ncurses/tinfo/lib_win32con.c

/****************************************************************************
 * Copyright 2020-2021,2023 Thomas E. Dickey                                *
 * Copyright 1998-2009,2010 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: Juergen Pfeifer                                                 *
 *     and: Thomas E. Dickey                                                *
 ****************************************************************************/

/*
 * TODO - GetMousePos(POINT * result) from ntconio.c
 */

#include <curses.priv.h>

MODULE_ID("$Id: lib_win32con.c,v 1.14 2023/08/05 20:44:38 tom Exp $")

#ifdef _NC_WINDOWS

#ifdef _NC_MINGW
#include <wchar.h>
#else
#include <tchar.h>
#endif

#include <io.h>

#if USE_WIDEC_SUPPORT
#define write_screen WriteConsoleOutputW
#define read_screen  ReadConsoleOutputW
#else
#define write_screen WriteConsoleOutput
#define read_screen  ReadConsoleOutput
#endif

static bool read_screen_data(void);

#define GenMap(vKey,key) MAKELONG(key, vKey)
static const LONG keylist[] =
{
    GenMap(VK_PRIOR, KEY_PPAGE),
    GenMap(VK_NEXT, KEY_NPAGE),
    GenMap(VK_END, KEY_END),
    GenMap(VK_HOME, KEY_HOME),
    GenMap(VK_LEFT, KEY_LEFT),
    GenMap(VK_UP, KEY_UP),
    GenMap(VK_RIGHT, KEY_RIGHT),
    GenMap(VK_DOWN, KEY_DOWN),
    GenMap(VK_DELETE, KEY_DC),
    GenMap(VK_INSERT, KEY_IC)
};
static const LONG ansi_keys[] =
{
    GenMap(VK_PRIOR, 'I'),
    GenMap(VK_NEXT, 'Q'),
    GenMap(VK_END, 'O'),
    GenMap(VK_HOME, 'H'),
    GenMap(VK_LEFT, 'K'),
    GenMap(VK_UP, 'H'),
    GenMap(VK_RIGHT, 'M'),
    GenMap(VK_DOWN, 'P'),
    GenMap(VK_DELETE, 'S'),
    GenMap(VK_INSERT, 'R')
};
#define array_length(a) (sizeof(a)/sizeof(a[0]))
#define N_INI ((int)array_length(keylist))
#define FKEYS 24
#define MAPSIZE (FKEYS + N_INI)

/*   A process can only have a single console, so it is safe
     to maintain all the information about it in a single
     static structure.
 */
NCURSES_EXPORT_VAR(ConsoleInfo) _nc_CONSOLE;
static bool console_initialized = FALSE;

#define EnsureInit() (void)(console_initialized ? TRUE : _nc_console_checkinit(TRUE, TRUE))

#define REQUIRED_MAX_V (DWORD)10
#define REQUIRED_MIN_V (DWORD)0
#define REQUIRED_BUILD (DWORD)17763
/*
  This function returns 0 if the Windows version has no support for
  the modern Console interface, otherwise it returns 1
 */
NCURSES_EXPORT(int)
_nc_console_vt_supported(void)
{
    OSVERSIONINFO osvi;
    int res = 0;

    T((T_CALLED("lib_win32con::_nc_console_vt_supported")));
    ZeroMemory(&osvi, sizeof(OSVERSIONINFO));
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);

    GetVersionEx(&osvi);
    T(("GetVersionEx returnedMajor=%ld, Minor=%ld, Build=%ld",
       osvi.dwMajorVersion,
       osvi.dwMinorVersion,
       osvi.dwBuildNumber));
    if (osvi.dwMajorVersion >= REQUIRED_MAX_V) {
	if (osvi.dwMajorVersion == REQUIRED_MAX_V) {
	    if (((osvi.dwMinorVersion == REQUIRED_MIN_V) &&
		 (osvi.dwBuildNumber >= REQUIRED_BUILD)) ||
		((osvi.dwMinorVersion > REQUIRED_MIN_V)))
		res = 1;
	} else
	    res = 1;
    }
    returnCode(res);
}

NCURSES_EXPORT(void)
_nc_console_size(int *Lines, int *Cols)
{
    EnsureInit();
    if (Lines != NULL && Cols != NULL) {
	if (WINCONSOLE.buffered) {
	    *Lines = (int) (WINCONSOLE.SBI.dwSize.Y);
	    *Cols = (int) (WINCONSOLE.SBI.dwSize.X);
	} else {
	    *Lines = (int) (WINCONSOLE.SBI.srWindow.Bottom + 1 -
			    WINCONSOLE.SBI.srWindow.Top);
	    *Cols = (int) (WINCONSOLE.SBI.srWindow.Right + 1 -
			   WINCONSOLE.SBI.srWindow.Left);
	}
    }
}

/* Convert a file descriptor into a HANDLE
   That's not necessarily a console HANDLE
*/
NCURSES_EXPORT(HANDLE)
_nc_console_handle(int fd)
{
    intptr_t value = _get_osfhandle(fd);
    return (HANDLE) value;
}

/* Validate that a HANDLE is actually a
   console HANDLE
*/
static BOOL
IsConsoleHandle(HANDLE hdl)
{
    DWORD dwFlag = 0;
    BOOL result = FALSE;

    T((T_CALLED("lib_win32con::IsConsoleHandle(HANDLE=%p"), hdl));

