latter by
  	     * xterm.  Those will not show up in ncurses' traces.
  	     */
  	    result = (my_Gpm_Open(&sp->_mouse_gpm_connect, 0) >= 0);
  	} else {
  	    result = FALSE;
  	}
  	sp->_mouse_active = result;
  	T(("GPM open %s", result ? "succeeded" : "failed"));
      } else {
  	if (!enable && sp->_mouse_active) {
  	    /* GPM: close connection to gpm server */
  	    my_Gpm_Close();
  	    sp->_mouse_active = FALSE;
  	    T(("GPM closed"));
  	}
  	result = enable;
      }
  #ifdef HAVE_LIBDL
      if (!result) {
  	unload_gpm_library(sp);
      }
  #endif
      returnBool(result);
  }
  #endif /* USE_GPM_SUPPORT */
  
  #define xterm_kmous "\033[M"
  
  static void
  initialize_mousetype(SCREEN *sp)
  {
      T((T_CALLED("initialize_mousetype()")));
  
      /* Try gpm first, because gpm may be configured to run in xterm */
  #if USE_GPM_SUPPORT
      if (allow_gpm_mouse()) {
  	if (!sp->_mouse_gpm_loaded) {
  #ifdef HAVE_LIBDL
  	    load_gpm_library(sp);
  #else /* !HAVE_LIBDL */
  	    sp->_mouse_gpm_found = TRUE;
  	    sp->_mouse_gpm_loaded = TRUE;
  #endif
  	}
  
  	/*
  	 * The gpm_fd file-descriptor may be negative (xterm).  So we have to
  	 * maintain our notion of whether the mouse connection is active
  	 * without testing the file-descriptor.
  	 */
  	if (sp->_mouse_gpm_found && enable_gpm_mouse(sp, TRUE)) {
  	    sp->_mouse_type = M_GPM;
  	    sp->_mouse_fd = *(my_gpm_fd);
  	    T(("GPM mouse_fd %d", sp->_mouse_fd));
  	    returnVoid;
  	}
      }
  #endif /* USE_GPM_SUPPORT */
  
      /* OS/2 VIO */
  #if USE_EMX_MOUSE
      if (!sp->_emxmouse_thread
  	&& strstr(cur_term->type.term_names, "xterm") == 0
  	&& key_mouse) {
  	int handles[2];
  
  	if (pipe(handles) < 0) {
  	    perror("mouse pipe error");
  	    returnVoid;
  	} else {
  	    int rc;
  
  	    if (!sp->_emxmouse_buttons[0]) {
  		char *s = getenv("MOUSE_BUTTONS_123");
  
  		sp->_emxmouse_buttons[0] = 1;
  		if (s && strlen(s) >= 3) {
  		    sp->_emxmouse_buttons[1] = s[0] - '0';
  		    sp->_emxmouse_buttons[2] = s[1] - '0';
  		    sp->_emxmouse_buttons[3] = s[2] - '0';
  		} else {
  		    sp->_emxmouse_buttons[1] = 1;
  		    sp->_emxmouse_buttons[2] = 3;
  		    sp->_emxmouse_buttons[3] = 2;
  		}
  	    }
  	    sp->_emxmouse_wfd = handles[1];
  	    M_FD(sp) = handles[0];
  	    /* Needed? */
  	    setmode(handles[0], O_BINARY);
  	    setmode(handles[1], O_BINARY);
  	    /* Do not use CRT functions, we may single-threaded. */
  	    rc = DosCreateThread((unsigned long *) &sp->_emxmouse_thread,
  				 mouse_server, (long) sp, 0, 8192);
  	    if (rc) {
  		printf("mouse thread error %d=%#x", rc, rc);
  	    } else {
  		sp->_mouse_type = M_XTERM;
  	    }
  	    returnVoid;
  	}
      }
  #endif /* USE_EMX_MOUSE */
  
