Imported nx-X11-3.1.0-1.tar.gznx-X11/3.1.0-1

Summary: Imported nx-X11-3.1.0-1.tar.gz
Keywords:

Imported nx-X11-3.1.0-1.tar.gz
into Git repository

1 files changed, 682 insertions, 0 deletions

diff --git a/nx-X11/programs/xterm/scrollbar.c b/nx-X11/programs/xterm/scrollbar.c
new file mode 100644
index 000000000..6dccf6e56
--- /dev/null
+++ b/nx-X11/programs/xterm/scrollbar.c
@@ -0,0 +1,682 @@
+/* $XTermId: scrollbar.c,v 1.116 2005/11/03 13:17:28 tom Exp $ */
+
+/*
+ *	$Xorg: scrollbar.c,v 1.4 2000/08/17 19:55:09 cpqbld Exp $
+ */
+
+/* $XFree86: xc/programs/xterm/scrollbar.c,v 3.45 2005/11/03 13:17:28 dickey Exp $ */
+
+/*
+ * Copyright 2000-2004,2005 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.
+ */
+
+#include <xterm.h>
+
+#include <X11/Xatom.h>
+
+#if defined(HAVE_LIB_XAW)
+#include <X11/Xaw/Scrollbar.h>
+#elif defined(HAVE_LIB_XAW3D)
+#include <X11/Xaw3d/Scrollbar.h>
+#elif defined(HAVE_LIB_NEXTAW)
+#include <X11/neXtaw/Scrollbar.h>
+#elif defined(HAVE_LIB_XAWPLUS)
+#include <X11/XawPlus/Scrollbar.h>
+#endif
+
+#include <data.h>
+#include <error.h>
+#include <menu.h>
+#include <xcharmouse.h>
+
+/*
+ * The scrollbar's border overlaps the border of the vt100 window.  If there
+ * is no border for the vt100, there can be no border for the scrollbar.
+ */
+#define SCROLLBAR_BORDER(xw) ((xw)->screen.scrollBarBorder)
+#if OPT_TOOLBAR
+#define ScrollBarBorder(xw) (BorderWidth(xw) ? SCROLLBAR_BORDER(xw) : 0)
+#else
+#define ScrollBarBorder(xw) SCROLLBAR_BORDER(xw)
+#endif
+
+/* Event handlers */
+
+static void ScrollTextTo PROTO_XT_CALLBACK_ARGS;
+static void ScrollTextUpDownBy PROTO_XT_CALLBACK_ARGS;
+
+/* Resize the text window for a terminal screen, modifying the
+ * appropriate WM_SIZE_HINTS and taking advantage of bit gravity.
+ */
+void
+DoResizeScreen(XtermWidget xw)
+{
+    TScreen *screen = &xw->screen;
+
+    int border = 2 * xw->screen.border;
+    int min_wide = border + xw->screen.fullVwin.sb_info.width;
+    int min_high = border;
+#if 1				/* ndef nothack */
+    XSizeHints sizehints;
+    long supp;
+#endif
+    XtGeometryResult geomreqresult;
+    Dimension reqWidth, reqHeight, repWidth, repHeight;
+#ifndef NO_ACTIVE_ICON
+    struct _vtwin *saveWin = WhichVWin(screen);
+
+    /* all units here want to be in the normal font units */
+    WhichVWin(screen) = &screen->fullVwin;
+#endif /* NO_ACTIVE_ICON */
+
+    /*
+     * I'm going to try to explain, as I understand it, why we
+     * have to do XGetWMNormalHints and XSetWMNormalHints here,
+     * although I can't guarantee that I've got it right.
+     *
+     * In a correctly written toolkit program, the Shell widget
+     * parses the user supplied geometry argument.  However,
+     * because of the way xterm does things, the VT100 widget does
+     * the parsing of the geometry option, not the Shell widget.
+     * The result of this is that the Shell widget doesn't set the
+     * correct window manager hints, and doesn't know that the
+     * user has specified a geometry.