    EnsureInit();

    if (!GetConsoleMode(hdl, &dwFlag)) {
	T(("GetConsoleMode failed"));
    } else {
	result = TRUE;
    }

    returnBool(result);
}

/*   This is used when running in terminfo mode to discover,
     whether or not the "terminal" is actually a Windows
     Console. It is the responsibility of the console to deal
     with the terminal escape sequences that are sent by
     terminfo.
 */
NCURSES_EXPORT(int)
_nc_console_test(int fd)
{
    int code = 0;
    HANDLE hdl = INVALID_HANDLE_VALUE;
    T((T_CALLED("lib_win32con::_nc_console_test(%d)"), fd));
    hdl = _nc_console_handle(fd);
    code = (int) IsConsoleHandle(hdl);
    returnCode(code);
}

#define OutHandle() ((WINCONSOLE.isTermInfoConsole || WINCONSOLE.progMode) ? WINCONSOLE.hdl : WINCONSOLE.out)

NCURSES_EXPORT(void)
_nc_console_selectActiveHandle(void)
{
    if (WINCONSOLE.lastOut != WINCONSOLE.hdl) {
	WINCONSOLE.lastOut = WINCONSOLE.hdl;
	SetConsoleActiveScreenBuffer(WINCONSOLE.lastOut);
    }
}

NCURSES_EXPORT(HANDLE)
_nc_console_fd2handle(int fd)
{
    HANDLE hdl = _nc_console_handle(fd);
    if (hdl == WINCONSOLE.inp) {
	T(("lib_win32con:validateHandle %d -> WINCONSOLE.inp", fd));
    } else if (hdl == WINCONSOLE.hdl) {
	T(("lib_win32con:validateHandle %d -> WINCONSOLE.hdl", fd));
    } else if (hdl == WINCONSOLE.out) {
	T(("lib_win32con:validateHandle %d -> WINCONSOLE.out", fd));
    } else {
	T(("lib_win32con:validateHandle %d maps to unknown HANDLE", fd));
	hdl = INVALID_HANDLE_VALUE;
    }
#if 1
    assert(hdl != INVALID_HANDLE_VALUE);
#endif
    if (hdl != INVALID_HANDLE_VALUE) {
	if (hdl != WINCONSOLE.inp && (!WINCONSOLE.isTermInfoConsole && WINCONSOLE.progMode)) {
	    if (hdl == WINCONSOLE.out && hdl != WINCONSOLE.hdl) {
		T(("lib_win32con:validateHandle forcing WINCONSOLE.out -> WINCONSOLE.hdl"));
		hdl = WINCONSOLE.hdl;
	    }
	}
    }
    return hdl;
}

NCURSES_EXPORT(int)
_nc_console_setmode(HANDLE hdl, const TTY * arg)
{
    DWORD dwFlag = 0;
    int code = ERR;
    HANDLE alt;

    if (arg) {
#ifdef TRACE
	TTY TRCTTY;
#define TRCTTYOUT(flag) TRCTTY.dwFlagOut = flag
#define TRCTTYIN(flag)  TRCTTY.dwFlagIn = flag
#else
#define TRCTTYOUT(flag)
#define TRCTTYIN(flag)
#endif
	T(("lib_win32con:_nc_console_setmode %s", _nc_trace_ttymode(arg)));
	if (hdl == WINCONSOLE.inp) {
	    dwFlag = arg->dwFlagIn | ENABLE_MOUSE_INPUT | VT_FLAG_IN;
	    if (WINCONSOLE.isTermInfoConsole)
		dwFlag |= (VT_FLAG_IN);
	    else
		dwFlag &= (DWORD) ~ (VT_FLAG_IN);
	    TRCTTYIN(dwFlag);
	    SetConsoleMode(hdl, dwFlag);

	    alt = OutHandle();
	    dwFlag = arg->dwFlagOut;
	    if (WINCONSOLE.isTermInfoConsole)
		dwFlag |= (VT_FLAG_OUT);
	    else
		dwFlag |= (VT_FLAG_OUT);
	    TRCTTYOUT(dwFlag);
	    SetConsoleMode(alt, dwFlag);
	} else {
	    dwFlag = arg->dwFlagOut;
	    if (WINCONSOLE.isTermInfoConsole)
		dwFlag |= (VT_FLAG_OUT);
	    else
		dwFlag |= (VT_FLAG_OUT);
	    TRCTTYOUT(dwFlag);
	    SetConsoleMode(hdl, dwFlag);

	    alt = WINCONSOLE.inp;
	    dwFlag = arg->dwFlagIn | ENABLE_MOUSE_INPUT;
	    if (WINCONSOLE.isTermInfoConsole)
		dwFlag |= (VT_FLAG_IN);
	    else
		dwFlag &= (DWORD) ~ (VT_FLAG_IN);
	    TRCTTYIN(dwFlag);
	    SetConsoleMode(alt, dwFlag);
	    T(("effective mode set %s", _nc_trace_ttymode(&TRCTTY)));
	}
	code = OK;
    }
    return (code);
}

