path: root/app/xterm/util.c

/* $XTermId: util.c,v 1.587 2012/05/10 11:06:37 tom Exp $ */

/*
 * Copyright 1999-2011,2012 by Thomas E. Dickey
 *
 *                         All Rights Reserved
 *
 * 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, 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 LISTED COPYRIGHT HOLDER(S) 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.
 *
 *
 * Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
 *
 *                         All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and that
 * both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of Digital Equipment
 * Corporation not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior permission.
 *
 *
 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/* util.c */

#include <xterm.h>

#include <data.h>
#include <error.h>
#include <menu.h>
#include <fontutils.h>
#include <xstrings.h>

#include <stdio.h>
#include <ctype.h>
#include <assert.h>

#if OPT_WIDE_CHARS
#if defined(HAVE_WCHAR_H) && defined(HAVE_WCWIDTH)
#include <wchar.h>
#endif
#include <wcwidth.h>
#endif

static int handle_translated_exposure(XtermWidget xw,
				      int rect_x,
				      int rect_y,
				      int rect_width,
				      int rect_height);
static void ClearLeft(XtermWidget xw);
static void CopyWait(XtermWidget xw);
static void horizontal_copy_area(XtermWidget xw,
				 int firstchar,
				 int nchars,
				 int amount);
static void vertical_copy_area(XtermWidget xw,
			       int firstline,
			       int nlines,
			       int amount,
			       int left,
			       int right);

#if OPT_WIDE_CHARS
unsigned first_widechar;
int (*my_wcwidth) (wchar_t);
#endif

#if OPT_WIDE_CHARS
/*
 * We will modify the 'n' cells beginning at the current position.
 * Some of those cells may be part of multi-column characters, including
 * carryover from the left.  Find the limits of the multi-column characters
 * that we should fill with blanks, return true if filling is needed.
 */
int
DamagedCells(TScreen * screen, unsigned n, int *klp, int *krp, int row, int col)
{
    LineData *ld = getLineData(screen, row);
    int result = False;

    assert(ld);
    if (col < (int) ld->lineSize) {
	int nn = (int) n;
	int kl = col;
	int kr = col + nn;

	if (kr >= (int) ld->lineSize) {
	    nn = (ld->lineSize - col - 1);
	    kr = col + nn;
	}

	if (nn > 0) {
	    assert(kl < (int) ld->lineSize);
	    if (ld->charData[kl] == HIDDEN_CHAR) {
		while (kl > 0) {
		    if (ld->charData[--kl] != HIDDEN_CHAR) {
			break;
		    }
		}
	    } else {
		kl = col + 1;
	    }

	    assert(kr < (int) ld->lineSize);
	    if (ld->charData[kr] == HIDDEN_CHAR) {
		while (kr < screen->max_col) {
		    assert((kr + 1) < (int) ld->lineSize);
		    if (ld->charData[++kr] != HIDDEN_CHAR) {
			--kr;
			break;
		    }
		}
	    } else {
		kr = col - 1;
	    }

	    if (klp)
		*klp = kl;
	    if (krp)
		*krp = kr;
	    result = (kr >= kl);
	}
    }

    return result;
}

int
DamagedCurCells(TScreen * screen, unsigned n, int *klp, int *krp)
{
    return DamagedCells(screen, n, klp, krp, screen->cur_row, screen->cur_col);
}
#endif /* OPT_WIDE_CHARS */

/*
 * These routines are used for the jump scroll feature
 */
void
FlushScroll(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    int i;
    int shift = INX2ROW(screen, 0);
    int bot = screen->max_row - shift;
    int refreshtop;
    int refreshheight;
    int scrolltop;
    int scrollheight;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);
    Boolean full_lines = (Boolean) ((left == 0) && (right == screen->max_col));

    if (screen->cursor_state)
	HideCursor();

    TRACE(("FlushScroll %s-lines scroll:%d refresh %d\n",
	   full_lines ? "full" : "partial",
	   screen->scroll_amt,
	   screen->refresh_amt));

    if (screen->scroll_amt > 0) {
	/*
	 * Lines will be scrolled "up".
	 */
	refreshheight = screen->refresh_amt;
	scrollheight = screen->bot_marg - screen->top_marg - refreshheight + 1;
	refreshtop = screen->bot_marg - refreshheight + 1 + shift;
	i = screen->max_row - screen->scroll_amt + 1;
	if (refreshtop > i) {
	    refreshtop = i;
	}

	/*
	 * If this is the normal (not alternate) screen, and the top margin is
	 * at the top of the screen, then we will shift full lines scrolled out
	 * of the scrolling region into the saved-lines.
	 */
	if (screen->scrollWidget
	    && !screen->whichBuf
	    && full_lines
	    && screen->top_marg == 0) {
	    scrolltop = 0;
	    scrollheight += shift;
	    if (scrollheight > i)
		scrollheight = i;
	    i = screen->bot_marg - bot;
	    if (i > 0) {
		refreshheight -= i;
		if (refreshheight < screen->scroll_amt) {
		    refreshheight = screen->scroll_amt;
		}
	    }
	    i = screen->savedlines;
	    if (i < screen->savelines) {
		i += screen->scroll_amt;
		if (i > screen->savelines) {
		    i = screen->savelines;
		}
		screen->savedlines = i;
		ScrollBarDrawThumb(screen->scrollWidget);
	    }
	} else {
	    scrolltop = screen->top_marg + shift;
	    i = bot - (screen->bot_marg - screen->refresh_amt + screen->scroll_amt);
	    if (i > 0) {
		if (bot < screen->bot_marg) {
		    refreshheight = screen->scroll_amt + i;
		}
	    } else {
		scrollheight += i;
		refreshheight = screen->scroll_amt;
		i = screen->top_marg + screen->scroll_amt - 1 - bot;
		if (i > 0) {
		    refreshtop += i;
		    refreshheight -= i;
		}
	    }
	}
    } else {
	/*
	 * Lines will be scrolled "down".
	 */
	refreshheight = -screen->refresh_amt;
	scrollheight = screen->bot_marg - screen->top_marg - refreshheight + 1;
	refreshtop = screen->top_marg + shift;
	scrolltop = refreshtop + refreshheight;
	i = screen->bot_marg - bot;
	if (i > 0) {
	    scrollheight -= i;
	}
	i = screen->top_marg + refreshheight - 1 - bot;
	if (i > 0) {
	    refreshheight -= i;
	}
    }

    vertical_copy_area(xw,
		       scrolltop + screen->scroll_amt,
		       scrollheight,
		       screen->scroll_amt,
		       left,
		       right);
    ScrollSelection(screen, -(screen->scroll_amt), False);
    screen->scroll_amt = 0;
    screen->refresh_amt = 0;

    if (refreshheight > 0) {
	ClearCurBackground(xw,
			   refreshtop,
			   left,
			   (unsigned) refreshheight,
			   (unsigned) (right + 1 - left),
			   (unsigned) FontWidth(screen));
	ScrnRefresh(xw,
		    refreshtop,
		    0,
		    refreshheight,
		    MaxCols(screen),
		    False);
    }
    return;
}

/*
 * Returns true if there are lines off-screen due to scrolling which should
 * include the current line.  If false, the line is visible and we should
 * paint it now rather than waiting for the line to become visible.
 */
static Bool
AddToRefresh(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    int amount = screen->refresh_amt;
    int row = screen->cur_row;
    Bool result;

    if (amount == 0) {
	result = False;
    } else if (amount > 0) {
	int bottom;

	if (row == (bottom = screen->bot_marg) - amount) {
	    screen->refresh_amt++;
	    result = True;
	} else {
	    result = (row >= bottom - amount + 1 && row <= bottom);
	}
    } else {
	int top;

	amount = -amount;
	if (row == (top = screen->top_marg) + amount) {
	    screen->refresh_amt--;
	    result = True;
	} else {
	    result = (row <= top + amount - 1 && row >= top);
	}
    }

    /*
     * If this line is visible, and there are scrolled-off lines, flush out
     * those which are now visible.
     */
    if (!result && screen->scroll_amt)
	FlushScroll(xw);

    return result;
}

/*
 * Returns true if the current row is in the visible area (it should be for
 * screen operations) and incidentally flush the scrolled-in lines which
 * have newly become visible.
 */
static Bool
AddToVisible(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    Bool result = False;

    if (INX2ROW(screen, screen->cur_row) <= screen->max_row) {
	if (!AddToRefresh(xw)) {
	    result = True;
	}
    }
    return result;
}

/*
 * If we're scrolling, leave the selection intact if possible.
 * If it will bump into one of the extremes of the saved-lines, truncate that.
 * If the selection is not entirely contained within the margins and not
 * entirely outside the margins, clear it.
 */
static void
adjustHiliteOnFwdScroll(XtermWidget xw, int amount, Bool all_lines)
{
    TScreen *screen = TScreenOf(xw);
    int lo_row = (all_lines
		  ? (screen->bot_marg - screen->savelines)
		  : screen->top_marg);
    int hi_row = screen->bot_marg;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);

    TRACE2(("adjustSelection FWD %s by %d (%s)\n",
	    screen->whichBuf ? "alternate" : "normal",
	    amount,
	    all_lines ? "all" : "visible"));
    TRACE2(("  before highlite %d.%d .. %d.%d\n",
	    screen->startH.row,
	    screen->startH.col,
	    screen->endH.row,
	    screen->endH.col));
    TRACE2(("  margins %d..%d\n", screen->top_marg, screen->bot_marg));
    TRACE2(("  limits  %d..%d\n", lo_row, hi_row));

    if ((left > 0 || right < screen->max_col) &&
	((screen->startH.row >= lo_row &&
	  screen->startH.row - amount <= hi_row) ||
	 (screen->endH.row >= lo_row &&
	  screen->endH.row - amount <= hi_row))) {
	/*
	 * This could be improved slightly by excluding the special case where
	 * the selection is on a single line outside left/right margins.
	 */
	TRACE2(("deselect because selection overlaps with scrolled partial-line\n"));
	ScrnDisownSelection(xw);
    } else if (screen->startH.row >= lo_row
	       && screen->startH.row - amount < lo_row) {
	/* truncate the selection because its start would move out of region */
	if (lo_row + amount <= screen->endH.row) {
	    TRACE2(("truncate selection by changing start %d.%d to %d.%d\n",
		    screen->startH.row,
		    screen->startH.col,
		    lo_row + amount,
		    0));
	    screen->startH.row = lo_row + amount;
	    screen->startH.col = 0;
	} else {
	    TRACE2(("deselect because %d.%d .. %d.%d shifted %d is outside margins %d..%d\n",
		    screen->startH.row,
		    screen->startH.col,
		    screen->endH.row,
		    screen->endH.col,
		    -amount,
		    lo_row,
		    hi_row));
	    ScrnDisownSelection(xw);
	}
    } else if (screen->startH.row <= hi_row && screen->endH.row > hi_row) {
	TRACE2(("deselect because selection straddles top-margin\n"));
	ScrnDisownSelection(xw);
    } else if (screen->startH.row < lo_row && screen->endH.row > lo_row) {
	TRACE2(("deselect because selection straddles bottom-margin\n"));
	ScrnDisownSelection(xw);
    }

    TRACE2(("  after highlite %d.%d .. %d.%d\n",
	    screen->startH.row,
	    screen->startH.col,
	    screen->endH.row,
	    screen->endH.col));
}

/*
 * This is the same as adjustHiliteOnFwdScroll(), but reversed.  In this case,
 * only the visible lines are affected.
 */
static void
adjustHiliteOnBakScroll(XtermWidget xw, int amount)
{
    TScreen *screen = TScreenOf(xw);
    int lo_row = screen->top_marg;
    int hi_row = screen->bot_marg;

    TRACE2(("adjustSelection BAK %s by %d (%s)\n",
	    screen->whichBuf ? "alternate" : "normal",
	    amount,
	    "visible"));
    TRACE2(("  before highlite %d.%d .. %d.%d\n",
	    screen->startH.row,
	    screen->startH.col,
	    screen->endH.row,
	    screen->endH.col));
    TRACE2(("  margins %d..%d\n", screen->top_marg, screen->bot_marg));

    if (screen->endH.row >= hi_row
	&& screen->endH.row + amount > hi_row) {
	/* truncate the selection because its start would move out of region */
	if (hi_row - amount >= screen->startH.row) {
	    TRACE2(("truncate selection by changing start %d.%d to %d.%d\n",
		    screen->startH.row,
		    screen->startH.col,
		    hi_row - amount,
		    0));
	    screen->endH.row = hi_row - amount;
	    screen->endH.col = 0;
	} else {
	    TRACE2(("deselect because %d.%d .. %d.%d shifted %d is outside margins %d..%d\n",
		    screen->startH.row,
		    screen->startH.col,
		    screen->endH.row,
		    screen->endH.col,
		    amount,
		    lo_row,
		    hi_row));
	    ScrnDisownSelection(xw);
	}
    } else if (screen->endH.row >= lo_row && screen->startH.row < lo_row) {
	ScrnDisownSelection(xw);
    } else if (screen->endH.row > hi_row && screen->startH.row > hi_row) {
	ScrnDisownSelection(xw);
    }

    TRACE2(("  after highlite %d.%d .. %d.%d\n",
	    screen->startH.row,
	    screen->startH.col,
	    screen->endH.row,
	    screen->endH.col));
}

/*
 * Move cells in LineData's on the current screen to simulate scrolling by the
 * given amount of lines.
 */
static void
scrollInMargins(XtermWidget xw, int amount, int top)
{
    TScreen *screen = TScreenOf(xw);
    LineData *src;
    LineData *dst;
    int row;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);
    int length = right + 1 - left;

    if (amount > 0) {
	for (row = top; row <= screen->bot_marg - amount; ++row) {
	    if ((src = getLineData(screen, row + amount)) != 0
		&& (dst = getLineData(screen, row)) != 0) {
		CopyCells(screen, src, dst, left, length);
	    }
	}
	while (row <= screen->bot_marg) {
	    ClearCells(xw, 0, (unsigned) length, row, left);
	    ++row;
	}
    } else if (amount < 0) {
	for (row = screen->bot_marg; row >= top - amount; --row) {
	    if ((src = getLineData(screen, row + amount)) != 0
		&& (dst = getLineData(screen, row)) != 0) {
		CopyCells(screen, src, dst, left, length);
	    }
	}
	while (row >= top) {
	    ClearCells(xw, 0, (unsigned) length, row, left);
	    --row;
	}
    }
}

/*
 * scrolls the screen by amount lines, erases bottom, doesn't alter
 * cursor position (i.e. cursor moves down amount relative to text).
 * All done within the scrolling region, of course.
 * requires: amount > 0
 */
void
xtermScroll(XtermWidget xw, int amount)
{
    TScreen *screen = TScreenOf(xw);
    int i;
    int shift;
    int bot;
    int refreshtop = 0;
    int refreshheight;
    int scrolltop;
    int scrollheight;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);
    Boolean scroll_all_lines = (Boolean) (screen->scrollWidget
					  && !screen->whichBuf
					  && screen->top_marg == 0);

    TRACE(("xtermScroll count=%d\n", amount));

    screen->cursor_busy += 1;
    screen->cursor_moved = True;

    if (screen->cursor_state)
	HideCursor();

    i = screen->bot_marg - screen->top_marg + 1;
    if (amount > i)
	amount = i;