  #if USE_SYSMOUSE
      {
  	struct mouse_info the_mouse;
  	char *the_device = 0;
  
  	if (isatty(sp->_ifd))
  	    the_device = ttyname(sp->_ifd);
  	if (the_device == 0)
  	    the_device = "/dev/tty";
  
  	sp->_mouse_fd = open(the_device, O_RDWR);
  
  	if (sp->_mouse_fd >= 0) {
  	    /*
  	     * sysmouse does not have a usable user interface for obtaining
  	     * mouse events.  The logical way to proceed (reading data on a
  	     * stream) only works if one opens the device as root.  Even in
  	     * that mode, careful examination shows we lose events
  	     * occasionally.  The interface provided for user programs is to
  	     * establish a signal handler.  really.
  	     *
  	     * Take over SIGUSR2 for this purpose since SIGUSR1 is more
  	     * likely to be used by an application.  getch() will have to
  	     * handle the misleading EINTR's.
  	     */
  	    signal(SIGUSR2, SIG_IGN);
  	    the_mouse.operation = MOUSE_MODE;
  	    the_mouse.u.mode.mode = 0;
  	    the_mouse.u.mode.signal = SIGUSR2;
  	    if (ioctl(sp->_mouse_fd, CONS_MOUSECTL, &the_mouse) != -1) {
  		signal(SIGUSR2, handle_sysmouse);
  		the_mouse.operation = MOUSE_SHOW;
  		ioctl(sp->_mouse_fd, CONS_MOUSECTL, &the_mouse);
  
  #if defined(FBIO_MODEINFO) || defined(CONS_MODEINFO)	/* FreeBSD > 2.x */
  		{
  #ifndef FBIO_GETMODE		/* FreeBSD 3.x */
  #define FBIO_GETMODE    CONS_GET
  #define FBIO_MODEINFO   CONS_MODEINFO
  #endif /* FBIO_GETMODE */
  		    video_info_t the_video;
  
  		    if (ioctl(sp->_mouse_fd,
  			      FBIO_GETMODE,
  			      &the_video.vi_mode) != -1
  			&& ioctl(sp->_mouse_fd,
  				 FBIO_MODEINFO,
  				 &the_video) != -1) {
  			sp->_sysmouse_char_width = the_video.vi_cwidth;
  			sp->_sysmouse_char_height = the_video.vi_cheight;
  		    }
  		}
  #endif /* defined(FBIO_MODEINFO) || defined(CONS_MODEINFO) */
  
  		if (sp->_sysmouse_char_width <= 0)
  		    sp->_sysmouse_char_width = 8;
  		if (sp->_sysmouse_char_height <= 0)
  		    sp->_sysmouse_char_height = 16;
  		sp->_mouse_type = M_SYSMOUSE;
  		returnVoid;
  	    }
  	}
      }
  #endif /* USE_SYSMOUSE */
  
      /* we know how to recognize mouse events under "xterm" */
      if (key_mouse != 0) {
  	if (!strcmp(key_mouse, xterm_kmous)
  	    || strstr(cur_term->type.term_names, "xterm") != 0) {
  	    init_xterm_mouse(sp);
  	}
      } else if (strstr(cur_term->type.term_names, "xterm") != 0) {
  	if (_nc_add_to_try(&(sp->_keytry), xterm_kmous, KEY_MOUSE) == OK)
  	    init_xterm_mouse(sp);
      }
      returnVoid;
  }
  
  static bool
  _nc_mouse_init(SCREEN *sp)
  /* initialize the mouse */
  {
      bool result = FALSE;
      int i;
  
      if (sp != 0) {
  	if (!sp->_mouse_initialized) {
  	    sp->_mouse_initialized = TRUE;
  
  	    TR(MY_TRACE, ("_nc_mouse_init() called"));
  
  	    sp->_mouse_eventp = FirstEV(sp);
  	    for (i = 0; i < EV_MAX; i++)
  		sp->_mouse_events[i].id = INVALID_EVENT;
  
  	    initialize_mousetype(sp);
  
  	    T(("_nc_mouse_init() set mousetype to %d", sp->_mouse_type));
  	}
  	result = sp->_mouse_initialized;
      }
      return result;
  }
  
  /*
   * Query to see if there is a pending mouse event.  This is called from
   * fifo_push() in lib_getch.c
   */
  static bool
  _nc_mouse_event(SCREEN *sp GCC_UNUSED)
  {
      MEVENT *eventp = sp->_mouse_eventp;
      bool result = FALSE;
  
      (void) eventp;
  
      switch (sp->_mouse_type) {
      case M_XTERM:
  	/* xterm: never have to query, mouse events are in the keyboard stream */
  #if USE_EMX_MOUSE
  	{
  	    char kbuf[3];
  
  	    int i, res = read(M_FD(sp), &kbuf, 3);	/* Eat the prefix */
  	    if (res != 3)
  		printf("Got %d chars instead of 3 for prefix.\n", res);
  	    for (i = 0; i < res; i++) {
  		if (kbuf[i] != key_mouse[i])
  		    printf("Got char %d instead of %d for prefix.\n",
  			   (int) kbuf[i], (int) key_mouse[i]);
  	    }
  	    result = TRUE;
  	}
  #endif /* USE_EMX_MOUSE */
  	break;
  