NCURSES_EXPORT(int)
_nc_console_getmode(HANDLE hdl, TTY * arg)
{
    int code = ERR;

    if (arg) {
	DWORD dwFlag = 0;
	HANDLE alt;

	if (hdl == WINCONSOLE.inp) {
	    if (GetConsoleMode(hdl, &dwFlag)) {
		arg->dwFlagIn = dwFlag;
		alt = OutHandle();
		if (GetConsoleMode(alt, &dwFlag)) {
		    arg->dwFlagOut = dwFlag;
		    code = OK;
		}
	    }
	} else {
	    if (GetConsoleMode(hdl, &dwFlag)) {
		arg->dwFlagOut = dwFlag;
		alt = WINCONSOLE.inp;
		if (GetConsoleMode(alt, &dwFlag)) {
		    arg->dwFlagIn = dwFlag;
		    code = OK;
		}
	    }
	}
    }
    T(("lib_win32con:_nc_console_getmode %s", _nc_trace_ttymode(arg)));
    return (code);
}

NCURSES_EXPORT(int)
_nc_console_flush(HANDLE hdl)
{
    int code = OK;

    T((T_CALLED("lib_win32con::_nc_console_flush(hdl=%p"), hdl));

    if (hdl != INVALID_HANDLE_VALUE) {
	if (hdl == WINCONSOLE.hdl ||
	    hdl == WINCONSOLE.inp ||
	    hdl == WINCONSOLE.out) {
	    if (!FlushConsoleInputBuffer(WINCONSOLE.inp))
		code = ERR;
	} else {
	    code = ERR;
	    T(("_nc_console_flush not requesting a handle owned by console."));
	}
    }
    returnCode(code);
}

NCURSES_EXPORT(WORD)
_nc_console_MapColor(bool fore, int color)
{
    static const int _cmap[] =
    {0, 4, 2, 6, 1, 5, 3, 7};
    int a;
    if (color < 0 || color > 7)
	a = fore ? 7 : 0;
    else
	a = _cmap[color];
    if (!fore)
	a = a << 4;
    return (WORD) a;
}

/*
 * Attempt to save the screen contents.  PDCurses does this if
 * PDC_RESTORE_SCREEN is set, giving the same visual appearance on
 * restoration as if the library had allocated a console buffer.  MSDN
 * says that the data which can be read is limited to 64Kb (and may be
 * less).
 */
static bool
save_original_screen(void)
{
    bool result = FALSE;

    WINCONSOLE.save_region.Top = 0;
    WINCONSOLE.save_region.Left = 0;
    WINCONSOLE.save_region.Bottom = (SHORT) (WINCONSOLE.SBI.dwSize.Y - 1);
    WINCONSOLE.save_region.Right = (SHORT) (WINCONSOLE.SBI.dwSize.X - 1);

    if (read_screen_data()) {
	result = TRUE;
    } else {

	WINCONSOLE.save_region.Top = WINCONSOLE.SBI.srWindow.Top;
	WINCONSOLE.save_region.Left = WINCONSOLE.SBI.srWindow.Left;
	WINCONSOLE.save_region.Bottom = WINCONSOLE.SBI.srWindow.Bottom;
	WINCONSOLE.save_region.Right = WINCONSOLE.SBI.srWindow.Right;

	WINCONSOLE.window_only = TRUE;

	if (read_screen_data()) {
	    result = TRUE;
	}
    }

    T(("... save original screen contents %s", result ? "ok" : "err"));
    return result;
}

#if 0
static bool
restore_original_screen(void)
{
    COORD bufferCoord;
    bool result = FALSE;
    SMALL_RECT save_region = WINCONSOLE.save_region;

    T(("... restoring %s",
       WINCONSOLE.window_only ? "window" : "entire buffer"));

    bufferCoord.X = (SHORT) (WINCONSOLE.window_only ?
			     WINCONSOLE.SBI.srWindow.Left : 0);
    bufferCoord.Y = (SHORT) (WINCONSOLE.window_only ?
			     WINCONSOLE.SBI.srWindow.Top : 0);

    if (write_screen(WINCONSOLE.hdl,
		     WINCONSOLE.save_screen,
		     WINCONSOLE.save_size,
		     bufferCoord,
		     &save_region)) {
	result = TRUE;
	mvcur(-1, -1, LINES - 2, 0);
	T(("... restore original screen contents ok %dx%d (%d,%d - %d,%d)",
	   WINCONSOLE.save_size.Y,
	   WINCONSOLE.save_size.X,
	   save_region.Top,
	   save_region.Left,
	   save_region.Bottom,
	   save_region.Right));
    } else {
	T(("... restore original screen contents err"));
    }
    return result;
}
#endif

static bool
read_screen_data(void)
{
    bool result = FALSE;
    COORD bufferCoord;
    size_t want;

    WINCONSOLE.save_size.X = (SHORT) (WINCONSOLE.save_region.Right
				      - WINCONSOLE.save_region.Left + 1);
    WINCONSOLE.save_size.Y = (SHORT) (WINCONSOLE.save_region.Bottom
				      - WINCONSOLE.save_region.Top + 1);

    want = (size_t) (WINCONSOLE.save_size.X * WINCONSOLE.save_size.Y);

    if ((WINCONSOLE.save_screen = malloc(want * sizeof(CHAR_INFO))) != 0) {
	bufferCoord.X = (SHORT) (WINCONSOLE.window_only ?
				 WINCONSOLE.SBI.srWindow.Left : 0);
	bufferCoord.Y = (SHORT) (WINCONSOLE.window_only ?
				 WINCONSOLE.SBI.srWindow.Top : 0);