#if OPT_SCROLL_LOCK
    if (screen->allowScrollLock && screen->scroll_lock) {
	refreshheight = 0;
	screen->scroll_amt = 0;
	screen->refresh_amt = 0;
	if (--(screen->topline) < -screen->savelines) {
	    screen->topline = -screen->savelines;
	    screen->scroll_dirty = True;
	}
	if (++(screen->savedlines) > screen->savelines) {
	    screen->savedlines = screen->savelines;
	}
    } else
#endif
    {
	if (ScrnHaveSelection(screen))
	    adjustHiliteOnFwdScroll(xw, amount, scroll_all_lines);

	if (screen->jumpscroll) {
	    if (screen->scroll_amt > 0) {
		if (!screen->fastscroll) {
		    if (screen->refresh_amt + amount > i)
			FlushScroll(xw);
		}
		screen->scroll_amt += amount;
		screen->refresh_amt += amount;
	    } else {
		if (!screen->fastscroll) {
		    if (screen->scroll_amt < 0)
			FlushScroll(xw);
		}
		screen->scroll_amt = amount;
		screen->refresh_amt = amount;
	    }
	    refreshheight = 0;
	} else {
	    ScrollSelection(screen, -(amount), False);
	    if (amount == i) {
		ClearScreen(xw);
		screen->cursor_busy -= 1;
		return;
	    }

	    shift = INX2ROW(screen, 0);
	    bot = screen->max_row - shift;
	    scrollheight = i - amount;
	    refreshheight = amount;

	    if ((refreshtop = screen->bot_marg - refreshheight + 1 + shift) >
		(i = screen->max_row - refreshheight + 1))
		refreshtop = i;

	    if (scroll_all_lines) {
		scrolltop = 0;
		if ((scrollheight += shift) > i)
		    scrollheight = i;
		if ((i = screen->savedlines) < screen->savelines) {
		    if ((i += amount) > screen->savelines)
			i = screen->savelines;
		    screen->savedlines = i;
		    ScrollBarDrawThumb(screen->scrollWidget);
		}
	    } else {
		scrolltop = screen->top_marg + shift;
		if ((i = screen->bot_marg - bot) > 0) {
		    scrollheight -= i;
		    if ((i = screen->top_marg + amount - 1 - bot) >= 0) {
			refreshtop += i;
			refreshheight -= i;
		    }
		}
	    }

	    if (screen->multiscroll && amount == 1 &&
		screen->topline == 0 && screen->top_marg == 0 &&
		screen->bot_marg == screen->max_row) {
		if (screen->incopy < 0 && screen->scrolls == 0)
		    CopyWait(xw);
		screen->scrolls++;
	    }

	    vertical_copy_area(xw,
			       scrolltop + amount,
			       scrollheight,
			       amount,
			       left,
			       right);

	    if (refreshheight > 0) {
		ClearCurBackground(xw,
				   refreshtop,
				   left,
				   (unsigned) refreshheight,
				   (unsigned) (right + 1 - left),
				   (unsigned) FontWidth(screen));
		if (refreshheight > shift)
		    refreshheight = shift;
	    }
	}
    }

    if (amount > 0) {
	if (left > 0 || right < screen->max_col) {
	    scrollInMargins(xw, amount, screen->top_marg);
	} else if (scroll_all_lines) {
	    ScrnDeleteLine(xw,
			   screen->saveBuf_index,
			   screen->bot_marg + screen->savelines,
			   0,
			   (unsigned) amount);
	} else {
	    ScrnDeleteLine(xw,
			   screen->visbuf,
			   screen->bot_marg,
			   screen->top_marg,
			   (unsigned) amount);
	}
    }

    if (refreshheight > 0) {
	ScrnRefresh(xw,
		    refreshtop,
		    left,
		    refreshheight,
		    right + 1 - left,
		    False);
    }

    screen->cursor_busy -= 1;
    return;
}

/*
 * This is from ISO 6429, not found in any of DEC's terminals.
 */
void
xtermScrollLR(XtermWidget xw, int amount, Bool toLeft)
{
    if (amount > 0) {
	xtermColScroll(xw, amount, toLeft, 0);
    }
}

/*
 * Implement DECBI/DECFI (back/forward column index)
 */
void
xtermColIndex(XtermWidget xw, Bool toLeft)
{
    TScreen *screen = TScreenOf(xw);
    int margin;

    if (toLeft) {
	margin = ScrnLeftMargin(xw);
	if (screen->cur_col > margin) {
	    CursorBack(xw, 1);
	} else if (screen->cur_col == margin) {
	    xtermColScroll(xw, 1, False, screen->cur_col);
	}
    } else {
	margin = ScrnRightMargin(xw);
	if (screen->cur_col < margin) {
	    CursorForward(xw, 1);
	} else if (screen->cur_col == margin) {
	    xtermColScroll(xw, 1, True, ScrnLeftMargin(xw));
	}
    }
}

/*
 * Implement DECDC/DECIC (delete/insert column)
 */
void
xtermColScroll(XtermWidget xw, int amount, Bool toLeft, int at_col)
{
    TScreen *screen = TScreenOf(xw);

    if (amount > 0) {
	int min_row;
	int max_row;

	if (ScrnHaveRowMargins(screen)) {
	    min_row = screen->top_marg;
	    max_row = screen->bot_marg;
	} else {
	    min_row = 0;
	    max_row = screen->max_row;
	}

	if (screen->cur_row >= min_row
	    && screen->cur_row <= max_row
	    && screen->cur_col >= screen->lft_marg
	    && screen->cur_col <= screen->rgt_marg) {
	    int save_row = screen->cur_row;
	    int save_col = screen->cur_col;
	    int row;

	    screen->cur_col = at_col;
	    if (toLeft) {
		for (row = min_row; row <= max_row; row++) {
		    screen->cur_row = row;
		    ScrnDeleteChar(xw, (unsigned) amount);
		}
	    } else {
		for (row = min_row; row <= max_row; row++) {
		    screen->cur_row = row;
		    ScrnInsertChar(xw, (unsigned) amount);
		}
	    }
	    screen->cur_row = save_row;
	    screen->cur_col = save_col;
	    xtermRepaint(xw);
	}
    }
}

/*
 * Reverse scrolls the screen by amount lines, erases top, doesn't alter
 * cursor position (i.e. cursor moves up amount relative to text).
 * All done within the scrolling region, of course.
 * Requires: amount > 0
 */
void
RevScroll(XtermWidget xw, int amount)
{
    TScreen *screen = TScreenOf(xw);
    int i = screen->bot_marg - screen->top_marg + 1;
    int shift;
    int bot;
    int refreshtop;
    int refreshheight;
    int scrolltop;
    int scrollheight;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);

    TRACE(("RevScroll count=%d\n", amount));

    screen->cursor_busy += 1;
    screen->cursor_moved = True;

    if (screen->cursor_state)
	HideCursor();

    if (amount > i)
	amount = i;

    if (ScrnHaveSelection(screen))
	adjustHiliteOnBakScroll(xw, amount);

    if (screen->jumpscroll) {
	if (screen->scroll_amt < 0) {
	    if (-screen->refresh_amt + amount > i)
		FlushScroll(xw);
	    screen->scroll_amt -= amount;
	    screen->refresh_amt -= amount;
	} else {
	    if (screen->scroll_amt > 0)
		FlushScroll(xw);
	    screen->scroll_amt = -amount;
	    screen->refresh_amt = -amount;
	}
    } else {
	shift = INX2ROW(screen, 0);
	bot = screen->max_row - shift;
	refreshheight = amount;
	scrollheight = screen->bot_marg - screen->top_marg - refreshheight + 1;
	refreshtop = screen->top_marg + shift;
	scrolltop = refreshtop + refreshheight;
	if ((i = screen->bot_marg - bot) > 0)
	    scrollheight -= i;
	if ((i = screen->top_marg + refreshheight - 1 - bot) > 0)
	    refreshheight -= i;

	if (screen->multiscroll && amount == 1 &&
	    screen->topline == 0 && screen->top_marg == 0 &&
	    screen->bot_marg == screen->max_row) {
	    if (screen->incopy < 0 && screen->scrolls == 0)
		CopyWait(xw);
	    screen->scrolls++;
	}

	vertical_copy_area(xw,
			   scrolltop - amount,
			   scrollheight,
			   -amount,
			   left,
			   right);

	if (refreshheight > 0) {
	    ClearCurBackground(xw,
			       refreshtop,
			       left,
			       (unsigned) refreshheight,
			       (unsigned) (right + 1 - left),
			       (unsigned) FontWidth(screen));
	}
    }
    if (amount > 0) {
	if (left > 0 || right < screen->max_col) {
	    scrollInMargins(xw, -amount, screen->top_marg);
	} else {
	    ScrnInsertLine(xw,
			   screen->visbuf,
			   screen->bot_marg,
			   screen->top_marg,
			   (unsigned) amount);
	}
    }
    screen->cursor_busy -= 1;
    return;
}

#if OPT_ZICONBEEP
void
initZIconBeep(void)
{
    if (resource.zIconBeep > 100 || resource.zIconBeep < -100) {
	resource.zIconBeep = 0;	/* was 100, but I prefer to defaulting off. */
	xtermWarning("a number between -100 and 100 is required for zIconBeep.  0 used by default\n");
    }
}

static void
setZIconBeep(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    /* Flag icon name with "***"  on window output when iconified.
     */
    if (resource.zIconBeep && mapstate == IsUnmapped && !screen->zIconBeep_flagged) {
	static char *icon_name;
	static Arg args[] =
	{
	    {XtNiconName, (XtArgVal) & icon_name}
	};

	icon_name = NULL;
	XtGetValues(toplevel, args, XtNumber(args));

	if (icon_name != NULL) {
	    screen->zIconBeep_flagged = True;
	    ChangeIconName(xw, icon_name);
	}
	xtermBell(xw, XkbBI_Info, 0);
    }
    mapstate = -1;
}

/*
 * If warning should be given then give it
 */
Boolean
showZIconBeep(XtermWidget xw, char *name)
{
    Boolean code = False;

    if (resource.zIconBeep && TScreenOf(xw)->zIconBeep_flagged) {
	char *format = resource.zIconFormat;
	char *newname = CastMallocN(char, strlen(name) + strlen(format) + 1);
	if (!newname) {
	    xtermWarning("malloc failed in showZIconBeep\n");
	} else {
	    char *marker = strstr(format, "%s");
	    char *result = newname;
	    if (marker != 0) {
		size_t skip = (size_t) (marker - format);
		if (skip) {
		    strncpy(result, format, skip);
		    result += skip;
		}
		strcpy(result, name);
		strcat(result, marker + 2);
	    } else {
		strcpy(result, format);
		strcat(result, name);
	    }
	    ChangeGroup(xw, XtNiconName, newname);
	    free(newname);
	}
	code = True;
    }
    return code;
}

/*
 * Restore the icon name, resetting the state for zIconBeep.
 */
void
resetZIconBeep(XtermWidget xw)
{
    static char *icon_name;
    static Arg args[] =
    {
	{XtNiconName, (XtArgVal) & icon_name}
    };
    TScreen *screen = TScreenOf(xw);

    if (screen->zIconBeep_flagged) {
	screen->zIconBeep_flagged = False;
	icon_name = NULL;
	XtGetValues(toplevel, args, XtNumber(args));
	if (icon_name != NULL) {
	    char *buf = CastMallocN(char, strlen(icon_name));
	    if (buf == NULL) {
		screen->zIconBeep_flagged = True;
	    } else {
		char *format = resource.zIconFormat;
		char *marker = strstr(format, "%s");
		Boolean found = False;

		if (marker != 0) {
		    if (marker == format
			|| !strncmp(icon_name, format, (size_t) (marker - format))) {
			found = True;
			strcpy(buf, icon_name + (marker - format));
			marker += 2;
			if (*marker != '\0') {
			    size_t len_m = strlen(marker);
			    size_t len_b = strlen(buf);
			    if (len_m < len_b
				&& !strcmp(buf + len_b - len_m, marker)) {
				buf[len_b - len_m] = '\0';
			    }
			}
		    }
		} else if (!strncmp(icon_name, format, strlen(format))) {
		    strcpy(buf, icon_name + strlen(format));
		    found = True;
		}
		if (found)
		    ChangeIconName(xw, buf);
		free(buf);
	    }
	}
    }
}
#else
#define setZIconBeep(xw)	/* nothing */
#endif /* OPT_ZICONBEEP */

/*
 * write a string str of length len onto the screen at
 * the current cursor position.  update cursor position.
 */
void
WriteText(XtermWidget xw, IChar * str, Cardinal len)
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld = 0;
    int fg;
    unsigned test;
    unsigned flags = xw->flags;
    CellColor fg_bg = makeColorPair(xw->cur_foreground, xw->cur_background);
    unsigned cells = visual_width(str, len);
    GC currentGC;

    TRACE(("WriteText %d (%2d,%2d) %3d:%s\n",
	   screen->topline,
	   screen->cur_row,
	   screen->cur_col,
	   len, visibleIChar(str, len)));

    if (cells + (unsigned) screen->cur_col > (unsigned) MaxCols(screen)) {
	cells = (unsigned) (MaxCols(screen) - screen->cur_col);
    }

    if (ScrnHaveSelection(screen)
	&& ScrnIsRowInSelection(screen, INX2ROW(screen, screen->cur_row))) {
	ScrnDisownSelection(xw);
    }

    /* if we are in insert-mode, reserve space for the new cells */
    if (flags & INSERT) {
	InsertChar(xw, cells);
    }

    if (AddToVisible(xw)
	&& ((ld = getLineData(screen, screen->cur_row))) != 0) {
	if (screen->cursor_state)
	    HideCursor();

	/*
	 * If we overwrite part of a multi-column character, fill the rest
	 * of it with blanks.
	 */
	if_OPT_WIDE_CHARS(screen, {
	    int kl;
	    int kr;
	    if (DamagedCurCells(screen, cells, &kl, &kr))
		ClearInLine(xw, screen->cur_row, kl, (unsigned) (kr - kl + 1));
	});

	if (flags & INVISIBLE) {
	    Cardinal n;
	    for (n = 0; n < cells; ++n)
		str[n] = ' ';
	}

	TRACE(("WriteText calling drawXtermText (%d) (%d,%d)\n",
	       LineCharSet(screen, ld),
	       screen->cur_col,
	       screen->cur_row));

	test = flags;
#if OPT_ISO_COLORS
	if (screen->colorAttrMode) {
	    fg = MapToColorMode(xw->cur_foreground, screen, flags);
	} else {
	    fg = xw->cur_foreground;
	}
	checkVeryBoldColors(test, fg);
#endif

	/* make sure that the correct GC is current */
	currentGC = updatedXtermGC(xw, flags, fg_bg, False);

	drawXtermText(xw, test & DRAWX_MASK, currentGC,
		      LineCursorX(screen, ld, screen->cur_col),
		      CursorY(screen, screen->cur_row),
		      LineCharSet(screen, ld),
		      str, len, 0);

	resetXtermGC(xw, flags, False);
    }

    ScrnWriteText(xw, str, flags, fg_bg, len);
    CursorForward(xw, (int) cells);
    setZIconBeep(xw);
    return;
}

/*
 * If cursor not in scrolling region, returns.  Else,
 * inserts n blank lines at the cursor's position.  Lines above the
 * bottom margin are lost.
 */
void
InsertLine(XtermWidget xw, int n)
{
    TScreen *screen = TScreenOf(xw);
    int i;
    int shift;
    int bot;
    int refreshtop;
    int refreshheight;
    int scrolltop;
    int scrollheight;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);

    if (!ScrnIsRowInMargins(screen, screen->cur_row)
	|| screen->cur_col < left
	|| screen->cur_col > right)
	return;

    TRACE(("InsertLine count=%d\n", n));

    if (screen->cursor_state)
	HideCursor();

    if (ScrnHaveSelection(screen)
	&& ScrnAreRowsInSelection(screen,
				  INX2ROW(screen, screen->top_marg),
				  INX2ROW(screen, screen->cur_row - 1))
	&& ScrnAreRowsInSelection(screen,
				  INX2ROW(screen, screen->cur_row),
				  INX2ROW(screen, screen->bot_marg))) {
	ScrnDisownSelection(xw);
    }

    screen->do_wrap = False;
    if (n > (i = screen->bot_marg - screen->cur_row + 1))
	n = i;
    if (screen->jumpscroll) {
	if (screen->scroll_amt <= 0 &&
	    screen->cur_row <= -screen->refresh_amt) {
	    if (-screen->refresh_amt + n > MaxRows(screen))
		FlushScroll(xw);
	    screen->scroll_amt -= n;
	    screen->refresh_amt -= n;
	} else {
	    if (screen->scroll_amt)
		FlushScroll(xw);
	}
    }
    if (!screen->scroll_amt) {
	shift = INX2ROW(screen, 0);
	bot = screen->max_row - shift;
	refreshheight = n;
	scrollheight = screen->bot_marg - screen->cur_row - refreshheight + 1;
	refreshtop = screen->cur_row + shift;
	scrolltop = refreshtop + refreshheight;
	if ((i = screen->bot_marg - bot) > 0)
	    scrollheight -= i;
	if ((i = screen->cur_row + refreshheight - 1 - bot) > 0)
	    refreshheight -= i;
	vertical_copy_area(xw, scrolltop - n, scrollheight, -n, left, right);
	if (refreshheight > 0) {
	    ClearCurBackground(xw,
			       refreshtop,
			       left,
			       (unsigned) refreshheight,
			       (unsigned) (right + 1 - left),
			       (unsigned) FontWidth(screen));
	}
    }
    if (n > 0) {
	if (left > 0 || right < screen->max_col) {
	    scrollInMargins(xw, -n, screen->cur_row);
	} else {
	    ScrnInsertLine(xw,
			   screen->visbuf,
			   screen->bot_marg,
			   screen->cur_row,
			   (unsigned) n);
	}
    }
}