+     *
+     * The XtVaSetValues call below tells the Shell widget to
+     * change its hints.  However, since it's confused about the
+     * hints to begin with, it doesn't get them all right when it
+     * does the SetValues -- it undoes some of what the VT100
+     * widget did when it originally set the hints.
+     *
+     * To fix this, we do the following:
+     *
+     * 1. Get the sizehints directly from the window, going around
+     *    the (confused) shell widget.
+     * 2. Call XtVaSetValues to let the shell widget know which
+     *    hints have changed.  Note that this may not even be
+     *    necessary, since we're going to right ahead after that
+     *    and set the hints ourselves, but it's good to put it
+     *    here anyway, so that when we finally do fix the code so
+     *    that the Shell does the right thing with hints, we
+     *    already have the XtVaSetValues in place.
+     * 3. We set the sizehints directly, this fixing up whatever
+     *    damage was done by the Shell widget during the
+     *    XtVaSetValues.
+     *
+     * Gross, huh?
+     *
+     * The correct fix is to redo VTRealize, VTInitialize and
+     * VTSetValues so that font processing happens early enough to
+     * give back responsibility for the size hints to the Shell.
+     *
+     * Someday, we hope to have time to do this.  Someday, we hope
+     * to have time to completely rewrite xterm.
+     */
+
+    TRACE(("DoResizeScreen\n"));
+
+#if 1				/* ndef nothack */
+    /*
+     * NOTE: the hints and the XtVaSetValues() must match.
+     */
+    TRACE(("%s@%d -- ", __FILE__, __LINE__));
+    TRACE_WM_HINTS(xw);
+    if (!XGetWMNormalHints(screen->display, XtWindow(SHELL_OF(xw)),
+			   &sizehints, &supp))
+	bzero(&sizehints, sizeof(sizehints));
+
+    xtermSizeHints(xw, &sizehints, ScrollbarWidth(screen));
+
+    /* These are obsolete, but old clients may use them */
+    sizehints.width = MaxCols(screen) * FontWidth(screen) + sizehints.min_width;
+    sizehints.height = MaxRows(screen) * FontHeight(screen) + sizehints.min_height;
+#endif
+
+    XSetWMNormalHints(screen->display, XtWindow(SHELL_OF(xw)), &sizehints);
+
+    reqWidth = MaxCols(screen) * FontWidth(screen) + min_wide;
+    reqHeight = MaxRows(screen) * FontHeight(screen) + min_high;
+
+    TRACE(("...requesting screensize chars %dx%d, pixels %dx%d\n",
+	   MaxRows(screen),
+	   MaxCols(screen),
+	   reqHeight, reqWidth));
+
+    geomreqresult = XtMakeResizeRequest((Widget) xw, reqWidth, reqHeight,
+					&repWidth, &repHeight);
+    TRACE(("scrollbar.c XtMakeResizeRequest %dx%d -> %dx%d (status %d)\n",
+	   reqHeight, reqWidth,
+	   repHeight, repWidth,
+	   geomreqresult));
+
+    if (geomreqresult == XtGeometryAlmost) {
+	TRACE(("...almost, retry screensize %dx%d\n", repHeight, repWidth));
+	geomreqresult = XtMakeResizeRequest((Widget) xw, repWidth,
+					    repHeight, NULL, NULL);
+    }
+#if 1				/* ndef nothack */
+    /*
+     * XtMakeResizeRequest() has the undesirable side-effect of clearing
+     * the window manager's hints, even on a failed request.  This would
+     * presumably be fixed if the shell did its own work.