	T(("... reading console %s %dx%d into %d,%d - %d,%d at %d,%d",
	   WINCONSOLE.window_only ? "window" : "buffer",
	   WINCONSOLE.save_size.Y, WINCONSOLE.save_size.X,
	   WINCONSOLE.save_region.Top,
	   WINCONSOLE.save_region.Left,
	   WINCONSOLE.save_region.Bottom,
	   WINCONSOLE.save_region.Right,
	   bufferCoord.Y,
	   bufferCoord.X));

	if (read_screen(WINCONSOLE.hdl,
			WINCONSOLE.save_screen,
			WINCONSOLE.save_size,
			bufferCoord,
			&WINCONSOLE.save_region)) {
	    result = TRUE;
	} else {
	    T((" error %#lx", (unsigned long) GetLastError()));
	    FreeAndNull(WINCONSOLE.save_screen);
	}
    }

    return result;
}

NCURSES_EXPORT(bool)
_nc_console_get_SBI(void)
{
    bool rc = FALSE;
    if (GetConsoleScreenBufferInfo(WINCONSOLE.hdl, &(WINCONSOLE.SBI))) {
	T(("GetConsoleScreenBufferInfo"));
	T(("... buffer(X:%d Y:%d)",
	   WINCONSOLE.SBI.dwSize.X,
	   WINCONSOLE.SBI.dwSize.Y));
	T(("... window(X:%d Y:%d)",
	   WINCONSOLE.SBI.dwMaximumWindowSize.X,
	   WINCONSOLE.SBI.dwMaximumWindowSize.Y));
	T(("... cursor(X:%d Y:%d)",
	   WINCONSOLE.SBI.dwCursorPosition.X,
	   WINCONSOLE.SBI.dwCursorPosition.Y));
	T(("... display(Top:%d Bottom:%d Left:%d Right:%d)",
	   WINCONSOLE.SBI.srWindow.Top,
	   WINCONSOLE.SBI.srWindow.Bottom,
	   WINCONSOLE.SBI.srWindow.Left,
	   WINCONSOLE.SBI.srWindow.Right));
	if (WINCONSOLE.buffered) {
	    WINCONSOLE.origin.X = 0;
	    WINCONSOLE.origin.Y = 0;
	} else {
	    WINCONSOLE.origin.X = WINCONSOLE.SBI.srWindow.Left;
	    WINCONSOLE.origin.Y = WINCONSOLE.SBI.srWindow.Top;
	}
	rc = TRUE;
    } else {
	T(("GetConsoleScreenBufferInfo ERR"));
    }
    return rc;
}

#define MIN_WIDE 80
#define MIN_HIGH 24

/*
 * In "normal" mode, reset the buffer- and window-sizes back to their original values.
 */
NCURSES_EXPORT(void)
_nc_console_set_scrollback(bool normal, CONSOLE_SCREEN_BUFFER_INFO * info)
{
    SMALL_RECT rect;
    COORD coord;
    bool changed = FALSE;

    T((T_CALLED("lib_win32con::_nc_console_set_scrollback(%s)"),
       (normal
	? "normal"
	: "application")));

    T(("... SBI.srWindow %d,%d .. %d,%d",
       info->srWindow.Top,
       info->srWindow.Left,
       info->srWindow.Bottom,
       info->srWindow.Right));
    T(("... SBI.dwSize %dx%d",
       info->dwSize.Y,
       info->dwSize.X));

    if (normal) {
	rect = info->srWindow;
	coord = info->dwSize;
	if (memcmp(info, &WINCONSOLE.SBI, sizeof(*info)) != 0) {
	    changed = TRUE;
	    WINCONSOLE.SBI = *info;
	}
    } else {
	int high = info->srWindow.Bottom - info->srWindow.Top + 1;
	int wide = info->srWindow.Right - info->srWindow.Left + 1;

	if (high < MIN_HIGH) {
	    T(("... height %d < %d", high, MIN_HIGH));
	    high = MIN_HIGH;
	    changed = TRUE;
	}
	if (wide < MIN_WIDE) {
	    T(("... width %d < %d", wide, MIN_WIDE));
	    wide = MIN_WIDE;
	    changed = TRUE;
	}

	rect.Left =
	    rect.Top = 0;
	rect.Right = (SHORT) (wide - 1);
	rect.Bottom = (SHORT) (high - 1);

	coord.X = (SHORT) wide;
	coord.Y = (SHORT) high;

	if (info->dwSize.Y != high ||
	    info->dwSize.X != wide ||
	    info->srWindow.Top != 0 ||
	    info->srWindow.Left != 0) {
	    changed = TRUE;
	}

    }

    if (changed) {
	T(("... coord %d,%d", coord.Y, coord.X));
	T(("... rect %d,%d - %d,%d",
	   rect.Top, rect.Left,
	   rect.Bottom, rect.Right));
	SetConsoleScreenBufferSize(WINCONSOLE.hdl, coord);	/* dwSize */
	SetConsoleWindowInfo(WINCONSOLE.hdl, TRUE, &rect);	/* srWindow */
	_nc_console_get_SBI();
    }
    returnVoid;
}

static ULONGLONG
tdiff(FILETIME fstart, FILETIME fend)
{
    ULARGE_INTEGER ustart;
    ULARGE_INTEGER uend;
    ULONGLONG diff;

    ustart.LowPart = fstart.dwLowDateTime;
    ustart.HighPart = fstart.dwHighDateTime;
    uend.LowPart = fend.dwLowDateTime;
    uend.HighPart = fend.dwHighDateTime;

    diff = (uend.QuadPart - ustart.QuadPart) / 10000;
    return diff;
}

static int
Adjust(int milliseconds, int diff)
{
    if (milliseconds != INFINITY) {
	milliseconds -= diff;
	if (milliseconds < 0)
	    milliseconds = 0;
    }
    return milliseconds;
}