/*
 * If cursor not in scrolling region, returns.  Else, deletes n lines
 * at the cursor's position, lines added at bottom margin are blank.
 */
void
DeleteLine(XtermWidget xw, int n)
{
    TScreen *screen = TScreenOf(xw);
    int i;
    int shift;
    int bot;
    int refreshtop;
    int refreshheight;
    int scrolltop;
    int scrollheight;
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);
    Boolean scroll_all_lines = (Boolean) (screen->scrollWidget
					  && !screen->whichBuf
					  && screen->cur_row == 0);

    if (!ScrnIsRowInMargins(screen, screen->cur_row)
	|| screen->cur_col < left
	|| screen->cur_col > right)
	return;

    TRACE(("DeleteLine count=%d\n", n));

    if (screen->cursor_state)
	HideCursor();

    if (n > (i = screen->bot_marg - screen->cur_row + 1)) {
	n = i;
    }
    if (ScrnHaveSelection(screen)
	&& ScrnAreRowsInSelection(screen,
				  INX2ROW(screen, screen->cur_row),
				  INX2ROW(screen, screen->cur_row + n - 1))) {
	ScrnDisownSelection(xw);
    }

    screen->do_wrap = False;
    if (screen->jumpscroll) {
	if (screen->scroll_amt >= 0 && screen->cur_row == screen->top_marg) {
	    if (screen->refresh_amt + n > MaxRows(screen))
		FlushScroll(xw);
	    screen->scroll_amt += n;
	    screen->refresh_amt += n;
	} else {
	    if (screen->scroll_amt)
		FlushScroll(xw);
	}
    }

    /* adjust screen->buf */
    if (n > 0) {
	if (left > 0 || right < screen->max_col) {
	    scrollInMargins(xw, n, screen->cur_row);
	} else if (scroll_all_lines) {
	    ScrnDeleteLine(xw,
			   screen->saveBuf_index,
			   screen->bot_marg + screen->savelines,
			   0,
			   (unsigned) n);
	} else {
	    ScrnDeleteLine(xw,
			   screen->visbuf,
			   screen->bot_marg,
			   screen->cur_row,
			   (unsigned) n);
	}
    }

    /* repaint the screen, as needed */
    if (!screen->scroll_amt) {
	shift = INX2ROW(screen, 0);
	bot = screen->max_row - shift;
	scrollheight = i - n;
	refreshheight = n;
	if ((refreshtop = screen->bot_marg - refreshheight + 1 + shift) >
	    (i = screen->max_row - refreshheight + 1))
	    refreshtop = i;
	if (scroll_all_lines) {
	    scrolltop = 0;
	    if ((scrollheight += shift) > i)
		scrollheight = i;
	    if ((i = screen->savedlines) < screen->savelines) {
		if ((i += n) > screen->savelines)
		    i = screen->savelines;
		screen->savedlines = i;
		ScrollBarDrawThumb(screen->scrollWidget);
	    }
	} else {
	    scrolltop = screen->cur_row + shift;
	    if ((i = screen->bot_marg - bot) > 0) {
		scrollheight -= i;
		if ((i = screen->cur_row + n - 1 - bot) >= 0) {
		    refreshheight -= i;
		}
	    }
	}
	vertical_copy_area(xw, scrolltop + n, scrollheight, n, left, right);
	if (shift > 0 && refreshheight > 0) {
	    int rows = refreshheight;
	    if (rows > shift)
		rows = shift;
	    ScrnUpdate(xw, refreshtop, 0, rows, MaxCols(screen), True);
	    refreshtop += shift;
	    refreshheight -= shift;
	}
	if (refreshheight > 0) {
	    ClearCurBackground(xw,
			       refreshtop,
			       left,
			       (unsigned) refreshheight,
			       (unsigned) (right + 1 - left),
			       (unsigned) FontWidth(screen));
	}
    }
}

/*
 * Insert n blanks at the cursor's position, no wraparound
 */
void
InsertChar(XtermWidget xw, unsigned n)
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld;
    unsigned limit;
    int row = INX2ROW(screen, screen->cur_row);
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);

    if (screen->cursor_state)
	HideCursor();

    TRACE(("InsertChar count=%d\n", n));

    if (ScrnHaveSelection(screen)
	&& ScrnIsRowInSelection(screen, row)) {
	ScrnDisownSelection(xw);
    }
    screen->do_wrap = False;

    limit = (unsigned) (right + 1 - screen->cur_col);

    if (n > limit)
	n = limit;

    if (screen->cur_col < left || screen->cur_col > right) {
	n = 0;
    } else if (AddToVisible(xw)
	       && (ld = getLineData(screen, screen->cur_row)) != 0) {
	int col = right + 1 - (int) n;

	/*
	 * If we shift part of a multi-column character, fill the rest
	 * of it with blanks.  Do similar repair for the text which will
	 * be shifted into the right-margin.
	 */
	if_OPT_WIDE_CHARS(screen, {
	    int kl;
	    int kr = screen->cur_col;
	    if (DamagedCurCells(screen, n, &kl, (int *) 0) && kr > kl) {
		ClearInLine(xw, screen->cur_row, kl, (unsigned) (kr - kl + 1));
	    }
	    kr = screen->max_col - (int) n + 1;
	    if (DamagedCells(screen, n, &kl, (int *) 0,
			     screen->cur_row,
			     kr) && kr > kl) {
		ClearInLine(xw, screen->cur_row, kl, (unsigned) (kr - kl + 1));
	    }
	});

#if OPT_DEC_CHRSET
	if (CSET_DOUBLE(GetLineDblCS(ld))) {
	    col = MaxCols(screen) / 2 - (int) n;
	}
#endif
	/*
	 * prevent InsertChar from shifting the end of a line over
	 * if it is being appended to
	 */
	if (non_blank_line(screen, screen->cur_row,
			   screen->cur_col, MaxCols(screen))) {
	    horizontal_copy_area(xw, screen->cur_col,
				 col - screen->cur_col,
				 (int) n);
	}

	ClearCurBackground(xw,
			   screen->cur_row,
			   screen->cur_col,
			   1,
			   n,
			   (unsigned) LineFontWidth(screen, ld));
    }
    if (n != 0) {
	/* adjust screen->buf */
	ScrnInsertChar(xw, n);
    }
}

/*
 * Deletes n chars at the cursor's position, no wraparound.
 */
void
DeleteChar(XtermWidget xw, unsigned n)
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld;
    unsigned limit;
    int row = INX2ROW(screen, screen->cur_row);
    int left = ScrnLeftMargin(xw);
    int right = ScrnRightMargin(xw);

    if (screen->cursor_state)
	HideCursor();

    TRACE(("DeleteChar count=%d\n", n));

    if (ScrnHaveSelection(screen)
	&& ScrnIsRowInSelection(screen, row)) {
	ScrnDisownSelection(xw);
    }
    screen->do_wrap = False;

    limit = (unsigned) (right + 1 - screen->cur_col);

    if (n > limit)
	n = limit;

    if (screen->cur_col < left || screen->cur_col > right) {
	n = 0;
    } else if (AddToVisible(xw)
	       && (ld = getLineData(screen, screen->cur_row)) != 0) {
	int col = right + 1 - (int) n;

	/*
	 * If we delete part of a multi-column character, fill the rest
	 * of it with blanks.
	 */
	if_OPT_WIDE_CHARS(screen, {
	    int kl;
	    int kr;
	    if (DamagedCurCells(screen, n, &kl, &kr))
		ClearInLine(xw, screen->cur_row, kl, (unsigned) (kr - kl + 1));
	});

#if OPT_DEC_CHRSET
	if (CSET_DOUBLE(GetLineDblCS(ld))) {
	    col = MaxCols(screen) / 2 - (int) n;
	}
#endif
	horizontal_copy_area(xw,
			     (screen->cur_col + (int) n),
			     col - screen->cur_col,
			     -((int) n));

	ClearCurBackground(xw,
			   screen->cur_row,
			   col,
			   1,
			   n,
			   (unsigned) LineFontWidth(screen, ld));
    }
    if (n != 0) {
	/* adjust screen->buf */
	ScrnDeleteChar(xw, n);
    }
}

/*
 * Clear from cursor position to beginning of display, inclusive.
 */
static void
ClearAbove(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    if (screen->protected_mode != OFF_PROTECT) {
	int row;
	unsigned len = (unsigned) MaxCols(screen);

	assert(screen->max_col >= 0);
	for (row = 0; row <= screen->max_row; row++)
	    ClearInLine(xw, row, 0, len);
    } else {
	int top, height;

	if (screen->cursor_state)
	    HideCursor();
	if ((top = INX2ROW(screen, 0)) <= screen->max_row) {
	    if (screen->scroll_amt)
		FlushScroll(xw);
	    if ((height = screen->cur_row + top) > screen->max_row)
		height = screen->max_row + 1;
	    if ((height -= top) > 0) {
		ClearCurBackground(xw,
				   top,
				   0,
				   (unsigned) height,
				   (unsigned) MaxCols(screen),
				   (unsigned) FontWidth(screen));
	    }
	}
	ClearBufRows(xw, 0, screen->cur_row - 1);
    }

    ClearLeft(xw);
}

/*
 * Clear from cursor position to end of display, inclusive.
 */
static void
ClearBelow(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    ClearRight(xw, -1);

    if (screen->protected_mode != OFF_PROTECT) {
	int row;
	unsigned len = (unsigned) MaxCols(screen);

	assert(screen->max_col >= 0);
	for (row = screen->cur_row + 1; row <= screen->max_row; row++)
	    ClearInLine(xw, row, 0, len);
    } else {
	int top;

	if ((top = INX2ROW(screen, screen->cur_row)) <= screen->max_row) {
	    if (screen->scroll_amt)
		FlushScroll(xw);
	    if (++top <= screen->max_row) {
		ClearCurBackground(xw,
				   top,
				   0,
				   (unsigned) (screen->max_row - top + 1),
				   (unsigned) MaxCols(screen),
				   (unsigned) FontWidth(screen));
	    }
	}
	ClearBufRows(xw, screen->cur_row + 1, screen->max_row);
    }
}

/*
 * Clear the given row, for the given range of columns, returning 1 if no
 * protected characters were found, 0 otherwise.
 */
static int
ClearInLine2(XtermWidget xw, int flags, int row, int col, unsigned len)
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld;
    int rc = 1;

    TRACE(("ClearInLine(row=%d, col=%d, len=%d) vs %d..%d\n",
	   row, col, len,
	   screen->startH.row,
	   screen->startH.col));

    if (ScrnHaveSelection(screen)
	&& ScrnIsRowInSelection(screen, row)) {
	ScrnDisownSelection(xw);
    }

    if (col + (int) len >= MaxCols(screen)) {
	len = (unsigned) (MaxCols(screen) - col);
    }

    /* If we've marked protected text on the screen, we'll have to
     * check each time we do an erase.
     */
    if (screen->protected_mode != OFF_PROTECT) {
	unsigned n;
	Char *attrs = getLineData(screen, row)->attribs + col;
	int saved_mode = screen->protected_mode;
	Bool done;

	/* disable this branch during recursion */
	screen->protected_mode = OFF_PROTECT;

	do {
	    done = True;
	    for (n = 0; n < len; n++) {
		if (attrs[n] & PROTECTED) {
		    rc = 0;	/* found a protected segment */
		    if (n != 0) {
			ClearInLine(xw, row, col, n);
		    }
		    while ((n < len)
			   && (attrs[n] & PROTECTED)) {
			n++;
		    }
		    done = False;
		    break;
		}
	    }
	    /* setup for another segment, past the protected text */
	    if (!done) {
		attrs += n;
		col += (int) n;
		len -= n;
	    }
	} while (!done);

	screen->protected_mode = saved_mode;
	if ((int) len <= 0) {
	    return 0;
	}
    }
    /* fall through to the final non-protected segment */

    if (screen->cursor_state)
	HideCursor();
    screen->do_wrap = False;

    if (AddToVisible(xw)
	&& (ld = getLineData(screen, row)) != 0) {

	ClearCurBackground(xw,
			   row,
			   col,
			   1,
			   len,
			   (unsigned) LineFontWidth(screen, ld));
    }

    if (len != 0) {
	ClearCells(xw, flags, len, row, col);
    }

    return rc;
}

int
ClearInLine(XtermWidget xw, int row, int col, unsigned len)
{
    TScreen *screen = TScreenOf(xw);
    int flags = 0;

    /*
     * If we're clearing to the end of the line, we won't count this as
     * "drawn" characters.  We'll only do cut/paste on "drawn" characters,
     * so this has the effect of suppressing trailing blanks from a
     * selection.
     */
    if (col + (int) len < MaxCols(screen)) {
	flags |= CHARDRAWN;
    }
    return ClearInLine2(xw, flags, row, col, len);
}

/*
 * Clear the next n characters on the cursor's line, including the cursor's
 * position.
 */
void
ClearRight(XtermWidget xw, int n)
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld;
    unsigned len = (unsigned) (MaxCols(screen) - screen->cur_col);

    assert(screen->max_col >= 0);
    assert(screen->max_col >= screen->cur_col);

    if (n < 0)			/* the remainder of the line */
	n = MaxCols(screen);
    if (n == 0)			/* default for 'ECH' */
	n = 1;

    if (len > (unsigned) n)
	len = (unsigned) n;

    ld = getLineData(screen, screen->cur_row);
    if (AddToVisible(xw)) {
	if_OPT_WIDE_CHARS(screen, {
	    int col = screen->cur_col;
	    int row = screen->cur_row;
	    int kl;
	    int kr;
	    int xx;
	    if (DamagedCurCells(screen, len, &kl, &kr) && kr >= kl) {
		xx = col;
		if (kl < xx) {
		    ClearInLine2(xw, 0, row, kl, (unsigned) (xx - kl));
		}
		xx = col + (int) len - 1;
		if (kr > xx) {
		    ClearInLine2(xw, 0, row, xx + 1, (unsigned) (kr - xx));
		}
	    }
	});
	(void) ClearInLine(xw, screen->cur_row, screen->cur_col, len);
    } else {
	ScrnClearCells(xw, screen->cur_row, screen->cur_col, len);
    }

    /* with the right part cleared, we can't be wrapping */
    LineClrWrapped(ld);
    if (screen->show_wrap_marks) {
	ShowWrapMarks(xw, screen->cur_row, ld);
    }
    screen->do_wrap = False;
}

/*
 * Clear first part of cursor's line, inclusive.
 */
static void
ClearLeft(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    unsigned len = (unsigned) screen->cur_col + 1;

    assert(screen->cur_col >= 0);
    if (AddToVisible(xw)) {
	if_OPT_WIDE_CHARS(screen, {
	    int row = screen->cur_row;
	    int kl;
	    int kr;
	    if (DamagedCurCells(screen, 1, &kl, &kr) && kr >= kl) {
		ClearInLine2(xw, 0, row, kl, (unsigned) (kr - kl + 1));
	    }
	});
	(void) ClearInLine(xw, screen->cur_row, 0, len);
    } else {
	ScrnClearCells(xw, screen->cur_row, 0, len);
    }
}

/*
 * Erase the cursor's line.
 */
static void
ClearLine(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    unsigned len = (unsigned) MaxCols(screen);

    assert(screen->max_col >= 0);
    (void) ClearInLine(xw, screen->cur_row, 0, len);
}

void
ClearScreen(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    int top;

    if (screen->cursor_state)
	HideCursor();

    ScrnDisownSelection(xw);
    screen->do_wrap = False;
    if ((top = INX2ROW(screen, 0)) <= screen->max_row) {
	if (screen->scroll_amt)
	    FlushScroll(xw);
	ClearCurBackground(xw,
			   top,
			   0,
			   (unsigned) (screen->max_row - top + 1),
			   (unsigned) MaxCols(screen),
			   (unsigned) FontWidth(screen));
    }
    ClearBufRows(xw, 0, screen->max_row);
}

/*
 * If we've written protected text DEC-style, and are issuing a non-DEC
 * erase, temporarily reset the protected_mode flag so that the erase will
 * ignore the protected flags.
 */
void
do_erase_line(XtermWidget xw, int param, int mode)
{
    TScreen *screen = TScreenOf(xw);
    int saved_mode = screen->protected_mode;

    if (saved_mode == DEC_PROTECT
	&& saved_mode != mode) {
	screen->protected_mode = OFF_PROTECT;
    }

    switch (param) {
    case -1:			/* DEFAULT */
    case 0:
	ClearRight(xw, -1);
	break;
    case 1:
	ClearLeft(xw);
	break;
    case 2:
	ClearLine(xw);
	break;
    }
    screen->protected_mode = saved_mode;
}