+     */
+    if (sizehints.flags
+	&& repHeight
+	&& repWidth) {
+	sizehints.height = repHeight;
+	sizehints.width = repWidth;
+	TRACE_HINTS(&sizehints);
+	XSetWMNormalHints(screen->display, VShellWindow, &sizehints);
+    }
+#endif
+    XSync(screen->display, FALSE);	/* synchronize */
+    if (XtAppPending(app_con))
+	xevents();
+
+#ifndef NO_ACTIVE_ICON
+    WhichVWin(screen) = saveWin;
+#endif /* NO_ACTIVE_ICON */
+}
+
+static Widget
+CreateScrollBar(XtermWidget xw, int x, int y, int height)
+{
+    Widget result;
+    Arg args[6];
+
+    XtSetArg(args[0], XtNx, x);
+    XtSetArg(args[1], XtNy, y);
+    XtSetArg(args[2], XtNheight, height);
+    XtSetArg(args[3], XtNreverseVideo, xw->misc.re_verse);
+    XtSetArg(args[4], XtNorientation, XtorientVertical);
+    XtSetArg(args[5], XtNborderWidth, ScrollBarBorder(xw));
+
+    result = XtCreateWidget("scrollbar", scrollbarWidgetClass,
+			    (Widget) xw, args, XtNumber(args));
+    XtAddCallback(result, XtNscrollProc, ScrollTextUpDownBy, 0);
+    XtAddCallback(result, XtNjumpProc, ScrollTextTo, 0);
+    return (result);
+}
+
+void
+ScrollBarReverseVideo(Widget scrollWidget)
+{
+    SbInfo *sb = &(term->screen.fullVwin.sb_info);
+    Arg args[4];
+    Cardinal nargs = XtNumber(args);
+
+    /*
+     * Remember the scrollbar's original colors.
+     */
+    if (sb->rv_cached == False) {
+	XtSetArg(args[0], XtNbackground, &(sb->bg));
+	XtSetArg(args[1], XtNforeground, &(sb->fg));
+	XtSetArg(args[2], XtNborderColor, &(sb->bdr));
+	XtSetArg(args[3], XtNborderPixmap, &(sb->bdpix));
+	XtGetValues(scrollWidget, args, nargs);
+	sb->rv_cached = True;
+	sb->rv_active = 0;
+    }
+
+    sb->rv_active = !(sb->rv_active);
+    XtSetArg(args[!(sb->rv_active)], XtNbackground, sb->bg);
+    XtSetArg(args[(sb->rv_active)], XtNforeground, sb->fg);
+    nargs = 2;			/* don't set border_pixmap */
+    if (sb->bdpix == XtUnspecifiedPixmap) {	/* if not pixmap then pixel */
+	if (sb->rv_active) {	/* keep border visible */
+	    XtSetArg(args[2], XtNborderColor, args[1].value);
+	} else {
+	    XtSetArg(args[2], XtNborderColor, sb->bdr);
+	}
+	nargs = 3;
+    }
+    XtSetValues(scrollWidget, args, nargs);
+}
+
+void
+ScrollBarDrawThumb(Widget scrollWidget)
+{
+    TScreen *screen = &term->screen;
+    int thumbTop, thumbHeight, totalHeight;
+
+    thumbTop = screen->topline + screen->savedlines;
+    thumbHeight = MaxRows(screen);
+    totalHeight = thumbHeight + screen->savedlines;
+
+    XawScrollbarSetThumb(scrollWidget,
+			 ((float) thumbTop) / totalHeight,
+			 ((float) thumbHeight) / totalHeight);
+}
+
+void
+ResizeScrollBar(XtermWidget xw)
+{
+    TScreen *screen = &(xw->screen);
+
+    int height = screen->fullVwin.height + screen->border * 2;
+    int width = screen->scrollWidget->core.width;
+    int ypos = -ScrollBarBorder(xw);
+#ifdef SCROLLBAR_RIGHT
+    int xpos = ((term->misc.useRight)
+		? (screen->fullVwin.fullwidth -
+		   screen->scrollWidget->core.width -
+		   BorderWidth(screen->scrollWidget))
+		: -ScrollBarBorder(xw));