#define BUTTON_MASK (FROM_LEFT_1ST_BUTTON_PRESSED | \
                     FROM_LEFT_2ND_BUTTON_PRESSED | \
                     FROM_LEFT_3RD_BUTTON_PRESSED | \
                     FROM_LEFT_4TH_BUTTON_PRESSED | \
                     RIGHTMOST_BUTTON_PRESSED)

static mmask_t
decode_mouse(SCREEN *sp, int mask)
{
    mmask_t result = 0;

    (void) sp;
    assert(sp && console_initialized);

    if (mask & FROM_LEFT_1ST_BUTTON_PRESSED)
	result |= BUTTON1_PRESSED;
    if (mask & FROM_LEFT_2ND_BUTTON_PRESSED)
	result |= BUTTON2_PRESSED;
    if (mask & FROM_LEFT_3RD_BUTTON_PRESSED)
	result |= BUTTON3_PRESSED;
    if (mask & FROM_LEFT_4TH_BUTTON_PRESSED)
	result |= BUTTON4_PRESSED;

    if (mask & RIGHTMOST_BUTTON_PRESSED) {
	switch (WINCONSOLE.numButtons) {
	case 1:
	    result |= BUTTON1_PRESSED;
	    break;
	case 2:
	    result |= BUTTON2_PRESSED;
	    break;
	case 3:
	    result |= BUTTON3_PRESSED;
	    break;
	case 4:
	    result |= BUTTON4_PRESSED;
	    break;
	}
    }

    return result;
}

#define AdjustY() (WINCONSOLE.buffered ? 0 : (int) WINCONSOLE.SBI.srWindow.Top)

static bool
handle_mouse(SCREEN *sp, MOUSE_EVENT_RECORD mer)
{
    MEVENT work;
    bool result = FALSE;

    assert(sp);

    sp->_drv_mouse_old_buttons = sp->_drv_mouse_new_buttons;
    sp->_drv_mouse_new_buttons = mer.dwButtonState & BUTTON_MASK;

    /*
     * We're only interested if the button is pressed or released.
     * FIXME: implement continuous event-tracking.
     */
    if (sp->_drv_mouse_new_buttons != sp->_drv_mouse_old_buttons) {
	memset(&work, 0, sizeof(work));

	if (sp->_drv_mouse_new_buttons) {
	    work.bstate |= decode_mouse(sp, sp->_drv_mouse_new_buttons);
	} else {
	    /* cf: BUTTON_PRESSED, BUTTON_RELEASED */
	    work.bstate |= (decode_mouse(sp, sp->_drv_mouse_old_buttons)
			    >> 1);
	    result = TRUE;
	}

	work.x = mer.dwMousePosition.X;
	work.y = mer.dwMousePosition.Y - AdjustY();

	sp->_drv_mouse_fifo[sp->_drv_mouse_tail] = work;
	sp->_drv_mouse_tail += 1;
    }
    return result;
}

static int
rkeycompare(const void *el1, const void *el2)
{
    WORD key1 = (LOWORD((*((const LONG *) el1)))) & 0x7fff;
    WORD key2 = (LOWORD((*((const LONG *) el2)))) & 0x7fff;

    return ((key1 < key2) ? -1 : ((key1 == key2) ? 0 : 1));
}

static int
keycompare(const void *el1, const void *el2)
{
    WORD key1 = HIWORD((*((const LONG *) el1)));
    WORD key2 = HIWORD((*((const LONG *) el2)));

    return ((key1 < key2) ? -1 : ((key1 == key2) ? 0 : 1));
}

static int
MapKey(WORD vKey)
{
    int code = -1;

    if (!WINCONSOLE.isTermInfoConsole) {
	WORD nKey = 0;
	void *res;
	LONG key = GenMap(vKey, 0);

	res = bsearch(&key,
		      WINCONSOLE.map,
		      (size_t) (N_INI + FKEYS),
		      sizeof(keylist[0]),
		      keycompare);
	if (res) {
	    key = *((LONG *) res);
	    nKey = LOWORD(key);
	    code = (int) (nKey & 0x7fff);
	    if (nKey & 0x8000)
		code = -code;
	}
    }
    return code;
}

static int
AnsiKey(WORD vKey)
{
    int code = -1;

    if (!WINCONSOLE.isTermInfoConsole) {
	WORD nKey = 0;
	void *res;
	LONG key = GenMap(vKey, 0);

	res = bsearch(&key,
		      WINCONSOLE.ansi_map,
		      (size_t) (N_INI + FKEYS),
		      sizeof(keylist[0]),
		      keycompare);
	if (res) {
	    key = *((LONG *) res);
	    nKey = LOWORD(key);
	    code = (int) (nKey & 0x7fff);
	    if (nKey & 0x8000)
		code = -code;
	}
    }
    return code;
}