/*
 * Just like 'do_erase_line()', except that this intercepts ED controls.  If we
 * clear the whole screen, we'll get the return-value from ClearInLine, and
 * find if there were any protected characters left.  If not, reset the
 * protected mode flag in the screen data (it's slower).
 */
void
do_erase_display(XtermWidget xw, int param, int mode)
{
    TScreen *screen = TScreenOf(xw);
    int saved_mode = screen->protected_mode;

    if (saved_mode == DEC_PROTECT
	&& saved_mode != mode)
	screen->protected_mode = OFF_PROTECT;

    switch (param) {
    case -1:			/* DEFAULT */
    case 0:
	if (screen->cur_row == 0
	    && screen->cur_col == 0) {
	    screen->protected_mode = saved_mode;
	    do_erase_display(xw, 2, mode);
	    saved_mode = screen->protected_mode;
	} else
	    ClearBelow(xw);
	break;

    case 1:
	if (screen->cur_row == screen->max_row
	    && screen->cur_col == screen->max_col) {
	    screen->protected_mode = saved_mode;
	    do_erase_display(xw, 2, mode);
	    saved_mode = screen->protected_mode;
	} else
	    ClearAbove(xw);
	break;

    case 2:
	/*
	 * We use 'ClearScreen()' throughout the remainder of the
	 * program for places where we don't care if the characters are
	 * protected or not.  So we modify the logic around this call
	 * on 'ClearScreen()' to handle protected characters.
	 */
	if (screen->protected_mode != OFF_PROTECT) {
	    int row;
	    int rc = 1;
	    unsigned len = (unsigned) MaxCols(screen);

	    assert(screen->max_col >= 0);
	    for (row = 0; row <= screen->max_row; row++)
		rc &= ClearInLine(xw, row, 0, len);
	    if (rc != 0)
		saved_mode = OFF_PROTECT;
	} else {
	    ClearScreen(xw);
	}
	break;

    case 3:
	/* xterm addition - erase saved lines. */
	screen->savedlines = 0;
	ScrollBarDrawThumb(screen->scrollWidget);
	break;
    }
    screen->protected_mode = saved_mode;
}

static void
CopyWait(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    XEvent reply;
    XEvent *rep = &reply;

    for (;;) {
	XWindowEvent(screen->display, VWindow(screen),
		     ExposureMask, &reply);
	switch (reply.type) {
	case Expose:
	    HandleExposure(xw, &reply);
	    break;
	case NoExpose:
	case GraphicsExpose:
	    if (screen->incopy <= 0) {
		screen->incopy = 1;
		if (screen->scrolls > 0)
		    screen->scrolls--;
	    }
	    if (reply.type == GraphicsExpose)
		HandleExposure(xw, &reply);

	    if ((reply.type == NoExpose) ||
		((XExposeEvent *) rep)->count == 0) {
		if (screen->incopy <= 0 && screen->scrolls > 0)
		    screen->scrolls--;
		if (screen->scrolls == 0) {
		    screen->incopy = 0;
		    return;
		}
		screen->incopy = -1;
	    }
	    break;
	}
    }
}

/*
 * used by vertical_copy_area and and horizontal_copy_area
 */
static void
copy_area(XtermWidget xw,
	  int src_x,
	  int src_y,
	  unsigned width,
	  unsigned height,
	  int dest_x,
	  int dest_y)
{
    TScreen *screen = TScreenOf(xw);

    if (width != 0 && height != 0) {
	/* wait for previous CopyArea to complete unless
	   multiscroll is enabled and active */
	if (screen->incopy && screen->scrolls == 0)
	    CopyWait(xw);
	screen->incopy = -1;

	/* save for translating Expose events */
	screen->copy_src_x = src_x;
	screen->copy_src_y = src_y;
	screen->copy_width = width;
	screen->copy_height = height;
	screen->copy_dest_x = dest_x;
	screen->copy_dest_y = dest_y;

	XCopyArea(screen->display,
		  VWindow(screen), VWindow(screen),
		  NormalGC(xw, screen),
		  src_x, src_y, width, height, dest_x, dest_y);
    }
}

/*
 * use when inserting or deleting characters on the current line
 */
static void
horizontal_copy_area(XtermWidget xw,
		     int firstchar,	/* char pos on screen to start copying at */
		     int nchars,
		     int amount)	/* number of characters to move right */
{
    TScreen *screen = TScreenOf(xw);
    LineData *ld;

    if ((ld = getLineData(screen, screen->cur_row)) != 0) {
	int src_x = LineCursorX(screen, ld, firstchar);
	int src_y = CursorY(screen, screen->cur_row);

	copy_area(xw, src_x, src_y,
		  (unsigned) (nchars * LineFontWidth(screen, ld)),
		  (unsigned) FontHeight(screen),
		  src_x + amount * LineFontWidth(screen, ld), src_y);
    }
}

/*
 * use when inserting or deleting lines from the screen
 */
static void
vertical_copy_area(XtermWidget xw,
		   int firstline,	/* line on screen to start copying at */
		   int nlines,
		   int amount,	/* number of lines to move up (neg=down) */
		   int left,
		   int right)
{
    TScreen *screen = TScreenOf(xw);

    if (nlines > 0) {
	int src_x = CursorX(screen, left);
	int src_y = firstline * FontHeight(screen) + screen->border;

	copy_area(xw, src_x, src_y,
		  (unsigned) ((right + 1 - left) * FontWidth(screen)),
		  (unsigned) (nlines * FontHeight(screen)),
		  src_x, src_y - amount * FontHeight(screen));

	if (screen->show_wrap_marks) {
	    LineData *ld;
	    int row;
	    for (row = firstline; row < firstline + nlines; ++row) {
		if ((ld = getLineData(screen, row)) != 0) {
		    ShowWrapMarks(xw, row, ld);
		}
	    }
	}
    }
}

/*
 * use when scrolling the entire screen
 */
void
scrolling_copy_area(XtermWidget xw,
		    int firstline,	/* line on screen to start copying at */
		    int nlines,
		    int amount)	/* number of lines to move up (neg=down) */
{

    if (nlines > 0) {
	vertical_copy_area(xw, firstline, nlines, amount, 0, TScreenOf(xw)->max_col);
    }
}

/*
 * Handler for Expose events on the VT widget.
 * Returns 1 iff the area where the cursor was got refreshed.
 */
int
HandleExposure(XtermWidget xw, XEvent * event)
{
    TScreen *screen = TScreenOf(xw);
    XExposeEvent *reply = (XExposeEvent *) event;

#ifndef NO_ACTIVE_ICON
    if (reply->window == screen->iconVwin.window) {
	WhichVWin(screen) = &screen->iconVwin;
	TRACE(("HandleExposure - icon"));
    } else {
	WhichVWin(screen) = &screen->fullVwin;
	TRACE(("HandleExposure - normal"));
    }
    TRACE((" event %d,%d %dx%d\n",
	   reply->y,
	   reply->x,
	   reply->height,
	   reply->width));
#endif /* NO_ACTIVE_ICON */

    /* if not doing CopyArea or if this is a GraphicsExpose, don't translate */
    if (!screen->incopy || event->type != Expose)
	return handle_translated_exposure(xw, reply->x, reply->y,
					  reply->width,
					  reply->height);
    else {
	/* compute intersection of area being copied with
	   area being exposed. */
	int both_x1 = Max(screen->copy_src_x, reply->x);
	int both_y1 = Max(screen->copy_src_y, reply->y);
	int both_x2 = Min(screen->copy_src_x + (int) screen->copy_width,
			  (reply->x + (int) reply->width));
	int both_y2 = Min(screen->copy_src_y + (int) screen->copy_height,
			  (reply->y + (int) reply->height));
	int value = 0;

	/* was anything copied affected? */
	if (both_x2 > both_x1 && both_y2 > both_y1) {
	    /* do the copied area */
	    value = handle_translated_exposure
		(xw, reply->x + screen->copy_dest_x - screen->copy_src_x,
		 reply->y + screen->copy_dest_y - screen->copy_src_y,
		 reply->width, reply->height);
	}
	/* was anything not copied affected? */
	if (reply->x < both_x1 || reply->y < both_y1
	    || reply->x + reply->width > both_x2
	    || reply->y + reply->height > both_y2)
	    value = handle_translated_exposure(xw, reply->x, reply->y,
					       reply->width, reply->height);

	return value;
    }
}

static void
set_background(XtermWidget xw, int color GCC_UNUSED)
{
    TScreen *screen = TScreenOf(xw);
    Pixel c = getXtermBackground(xw, xw->flags, color);

    TRACE(("set_background(%d) %#lx\n", color, c));
    XSetWindowBackground(screen->display, VShellWindow(xw), c);
    XSetWindowBackground(screen->display, VWindow(screen), c);
}

/*
 * Called by the ExposeHandler to do the actual repaint after the coordinates
 * have been translated to allow for any CopyArea in progress.
 * The rectangle passed in is pixel coordinates.
 */
static int
handle_translated_exposure(XtermWidget xw,
			   int rect_x,
			   int rect_y,
			   int rect_width,
			   int rect_height)
{
    TScreen *screen = TScreenOf(xw);
    int toprow, leftcol, nrows, ncols;
    int x0, x1;
    int y0, y1;
    int result = 0;

    TRACE(("handle_translated_exposure at %d,%d size %dx%d\n",
	   rect_y, rect_x, rect_height, rect_width));

    x0 = (rect_x - OriginX(screen));
    x1 = (x0 + rect_width);

    y0 = (rect_y - OriginY(screen));
    y1 = (y0 + rect_height);

    if ((x0 < 0 ||
	 y0 < 0 ||
	 x1 > Width(screen) ||
	 y1 > Height(screen))) {
	set_background(xw, -1);
	XClearArea(screen->display, VWindow(screen),
		   rect_x,
		   rect_y,
		   (unsigned) rect_width,
		   (unsigned) rect_height, False);
    }
    toprow = y0 / FontHeight(screen);
    if (toprow < 0)
	toprow = 0;

    leftcol = x0 / FontWidth(screen);
    if (leftcol < 0)
	leftcol = 0;

    nrows = (y1 - 1) / FontHeight(screen) - toprow + 1;
    ncols = (x1 - 1) / FontWidth(screen) - leftcol + 1;
    toprow -= screen->scrolls;
    if (toprow < 0) {
	nrows += toprow;
	toprow = 0;
    }
    if (toprow + nrows > MaxRows(screen))
	nrows = MaxRows(screen) - toprow;
    if (leftcol + ncols > MaxCols(screen))
	ncols = MaxCols(screen) - leftcol;

    if (nrows > 0 && ncols > 0) {
	ScrnRefresh(xw, toprow, leftcol, nrows, ncols, True);
	first_map_occurred();
	if (screen->cur_row >= toprow &&
	    screen->cur_row < toprow + nrows &&
	    screen->cur_col >= leftcol &&
	    screen->cur_col < leftcol + ncols) {
	    result = 1;
	}

    }
    TRACE(("...handle_translated_exposure %d\n", result));
    return (result);
}

/***====================================================================***/

void
GetColors(XtermWidget xw, ScrnColors * pColors)
{
    TScreen *screen = TScreenOf(xw);
    int n;

    pColors->which = 0;
    for (n = 0; n < NCOLORS; ++n) {
	SET_COLOR_VALUE(pColors, n, T_COLOR(screen, n));
    }
}

void
ChangeColors(XtermWidget xw, ScrnColors * pNew)
{
    Bool repaint = False;
    TScreen *screen = TScreenOf(xw);
    VTwin *win = WhichVWin(screen);

    TRACE(("ChangeColors\n"));

    if (COLOR_DEFINED(pNew, TEXT_CURSOR)) {
	T_COLOR(screen, TEXT_CURSOR) = COLOR_VALUE(pNew, TEXT_CURSOR);
	TRACE(("... TEXT_CURSOR: %#lx\n", T_COLOR(screen, TEXT_CURSOR)));
	/* no repaint needed */
    } else if ((T_COLOR(screen, TEXT_CURSOR) == T_COLOR(screen, TEXT_FG)) &&
	       (COLOR_DEFINED(pNew, TEXT_FG))) {
	if (T_COLOR(screen, TEXT_CURSOR) != COLOR_VALUE(pNew, TEXT_FG)) {
	    T_COLOR(screen, TEXT_CURSOR) = COLOR_VALUE(pNew, TEXT_FG);
	    TRACE(("... TEXT_CURSOR: %#lx\n", T_COLOR(screen, TEXT_CURSOR)));
	    if (screen->Vshow)
		repaint = True;
	}
    }

    if (COLOR_DEFINED(pNew, TEXT_FG)) {
	Pixel fg = COLOR_VALUE(pNew, TEXT_FG);
	T_COLOR(screen, TEXT_FG) = fg;
	TRACE(("... TEXT_FG: %#lx\n", T_COLOR(screen, TEXT_FG)));
	if (screen->Vshow) {
	    setCgsFore(xw, win, gcNorm, fg);
	    setCgsBack(xw, win, gcNormReverse, fg);
	    setCgsFore(xw, win, gcBold, fg);
	    setCgsBack(xw, win, gcBoldReverse, fg);
	    repaint = True;
	}
    }

    if (COLOR_DEFINED(pNew, TEXT_BG)) {
	Pixel bg = COLOR_VALUE(pNew, TEXT_BG);
	T_COLOR(screen, TEXT_BG) = bg;
	TRACE(("... TEXT_BG: %#lx\n", T_COLOR(screen, TEXT_BG)));
	if (screen->Vshow) {
	    setCgsBack(xw, win, gcNorm, bg);
	    setCgsFore(xw, win, gcNormReverse, bg);
	    setCgsBack(xw, win, gcBold, bg);
	    setCgsFore(xw, win, gcBoldReverse, bg);
	    set_background(xw, -1);
	    repaint = True;
	}
    }
#if OPT_HIGHLIGHT_COLOR
    if (COLOR_DEFINED(pNew, HIGHLIGHT_BG)) {
	if (T_COLOR(screen, HIGHLIGHT_BG) != COLOR_VALUE(pNew, HIGHLIGHT_BG)) {
	    T_COLOR(screen, HIGHLIGHT_BG) = COLOR_VALUE(pNew, HIGHLIGHT_BG);
	    TRACE(("... HIGHLIGHT_BG: %#lx\n", T_COLOR(screen, HIGHLIGHT_BG)));
	    if (screen->Vshow)
		repaint = True;
	}
    }
    if (COLOR_DEFINED(pNew, HIGHLIGHT_FG)) {
	if (T_COLOR(screen, HIGHLIGHT_FG) != COLOR_VALUE(pNew, HIGHLIGHT_FG)) {
	    T_COLOR(screen, HIGHLIGHT_FG) = COLOR_VALUE(pNew, HIGHLIGHT_FG);
	    TRACE(("... HIGHLIGHT_FG: %#lx\n", T_COLOR(screen, HIGHLIGHT_FG)));
	    if (screen->Vshow)
		repaint = True;
	}
    }
#endif

    if (COLOR_DEFINED(pNew, MOUSE_FG) || (COLOR_DEFINED(pNew, MOUSE_BG))) {
	if (COLOR_DEFINED(pNew, MOUSE_FG)) {
	    T_COLOR(screen, MOUSE_FG) = COLOR_VALUE(pNew, MOUSE_FG);
	    TRACE(("... MOUSE_FG: %#lx\n", T_COLOR(screen, MOUSE_FG)));
	}
	if (COLOR_DEFINED(pNew, MOUSE_BG)) {
	    T_COLOR(screen, MOUSE_BG) = COLOR_VALUE(pNew, MOUSE_BG);
	    TRACE(("... MOUSE_BG: %#lx\n", T_COLOR(screen, MOUSE_BG)));
	}

	if (screen->Vshow) {
	    recolor_cursor(screen,
			   screen->pointer_cursor,
			   T_COLOR(screen, MOUSE_FG),
			   T_COLOR(screen, MOUSE_BG));
	    XDefineCursor(screen->display, VWindow(screen),
			  screen->pointer_cursor);
	}
#if OPT_TEK4014
	if (TEK4014_SHOWN(xw)) {
	    TekScreen *tekscr = TekScreenOf(tekWidget);
	    Window tekwin = TWindow(tekscr);
	    if (tekwin) {
		recolor_cursor(screen,
			       tekscr->arrow,
			       T_COLOR(screen, MOUSE_FG),
			       T_COLOR(screen, MOUSE_BG));
		XDefineCursor(screen->display, tekwin, tekscr->arrow);
	    }
	}
#endif
	/* no repaint needed */
    }

    if (COLOR_DEFINED(pNew, TEXT_FG) ||
	COLOR_DEFINED(pNew, TEXT_BG) ||
	COLOR_DEFINED(pNew, TEXT_CURSOR)) {
	if (set_cursor_gcs(xw) && screen->Vshow) {
	    repaint = True;
	}
    }
#if OPT_TEK4014
    if (COLOR_DEFINED(pNew, TEK_FG) ||
	COLOR_DEFINED(pNew, TEK_BG)) {
	ChangeTekColors(tekWidget, screen, pNew);
	if (TEK4014_SHOWN(xw)) {
	    TekRepaint(tekWidget);
	}
    } else if (COLOR_DEFINED(pNew, TEK_CURSOR)) {
	ChangeTekColors(tekWidget, screen, pNew);
    }
#endif
    if (repaint)
	xtermRepaint(xw);
}

void
xtermClear(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    TRACE(("xtermClear\n"));
    XClearWindow(screen->display, VWindow(screen));
}

void
xtermRepaint(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);