  #if USE_GPM_SUPPORT
      case M_GPM:
  	if (sp->_mouse_fd >= 0) {
  	    /* query server for event, return TRUE if we find one */
  	    Gpm_Event ev;
  
  	    switch (my_Gpm_GetEvent(&ev)) {
  	    case 0:
  		/* Connection closed, drop the mouse. */
  		sp->_mouse_fd = -1;
  		break;
  	    case 1:
  		/* there's only one mouse... */
  		eventp->id = NORMAL_EVENT;
  
  		eventp->bstate = 0;
  		switch (ev.type & 0x0f) {
  		case (GPM_DOWN):
  		    if (ev.buttons & GPM_B_LEFT)
  			eventp->bstate |= BUTTON1_PRESSED;
  		    if (ev.buttons & GPM_B_MIDDLE)
  			eventp->bstate |= BUTTON2_PRESSED;
  		    if (ev.buttons & GPM_B_RIGHT)
  			eventp->bstate |= BUTTON3_PRESSED;
  		    break;
  		case (GPM_UP):
  		    if (ev.buttons & GPM_B_LEFT)
  			eventp->bstate |= BUTTON1_RELEASED;
  		    if (ev.buttons & GPM_B_MIDDLE)
  			eventp->bstate |= BUTTON2_RELEASED;
  		    if (ev.buttons & GPM_B_RIGHT)
  			eventp->bstate |= BUTTON3_RELEASED;
  		    break;
  		default:
  		    break;
  		}
  
  		eventp->x = ev.x - 1;
  		eventp->y = ev.y - 1;
  		eventp->z = 0;
  
  		/* bump the next-free pointer into the circular list */
  		sp->_mouse_eventp = eventp = NEXT(eventp);
  		result = TRUE;
  		break;
  	    }
  	}
  	break;
  #endif
  
  #if USE_SYSMOUSE
      case M_SYSMOUSE:
  	if (sp->_sysmouse_head < sp->_sysmouse_tail) {
  	    *eventp = sp->_sysmouse_fifo[sp->_sysmouse_head];
  
  	    /*
  	     * Point the fifo-head to the next possible location.  If there
  	     * are none, reset the indices.  This may be interrupted by the
  	     * signal handler, doing essentially the same reset.
  	     */
  	    sp->_sysmouse_head += 1;
  	    if (sp->_sysmouse_head == sp->_sysmouse_tail) {
  		sp->_sysmouse_tail = 0;
  		sp->_sysmouse_head = 0;
  	    }
  
  	    /* bump the next-free pointer into the circular list */
  	    sp->_mouse_eventp = eventp = NEXT(eventp);
  	    result = TRUE;
  	}
  	break;
  #endif /* USE_SYSMOUSE */
  
      case M_NONE:
  	break;
      }
  
      return result;		/* true if we found an event */
  }
  
  static bool
  _nc_mouse_inline(SCREEN *sp)
  /* mouse report received in the keyboard stream -- parse its info */
  {
      int b;
      bool result = FALSE;
      MEVENT *eventp = sp->_mouse_eventp;
  
      TR(MY_TRACE, ("_nc_mouse_inline() called"));
  
      if (sp->_mouse_type == M_XTERM) {
  	unsigned char kbuf[4];
  	mmask_t prev;
  	size_t grabbed;
  	int res;
  
  	/* This code requires that your xterm entry contain the kmous
  	 * capability and that it be set to the \E[M documented in the
  	 * Xterm Control Sequences reference.  This is how we
  	 * arrange for mouse events to be reported via a KEY_MOUSE
  	 * return value from wgetch().  After this value is received,
  	 * _nc_mouse_inline() gets called and is immediately
  	 * responsible for parsing the mouse status information
  	 * following the prefix.
  	 *
  	 * The following quotes from the ctrlseqs.ms document in the
  	 * X distribution, describing the X mouse tracking feature:
  	 *
  	 * Parameters for all mouse tracking escape sequences
  	 * generated by xterm encode numeric parameters in a single
  	 * character as value+040.  For example, !  is 1.
  	 *
  	 * On button press or release, xterm sends ESC [ M CbCxCy.
  	 * The low two bits of Cb encode button information: 0=MB1
  	 * pressed, 1=MB2 pressed, 2=MB3 pressed, 3=release.  The
  	 * upper bits encode what modifiers were down when the
  	 * button was pressed and are added together.  4=Shift,
  	 * 8=Meta, 16=Control.  Cx and Cy are the x and y coordinates
  	 * of the mouse event.  The upper left corner is (1,1).
  	 *
  	 * (End quote)  By the time we get here, we've eaten the
  	 * key prefix.  FYI, the loop below is necessary because
  	 * mouse click info isn't guaranteed to present as a
  	 * single clist item.
  	 *
  	 * Wheel mice may return buttons 4 and 5 when the wheel is turned.
  	 * We encode those as button presses.
  	 */
  	for (grabbed = 0; grabbed < 3; grabbed += (size_t) res) {
  