NCURSES_EXPORT(int)
_nc_console_keyok(int keycode, int flag)
{
    int code = ERR;
    WORD nKey;
    WORD vKey;
    void *res;
    LONG key = GenMap(0, (WORD) keycode);

    T((T_CALLED("lib_win32con::_nc_console_keyok(%d, %d)"), keycode, flag));

    res = bsearch(&key,
		  WINCONSOLE.rmap,
		  (size_t) (N_INI + FKEYS),
		  sizeof(keylist[0]),
		  rkeycompare);
    if (res) {
	key = *((LONG *) res);
	vKey = HIWORD(key);
	nKey = (LOWORD(key)) & 0x7fff;
	if (!flag)
	    nKey |= 0x8000;
	*(LONG *) res = GenMap(vKey, nKey);
    }
    returnCode(code);
}

NCURSES_EXPORT(bool)
_nc_console_keyExist(int keycode)
{
    WORD nKey;
    void *res;
    bool found = FALSE;
    LONG key = GenMap(0, (WORD) keycode);

    T((T_CALLED("lib_win32con::_nc_console_keyExist(%d)"), keycode));
    res = bsearch(&key,
		  WINCONSOLE.rmap,
		  (size_t) (N_INI + FKEYS),
		  sizeof(keylist[0]),
		  rkeycompare);
    if (res) {
	key = *((LONG *) res);
	nKey = LOWORD(key);
	if (!(nKey & 0x8000))
	    found = TRUE;
    }
    returnCode(found);
}

NCURSES_EXPORT(int)
_nc_console_twait(
		     SCREEN *sp,
		     HANDLE hdl,
		     int mode,
		     int milliseconds,
		     int *timeleft
		     EVENTLIST_2nd(_nc_eventlist * evl))
{
    INPUT_RECORD inp_rec;
    BOOL b;
    DWORD nRead = 0, rc = (DWORD) (-1);
    int code = 0;
    FILETIME fstart;
    FILETIME fend;
    int diff;
    bool isNoDelay = (milliseconds == 0);

#ifdef NCURSES_WGETCH_EVENTS
    (void) evl;			/* TODO: implement wgetch-events */
#endif

#define IGNORE_CTRL_KEYS (SHIFT_PRESSED|LEFT_ALT_PRESSED|RIGHT_ALT_PRESSED| \
                          LEFT_CTRL_PRESSED|RIGHT_CTRL_PRESSED)
#define CONSUME() ReadConsoleInput(hdl, &inp_rec, 1, &nRead)

    assert(sp);

    TR(TRACE_IEVENT, ("start twait: hdl=%p, %d milliseconds, mode: %d",
		      hdl, milliseconds, mode));

    if (milliseconds < 0)
	milliseconds = INFINITY;

    memset(&inp_rec, 0, sizeof(inp_rec));

    while (true) {
	if (!isNoDelay) {
	    GetSystemTimeAsFileTime(&fstart);
	    rc = WaitForSingleObject(hdl, (DWORD) milliseconds);
	    GetSystemTimeAsFileTime(&fend);
	    diff = (int) tdiff(fstart, fend);
	    milliseconds = Adjust(milliseconds, diff);
	    if (milliseconds < 0)
		break;
	}

	if (isNoDelay || (rc == WAIT_OBJECT_0)) {
	    if (mode) {
		nRead = 0;
		b = GetNumberOfConsoleInputEvents(hdl, &nRead);
		if (!b) {
		    T(("twait:err GetNumberOfConsoleInputEvents"));
		}
		if (isNoDelay && b) {
		    T(("twait: Events Available: %ld", nRead));
		    if (nRead == 0) {
			code = 0;
			goto end;
		    } else {
			DWORD n = 0;
			INPUT_RECORD *pInpRec =
			TypeAlloca(INPUT_RECORD, nRead);
			if (pInpRec != NULL) {
			    DWORD i;
			    BOOL f;
			    memset(pInpRec, 0, sizeof(INPUT_RECORD) * nRead);
			    f = PeekConsoleInput(hdl, pInpRec, nRead, &n);
			    if (f) {
				for (i = 0; i < n; i++) {
				    if (pInpRec[i].EventType == KEY_EVENT) {
					if (pInpRec[i].Event.KeyEvent.bKeyDown) {
					    DWORD ctrlMask =
					    (pInpRec[i].Event.KeyEvent.dwControlKeyState &
					     IGNORE_CTRL_KEYS);
					    if (!ctrlMask) {
						code = TW_INPUT;
						goto end;
					    }
					}
				    }
				}
			    } else {
				T(("twait:err PeekConsoleInput"));
			    }
			    code = 0;
			    goto end;
			} else {
			    T(("twait:err could not alloca input records"));
			}
		    }
		}
		if (b && nRead > 0) {
		    b = PeekConsoleInput(hdl, &inp_rec, 1, &nRead);
		    if (!b) {
			T(("twait:err PeekConsoleInput"));
		    }
		    if (b && nRead > 0) {
			switch (inp_rec.EventType) {
			case KEY_EVENT:
			    if (mode & TW_INPUT) {
				WORD vk =
				inp_rec.Event.KeyEvent.wVirtualKeyCode;
				char ch =
				inp_rec.Event.KeyEvent.uChar.AsciiChar;
				T(("twait:event KEY_EVENT"));
				T(("twait vk=%d, ch=%d, keydown=%d",
				   vk, ch, inp_rec.Event.KeyEvent.bKeyDown));
				if (inp_rec.Event.KeyEvent.bKeyDown) {
				    T(("twait:event KeyDown"));
				    if (!WINCONSOLE.isTermInfoConsole &&
					(0 == ch)) {
					int nKey = MapKey(vk);
					if (nKey < 0) {
					    CONSUME();
					    continue;
					}
				    }
				    code = TW_INPUT;
				    goto end;
				} else {
				    CONSUME();
				}
			    }
			    continue;
			case MOUSE_EVENT:
			    T(("twait:event MOUSE_EVENT"));
			    if (decode_mouse(sp,
					     (inp_rec.Event.MouseEvent.dwButtonState
					      & BUTTON_MASK)) == 0) {
				CONSUME();
			    } else if (mode & TW_MOUSE) {
				code = TW_MOUSE;
				goto end;
			    }
			    continue;
			    /* e.g., FOCUS_EVENT */
			default:
			    T(("twait:event Tyoe %d", inp_rec.EventType));
			    CONSUME();
			    _nc_console_selectActiveHandle();
			    continue;
			}
		    }
		}
	    }
	    continue;
	} else {
	    if (rc != WAIT_TIMEOUT) {
		code = -1;
		break;
	    } else {
		code = 0;
		break;
	    }
	}
    }
  end:

    TR(TRACE_IEVENT, ("end twait: returned %d (%lu), remaining time %d msec",
		      code, GetLastError(), milliseconds));

    if (timeleft)
	*timeleft = milliseconds;

    return code;
}

NCURSES_EXPORT(int)
_nc_console_testmouse(
			 SCREEN *sp,
			 HANDLE hdl,
			 int delay
			 EVENTLIST_2nd(_nc_eventlist * evl))
{
    int rc = 0;

    assert(sp);

    if (sp->_drv_mouse_head < sp->_drv_mouse_tail) {
	rc = TW_MOUSE;
    } else {
	rc = _nc_console_twait(sp,
			       hdl,
			       TWAIT_MASK,
			       delay,
			       (int *) 0
			       EVENTLIST_2nd(evl));
    }
    return rc;
}

NCURSES_EXPORT(int)
_nc_console_read(
		    SCREEN *sp,
		    HANDLE hdl,
		    int *buf)
{
    int rc = -1;
    INPUT_RECORD inp_rec;
    BOOL b;
    DWORD nRead;
    WORD vk;

    assert(sp);
    assert(buf);

    memset(&inp_rec, 0, sizeof(inp_rec));

    T((T_CALLED("lib_win32con::_nc_console_read(%p)"), sp));

    while ((b = ReadConsoleInput(hdl, &inp_rec, 1, &nRead))) {
	if (b && nRead > 0) {
	    if (rc < 0)
		rc = 0;
	    rc = rc + (int) nRead;
	    if (inp_rec.EventType == KEY_EVENT) {
		if (!inp_rec.Event.KeyEvent.bKeyDown)
		    continue;
		*buf = (int) inp_rec.Event.KeyEvent.uChar.AsciiChar;
		vk = inp_rec.Event.KeyEvent.wVirtualKeyCode;
		/*
		 * There are 24 virtual function-keys, and typically
		 * 12 function-keys on a keyboard.  Use the shift-modifier
		 * to provide the remaining 12 keys.
		 */
		if (vk >= VK_F1 && vk <= VK_F12) {
		    if (inp_rec.Event.KeyEvent.dwControlKeyState &
			SHIFT_PRESSED) {
			vk = (WORD) (vk + 12);
		    }
		}
		if (*buf == 0) {
		    int key = MapKey(vk);
		    if (key < 0)
			continue;
		    if (sp->_keypad_on) {
			*buf = key;
		    } else {
			ungetch('\0');
			*buf = AnsiKey(vk);
		    }
		}
		break;
	    } else if (inp_rec.EventType == MOUSE_EVENT) {
		if (handle_mouse(sp,
				 inp_rec.Event.MouseEvent)) {
		    *buf = KEY_MOUSE;
		    break;
		}
	    }
	    continue;
	}
    }
    returnCode(rc);
}

/*   Our replacement for the systems _isatty to include also
     a test for mintty. This is called from the NC_ISATTY macro
     defined in curses.priv.h

     Return codes:
     - 0 : Not a TTY
     - 1 : A Windows character device detected by _isatty
     - 2 : A future implementation may return 2 for mintty
 */
NCURSES_EXPORT(int)
_nc_console_isatty(int fd)
{
    int result = 0;
    T((T_CALLED("lib_win32con::_nc_console_isatty(%d"), fd));

    if (_isatty(fd))
	result = 1;
#ifdef _NC_CHECK_MINTTY
    else {
	if (_nc_console_checkmintty(fd, NULL)) {
	    result = 2;
	    fprintf(stderr,
		    "ncurses on Windows must run in a Windows console.\n"
		    "On newer versions of Windows, the calling program should create a PTY-like.\n"
		    "device using the CreatePseudoConsole Windows API call.\n");
	    exit(EXIT_FAILURE);
	}
    }
#endif
    returnCode(result);
}

NCURSES_EXPORT(bool)
_nc_console_checkinit(bool initFlag, bool assumeTermInfo)
{
    bool res = FALSE;