    TRACE(("xtermRepaint\n"));
    xtermClear(xw);
    ScrnRefresh(xw, 0, 0, MaxRows(screen), MaxCols(screen), True);
}

/***====================================================================***/

Boolean
isDefaultForeground(const char *name)
{
    return (Boolean) ! x_strcasecmp(name, XtDefaultForeground);
}

Boolean
isDefaultBackground(const char *name)
{
    return (Boolean) ! x_strcasecmp(name, XtDefaultBackground);
}

#if OPT_WIDE_CHARS
/*
 * Check for Unicode BIDI control characters, which may be miscategorized via
 * wcwidth() and iswprint() as zero-width printable characters.
 */
Boolean
isWideControl(unsigned ch)
{
    Boolean result;

    switch (ch) {
    case 0x200E:
    case 0x200F:
    case 0x202A:
    case 0x202B:
    case 0x202C:
    case 0x202D:
    case 0x202E:
	result = True;
	break;
    default:
	result = False;
	break;
    }
    return result;
}
#endif

/***====================================================================***/

typedef struct {
    Pixel fg;
    Pixel bg;
} ToSwap;

#if OPT_HIGHLIGHT_COLOR
#define hc_param ,Bool hilite_color
#define hc_value ,screen->hilite_color
#else
#define hc_param		/* nothing */
#define hc_value		/* nothing */
#endif

/*
 * Use this to swap the foreground/background color values in the resource
 * data, and to build up a list of the pairs which must be swapped in the
 * GC cache.
 */
static void
swapLocally(ToSwap * list, int *count, ColorRes * fg, ColorRes * bg hc_param)
{
    ColorRes tmp;
    int n;
    Boolean found = False;

#if OPT_COLOR_RES
    Pixel fg_color = fg->value;
    Pixel bg_color = bg->value;
#else
    Pixel fg_color = *fg;
    Pixel bg_color = *bg;
#endif

#if OPT_HIGHLIGHT_COLOR
    if ((fg_color != bg_color) || !hilite_color)
#endif
    {
	EXCHANGE(*fg, *bg, tmp);
	for (n = 0; n < *count; ++n) {
	    if ((list[n].fg == fg_color && list[n].bg == bg_color)
		|| (list[n].fg == bg_color && list[n].bg == fg_color)) {
		found = True;
		break;
	    }
	}
	if (!found) {
	    list[*count].fg = fg_color;
	    list[*count].bg = bg_color;
	    *count = *count + 1;
	    TRACE(("swapLocally fg %#lx, bg %#lx ->%d\n",
		   fg_color, bg_color, *count));
	}
    }
}

static void
reallySwapColors(XtermWidget xw, ToSwap * list, int count)
{
    int j, k;

    TRACE(("reallySwapColors\n"));
    for (j = 0; j < count; ++j) {
	for_each_text_gc(k) {
	    redoCgs(xw, list[j].fg, list[j].bg, (CgsEnum) k);
	}
    }
}

static void
swapVTwinGCs(XtermWidget xw, VTwin * win)
{
    swapCgs(xw, win, gcNorm, gcNormReverse);
    swapCgs(xw, win, gcBold, gcBoldReverse);
}

void
ReverseVideo(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    ToSwap listToSwap[5];
    int numToSwap = 0;

    TRACE(("ReverseVideo\n"));

    /*
     * Swap SGR foreground and background colors.  By convention, these are
     * the colors assigned to "black" (SGR #0) and "white" (SGR #7).  Also,
     * SGR #8 and SGR #15 are the bold (or bright) versions of SGR #0 and
     * #7, respectively.
     *
     * We don't swap colors that happen to match the screen's foreground
     * and background because that tends to produce bizarre effects.
     */
#define swapAnyColor(name,a,b) swapLocally(listToSwap, &numToSwap, &(screen->name[a]), &(screen->name[b]) hc_value)
#define swapAColor(a,b) swapAnyColor(Acolors, a, b)
    if_OPT_ISO_COLORS(screen, {
	swapAColor(0, 7);
	swapAColor(8, 15);
    });

    if (T_COLOR(screen, TEXT_CURSOR) == T_COLOR(screen, TEXT_FG))
	T_COLOR(screen, TEXT_CURSOR) = T_COLOR(screen, TEXT_BG);

#define swapTColor(a,b) swapAnyColor(Tcolors, a, b)
    swapTColor(TEXT_FG, TEXT_BG);
    swapTColor(MOUSE_FG, MOUSE_BG);

    reallySwapColors(xw, listToSwap, numToSwap);

    swapVTwinGCs(xw, &(screen->fullVwin));
#ifndef NO_ACTIVE_ICON
    swapVTwinGCs(xw, &(screen->iconVwin));
#endif /* NO_ACTIVE_ICON */

    xw->misc.re_verse = (Boolean) ! xw->misc.re_verse;

    if (XtIsRealized((Widget) xw)) {
	xtermDisplayCursor(xw);
    }
#if OPT_TEK4014
    if (TEK4014_SHOWN(xw)) {
	TekScreen *tekscr = TekScreenOf(tekWidget);
	Window tekwin = TWindow(tekscr);
	recolor_cursor(screen,
		       tekscr->arrow,
		       T_COLOR(screen, MOUSE_FG),
		       T_COLOR(screen, MOUSE_BG));
	XDefineCursor(screen->display, tekwin, tekscr->arrow);
    }
#endif

    if (screen->scrollWidget)
	ScrollBarReverseVideo(screen->scrollWidget);

    if (XtIsRealized((Widget) xw)) {
	set_background(xw, -1);
    }
#if OPT_TEK4014
    TekReverseVideo(tekWidget);
#endif
    if (XtIsRealized((Widget) xw)) {
	xtermRepaint(xw);
    }
#if OPT_TEK4014
    if (TEK4014_SHOWN(xw)) {
	TekRepaint(tekWidget);
    }
#endif
    ReverseOldColors();
    set_cursor_gcs(xw);
    update_reversevideo();
    TRACE(("...ReverseVideo\n"));
}

void
recolor_cursor(TScreen * screen,
	       Cursor cursor,	/* X cursor ID to set */
	       unsigned long fg,	/* pixel indexes to look up */
	       unsigned long bg)	/* pixel indexes to look up */
{
    Display *dpy = screen->display;
    XColor colordefs[2];	/* 0 is foreground, 1 is background */

    colordefs[0].pixel = fg;
    colordefs[1].pixel = bg;
    XQueryColors(dpy, DefaultColormap(dpy, DefaultScreen(dpy)),
		 colordefs, 2);
    XRecolorCursor(dpy, cursor, colordefs, colordefs + 1);
    return;
}

#if OPT_RENDERFONT
static XftColor *
getXftColor(XtermWidget xw, Pixel pixel)
{
#define CACHE_SIZE  4
    static struct {
	XftColor color;
	int use;
    } cache[CACHE_SIZE];
    static int use;
    int i;
    int oldest, oldestuse;
    XColor color;

    oldestuse = 0x7fffffff;
    oldest = 0;
    for (i = 0; i < CACHE_SIZE; i++) {
	if (cache[i].use) {
	    if (cache[i].color.pixel == pixel) {
		cache[i].use = ++use;
		return &cache[i].color;
	    }
	}
	if (cache[i].use < oldestuse) {
	    oldestuse = cache[i].use;
	    oldest = i;
	}
    }
    i = oldest;
    color.pixel = pixel;
    XQueryColor(TScreenOf(xw)->display, xw->core.colormap, &color);
    cache[i].color.color.red = color.red;
    cache[i].color.color.green = color.green;
    cache[i].color.color.blue = color.blue;
    cache[i].color.color.alpha = 0xffff;
    cache[i].color.pixel = pixel;
    cache[i].use = ++use;
    return &cache[i].color;
}

/*
 * The cell-width is related to, but not the same as the wide-character width.
 * We will only get useful values from wcwidth() for codes above 255.
 * Otherwise, interpret according to internal data.
 */
#if OPT_RENDERWIDE

#if OPT_C1_PRINT
#define XtermCellWidth(xw, ch) \
	(((ch) == 0 || (ch) == 127) \
	  ? 0 \
	  : (((ch) < 256) \
	      ? (((ch) >= 128 && (ch) < 160) \
	          ? (TScreenOf(xw)->c1_printable ? 1 : 0) \
	          : 1) \
	      : my_wcwidth(ch)))
#else
#define XtermCellWidth(xw, ch) \
	(((ch) == 0 || (ch) == 127) \
	  ? 0 \
	  : (((ch) < 256) \
	      ? 1 \
	      : my_wcwidth(ch)))
#endif

#endif /* OPT_RENDERWIDE */

#define XFT_FONT(name) screen->name.font

#if OPT_ISO_COLORS
#define UseBoldFont(screen) (!(screen)->colorBDMode || ((screen)->veryBoldColors & BOLD))
#else
#define UseBoldFont(screen) 1
#endif
/*
 * fontconfig/Xft combination prior to 2.2 has a problem with
 * CJK truetype 'double-width' (bi-width/monospace) fonts leading
 * to the 's p a c e d o u t' rendering. Consequently, we can't
 * rely on XftDrawString8/16  when one of  those fonts is used.
 * Instead, we need to roll out our own using XftDrawCharSpec.
 * A patch in the same spirit (but in a rather different form)
 * was applied to gnome vte and gtk2 port of vim.
 * See http://bugzilla.mozilla.org/show_bug.cgi?id=196312
 */
static int
xtermXftDrawString(XtermWidget xw,
		   unsigned flags GCC_UNUSED,
		   XftColor * color,
		   XftFont * font,
		   int x,
		   int y,
		   IChar * text,
		   Cardinal len,
		   Bool really)
{
    TScreen *screen = TScreenOf(xw);
    int ncells = 0;

    if (len != 0) {
#if OPT_RENDERWIDE
	XftCharSpec *sbuf;
	XftFont *wfont;
	Cardinal src, dst;
	XftFont *lastFont = 0;
	XftFont *currFont = 0;
	Cardinal start = 0;
	int charWidth;
	int fontnum = screen->menu_font_number;
	int fwidth = FontWidth(screen);

#if OPT_ISO_COLORS
	if ((flags & UNDERLINE)
	    && !screen->colorULMode
	    && screen->italicULMode
	    && XFT_FONT(renderWideItal[fontnum])) {
	    wfont = XFT_FONT(renderWideItal[fontnum]);
	} else
#endif
	    if ((flags & BOLDATTR(screen))
		&& UseBoldFont(screen)
		&& XFT_FONT(renderWideBold[fontnum])) {
	    wfont = XFT_FONT(renderWideBold[fontnum]);
	} else {
	    wfont = XFT_FONT(renderWideNorm[fontnum]);
	}

	BumpTypedBuffer(XftCharSpec, len);
	sbuf = BfBuf(XftCharSpec);

	for (src = dst = 0; src < len; src++) {
	    FcChar32 wc = *text++;

	    charWidth = XtermCellWidth(xw, (wchar_t) wc);
	    if (charWidth < 0)
		continue;

	    sbuf[dst].ucs4 = wc;
	    sbuf[dst].x = (short) (x + fwidth * ncells);
	    sbuf[dst].y = (short) (y);

	    currFont = (charWidth == 2 && wfont != 0) ? wfont : font;
	    ncells += charWidth;

	    if (lastFont != currFont) {
		if ((lastFont != 0) && really) {
		    XftDrawCharSpec(screen->renderDraw,
				    color,
				    lastFont,
				    sbuf + start,
				    (int) (dst - start));
		}
		start = dst;
		lastFont = currFont;
	    }
	    ++dst;
	}
	if ((dst != start) && really) {
	    XftDrawCharSpec(screen->renderDraw,
			    color,
			    lastFont,
			    sbuf + start,
			    (int) (dst - start));
	}
#else /* !OPT_RENDERWIDE */
	if (really) {
	    XftChar8 *buffer;
	    int dst;

	    BumpTypedBuffer(XftChar8, len);
	    buffer = BfBuf(XftChar8);

	    for (dst = 0; dst < (int) len; ++dst)
		buffer[dst] = CharOf(text[dst]);

	    XftDrawString8(screen->renderDraw,
			   color,
			   font,
			   x, y, buffer, (int) len);
	}
	ncells = (int) len;
#endif
    }
    return ncells;
}
#define xtermXftWidth(xw, flags, color, font, x, y, chars, len) \
   xtermXftDrawString(xw, flags, color, font, x, y, chars, len, False)
#endif /* OPT_RENDERFONT */

#if OPT_WIDE_CHARS
/*
 * Map characters commonly "fixed" by groff back to their ASCII equivalents.
 * Also map other useful equivalents.
 */
unsigned
AsciiEquivs(unsigned ch)
{
    switch (ch) {
    case 0x2010:		/* groff "-" */
    case 0x2011:
    case 0x2012:
    case 0x2013:
    case 0x2014:
    case 0x2015:
    case 0x2212:		/* groff "\-" */
	ch = '-';
	break;
    case 0x2018:		/* groff "`" */
	ch = '`';
	break;
    case 0x2019:		/* groff ' */
	ch = '\'';
	break;
    case 0x201C:		/* groff lq */
    case 0x201D:		/* groff rq */
	ch = '"';
	break;
    case 0x2329:		/* groff ".URL" */
	ch = '<';
	break;
    case 0x232a:		/* groff ".URL" */
	ch = '>';
	break;
    default:
	if (ch >= 0xff01 && ch <= 0xff5e) {
	    /* "Fullwidth" codes (actually double-width) */
	    ch -= 0xff00;
	    ch += ANSI_SPA;
	    break;
	}
    }
    return ch;
}

/*
 * Actually this should be called "groff_workaround()" - for the places where
 * groff stomps on compatibility.  Still, if enough people get used to it,
 * this might someday become a quasi-standard.
 */
static int
ucs_workaround(XtermWidget xw,
	       unsigned ch,
	       unsigned flags,
	       GC gc,
	       int x,
	       int y,
	       int chrset,
	       int on_wide)
{
    TScreen *screen = TScreenOf(xw);
    int fixed = False;

    if (screen->wide_chars && screen->utf8_mode && ch > 256) {
	IChar eqv = (IChar) AsciiEquivs(ch);

	if (eqv != (IChar) ch) {
	    int width = my_wcwidth((int) ch);

	    do {
		drawXtermText(xw,
			      flags,
			      gc,
			      x,
			      y,
			      chrset,
			      &eqv,
			      1,
			      on_wide);
		x += FontWidth(screen);
		eqv = '?';
	    } while (width-- > 1);

	    fixed = True;
	} else if (ch == HIDDEN_CHAR) {
	    fixed = True;
	}
    }
    return fixed;
}
#endif