  	    /* For VIO mouse we add extra bit 64 to disambiguate button-up. */
  #if USE_EMX_MOUSE
  	    res = read(M_FD(sp) >= 0 ? M_FD(sp) : sp->_ifd, &kbuf, 3);
  #else
  	    res = read(sp->_ifd, kbuf + grabbed, 3 - grabbed);
  #endif
  	    if (res == -1)
  		break;
  	}
  	kbuf[3] = '\0';
  
  	TR(TRACE_IEVENT,
  	   ("_nc_mouse_inline sees the following xterm data: '%s'", kbuf));
  
  	/* there's only one mouse... */
  	eventp->id = NORMAL_EVENT;
  
  	/* processing code goes here */
  	eventp->bstate = 0;
  	prev = PREV(eventp)->bstate;
  
  #if USE_EMX_MOUSE
  #define PRESS_POSITION(n) \
  	eventp->bstate = MASK_PRESS(n); \
  	if (kbuf[0] & 0x40) \
  	    eventp->bstate = MASK_RELEASE(n)
  #else
  #define PRESS_POSITION(n) \
  	eventp->bstate = (mmask_t) (prev & MASK_PRESS(n) \
  				    ? REPORT_MOUSE_POSITION \
  				    : MASK_PRESS(n))
  #endif
  
  	switch (kbuf[0] & 0x3) {
  	case 0x0:
  	    if (kbuf[0] & 64)
  		eventp->bstate = MASK_PRESS(4);
  	    else
  		PRESS_POSITION(1);
  	    break;
  
  	case 0x1:
  #if NCURSES_MOUSE_VERSION == 2
  	    if (kbuf[0] & 64)
  		eventp->bstate = MASK_PRESS(5);
  	    else
  #endif
  		PRESS_POSITION(2);
  	    break;
  
  	case 0x2:
  	    PRESS_POSITION(3);
  	    break;
  
  	case 0x3:
  	    /*
  	     * Release events aren't reported for individual buttons, just for
  	     * the button set as a whole.  However, because there are normally
  	     * no mouse events under xterm that intervene between press and
  	     * release, we can infer the button actually released by looking at
  	     * the previous event.
  	     */
  	    if (prev & (BUTTON_PRESSED | BUTTON_RELEASED)) {
  		eventp->bstate = BUTTON_RELEASED;
  		for (b = 1; b <= MAX_BUTTONS; ++b) {
  		    if (!(prev & MASK_PRESS(b)))
  			eventp->bstate &= ~MASK_RELEASE(b);
  		}
  	    } else {
  		/*
  		 * XFree86 xterm will return a stream of release-events to
  		 * let the application know where the mouse is going, if the
  		 * private mode 1002 or 1003 is enabled.
  		 */
  		eventp->bstate = REPORT_MOUSE_POSITION;
  	    }
  	    break;
  	}
  	result = (eventp->bstate & REPORT_MOUSE_POSITION) ? TRUE : FALSE;
  
  	if (kbuf[0] & 4) {
  	    eventp->bstate |= BUTTON_SHIFT;
  	}
  	if (kbuf[0] & 8) {
  	    eventp->bstate |= BUTTON_ALT;
  	}
  	if (kbuf[0] & 16) {
  	    eventp->bstate |= BUTTON_CTRL;
  	}
  
  	eventp->x = (kbuf[1] - ' ') - 1;
  	eventp->y = (kbuf[2] - ' ') - 1;
  	TR(MY_TRACE,
  	   ("_nc_mouse_inline: primitive mouse-event %s has slot %ld",
  	    _nc_tracemouse(sp, eventp),
  	    (long) IndexEV(sp, eventp)));
  