+#else
+    int xpos = -ScrollBarBorder(xw);
+#endif
+
+    TRACE(("ResizeScrollBar at %d,%d %dx%d\n", ypos, xpos, height, width));
+
+    XtConfigureWidget(
+			 screen->scrollWidget,
+			 xpos,
+			 ypos,
+			 width,
+			 height,
+			 BorderWidth(screen->scrollWidget));
+    ScrollBarDrawThumb(screen->scrollWidget);
+}
+
+void
+WindowScroll(TScreen * screen, int top)
+{
+    int i, lines;
+    int scrolltop, scrollheight, refreshtop;
+
+    if (top < -screen->savedlines)
+	top = -screen->savedlines;
+    else if (top > 0)
+	top = 0;
+    if ((i = screen->topline - top) == 0) {
+	ScrollBarDrawThumb(screen->scrollWidget);
+	return;
+    }
+
+    if (screen->cursor_state)
+	HideCursor();
+    lines = i > 0 ? i : -i;
+    if (lines > MaxRows(screen))
+	lines = MaxRows(screen);
+    scrollheight = screen->max_row - lines + 1;
+    if (i > 0)
+	refreshtop = scrolltop = 0;
+    else {
+	scrolltop = lines;
+	refreshtop = scrollheight;
+    }
+    scrolling_copy_area(screen, scrolltop, scrollheight, -i);
+    screen->topline = top;
+
+    ScrollSelection(screen, i, True);
+
+    XClearArea(
+		  screen->display,
+		  VWindow(screen),
+		  OriginX(screen),
+		  OriginY(screen) + refreshtop * FontHeight(screen),
+		  (unsigned) Width(screen),
+		  (unsigned) lines * FontHeight(screen),
+		  FALSE);
+    ScrnRefresh(screen, refreshtop, 0, lines, MaxCols(screen), False);
+
+    ScrollBarDrawThumb(screen->scrollWidget);
+}
+
+#ifdef SCROLLBAR_RIGHT
+/*
+ * Adjust the scrollbar position if we're asked to turn on scrollbars for the
+ * first time (or after resizing) after the xterm is already running.  That
+ * makes the window grow after we've initially configured the scrollbar's
+ * position.  (There must be a better way).
+ */
+void
+updateRightScrollbar(XtermWidget xw)
+{
+    TScreen *screen = &xw->screen;
+
+    if (xw->misc.useRight
+	&& screen->fullVwin.fullwidth < xw->core.width)
+	XtVaSetValues(screen->scrollWidget,
+		      XtNx, screen->fullVwin.fullwidth - BorderWidth(screen->scrollWidget),
+		      (XtPointer) 0);
+}
+
+#endif
+void
+ScrollBarOn(XtermWidget xw, int init, int doalloc)
+{
+    TScreen *screen = &xw->screen;
+    int i, j, k;
+
+    if (screen->fullVwin.sb_info.width || IsIcon(screen))
+	return;
+
+    TRACE(("ScrollBarOn\n"));
+    if (init) {			/* then create it only */
+	if (screen->scrollWidget == 0) {
+	    /* make it a dummy size and resize later */
+	    screen->scrollWidget = CreateScrollBar(xw,
+						   -ScrollBarBorder(xw),
+						   -ScrollBarBorder(xw),
+						   5);
+	    if (screen->scrollWidget == NULL) {
+		Bell(XkbBI_MinorError, 0);
+	    }
+	}
+    } else if (!screen->scrollWidget || !XtIsRealized((Widget) term)) {
+	Bell(XkbBI_MinorError, 0);
+	Bell(XkbBI_MinorError, 0);
+    } else {
+
+	if (doalloc && screen->allbuf) {
+	    /* FIXME: this is not integrated well with Allocate */
+	    if ((screen->allbuf =
+		 TypeRealloc(ScrnPtr,
+			     MAX_PTRS * (screen->max_row + 2 + screen->savelines),
+			     screen->visbuf)) == NULL) {