/*
 * Use this when the characters will not fill the cell area properly.  Fill the
 * area where we'll write the characters, otherwise we'll get gaps between
 * them, e.g., in the original background color.
 *
 * The cursor is a special case, because the XFillRectangle call only uses the
 * foreground, while we've set the cursor color in the background.  So we need
 * a special GC for that.
 */
static void
xtermFillCells(XtermWidget xw,
	       unsigned flags,
	       GC gc,
	       int x,
	       int y,
	       Cardinal len)
{
    TScreen *screen = TScreenOf(xw);
    VTwin *currentWin = WhichVWin(screen);

    if (!(flags & NOBACKGROUND)) {
	CgsEnum srcId = getCgsId(xw, currentWin, gc);
	CgsEnum dstId = gcMAX;
	Pixel fg = getCgsFore(xw, currentWin, gc);
	Pixel bg = getCgsBack(xw, currentWin, gc);

	switch (srcId) {
	case gcVTcursNormal:
	case gcVTcursReverse:
	    dstId = gcVTcursOutline;
	    break;
	case gcVTcursFilled:
	case gcVTcursOutline:
	    /* FIXME */
	    break;
	case gcNorm:
	    dstId = gcNormReverse;
	    break;
	case gcNormReverse:
	    dstId = gcNorm;
	    break;
	case gcBold:
	    dstId = gcBoldReverse;
	    break;
	case gcBoldReverse:
	    dstId = gcBold;
	    break;
#if OPT_BOX_CHARS
	case gcLine:
	case gcDots:
	    /* FIXME */
	    break;
#endif
#if OPT_DEC_CHRSET
	case gcCNorm:
	case gcCBold:
	    /* FIXME */
	    break;
#endif
#if OPT_WIDE_CHARS
	case gcWide:
	    dstId = gcWideReverse;
	    break;
	case gcWBold:
	    dstId = gcBoldReverse;
	    break;
	case gcWideReverse:
	case gcWBoldReverse:
	    /* FIXME */
	    break;
#endif
#if OPT_TEK4014
	case gcTKcurs:
	    /* FIXME */
	    break;
#endif
	case gcMAX:
	    break;
	}

	if (dstId != gcMAX) {
	    setCgsFore(xw, currentWin, dstId, bg);
	    setCgsBack(xw, currentWin, dstId, fg);

	    XFillRectangle(screen->display, VWindow(screen),
			   getCgsGC(xw, currentWin, dstId),
			   x, y,
			   len * (Cardinal) FontWidth(screen),
			   (unsigned) FontHeight(screen));
	}
    }
}

#if OPT_TRACE
static void
xtermSetClipRectangles(Display * dpy,
		       GC gc,
		       int x,
		       int y,
		       XRectangle * rp,
		       Cardinal nr,
		       int order)
{
#if 0
    TScreen *screen = TScreenOf(term);
    Drawable draw = VWindow(screen);

    XSetClipMask(dpy, gc, None);
    XDrawRectangle(screen->display, draw, gc,
		   x + rp->x - 1,
		   y + rp->y - 1,
		   rp->width,
		   rp->height);
#endif

    XSetClipRectangles(dpy, gc,
		       x, y, rp, (int) nr, order);
    TRACE(("clipping @(%3d,%3d) (%3d,%3d)..(%3d,%3d)\n",
	   y, x,
	   rp->y, rp->x, rp->height, rp->width));
}

#else
#define xtermSetClipRectangles(dpy, gc, x, y, rp, nr, order) \
	    XSetClipRectangles(dpy, gc, x, y, rp, (int) nr, order)
#endif

#if OPT_CLIP_BOLD
/*
 * This special case is a couple of percent slower, but avoids a lot of pixel
 * trash in rxcurses' hanoi.cmd demo (e.g., 10x20 font).
 */
#define beginClipping(screen,gc,pwidth,plength) \
	    if (screen->use_clipping && (pwidth > 2)) { \
		XRectangle clip; \
		int clip_x = x; \
		int clip_y = y - FontHeight(screen) + FontDescent(screen); \
		clip.x = 0; \
		clip.y = 0; \
		clip.height = (unsigned short) FontHeight(screen); \
		clip.width = (unsigned short) (pwidth * plength); \
		xtermSetClipRectangles(screen->display, gc, \
				       clip_x, clip_y, \
				       &clip, 1, Unsorted); \
	    }
#define endClipping(screen,gc) \
	    XSetClipMask(screen->display, gc, None)
#else
#define beginClipping(screen,gc,pwidth,plength)		/* nothing */
#define endClipping(screen,gc)	/* nothing */
#endif /* OPT_CLIP_BOLD */

#if OPT_CLIP_BOLD && OPT_RENDERFONT && defined(HAVE_XFTDRAWSETCLIP) && defined(HAVE_XFTDRAWSETCLIPRECTANGLES)
#define beginXftClipping(screen,px,py,plength) \
	    if (screen->use_clipping && (FontWidth(screen) > 2)) { \
		XRectangle clip; \
		double adds = (screen->scale_height - 1.0) * FontHeight(screen); \
		int height = dimRound(adds + FontHeight(screen)); \
		int descnt = dimRound(adds / 2.0) + FontDescent(screen); \
		int clip_x = px; \
		int clip_y = py - height + descnt; \
		clip.x = 0; \
		clip.y = 0; \
		clip.height = (unsigned short) height; \
		clip.width = (unsigned short) (FontWidth(screen) * plength); \
		XftDrawSetClipRectangles (screen->renderDraw, \
					  clip_x, clip_y, \
					  &clip, 1); \
	    }
#define endXftClipping(screen) \
	    XftDrawSetClip (screen->renderDraw, 0)
#else
#define beginXftClipping(screen,px,py,plength)	/* nothing */
#define endXftClipping(screen)	/* nothing */
#endif /* OPT_CLIP_BOLD */

#if OPT_RENDERFONT
static int
drawClippedXftString(XtermWidget xw,
		     unsigned flags,
		     XftFont * font,
		     XftColor * fg_color,
		     int x,
		     int y,
		     IChar * text,
		     Cardinal len)
{
    int ncells = xtermXftWidth(xw, flags,
			       fg_color,
			       font, x, y,
			       text,
			       len);
    TScreen *screen = TScreenOf(xw);

    beginXftClipping(screen, x, y, ncells);
    xtermXftDrawString(xw, flags,
		       fg_color,
		       font, x, y,
		       text,
		       len,
		       True);
    endXftClipping(screen);
    return ncells;
}
#endif

#ifndef NO_ACTIVE_ICON
#define WhichVFontData(screen,name) \
		(IsIcon(screen) ? &((screen)->fnt_icon) \
				: &((screen)->name))
#else
#define WhichVFontData(screen,name) \
				(&((screen)->name))
#endif

/*
 * Draws text with the specified combination of bold/underline.  The return
 * value is the updated x position.
 */
int
drawXtermText(XtermWidget xw,
	      unsigned flags,
	      GC gc,
	      int x,
	      int y,
	      int chrset,
	      IChar * text,
	      Cardinal len,
	      int on_wide)
{
    TScreen *screen = TScreenOf(xw);
    Cardinal real_length = len;
    Cardinal underline_len = 0;
    /* Intended width of the font to draw (as opposed to the actual width of
       the X font, and the width of the default font) */
    int font_width = ((flags & DOUBLEWFONT) ? 2 : 1) * screen->fnt_wide;
    Bool did_ul = False;

#if OPT_WIDE_CHARS
    if (text == 0)
	return 0;
#endif
#if OPT_DEC_CHRSET
    if (CSET_DOUBLE(chrset)) {
	/* We could try drawing double-size characters in the icon, but
	 * given that the icon font is usually nil or nil2, there
	 * doesn't seem to be much point.
	 */
	int inx = 0;
	GC gc2 = ((!IsIcon(screen) && screen->font_doublesize)
		  ? xterm_DoubleGC(xw, (unsigned) chrset, flags, gc, &inx)
		  : 0);

	TRACE(("DRAWTEXT%c[%4d,%4d] (%d)%3d:%s\n",
	       screen->cursor_state == OFF ? ' ' : '*',
	       y, x, chrset, len,
	       visibleIChars(text, len)));

	if (gc2 != 0) {		/* draw actual double-sized characters */
	    XFontStruct *fs = screen->double_fonts[inx].fs;

#if OPT_RENDERFONT
	    if (!UsingRenderFont(xw))
#endif
	    {
		XRectangle rect, *rp = &rect;
		Cardinal nr = 1;

		font_width *= 2;
		flags |= DOUBLEWFONT;

		rect.x = 0;
		rect.y = 0;
		rect.width = (unsigned short) ((int) len * font_width);
		rect.height = (unsigned short) (FontHeight(screen));

		TRACE(("drawing %s\n", visibleChrsetName((unsigned) chrset)));
		switch (chrset) {
		case CSET_DHL_TOP:
		    rect.y = (short) -(fs->ascent / 2);
		    y -= rect.y;
		    flags |= DOUBLEHFONT;
		    break;
		case CSET_DHL_BOT:
		    rect.y = (short) (rect.height - (fs->ascent / 2));
		    y -= rect.y;
		    flags |= DOUBLEHFONT;
		    break;
		default:
		    nr = 0;
		    break;
		}

		if (nr) {
		    xtermSetClipRectangles(screen->display, gc2,
					   x, y, rp, nr, YXBanded);
		} else {
		    XSetClipMask(screen->display, gc2, None);
		}
	    }

	    /* Call ourselves recursively with the new gc */

	    /*
	     * If we're trying to use proportional font, or if the
	     * font server didn't give us what we asked for wrt
	     * width, position each character independently.
	     */
	    if (screen->fnt_prop
		|| (fs->min_bounds.width != fs->max_bounds.width)
		|| (fs->min_bounds.width != 2 * FontWidth(screen))) {
		/* It is hard to fall-through to the main
		   branch: in a lot of places the check
		   for the cached font info is for
		   normal/bold fonts only. */
		while (len--) {
		    x = drawXtermText(xw, flags, gc2,
				      x, y, 0,
				      text++,
				      1, on_wide);
		    x += FontWidth(screen);
		}
	    } else {
		x = drawXtermText(xw, flags, gc2,
				  x, y, 0,
				  text,
				  len, on_wide);
		x += (int) len *FontWidth(screen);
	    }

	    TRACE(("drawtext [%4d,%4d]\n", y, x));
	} else {		/* simulate double-sized characters */
	    unsigned need = 2 * len;
	    IChar *temp = TypeMallocN(IChar, need);
	    unsigned n = 0;

	    while (len--) {
		temp[n++] = *text++;
		temp[n++] = ' ';
	    }
	    x = drawXtermText(xw,
			      flags,
			      gc,
			      x, y,
			      0,
			      temp,
			      n,
			      on_wide);
	    free(temp);
	}
	return x;
    }
#endif
#if OPT_RENDERFONT
    if (UsingRenderFont(xw)) {
	VTwin *currentWin = WhichVWin(screen);
	Display *dpy = screen->display;
	XftFont *font;
	XGCValues values;
	int fontnum = screen->menu_font_number;
	int ncells;

	if (!screen->renderDraw) {
	    int scr;
	    Drawable draw = VWindow(screen);
	    Visual *visual;

	    scr = DefaultScreen(dpy);
	    visual = DefaultVisual(dpy, scr);
	    screen->renderDraw = XftDrawCreate(dpy, draw, visual,
					       DefaultColormap(dpy, scr));
	}
#if OPT_ISO_COLORS
	if ((flags & UNDERLINE)
	    && !screen->colorULMode
	    && screen->italicULMode
	    && XFT_FONT(renderFontItal[fontnum])) {
	    font = XFT_FONT(renderFontItal[fontnum]);
	    did_ul = True;
	} else
#endif
	    if ((flags & BOLDATTR(screen))
		&& UseBoldFont(screen)
		&& XFT_FONT(renderFontBold[fontnum])) {
	    font = XFT_FONT(renderFontBold[fontnum]);
	} else {
	    font = XFT_FONT(renderFontNorm[fontnum]);
	}
	values.foreground = getCgsFore(xw, currentWin, gc);
	values.background = getCgsBack(xw, currentWin, gc);

	if (!(flags & NOBACKGROUND)) {
	    XftColor *bg_color = getXftColor(xw, values.background);
	    ncells = xtermXftWidth(xw, flags,
				   bg_color,
				   font, x, y,
				   text,
				   len);
	    XftDrawRect(screen->renderDraw,
			bg_color,
			x, y,
			(unsigned) (ncells * FontWidth(screen)),
			(unsigned) FontHeight(screen));
	}

	y += font->ascent;
#if OPT_BOX_CHARS
	{
	    /* adding code to substitute simulated line-drawing characters */
	    int last, first = 0;
	    Dimension old_wide, old_high = 0;
	    int curX = x;

	    for (last = 0; last < (int) len; last++) {
		Boolean replace = False;
		Boolean missing = False;
		unsigned ch = (unsigned) text[last];
		int nc;
#if OPT_WIDE_CHARS

		if (xtermIsDecGraphic(ch)) {
		    /*
		     * Xft generally does not have the line-drawing characters
		     * in cells 1-31.  Assume this (we cannot inspect the
		     * picture easily...), and attempt to fill in from real
		     * line-drawing character in the font at the Unicode
		     * position.  Failing that, use our own box-characters.
		     */
		    if (screen->force_box_chars
			|| xtermXftMissing(xw, font, dec2ucs(ch))) {
			missing = 1;
		    } else {
			ch = dec2ucs(ch);
			replace = True;
		    }
		} else if (ch >= 256) {
		    /*
		     * If we're reading UTF-8 from the client, we may have a
		     * line-drawing character.  Translate it back to our
		     * box-code if Xft tells us that the glyph is missing.
		     */
		    if_OPT_WIDE_CHARS(screen, {
			unsigned part = ucs2dec(ch);
			if (xtermIsDecGraphic(part) &&
			    (screen->force_box_chars
			     || xtermXftMissing(xw, font, ch))) {
			    ch = part;
			    missing = True;
			}
		    });
		}
#else
		if (xtermIsDecGraphic(ch)) {
		    /*
		     * Xft generally does not have the line-drawing characters
		     * in cells 1-31.  Check for this, and attempt to fill in
		     * from real line-drawing character in the font at the
		     * Unicode position.  Failing that, use our own
		     * box-characters.
		     */
		    if (xtermXftMissing(xw, font, ch)) {
			missing = 1;
		    }
		}
#endif

		/*
		 * If we now have one of our box-codes, draw it directly.
		 */
		if (missing || replace) {
		    /* line drawing character time */
		    if (last > first) {
			nc = drawClippedXftString(xw,
						  flags,
						  font,
						  getXftColor(xw, values.foreground),
						  curX,
						  y,
						  text + first,
						  (Cardinal) (last - first));
			curX += nc * FontWidth(screen);
			underline_len += (Cardinal) nc;
		    }
		    if (missing) {
			old_wide = screen->fnt_wide;
			old_high = screen->fnt_high;
			screen->fnt_wide = (Dimension) FontWidth(screen);
			screen->fnt_high = (Dimension) FontHeight(screen);
			xtermDrawBoxChar(xw, ch, flags, gc,
					 curX, y - FontAscent(screen), 1);
			curX += FontWidth(screen);
			underline_len += 1;
			screen->fnt_wide = old_wide;
			screen->fnt_high = old_high;
		    } else {
			IChar ch2 = (IChar) ch;
			nc = drawClippedXftString(xw,
						  flags,
						  font,
						  getXftColor(xw, values.foreground),
						  curX,
						  y,
						  &ch2,
						  1);
			curX += nc * FontWidth(screen);
			underline_len += (Cardinal) nc;
		    }
		    first = last + 1;
		}
	    }
	    if (last > first) {
		underline_len += (Cardinal)
		    drawClippedXftString(xw,
					 flags,
					 font,
					 getXftColor(xw, values.foreground),
					 curX,
					 y,
					 text + first,
					 (Cardinal) (last - first));
	    }
	}
#else
	{
	    underline_len += (Cardinal)
		drawClippedXftString(xw,
				     flags,
				     font,
				     getXftColor(xw, values.foreground),
				     x,
				     y,
				     text,
				     len);
	}
#endif /* OPT_BOX_CHARS */

	if ((flags & UNDERLINE) && screen->underline && !did_ul) {
	    if (FontDescent(screen) > 1)
		y++;
	    XDrawLine(screen->display, VWindow(screen), gc,
		      x, y,
		      x + (int) underline_len * FontWidth(screen) - 1,
		      y);
	}
	return x + (int) len *FontWidth(screen);
    }
#endif /* OPT_RENDERFONT */
    /*
     * If we're asked to display a proportional font, do this with a fixed
     * pitch.  Yes, it's ugly.  But we cannot distinguish the use of xterm
     * as a dumb terminal vs its use as in fullscreen programs such as vi.
     * Hint: do not try to use a proportional font in the icon.
     */
    if (!IsIcon(screen) && !(flags & CHARBYCHAR) && screen->fnt_prop) {
	int adj, width;
	XTermFonts *font = ((flags & BOLDATTR(screen))
			    ? WhichVFontData(screen, fnts[fBold])
			    : WhichVFontData(screen, fnts[fNorm]));