  	/* bump the next-free pointer into the circular list */
  	sp->_mouse_eventp = NEXT(eventp);
  #if 0				/* this return would be needed for QNX's mods to lib_getch.c */
  	return (TRUE);
  #endif
      }
  
      return (result);
  }
  
  static void
  mouse_activate(SCREEN *sp, bool on)
  {
      if (!on && !sp->_mouse_initialized)
  	return;
  
      if (!_nc_mouse_init(sp))
  	return;
  
      if (on) {
  
  	switch (sp->_mouse_type) {
  	case M_XTERM:
  #if NCURSES_EXT_FUNCS
  	    keyok(KEY_MOUSE, on);
  #endif
  	    TPUTS_TRACE("xterm mouse initialization");
  	    enable_xterm_mouse(sp, 1);
  	    break;
  #if USE_GPM_SUPPORT
  	case M_GPM:
  	    if (enable_gpm_mouse(sp, TRUE)) {
  		sp->_mouse_fd = *(my_gpm_fd);
  		T(("GPM mouse_fd %d", sp->_mouse_fd));
  	    }
  	    break;
  #endif
  #if USE_SYSMOUSE
  	case M_SYSMOUSE:
  	    signal(SIGUSR2, handle_sysmouse);
  	    sp->_mouse_active = TRUE;
  	    break;
  #endif
  	case M_NONE:
  	    return;
  	}
  	/* Make runtime binding to cut down on object size of applications that
  	 * do not use the mouse (e.g., 'clear').
  	 */
  	sp->_mouse_event = _nc_mouse_event;
  	sp->_mouse_inline = _nc_mouse_inline;
  	sp->_mouse_parse = _nc_mouse_parse;
  	sp->_mouse_resume = _nc_mouse_resume;
  	sp->_mouse_wrap = _nc_mouse_wrap;
      } else {
  
  	switch (sp->_mouse_type) {
  	case M_XTERM:
  	    TPUTS_TRACE("xterm mouse deinitialization");
  	    enable_xterm_mouse(sp, 0);
  	    break;
  #if USE_GPM_SUPPORT
  	case M_GPM:
  	    enable_gpm_mouse(sp, FALSE);
  	    break;
  #endif
  #if USE_SYSMOUSE
  	case M_SYSMOUSE:
  	    signal(SIGUSR2, SIG_IGN);
  	    sp->_mouse_active = FALSE;
  	    break;
  #endif
  	case M_NONE:
  	    return;
  	}
      }
      _nc_flush();
  }
  
  /**************************************************************************
   *
   * Device-independent code
   *
   **************************************************************************/
  
  static bool
  _nc_mouse_parse(SCREEN *sp, int runcount)
  /* parse a run of atomic mouse events into a gesture */
  {
      MEVENT *eventp = sp->_mouse_eventp;
      MEVENT *ep, *runp, *next, *prev = PREV(eventp);
      int n;
      int b;
      bool merge;
  
      TR(MY_TRACE, ("_nc_mouse_parse(%d) called", runcount));
  
      /*
       * When we enter this routine, the event list next-free pointer
       * points just past a run of mouse events that we know were separated
       * in time by less than the critical click interval. The job of this
       * routine is to collapse this run into a single higher-level event
       * or gesture.
       *
       * We accomplish this in two passes.  The first pass merges press/release
       * pairs into click events.  The second merges runs of click events into
       * double or triple-click events.
       *
       * It's possible that the run may not resolve to a single event (for
       * example, if the user quadruple-clicks).  If so, leading events
       * in the run are ignored.
       *
       * Note that this routine is independent of the format of the specific
       * format of the pointing-device's reports.  We can use it to parse
       * gestures on anything that reports press/release events on a per-
       * button basis, as long as the device-dependent mouse code puts stuff
       * on the queue in MEVENT format.
       */
      if (runcount == 1) {
  	TR(MY_TRACE,
  	   ("_nc_mouse_parse: returning simple mouse event %s at slot %ld",
  	    _nc_tracemouse(sp, prev),
  	    (long) IndexEV(sp, prev)));
  	return (prev->id >= NORMAL_EVENT)
  	    ? ((prev->bstate & sp->_mouse_mask) ? TRUE : FALSE)
  	    : FALSE;
      }
  
      /* find the start of the run */
      runp = eventp;
      for (n = runcount; n > 0; n--) {
  	runp = PREV(runp);
      }
  