+		SysError(ERROR_SBRALLOC);
+	    }
+	    screen->visbuf = &screen->allbuf[MAX_PTRS * screen->savelines];
+	    memmove((char *) screen->visbuf, (char *) screen->allbuf,
+		    MAX_PTRS * (screen->max_row + 2) * sizeof(char *));
+	    for (i = k = 0; i < screen->savelines; i++) {
+		k += BUF_HEAD;
+		for (j = BUF_HEAD; j < MAX_PTRS; j++) {
+		    if ((screen->allbuf[k++] =
+			 TypeCallocN(Char, (unsigned) MaxCols(screen))
+			) == NULL)
+			SysError(ERROR_SBRALLOC2);
+		}
+	    }
+	}
+
+	ResizeScrollBar(xw);
+	xtermAddInput(screen->scrollWidget);
+	XtRealizeWidget(screen->scrollWidget);
+	TRACE_TRANS("scrollbar", screen->scrollWidget);
+
+	screen->fullVwin.sb_info.rv_cached = False;
+
+	screen->fullVwin.sb_info.width = (screen->scrollWidget->core.width
+					  + BorderWidth(screen->scrollWidget));
+
+	TRACE(("setting scrollbar width %d = %d + %d\n",
+	       screen->fullVwin.sb_info.width,
+	       screen->scrollWidget->core.width,
+	       BorderWidth(screen->scrollWidget)));
+
+	ScrollBarDrawThumb(screen->scrollWidget);
+	DoResizeScreen(xw);
+
+#ifdef SCROLLBAR_RIGHT
+	updateRightScrollbar(term);
+#endif
+
+	XtMapWidget(screen->scrollWidget);
+	update_scrollbar();
+	if (screen->visbuf) {
+	    XClearWindow(screen->display, XtWindow(term));
+	    Redraw();
+	}
+    }
+}
+
+void
+ScrollBarOff(TScreen * screen)
+{
+    if (!screen->fullVwin.sb_info.width || IsIcon(screen))
+	return;
+
+    TRACE(("ScrollBarOff\n"));
+    if (XtIsRealized((Widget) term)) {
+	XtUnmapWidget(screen->scrollWidget);
+	screen->fullVwin.sb_info.width = 0;
+	DoResizeScreen(term);
+	update_scrollbar();
+	if (screen->visbuf) {
+	    XClearWindow(screen->display, XtWindow(term));
+	    Redraw();
+	}
+    } else {
+	Bell(XkbBI_MinorError, 0);
+    }
+}
+
+/*
+ * Toggle the visibility of the scrollbars.
+ */
+void
+ToggleScrollBar(XtermWidget w)
+{
+    TScreen *screen = &w->screen;
+
+    if (IsIcon(screen)) {
+	Bell(XkbBI_MinorError, 0);
+    } else {
+	TRACE(("ToggleScrollBar{{\n"));
+	if (screen->fullVwin.sb_info.width) {
+	    ScrollBarOff(screen);
+	} else {
+	    ScrollBarOn(w, FALSE, FALSE);
+	}
+	update_scrollbar();
+	TRACE(("...ToggleScrollBar}}\n"));
+    }
+}
+
+/*ARGSUSED*/
+static void
+ScrollTextTo(
+		Widget scrollbarWidget GCC_UNUSED,
+		XtPointer client_data GCC_UNUSED,
+		XtPointer call_data)
+{
+    float *topPercent = (float *) call_data;
+    TScreen *screen = &term->screen;
+    int thumbTop;		/* relative to first saved line */
+    int newTopLine;
+
+    /*
+     * screen->savedlines : Number of offscreen text lines,
+     * MaxRows(screen)    : Number of onscreen  text lines,
+     * screen->topline    : -Number of lines above the last screen->max_row+1 lines
+     */
+
+    thumbTop = (int) (*topPercent * (screen->savedlines + MaxRows(screen)));
+    newTopLine = thumbTop - screen->savedlines;
+    WindowScroll(screen, newTopLine);
+}
+
+/*ARGSUSED*/
+static void
+ScrollTextUpDownBy(
+		      Widget scrollbarWidget GCC_UNUSED,
+		      XtPointer client_data GCC_UNUSED,