	while (len--) {
	    int cells = WideCells(*text);
#if OPT_BOX_CHARS
#if OPT_WIDE_CHARS
	    if (*text == HIDDEN_CHAR) {
		++text;
		continue;
	    } else
#endif
	    if (IsXtermMissingChar(screen, *text, font)) {
		adj = 0;
	    } else
#endif
	    {
		if_WIDE_OR_NARROW(screen, {
		    XChar2b temp[1];
		    temp[0].byte2 = LO_BYTE(*text);
		    temp[0].byte1 = HI_BYTE(*text);
		    width = XTextWidth16(font->fs, temp, 1);
		}
		, {
		    char temp[1];
		    temp[0] = (char) LO_BYTE(*text);
		    width = XTextWidth(font->fs, temp, 1);
		});
		adj = (FontWidth(screen) - width) / 2;
		if (adj < 0)
		    adj = 0;
	    }
	    xtermFillCells(xw, flags, gc, x, y, (Cardinal) cells);
	    x = drawXtermText(xw,
			      flags | NOBACKGROUND | CHARBYCHAR,
			      gc, x + adj, y, chrset,
			      text++, 1, on_wide) - adj;
	}
	return x;
    }
#if OPT_BOX_CHARS
    /* If the font is incomplete, draw some substitutions */
    if (!IsIcon(screen)
	&& !(flags & NOTRANSLATION)
	&& (!screen->fnt_boxes || screen->force_box_chars)) {
	/* Fill in missing box-characters.
	   Find regions without missing characters, and draw
	   them calling ourselves recursively.  Draw missing
	   characters via xtermDrawBoxChar(). */
	XTermFonts *font = ((flags & BOLDATTR(screen))
			    ? WhichVFontData(screen, fnts[fBold])
			    : WhichVFontData(screen, fnts[fNorm]));
	int last, first = 0;
	Bool drewBoxes = False;

	for (last = 0; last < (int) len; last++) {
	    unsigned ch = (unsigned) text[last];
	    Bool isMissing;
	    int ch_width;
#if OPT_WIDE_CHARS

	    if (ch == HIDDEN_CHAR) {
		if (last > first) {
		    x = drawXtermText(xw, flags | NOTRANSLATION, gc,
				      x, y,
				      chrset, text + first,
				      (unsigned) (last - first), on_wide);
		}
		first = last + 1;
		drewBoxes = True;
		continue;
	    }
	    ch_width = my_wcwidth((int) ch);
	    isMissing =
		IsXtermMissingChar(screen, ch,
				   ((on_wide || ch_width > 1)
				    && okFont(NormalWFont(screen)))
				   ? WhichVFontData(screen, fnts[fWide])
				   : font);
#else
	    isMissing = IsXtermMissingChar(screen, ch, font);
	    ch_width = 1;
#endif
	    /*
	     * If the character is not missing, but we're in wide-character
	     * mode and the character happens to be a wide-character that
	     * corresponds to the line-drawing set, allow the forceBoxChars
	     * resource (or menu entry) to force it to display using our
	     * tables.
	     */
	    if_OPT_WIDE_CHARS(screen, {
		if (!isMissing
		    && ch > 255
		    && ucs2dec(ch) < 32
		    && TScreenOf(xw)->force_box_chars) {
		    ch = ucs2dec(ch);
		    isMissing = True;
		}
	    });

	    if (isMissing) {
		if (last > first) {
		    x = drawXtermText(xw, flags | NOTRANSLATION, gc,
				      x, y,
				      chrset, text + first,
				      (unsigned) (last - first), on_wide);
		}
#if OPT_WIDE_CHARS
		if (ucs_workaround(xw, ch, flags, gc,
				   x, y,
				   chrset, on_wide)) {
		    /*
		     * if true, we drew at least one cell whether or not it is
		     * printable
		     */
		    if (ch_width <= 0)
			ch_width = 1;
		} else
#endif
		{
		    if (ch_width <= 0)
			ch_width = 1;
		    xtermDrawBoxChar(xw, ch, flags, gc,
				     x, y,
				     ch_width);
		}
		x += (ch_width * FontWidth(screen));
		first = last + 1;
		drewBoxes = True;
	    }
	}
	if (last <= first) {
	    return x;
	}
	text += first;
	len = (Cardinal) (last - first);
	flags |= NOTRANSLATION;
	if (drewBoxes) {
	    return drawXtermText(xw,
				 flags,
				 gc,
				 x,
				 y,
				 chrset,
				 text,
				 len,
				 on_wide);
	}
    }
#endif /* OPT_BOX_CHARS */
    /*
     * Behave as if the font has (maybe Unicode-replacements for) drawing
     * characters in the range 1-31 (either we were not asked to ignore them,
     * or the caller made sure that there is none).
     */
    TRACE(("drawtext%c[%4d,%4d] (%d) %d:%s\n",
	   screen->cursor_state == OFF ? ' ' : '*',
	   y, x, chrset, len,
	   visibleIChars(text, len)));
    if (screen->scale_height != 1.0) {
	xtermFillCells(xw, flags, gc, x, y, (Cardinal) len);
    }
    y += FontAscent(screen);

#if OPT_WIDE_CHARS

    if (screen->wide_chars || screen->unicode_font) {
	XChar2b *buffer;
	Bool needWide = False;
	int ascent_adjust = 0;
	int src, dst;

	BumpTypedBuffer(XChar2b, len);
	buffer = BfBuf(XChar2b);

	for (src = dst = 0; src < (int) len; src++) {
	    IChar ch = text[src];

	    if (ch == HIDDEN_CHAR)
		continue;

	    if (!needWide
		&& !IsIcon(screen)
		&& ((on_wide || my_wcwidth((int) ch) > 1)
		    && okFont(NormalWFont(screen)))) {
		needWide = True;
	    }

	    /*
	     * bitmap-fonts are limited to 16-bits.
	     */
#if OPT_WIDER_ICHAR
	    if (ch > 0xffff) {
		ch = UCS_REPL;
	    }
#endif
	    buffer[dst].byte2 = LO_BYTE(ch);
	    buffer[dst].byte1 = HI_BYTE(ch);
#if OPT_MINI_LUIT
#define UCS2SBUF(value)	buffer[dst].byte2 = LO_BYTE(value);\
	    		buffer[dst].byte1 = HI_BYTE(value)

#define Map2Sbuf(from,to) (text[src] == from) { UCS2SBUF(to); }

	    if (screen->latin9_mode && !screen->utf8_mode && text[src] < 256) {

		/* see http://www.cs.tut.fi/~jkorpela/latin9.html */
		/* *INDENT-OFF* */
		if Map2Sbuf(0xa4, 0x20ac)
		else if Map2Sbuf(0xa6, 0x0160)
		else if Map2Sbuf(0xa8, 0x0161)
		else if Map2Sbuf(0xb4, 0x017d)
		else if Map2Sbuf(0xb8, 0x017e)
		else if Map2Sbuf(0xbc, 0x0152)
		else if Map2Sbuf(0xbd, 0x0153)
		else if Map2Sbuf(0xbe, 0x0178)
		/* *INDENT-ON* */

	    }
	    if (screen->unicode_font
		&& (text[src] == ANSI_DEL ||
		    text[src] < ANSI_SPA)) {
		unsigned ni = dec2ucs((unsigned) ((text[src] == ANSI_DEL)
						  ? 0
						  : text[src]));
		UCS2SBUF(ni);
	    }
#endif /* OPT_MINI_LUIT */
	    ++dst;
	}
	/* FIXME This is probably wrong. But it works. */
	underline_len = len;

	/* Set the drawing font */
	if (!(flags & (DOUBLEHFONT | DOUBLEWFONT))) {
	    VTwin *currentWin = WhichVWin(screen);
	    VTFontEnum fntId;
	    CgsEnum cgsId;
	    Pixel fg = getCgsFore(xw, currentWin, gc);
	    Pixel bg = getCgsBack(xw, currentWin, gc);

	    if (needWide
		&& (okFont(NormalWFont(screen)) || okFont(BoldWFont(screen)))) {
		if ((flags & BOLDATTR(screen)) != 0
		    && okFont(BoldWFont(screen))) {
		    fntId = fWBold;
		    cgsId = gcWBold;
		} else {
		    fntId = fWide;
		    cgsId = gcWide;
		}
	    } else if ((flags & BOLDATTR(screen)) != 0
		       && okFont(BoldFont(screen))) {
		fntId = fBold;
		cgsId = gcBold;
	    } else {
		fntId = fNorm;
		cgsId = gcNorm;
	    }

	    setCgsFore(xw, currentWin, cgsId, fg);
	    setCgsBack(xw, currentWin, cgsId, bg);
	    gc = getCgsGC(xw, currentWin, cgsId);

	    if (fntId != fNorm) {
		XFontStruct *thisFp = WhichVFont(screen, fnts[fntId].fs);
		ascent_adjust = (thisFp->ascent
				 - NormalFont(screen)->ascent);
		if (thisFp->max_bounds.width ==
		    NormalFont(screen)->max_bounds.width * 2) {
		    underline_len = real_length = (Cardinal) (dst * 2);
		} else if (cgsId == gcWide || cgsId == gcWBold) {
		    underline_len = real_length = (Cardinal) (dst * 2);
		    xtermFillCells(xw,
				   flags,
				   gc,
				   x,
				   y - thisFp->ascent,
				   real_length);
		}
	    }
	}

	if (flags & NOBACKGROUND) {
	    XDrawString16(screen->display,
			  VWindow(screen), gc,
			  x, y + ascent_adjust,
			  buffer, dst);
	} else {
	    XDrawImageString16(screen->display,
			       VWindow(screen), gc,
			       x, y + ascent_adjust,
			       buffer, dst);
	}

	if ((flags & BOLDATTR(screen)) && screen->enbolden) {
	    beginClipping(screen, gc, (Cardinal) font_width, len);
	    XDrawString16(screen->display, VWindow(screen), gc,
			  x + 1,
			  y + ascent_adjust,
			  buffer, dst);
	    endClipping(screen, gc);
	}

    } else
#endif /* OPT_WIDE_CHARS */
    {
	int length = (int) len;	/* X should have used unsigned */
#if OPT_WIDE_CHARS
	char *buffer;
	int dst;

	BumpTypedBuffer(char, len);
	buffer = BfBuf(char);

	for (dst = 0; dst < length; ++dst)
	    buffer[dst] = (char) LO_BYTE(text[dst]);
#else
	char *buffer = (char *) text;
#endif

	if (flags & NOBACKGROUND) {
	    XDrawString(screen->display, VWindow(screen), gc,
			x, y, buffer, length);
	} else {
	    XDrawImageString(screen->display, VWindow(screen), gc,
			     x, y, buffer, length);
	}
	underline_len = (Cardinal) length;
	if ((flags & BOLDATTR(screen)) && screen->enbolden) {
	    beginClipping(screen, gc, font_width, length);
	    XDrawString(screen->display, VWindow(screen), gc,
			x + 1, y, buffer, length);
	    endClipping(screen, gc);
	}
    }

    if ((flags & UNDERLINE) && screen->underline && !did_ul) {
	if (FontDescent(screen) > 1)
	    y++;
	XDrawLine(screen->display, VWindow(screen), gc,
		  x, y, (x + (int) underline_len * font_width - 1), y);
    }

    return x + (int) real_length *FontWidth(screen);
}

#if OPT_WIDE_CHARS
/*
 * Allocate buffer - workaround for wide-character interfaces.
 */
void
allocXtermChars(ScrnPtr * buffer, Cardinal length)
{
    if (*buffer == 0) {
	*buffer = (ScrnPtr) XtMalloc(length);
    } else {
	*buffer = (ScrnPtr) XtRealloc((char *) *buffer, length);
    }
}
#endif

/* set up size hints for window manager; min 1 char by 1 char */
void
xtermSizeHints(XtermWidget xw, int scrollbarWidth)
{
    TScreen *screen = TScreenOf(xw);

    TRACE(("xtermSizeHints\n"));
    TRACE(("   border    %d\n", xw->core.border_width));
    TRACE(("   scrollbar %d\n", scrollbarWidth));

    xw->hints.base_width = 2 * screen->border + scrollbarWidth;
    xw->hints.base_height = 2 * screen->border;

#if OPT_TOOLBAR
    TRACE(("   toolbar   %d\n", ToolbarHeight(xw)));

    xw->hints.base_height += ToolbarHeight(xw);
    xw->hints.base_height += BorderWidth(xw) * 2;
    xw->hints.base_width += BorderWidth(xw) * 2;
#endif

    xw->hints.width_inc = FontWidth(screen);
    xw->hints.height_inc = FontHeight(screen);
    xw->hints.min_width = xw->hints.base_width + xw->hints.width_inc;
    xw->hints.min_height = xw->hints.base_height + xw->hints.height_inc;

    xw->hints.width = MaxCols(screen) * FontWidth(screen) + xw->hints.min_width;
    xw->hints.height = MaxRows(screen) * FontHeight(screen) + xw->hints.min_height;

    xw->hints.flags |= (PSize | PBaseSize | PMinSize | PResizeInc);

    TRACE_HINTS(&(xw->hints));
}

void
getXtermSizeHints(XtermWidget xw)
{
    TScreen *screen = TScreenOf(xw);
    long supp;

    if (!XGetWMNormalHints(screen->display, VShellWindow(xw),
			   &xw->hints, &supp))
	memset(&xw->hints, 0, sizeof(xw->hints));
    TRACE_HINTS(&(xw->hints));
}

/*
 * Returns a GC, selected according to the font (reverse/bold/normal) that is
 * required for the current position (implied).  The GC is updated with the
 * current screen foreground and background colors.
 */
GC
updatedXtermGC(XtermWidget xw, unsigned flags, unsigned fg_bg, Bool hilite)
{
    TScreen *screen = TScreenOf(xw);
    VTwin *win = WhichVWin(screen);
    CgsEnum cgsId = gcMAX;
    unsigned my_fg = extract_fg(xw, fg_bg, flags);
    unsigned my_bg = extract_bg(xw, fg_bg, flags);
    Pixel fg_pix = getXtermForeground(xw, flags, my_fg);
    Pixel bg_pix = getXtermBackground(xw, flags, my_bg);
    Pixel xx_pix;
#if OPT_HIGHLIGHT_COLOR
    Pixel selbg_pix = T_COLOR(screen, HIGHLIGHT_BG);
    Pixel selfg_pix = T_COLOR(screen, HIGHLIGHT_FG);
    Boolean always = screen->hilite_color;
    Boolean use_selbg = (Boolean) (always ||
				   isNotForeground(xw, fg_pix, bg_pix, selbg_pix));
    Boolean use_selfg = (Boolean) (always &&
				   isNotBackground(xw, fg_pix, bg_pix, selfg_pix));
#endif

    (void) fg_bg;
    (void) my_bg;
    (void) my_fg;

    /*
     * Discard video attributes overridden by colorXXXMode's.
     */
    checkVeryBoldColors(flags, my_fg);

    if (ReverseOrHilite(screen, flags, hilite)) {
	if (flags & BOLDATTR(screen)) {
	    cgsId = gcBoldReverse;
	} else {
	    cgsId = gcNormReverse;
	}

#if OPT_HIGHLIGHT_COLOR
	if (!screen->hilite_color) {
	    if (selbg_pix != T_COLOR(screen, TEXT_FG)
		&& selbg_pix != fg_pix
		&& selbg_pix != bg_pix
		&& selbg_pix != xw->dft_foreground) {
		bg_pix = fg_pix;
		fg_pix = selbg_pix;
	    }
	}
#endif
	EXCHANGE(fg_pix, bg_pix, xx_pix);
#if OPT_HIGHLIGHT_COLOR
	if (screen->hilite_color) {
	    if (screen->hilite_reverse) {
		if (use_selbg) {
		    if (use_selfg)
			bg_pix = fg_pix;
		    else
			fg_pix = bg_pix;
		}
		if (use_selbg)
		    bg_pix = selbg_pix;
		if (use_selfg)
		    fg_pix = selfg_pix;
	    }
	}
#endif
    } else {
	if (flags & BOLDATTR(screen)) {
	    cgsId = gcBold;
	} else {
	    cgsId = gcNorm;
	}
    }
#if OPT_HIGHLIGHT_COLOR
    if (!screen->hilite_color || !screen->hilite_reverse) {
	if (hilite && !screen->hilite_reverse) {
	    if (use_selbg)
		bg_pix = selbg_pix;
	    if (use_selfg)
		fg_pix = selfg_pix;
	}
    }
#endif