  #ifdef TRACE
      if (USE_TRACEF(TRACE_IEVENT)) {
  	_trace_slot(sp, "before mouse press/release merge:");
  	_tracef("_nc_mouse_parse: run starts at %ld, ends at %ld, count %d",
  		RunParams(sp, eventp, runp),
  		runcount);
  	_nc_unlock_global(tracef);
      }
  #endif /* TRACE */
  
      /* first pass; merge press/release pairs */
      do {
  	merge = FALSE;
  	for (ep = runp; (next = NEXT(ep)) != eventp; ep = next) {
  
  #define MASK_CHANGED(x) (!(ep->bstate & MASK_PRESS(x)) \
  		      == !(next->bstate & MASK_RELEASE(x)))
  
  	    if (ep->x == next->x && ep->y == next->y
  		&& (ep->bstate & BUTTON_PRESSED)
  		&& MASK_CHANGED(1)
  		&& MASK_CHANGED(2)
  		&& MASK_CHANGED(3)
  		&& MASK_CHANGED(4)
  #if NCURSES_MOUSE_VERSION == 2
  		&& MASK_CHANGED(5)
  #endif
  		) {
  		for (b = 1; b <= MAX_BUTTONS; ++b) {
  		    if ((sp->_mouse_mask & MASK_CLICK(b))
  			&& (ep->bstate & MASK_PRESS(b))) {
  			ep->bstate &= ~MASK_PRESS(b);
  			ep->bstate |= MASK_CLICK(b);
  			merge = TRUE;
  		    }
  		}
  		if (merge)
  		    next->id = INVALID_EVENT;
  	    }
  	}
      } while
  	(merge);
  
  #ifdef TRACE
      if (USE_TRACEF(TRACE_IEVENT)) {
  	_trace_slot(sp, "before mouse click merge:");
  	_tracef("_nc_mouse_parse: run starts at %ld, ends at %ld, count %d",
  		RunParams(sp, eventp, runp),
  		runcount);
  	_nc_unlock_global(tracef);
      }
  #endif /* TRACE */
  
      /*
       * Second pass; merge click runs.  At this point, click events are
       * each followed by one invalid event. We merge click events
       * forward in the queue.
       *
       * NOTE: There is a problem with this design!  If the application
       * allows enough click events to pile up in the circular queue so
       * they wrap around, it will cheerfully merge the newest forward
       * into the oldest, creating a bogus doubleclick and confusing
       * the queue-traversal logic rather badly.  Generally this won't
       * happen, because calling getmouse() marks old events invalid and
       * ineligible for merges.  The true solution to this problem would
       * be to timestamp each MEVENT and perform the obvious sanity check,
       * but the timer element would have to have sub-second resolution,
       * which would get us into portability trouble.
       */
      do {
  	MEVENT *follower;
  
  	merge = FALSE;
  	for (ep = runp; (next = NEXT(ep)) != eventp; ep = next)
  	    if (ep->id != INVALID_EVENT) {
  		if (next->id != INVALID_EVENT)
  		    continue;
  		follower = NEXT(next);
  		if (follower->id == INVALID_EVENT)
  		    continue;
  
  		/* merge click events forward */
  		if ((ep->bstate & BUTTON_CLICKED)
  		    && (follower->bstate & BUTTON_CLICKED)) {
  		    for (b = 1; b <= MAX_BUTTONS; ++b) {
  			if ((sp->_mouse_mask & MASK_DOUBLE_CLICK(b))
  			    && (follower->bstate & MASK_CLICK(b))) {
  			    follower->bstate &= ~MASK_CLICK(b);
  			    follower->bstate |= MASK_DOUBLE_CLICK(b);
  			    merge = TRUE;
  			}
  		    }
  		    if (merge)
  			ep->id = INVALID_EVENT;
  		}
  
  		/* merge double-click events forward */
  		if ((ep->bstate & BUTTON_DOUBLE_CLICKED)
  		    && (follower->bstate & BUTTON_CLICKED)) {
  		    for (b = 1; b <= MAX_BUTTONS; ++b) {
  			if ((sp->_mouse_mask & MASK_TRIPLE_CLICK(b))
  			    && (follower->bstate & MASK_CLICK(b))) {
  			    follower->bstate &= ~MASK_CLICK(b);
  			    follower->bstate |= MASK_TRIPLE_CLICK(b);
  			    merge = TRUE;
  			}
  		    }
  		    if (merge)
  			ep->id = INVALID_EVENT;
  		}
  	    }
      } while
  	(merge);
  