+		      XtPointer call_data)
+{
+    long pixels = (long) call_data;
+
+    TScreen *screen = &term->screen;
+    int rowOnScreen, newTopLine;
+
+    rowOnScreen = pixels / FontHeight(screen);
+    if (rowOnScreen == 0) {
+	if (pixels < 0)
+	    rowOnScreen = -1;
+	else if (pixels > 0)
+	    rowOnScreen = 1;
+    }
+    newTopLine = screen->topline + rowOnScreen;
+    WindowScroll(screen, newTopLine);
+}
+
+/*
+ * assume that b is lower case and allow plural
+ */
+static int
+specialcmplowerwiths(char *a, char *b, int *modifier)
+{
+    char ca, cb;
+
+    *modifier = 0;
+    if (!a || !b)
+	return 0;
+
+    while (1) {
+	ca = char2lower(*a);
+	cb = *b;
+	if (ca != cb || ca == '\0')
+	    break;		/* if not eq else both nul */
+	a++, b++;
+    }
+    if (cb != '\0')
+	return 0;
+
+    if (ca == 's')
+	ca = *++a;
+
+    switch (ca) {
+    case '+':
+    case '-':
+	*modifier = (ca == '-' ? -1 : 1) * atoi(a + 1);
+	return 1;
+
+    case '\0':
+	return 1;
+
+    default:
+	return 0;
+    }
+}
+
+static long
+params_to_pixels(TScreen * screen, String * params, Cardinal n)
+{
+    int mult = 1;
+    char *s;
+    int modifier;
+
+    switch (n > 2 ? 2 : n) {
+    case 2:
+	s = params[1];
+	if (specialcmplowerwiths(s, "page", &modifier)) {
+	    mult = (MaxRows(screen) + modifier) * FontHeight(screen);
+	} else if (specialcmplowerwiths(s, "halfpage", &modifier)) {
+	    mult = ((MaxRows(screen) + modifier) * FontHeight(screen)) / 2;
+	} else if (specialcmplowerwiths(s, "pixel", &modifier)) {
+	    mult = 1;
+	} else {
+	    /* else assume that it is Line */
+	    mult = FontHeight(screen);
+	}
+	mult *= atoi(params[0]);
+	break;
+    case 1:
+	mult = atoi(params[0]) * FontHeight(screen);	/* lines */
+	break;
+    default:
+	mult = screen->scrolllines * FontHeight(screen);
+	break;
+    }
+    return mult;
+}
+
+static long
+AmountToScroll(Widget gw, String * params, Cardinal nparams)
+{
+    if (gw != 0) {
+	if (IsXtermWidget(gw)) {
+	    TScreen *screen = &((XtermWidget) gw)->screen;
+	    if (nparams > 2
+		&& screen->send_mouse_pos != MOUSE_OFF)
+		return 0;
+	    return params_to_pixels(screen, params, nparams);
+	} else {
+	    /*
+	     * This may have been the scrollbar widget.  Try its parent, which
+	     * would be the VT100 widget.
+	     */
+	    return AmountToScroll(XtParent(gw), params, nparams);
+	}
+    }
+    return 0;
+}
+
+/*ARGSUSED*/
+void
+HandleScrollForward(
+		       Widget gw,
+		       XEvent * event GCC_UNUSED,
+		       String * params,
+		       Cardinal *nparams)
+{
+    long amount;
+
+    if ((amount = AmountToScroll(gw, params, *nparams)) != 0) {
+	ScrollTextUpDownBy(gw, (XtPointer) 0, (XtPointer) amount);
+    }
+}
+
+/*ARGSUSED*/
+void
+HandleScrollBack(
+		    Widget gw,
+		    XEvent * event GCC_UNUSED,
+		    String * params,
+		    Cardinal *nparams)
+{
+    long amount;
+
+    if ((amount = -AmountToScroll(gw, params, *nparams)) != 0) {
+	ScrollTextUpDownBy(gw, (XtPointer) 0, (XtPointer) amount);
+    }
+}