#if OPT_BLINK_TEXT
    if ((screen->blink_state == ON) && (!screen->blink_as_bold) && (flags & BLINK)) {
	fg_pix = bg_pix;
    }
#endif

    setCgsFore(xw, win, cgsId, fg_pix);
    setCgsBack(xw, win, cgsId, bg_pix);
    return getCgsGC(xw, win, cgsId);
}

/*
 * Resets the foreground/background of the GC returned by 'updatedXtermGC()'
 * to the values that would be set in SGR_Foreground and SGR_Background. This
 * duplicates some logic, but only modifies 1/4 as many GC's.
 */
void
resetXtermGC(XtermWidget xw, unsigned flags, Bool hilite)
{
    TScreen *screen = TScreenOf(xw);
    VTwin *win = WhichVWin(screen);
    CgsEnum cgsId = gcMAX;
    Pixel fg_pix = getXtermForeground(xw, flags, xw->cur_foreground);
    Pixel bg_pix = getXtermBackground(xw, flags, xw->cur_background);

    checkVeryBoldColors(flags, xw->cur_foreground);

    if (ReverseOrHilite(screen, flags, hilite)) {
	if (flags & BOLDATTR(screen)) {
	    cgsId = gcBoldReverse;
	} else {
	    cgsId = gcNormReverse;
	}

	setCgsFore(xw, win, cgsId, bg_pix);
	setCgsBack(xw, win, cgsId, fg_pix);

    } else {
	if (flags & BOLDATTR(screen)) {
	    cgsId = gcBold;
	} else {
	    cgsId = gcNorm;
	}

	setCgsFore(xw, win, cgsId, fg_pix);
	setCgsBack(xw, win, cgsId, bg_pix);
    }
}

#if OPT_ISO_COLORS
/*
 * Extract the foreground-color index from a color pair.
 * If we've got BOLD or UNDERLINE color-mode active, those will be used.
 */
unsigned
extract_fg(XtermWidget xw, unsigned color, unsigned flags)
{
    unsigned fg = ExtractForeground(color);

    if (TScreenOf(xw)->colorAttrMode
	|| (fg == ExtractBackground(color))) {
	fg = MapToColorMode(fg, TScreenOf(xw), flags);
    }
    return fg;
}

/*
 * Extract the background-color index from a color pair.
 * If we've got INVERSE color-mode active, that will be used.
 */
unsigned
extract_bg(XtermWidget xw, unsigned color, unsigned flags)
{
    unsigned bg = ExtractBackground(color);

    if (TScreenOf(xw)->colorAttrMode
	|| (bg == ExtractForeground(color))) {
	if (TScreenOf(xw)->colorRVMode && (flags & INVERSE))
	    bg = COLOR_RV;
    }
    return bg;
}

/*
 * Combine the current foreground and background into a single 8-bit number.
 * Note that we're storing the SGR foreground, since cur_foreground may be set
 * to COLOR_UL, COLOR_BD or COLOR_BL, which would make the code larger than 8
 * bits.
 *
 * This assumes that fg/bg are equal when we override with one of the special
 * attribute colors.
 */
CellColor
makeColorPair(int fg, int bg)
{
    unsigned my_bg = (bg >= 0) && (bg < NUM_ANSI_COLORS) ? (unsigned) bg : 0;
    unsigned my_fg = (fg >= 0) && (fg < NUM_ANSI_COLORS) ? (unsigned) fg : my_bg;

    return (CellColor) (my_fg | (my_bg << COLOR_BITS));
}

/*
 * Using the "current" SGR background, clear a rectangle.
 */
void
ClearCurBackground(XtermWidget xw,
		   int top,
		   int left,
		   unsigned height,
		   unsigned width,
		   unsigned fw)
{
    TScreen *screen = TScreenOf(xw);

    TRACE(("ClearCurBackground %d,%d %dx%d with %d\n",
	   top, left, height, width, xw->cur_background));

    assert((int) width > 0);
    assert((left + (int) width) <= screen->max_col + 1);
    assert((int) height <= screen->max_row + 1);

    if (VWindow(screen)) {
	set_background(xw, xw->cur_background);

	XClearArea(screen->display, VWindow(screen),
		   CursorX2(screen, left, fw),
		   CursorY(screen, top),
		   (width * fw),
		   (height * (unsigned) FontHeight(screen)),
		   False);

	set_background(xw, -1);
    }
}
#endif /* OPT_ISO_COLORS */

/*
 * Returns a single base character for the given cell.
 */
unsigned
getXtermCell(TScreen * screen, int row, int col)
{
    LineData *ld = getLineData(screen, row);

    assert(ld && (col < (int) ld->lineSize));
    return ((ld && (col < (int) ld->lineSize))
	    ? ld->charData[col]
	    : (unsigned) ' ');
}

/*
 * Sets a single base character for the given cell.
 */
void
putXtermCell(TScreen * screen, int row, int col, int ch)
{
    LineData *ld = getLineData(screen, row);

    assert(ld && (col < (int) ld->lineSize));
    if (ld && (col < (int) ld->lineSize)) {
	ld->charData[col] = (CharData) ch;
	if_OPT_WIDE_CHARS(screen, {
	    size_t off;
	    for_each_combData(off, ld) {
		ld->combData[off][col] = 0;
	    }
	});
    }
}

#if OPT_WIDE_CHARS
/*
 * Add a combining character for the given cell
 */
void
addXtermCombining(TScreen * screen, int row, int col, unsigned ch)
{
    if (ch != 0) {
	LineData *ld = getLineData(screen, row);
	size_t off;

	TRACE(("addXtermCombining %d,%d %#x (%d)\n",
	       row, col, ch, my_wcwidth((wchar_t) ch)));

	for_each_combData(off, ld) {
	    if (!ld->combData[off][col]) {
		ld->combData[off][col] = (CharData) ch;
		break;
	    }
	}
    }
}

unsigned
getXtermCombining(TScreen * screen, int row, int col, int off)
{
    LineData *ld = getLineData(screen, row);
    return ld->combData[off][col];
}
#endif

#ifdef HAVE_CONFIG_H
#ifdef USE_MY_MEMMOVE
void *
my_memmove(void *s1, void *s2, size_t n)
{
    if (n != 0) {
	char *p1 = (char *) s1;
	char *p2 = (char *) s2;

	if ((p1 + n > p2) && (p2 + n > p1)) {
	    static char *bfr;
	    static size_t length;
	    size_t j;
	    if (length < n) {
		length = (n * 3) / 2;
		bfr = ((bfr != 0)
		       ? TypeRealloc(char, length, bfr)
		       : TypeMallocN(char, length));
		if (bfr == NULL)
		    SysError(ERROR_MMALLOC);
	    }
	    for (j = 0; j < n; j++)
		bfr[j] = p2[j];
	    p2 = bfr;
	}
	while (n-- != 0)
	    p1[n] = p2[n];
    }
    return s1;
}
#endif /* USE_MY_MEMMOVE */

#ifndef HAVE_STRERROR
char *
my_strerror(int n)
{
    extern char *sys_errlist[];
    extern int sys_nerr;
    if (n > 0 && n < sys_nerr)
	return sys_errlist[n];
    return "?";
}
#endif
#endif

void
update_keyboard_type(void)
{
    update_delete_del();
    update_tcap_fkeys();
    update_old_fkeys();
    update_hp_fkeys();
    update_sco_fkeys();
    update_sun_fkeys();
    update_sun_kbd();
}

void
set_keyboard_type(XtermWidget xw, xtermKeyboardType type, Bool set)
{
    xtermKeyboardType save = xw->keyboard.type;

    TRACE(("set_keyboard_type(%s, %s) currently %s\n",
	   visibleKeyboardType(type),
	   BtoS(set),
	   visibleKeyboardType(xw->keyboard.type)));
    if (set) {
	xw->keyboard.type = type;
    } else {
	xw->keyboard.type = keyboardIsDefault;
    }

    if (save != xw->keyboard.type) {
	update_keyboard_type();
    }
}

void
toggle_keyboard_type(XtermWidget xw, xtermKeyboardType type)
{
    xtermKeyboardType save = xw->keyboard.type;

    TRACE(("toggle_keyboard_type(%s) currently %s\n",
	   visibleKeyboardType(type),
	   visibleKeyboardType(xw->keyboard.type)));
    if (xw->keyboard.type == type) {
	xw->keyboard.type = keyboardIsDefault;
    } else {
	xw->keyboard.type = type;
    }

    if (save != xw->keyboard.type) {
	update_keyboard_type();
    }
}

void
init_keyboard_type(XtermWidget xw, xtermKeyboardType type, Bool set)
{
    static Bool wasSet = False;

    TRACE(("init_keyboard_type(%s, %s) currently %s\n",
	   visibleKeyboardType(type),
	   BtoS(set),
	   visibleKeyboardType(xw->keyboard.type)));
    if (set) {
	if (wasSet) {
	    xtermWarning("Conflicting keyboard type option (%u/%u)\n",
			 xw->keyboard.type, type);
	}
	xw->keyboard.type = type;
	wasSet = True;
	update_keyboard_type();
    }
}

/*
 * If the keyboardType resource is set, use that, overriding the individual
 * boolean resources for different keyboard types.
 */
void
decode_keyboard_type(XtermWidget xw, XTERM_RESOURCE * rp)
{
#define DATA(n, t, f) { n, t, XtOffsetOf(XTERM_RESOURCE, f) }
#define FLAG(n) *(Boolean *)(((char *)rp) + table[n].offset)
    static struct {
	const char *name;
	xtermKeyboardType type;
	unsigned offset;
    } table[] = {
#if OPT_HP_FUNC_KEYS
	DATA(NAME_HP_KT, keyboardIsHP, hpFunctionKeys),
#endif
#if OPT_SCO_FUNC_KEYS
	    DATA(NAME_SCO_KT, keyboardIsSCO, scoFunctionKeys),
#endif
#if OPT_SUN_FUNC_KEYS
	    DATA(NAME_SUN_KT, keyboardIsSun, sunFunctionKeys),
#endif
#if OPT_SUNPC_KBD
	    DATA(NAME_VT220_KT, keyboardIsVT220, sunKeyboard),
#endif
#if OPT_TCAP_FKEYS
	    DATA(NAME_TCAP_KT, keyboardIsTermcap, termcapKeys),
#endif
    };
    Cardinal n;

    TRACE(("decode_keyboard_type(%s)\n", rp->keyboardType));
    if (!x_strcasecmp(rp->keyboardType, "unknown")) {
	/*
	 * Let the individual resources comprise the keyboard-type.
	 */
	for (n = 0; n < XtNumber(table); ++n)
	    init_keyboard_type(xw, table[n].type, FLAG(n));
    } else if (!x_strcasecmp(rp->keyboardType, "default")) {
	/*
	 * Set the keyboard-type to the Sun/PC type, allowing modified
	 * function keys, etc.
	 */
	for (n = 0; n < XtNumber(table); ++n)
	    init_keyboard_type(xw, table[n].type, False);
    } else {
	Bool found = False;

	/*
	 * Choose an individual keyboard type.
	 */
	for (n = 0; n < XtNumber(table); ++n) {
	    if (!x_strcasecmp(rp->keyboardType, table[n].name + 1)) {
		FLAG(n) = True;
		found = True;
	    } else {
		FLAG(n) = False;
	    }
	    init_keyboard_type(xw, table[n].type, FLAG(n));
	}
	if (!found) {
	    xtermWarning("KeyboardType resource \"%s\" not found\n",
			 rp->keyboardType);
	}
    }
#undef DATA
#undef FLAG
}

#if OPT_WIDE_CHARS
#if defined(HAVE_WCHAR_H) && defined(HAVE_WCWIDTH)
/*
 * If xterm is running in a UTF-8 locale, it is still possible to encounter
 * old runtime configurations which yield incomplete or inaccurate data.
 */
static Bool
systemWcwidthOk(int samplesize, int samplepass)
{
    wchar_t n;
    int oops = 0;

    for (n = 21; n <= 25; ++n) {
	int code = (int) dec2ucs((unsigned) n);
	int system_code = wcwidth(code);
	int intern_code = mk_wcwidth(code);

	/*
	 * Solaris 10 wcwidth() returns "2" for all of the line-drawing (page
	 * 0x2500) and most of the geometric shapes (a few are excluded, just
	 * to make it more difficult to use).  Do a sanity check to avoid using
	 * it.
	 */
	if ((system_code < 0 && intern_code >= 1)
	    || (system_code >= 0 && intern_code != system_code)) {
	    TRACE(("systemWcwidthOk: broken system line-drawing wcwidth\n"));
	    oops += (samplepass + 1);
	    break;
	}
    }

    for (n = 0; n < (wchar_t) samplesize; ++n) {
	int system_code = wcwidth(n);
	int intern_code = mk_wcwidth(n);

	/*
	 * Since mk_wcwidth() is designed to check for nonspacing characters,
	 * and has rough range-checks for double-width characters, it will
	 * generally not detect cases where a code has not been assigned.
	 *
	 * Some experimentation with GNU libc suggests that up to 1/4 of the
	 * codes would differ, simply because the runtime library would have a
	 * table listing the unassigned codes, and return -1 for those.  If
	 * mk_wcwidth() has no information about a code, it returns 1.  On the
	 * other hand, if the runtime returns a positive number, the two should
	 * agree.
	 *
	 * The "up to" is measured for 4k, 8k, 16k of data.  With only 1k, the
	 * number of differences was only 77.  However, that is only one
	 * system, and this is only a sanity check to avoid using broken
	 * libraries.
	 */
	if ((system_code < 0 && intern_code >= 1)
	    || (system_code >= 0 && intern_code != system_code)) {
	    ++oops;
	}
    }
    TRACE(("systemWcwidthOk: %d/%d mismatches, allowed %d\n",
	   oops, samplesize, samplepass));
    return (oops <= samplepass);
}
#endif /* HAVE_WCWIDTH */

void
decode_wcwidth(XtermWidget xw)
{
    int mode = ((xw->misc.cjk_width ? 2 : 0)
		+ (xw->misc.mk_width ? 1 : 0)
		+ 1);

    switch (mode) {
    default:
#if defined(HAVE_WCHAR_H) && defined(HAVE_WCWIDTH)
	if (xtermEnvUTF8() &&
	    systemWcwidthOk(xw->misc.mk_samplesize, xw->misc.mk_samplepass)) {
	    my_wcwidth = wcwidth;
	    TRACE(("using system wcwidth() function\n"));
	    break;
	}
	/* FALLTHRU */
#endif
    case 2:
	my_wcwidth = &mk_wcwidth;
	TRACE(("using MK wcwidth() function\n"));
	break;
    case 3:
    case 4:
	my_wcwidth = &mk_wcwidth_cjk;
	TRACE(("using MK-CJK wcwidth() function\n"));
	break;
    }

    for (first_widechar = 128; first_widechar < 4500; ++first_widechar) {
	if (my_wcwidth((int) first_widechar) > 1) {
	    TRACE(("first_widechar %#x\n", first_widechar));
	    break;
	}
    }
}
#endif

/*
 * Extend a (normally) boolean resource value by checking for additional values
 * which will be mapped into true/false.
 */
int
extendedBoolean(const char *value, FlagList * table, Cardinal limit)
{
    int result = -1;
    long check;
    char *next;
    Cardinal n;

    if ((x_strcasecmp(value, "true") == 0)
	|| (x_strcasecmp(value, "yes") == 0)
	|| (x_strcasecmp(value, "on") == 0)) {
	result = True;
    } else if ((x_strcasecmp(value, "false") == 0)
	       || (x_strcasecmp(value, "no") == 0)
	       || (x_strcasecmp(value, "off") == 0)) {
	result = False;
    } else if ((check = strtol(value, &next, 0)) >= 0 && *next == '\0') {
	if (check >= (long) limit)
	    check = True;
	result = (int) check;
    } else {
	for (n = 0; n < limit; ++n) {
	    if (x_strcasecmp(value, table[n].name) == 0) {
		result = table[n].code;
		break;
	    }
	}
    }

    if (result < 0) {
	xtermWarning("Unrecognized keyword: %s\n", value);
	result = False;
    }

    TRACE(("extendedBoolean(%s) = %d\n", value, result));
    return result;
}

/*
 * Something like round() from math library, but round() is less widely-used
 * than xterm.  Also, there are no negative numbers to complicate this.
 */
int
dimRound(double value)
{
    int result = (int) value;
    if (result < value)
	++result;
    return result;
}