  #ifdef TRACE
      if (USE_TRACEF(TRACE_IEVENT)) {
  	_trace_slot(sp, "before mouse event queue compaction:");
  	_tracef("_nc_mouse_parse: run starts at %ld, ends at %ld, count %d",
  		RunParams(sp, eventp, runp),
  		runcount);
  	_nc_unlock_global(tracef);
      }
  #endif /* TRACE */
  
      /*
       * Now try to throw away trailing events flagged invalid, or that
       * don't match the current event mask.
       */
      for (; runcount; prev = PREV(eventp), runcount--)
  	if (prev->id == INVALID_EVENT || !(prev->bstate & sp->_mouse_mask)) {
  	    sp->_mouse_eventp = eventp = prev;
  	}
  #ifdef TRACE
      if (USE_TRACEF(TRACE_IEVENT)) {
  	_trace_slot(sp, "after mouse event queue compaction:");
  	_tracef("_nc_mouse_parse: run starts at %ld, ends at %ld, count %d",
  		RunParams(sp, eventp, runp),
  		runcount);
  	_nc_unlock_global(tracef);
      }
      for (ep = runp; ep != eventp; ep = NEXT(ep))
  	if (ep->id != INVALID_EVENT)
  	    TR(MY_TRACE,
  	       ("_nc_mouse_parse: returning composite mouse event %s at slot %ld",
  		_nc_tracemouse(sp, ep),
  		(long) IndexEV(sp, ep)));
  #endif /* TRACE */
  
      /* after all this, do we have a valid event? */
      return (PREV(eventp)->id != INVALID_EVENT);
  }
  
  static void
  _nc_mouse_wrap(SCREEN *sp)
  /* release mouse -- called by endwin() before shellout/exit */
  {
      TR(MY_TRACE, ("_nc_mouse_wrap() called"));
  
      switch (sp->_mouse_type) {
      case M_XTERM:
  	if (sp->_mouse_mask)
  	    mouse_activate(sp, FALSE);
  	break;
  #if USE_GPM_SUPPORT
  	/* GPM: pass all mouse events to next client */
      case M_GPM:
  	if (sp->_mouse_mask)
  	    mouse_activate(sp, FALSE);
  	break;
  #endif
  #if USE_SYSMOUSE
      case M_SYSMOUSE:
  	mouse_activate(sp, FALSE);
  	break;
  #endif
      case M_NONE:
  	break;
      }
  }
  
  static void
  _nc_mouse_resume(SCREEN *sp)
  /* re-connect to mouse -- called by doupdate() after shellout */
  {
      TR(MY_TRACE, ("_nc_mouse_resume() called"));
  
      switch (sp->_mouse_type) {
      case M_XTERM:
  	/* xterm: re-enable reporting */
  	if (sp->_mouse_mask)
  	    mouse_activate(sp, TRUE);
  	break;
  
  #if USE_GPM_SUPPORT
      case M_GPM:
  	/* GPM: reclaim our event set */
  	if (sp->_mouse_mask)
  	    mouse_activate(sp, TRUE);
  	break;
  #endif
  
  #if USE_SYSMOUSE
      case M_SYSMOUSE:
  	mouse_activate(sp, TRUE);
  	break;
  #endif
      case M_NONE:
  	break;
      }
  }
  
  /**************************************************************************
   *
   * Mouse interface entry points for the API
   *
   **************************************************************************/
  
  static int
  _nc_getmouse(SCREEN *sp, MEVENT * aevent)
  {
      T((T_CALLED("getmouse(%p)"), aevent));
  
      if ((aevent != 0) && (sp != 0) && (sp->_mouse_type != M_NONE)) {
  	MEVENT *eventp = sp->_mouse_eventp;
  	/* compute the current-event pointer */
  	MEVENT *prev = PREV(eventp);
  
  	/* copy the event we find there */
  	*aevent = *prev;
  
  	TR(TRACE_IEVENT, ("getmouse: returning event %s from slot %ld",
  			  _nc_tracemouse(sp, prev),
  			  (long) IndexEV(sp, prev)));
  
  	prev->id = INVALID_EVENT;	/* so the queue slot becomes free */
  	returnCode(OK);
      }
      returnCode(ERR);
  }
  
  /* grab a copy of the current mouse event */
  NCURSES_EXPORT(int)
  getmouse(MEVENT * aevent)
  {
      return _nc_getmouse(SP, aevent);
  }
  
  static int
  _nc_ungetmouse(SCREEN *sp, MEVENT * aevent)
  {
      int result = ERR;
  