    T((T_CALLED("lib_win32con::_nc_console_checkinit(initFlag=%d, assumeTermInfo=%d)"),
       initFlag, assumeTermInfo));

    if (!initFlag) {
	res = console_initialized;
    } else {
	/* initialize once, or not at all */
	if (!console_initialized) {
	    int i;
	    DWORD num_buttons;
	    WORD a;
	    BOOL buffered = FALSE;
	    BOOL b;

	    START_TRACE();
	    WINCONSOLE.isTermInfoConsole = assumeTermInfo;

	    WINCONSOLE.map = (LPDWORD) malloc(sizeof(DWORD) * MAPSIZE);
	    WINCONSOLE.rmap = (LPDWORD) malloc(sizeof(DWORD) * MAPSIZE);
	    WINCONSOLE.ansi_map = (LPDWORD) malloc(sizeof(DWORD) * MAPSIZE);

	    for (i = 0; i < (N_INI + FKEYS); i++) {
		if (i < N_INI) {
		    WINCONSOLE.rmap[i] = WINCONSOLE.map[i] =
			(DWORD) keylist[i];
		    WINCONSOLE.ansi_map[i] = (DWORD) ansi_keys[i];
		} else {
		    WINCONSOLE.rmap[i] = WINCONSOLE.map[i] =
			(DWORD) GenMap((VK_F1 + (i - N_INI)),
				       (KEY_F(1) + (i - N_INI)));
		    WINCONSOLE.ansi_map[i] =
			(DWORD) GenMap((VK_F1 + (i - N_INI)),
				       (';' + (i - N_INI)));
		}
	    }
	    qsort(WINCONSOLE.ansi_map,
		  (size_t) (MAPSIZE),
		  sizeof(keylist[0]),
		  keycompare);
	    qsort(WINCONSOLE.map,
		  (size_t) (MAPSIZE),
		  sizeof(keylist[0]),
		  keycompare);
	    qsort(WINCONSOLE.rmap,
		  (size_t) (MAPSIZE),
		  sizeof(keylist[0]),
		  rkeycompare);

	    if (GetNumberOfConsoleMouseButtons(&num_buttons)) {
		WINCONSOLE.numButtons = (int) num_buttons;
	    } else {
		WINCONSOLE.numButtons = 1;
	    }

	    a = _nc_console_MapColor(true, COLOR_WHITE) |
		_nc_console_MapColor(false, COLOR_BLACK);
	    for (i = 0; i < CON_NUMPAIRS; i++)
		WINCONSOLE.pairs[i] = a;

#define SaveConsoleMode(handle, value) \
            GetConsoleMode(WINCONSOLE.handle, &WINCONSOLE.originalMode.value)

	    if (WINCONSOLE.isTermInfoConsole) {
		WINCONSOLE.inp = GetStdHandle(STD_INPUT_HANDLE);
		WINCONSOLE.out = GetStdHandle(STD_OUTPUT_HANDLE);
		WINCONSOLE.hdl = WINCONSOLE.out;

		SaveConsoleMode(inp, dwFlagIn);
		SaveConsoleMode(out, dwFlagOut);

	    } else {
		b = AllocConsole();

		if (!b)
		    b = AttachConsole(ATTACH_PARENT_PROCESS);

		WINCONSOLE.inp = GetDirectHandle("CONIN$", FILE_SHARE_READ);
		WINCONSOLE.out = GetDirectHandle("CONOUT$", FILE_SHARE_WRITE);

		SaveConsoleMode(inp, dwFlagIn);
		SaveConsoleMode(out, dwFlagOut);

		if (getenv("NCGDB") || getenv("NCURSES_CONSOLE2")) {
		    WINCONSOLE.hdl = WINCONSOLE.out;
		    T(("... will not buffer console"));
		} else {
		    T(("... creating console buffer"));
		    WINCONSOLE.hdl =
			CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE,
						  FILE_SHARE_READ | FILE_SHARE_WRITE,
						  NULL,
						  CONSOLE_TEXTMODE_BUFFER,
						  NULL);
		    buffered = TRUE;
		}
	    }

	    /* We set binary I/O even when using the console
	       driver to cover the situation, that the
	       TERM variable is set to #win32con, but actually
	       Windows supports virtual terminal processing.
	       So if terminfo functions are used in this setup,
	       they actually may work.
	     */
	    _setmode(fileno(stdin), _O_BINARY);
	    _setmode(fileno(stdout), _O_BINARY);

	    if (WINCONSOLE.hdl != INVALID_HANDLE_VALUE) {
		WINCONSOLE.buffered = buffered;
		_nc_console_get_SBI();
		WINCONSOLE.save_SBI = WINCONSOLE.SBI;
		if (!buffered) {
		    save_original_screen();
		    _nc_console_set_scrollback(FALSE, &WINCONSOLE.SBI);
		}
		GetConsoleCursorInfo(WINCONSOLE.hdl, &WINCONSOLE.save_CI);
		T(("... initial cursor is %svisible, %d%%",
		   (WINCONSOLE.save_CI.bVisible ? "" : "not-"),
		   (int) WINCONSOLE.save_CI.dwSize));
	    }

	    WINCONSOLE.initialized = TRUE;
	    console_initialized = TRUE;
	}
	res = (WINCONSOLE.hdl != INVALID_HANDLE_VALUE);
    }
    returnBool(res);
}

#endif // _NC_WINDOWS