      T((T_CALLED("ungetmouse(%p)"), aevent));
  
      if (aevent != 0 && sp != 0) {
  	MEVENT *eventp = sp->_mouse_eventp;
  
  	/* stick the given event in the next-free slot */
  	*eventp = *aevent;
  
  	/* bump the next-free pointer into the circular list */
  	sp->_mouse_eventp = NEXT(eventp);
  
  	/* push back the notification event on the keyboard queue */
  	result = _nc_ungetch(sp, KEY_MOUSE);
      }
      returnCode(result);
  }
  
  /* enqueue a synthesized mouse event to be seen by the next wgetch() */
  NCURSES_EXPORT(int)
  ungetmouse(MEVENT * aevent)
  {
      return _nc_ungetmouse(SP, aevent);
  }
  
  NCURSES_EXPORT(mmask_t)
  mousemask(mmask_t newmask, mmask_t * oldmask)
  /* set the mouse event mask */
  {
      mmask_t result = 0;
  
      T((T_CALLED("mousemask(%#lx,%p)"), (unsigned long) newmask, oldmask));
  
      if (SP != 0) {
  	if (oldmask)
  	    *oldmask = SP->_mouse_mask;
  
  	if (newmask || SP->_mouse_initialized) {
  	    _nc_mouse_init(SP);
  	    if (SP->_mouse_type != M_NONE) {
  		result = newmask &
  		    (REPORT_MOUSE_POSITION
  		     | BUTTON_ALT
  		     | BUTTON_CTRL
  		     | BUTTON_SHIFT
  		     | BUTTON_PRESSED
  		     | BUTTON_RELEASED
  		     | BUTTON_CLICKED
  		     | BUTTON_DOUBLE_CLICKED
  		     | BUTTON_TRIPLE_CLICKED);
  
  		mouse_activate(SP, (bool) (result != 0));
  
  		SP->_mouse_mask = result;
  	    }
  	}
      }
      returnBits(result);
  }
  
  NCURSES_EXPORT(bool)
  wenclose(const WINDOW *win, int y, int x)
  /* check to see if given window encloses given screen location */
  {
      bool result = FALSE;
  
      T((T_CALLED("wenclose(%p,%d,%d)"), win, y, x));
  
      if (win != 0) {
  	y -= win->_yoffset;
  	result = ((win->_begy <= y &&
  		   win->_begx <= x &&
  		   (win->_begx + win->_maxx) >= x &&
  		   (win->_begy + win->_maxy) >= y) ? TRUE : FALSE);
      }
      returnBool(result);
  }
  
  NCURSES_EXPORT(int)
  mouseinterval(int maxclick)
  /* set the maximum mouse interval within which to recognize a click */
  {
      int oldval;
  
      T((T_CALLED("mouseinterval(%d)"), maxclick));
  
      if (SP != 0) {
  	oldval = SP->_maxclick;
  	if (maxclick >= 0)
  	    SP->_maxclick = maxclick;
      } else {
  	oldval = DEFAULT_MAXCLICK;
      }
  
      returnCode(oldval);
  }
  
  /* This may be used by other routines to ask for the existence of mouse
     support */
  NCURSES_EXPORT(bool)
  _nc_has_mouse(SCREEN *sp)
  {
      return ((sp->_mouse_type == M_NONE) ? FALSE : TRUE);
  }
  
  NCURSES_EXPORT(bool)
  has_mouse(void)
  {
      return _nc_has_mouse(SP);
  }
  
  NCURSES_EXPORT(bool)
  wmouse_trafo(const WINDOW *win, int *pY, int *pX, bool to_screen)
  {
      bool result = FALSE;
  
      T((T_CALLED("wmouse_trafo(%p,%p,%p,%d)"), win, pY, pX, to_screen));
  
      if (win && pY && pX) {
  	int y = *pY;
  	int x = *pX;
  
  	if (to_screen) {
  	    y += win->_begy + win->_yoffset;
  	    x += win->_begx;
  	    if (wenclose(win, y, x))
  		result = TRUE;
  	} else {
  	    if (wenclose(win, y, x)) {
  		y -= (win->_begy + win->_yoffset);
  		x -= win->_begx;
  		result = TRUE;
  	    }
  	}
  	if (result) {
  	    *pX = x;
  	    *pY = y;
  	}
      }
      returnBool(result);
  }
  