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, 885 insertions, 0 deletions

diff --git a/nx-X11/lib/Xaw/Scrollbar.c b/nx-X11/lib/Xaw/Scrollbar.c
new file mode 100644
index 000000000..e6dea9c41
--- /dev/null
+++ b/nx-X11/lib/Xaw/Scrollbar.c
@@ -0,0 +1,885 @@
+/* $Xorg: Scrollbar.c,v 1.4 2001/02/09 02:03:45 xorgcvs Exp $ */
+
+/***********************************************************
+
+Copyright 1987, 1988, 1994, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+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
+OPEN GROUP 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 of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+
+Copyright 1987, 1988 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 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.
+
+******************************************************************/
+/* $XFree86: xc/lib/Xaw/Scrollbar.c,v 1.12 2001/01/17 19:42:29 dawes Exp $ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <X11/IntrinsicP.h>
+#include <X11/StringDefs.h>
+#include <X11/Xmu/Drawing.h>
+#include <X11/Xaw/ScrollbarP.h>
+#include <X11/Xaw/XawInit.h>
+#include "Private.h"
+
+#define NoButton	-1
+#define PICKLENGTH(widget, x, y)					\
+(((widget)->scrollbar.orientation == XtorientHorizontal) ? (x) : (y))
+
+/*
+ * Class Methods
+ */
+static void XawScrollbarClassInitialize(void);
+static void XawScrollbarDestroy(Widget);
+static void XawScrollbarInitialize(Widget, Widget, ArgList, Cardinal*_args);
+static void XawScrollbarRealize(Widget, Mask*, XSetWindowAttributes*);
+static void XawScrollbarRedisplay(Widget, XEvent*, Region);
+static void XawScrollbarResize(Widget);
+static Boolean XawScrollbarSetValues(Widget, Widget, Widget,
+				     ArgList, Cardinal*);
+
+/*
+ * Prototypes
+ */
+static Boolean CompareEvents(XEvent*, XEvent*);
+static void CreateGC(Widget);
+static float FloatInRange(float, float, float);
+static float FractionLoc(ScrollbarWidget, int, int);
+static void ExtractPosition(XEvent*, Position*, Position*);
+static int InRange(int, int, int);
+static void FillArea(ScrollbarWidget, int, int, int);
+static Bool LookAhead(Widget, XEvent*);
+static void PaintThumb(ScrollbarWidget);
+static Bool PeekNotifyEvent(Display*, XEvent*, char*);
+static void SetDimensions(ScrollbarWidget);
+
+/*
+ * Actions
+ */
+static void EndScroll(Widget, XEvent*, String*, Cardinal*);
+static void MoveThumb(Widget, XEvent*, String*, Cardinal*);
+static void NotifyScroll(Widget, XEvent*, String*, Cardinal*);
+static void NotifyThumb(Widget, XEvent*, String*, Cardinal*);
+static void StartScroll(Widget, XEvent*, String*, Cardinal*);
+
+/*
+ * Initialization
+ */
+static char defaultTranslations[] =
+"<Btn1Down>:"	"StartScroll(Forward)\n"
+"<Btn2Down>:"	"StartScroll(Continuous) MoveThumb() NotifyThumb()\n"
+"<Btn3Down>:"	"StartScroll(Backward)\n"
+"<Btn2Motion>:"	"MoveThumb() NotifyThumb()\n"
+"<BtnUp>:"	"NotifyScroll(Proportional) EndScroll()\n";
+
+static float floatZero = 0.0;
+
+#define Offset(field) XtOffsetOf(ScrollbarRec, field)
+
+static XtResource resources[] = {
+  {
+    XtNlength,
+    XtCLength,
+    XtRDimension,
+    sizeof(Dimension),
+    Offset(scrollbar.length),
+    XtRImmediate,
+    (XtPointer)1
+  },
+  {
+    XtNthickness,
+    XtCThickness,
+    XtRDimension,
+    sizeof(Dimension),
+    Offset(scrollbar.thickness),
+    XtRImmediate,
+    (XtPointer)14
+  },
+  {
+    XtNorientation,
+    XtCOrientation,
+    XtROrientation,
+    sizeof(XtOrientation),
+    Offset(scrollbar.orientation),
+    XtRImmediate,
+    (XtPointer)XtorientVertical
+  },
+  {
+    XtNscrollProc,
+    XtCCallback,
+    XtRCallback,
+    sizeof(XtPointer),
+    Offset(scrollbar.scrollProc),
+    XtRCallback,
+    NULL
+  },
+  {
+    XtNthumbProc,
+    XtCCallback,
+    XtRCallback,
+    sizeof(XtPointer),
+    Offset(scrollbar.thumbProc),
+    XtRCallback,
+    NULL
+  },
+  {
+    XtNjumpProc,
+    XtCCallback,
+    XtRCallback,
+    sizeof(XtPointer),
+    Offset(scrollbar.jumpProc),
+    XtRCallback,
+    NULL
+  },
+  {
+    XtNthumb,
+    XtCThumb,
+    XtRBitmap,
+    sizeof(Pixmap),
+    Offset(scrollbar.thumb),
+    XtRImmediate,
+    (XtPointer)XtUnspecifiedPixmap
+  },
+  {
+    XtNforeground,
+    XtCForeground,
+    XtRPixel,
+    sizeof(Pixel),
+    Offset(scrollbar.foreground),
+    XtRString,
+    XtDefaultForeground
+  },
+  {
+    XtNshown,
+    XtCShown,
+    XtRFloat,
+    sizeof(float),
+    Offset(scrollbar.shown),
+    XtRFloat,
+    (XtPointer)&floatZero
+  },
+  {
+    XtNtopOfThumb,
+    XtCTopOfThumb,
+    XtRFloat,
+    sizeof(float),
+    Offset(scrollbar.top),
+    XtRFloat,
+    (XtPointer)&floatZero
+  },
+  {
+    XtNscrollVCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.verCursor),
+    XtRString,
+    "sb_v_double_arrow"
+  },
+  {
+    XtNscrollHCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.horCursor),
+    XtRString,
+    "sb_h_double_arrow"
+  },
+  {
+    XtNscrollUCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.upCursor),
+    XtRString,
+    "sb_up_arrow"
+  },
+  {
+    XtNscrollDCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.downCursor),
+    XtRString,
+    "sb_down_arrow"
+  },
+  {
+    XtNscrollLCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.leftCursor),
+    XtRString,
+    "sb_left_arrow"
+  },
+  {
+    XtNscrollRCursor,
+    XtCCursor,
+    XtRCursor,
+    sizeof(Cursor),
+    Offset(scrollbar.rightCursor),
+    XtRString,
+    "sb_right_arrow"
+  },
+  {
+    XtNminimumThumb,
+    XtCMinimumThumb,
+    XtRDimension,
+    sizeof(Dimension),
+    Offset(scrollbar.min_thumb),
+    XtRImmediate,
+    (XtPointer)7
+  },
+};
+#undef Offset
+
+static XtActionsRec actions[] = {
+	{"StartScroll",		StartScroll},
+	{"MoveThumb",		MoveThumb},
+	{"NotifyThumb",		NotifyThumb},
+	{"NotifyScroll",	NotifyScroll},
+	{"EndScroll",		EndScroll},
+};
+
+#define Superclass (&simpleClassRec)
+ScrollbarClassRec scrollbarClassRec = {
+  /* core */
+  {
+    (WidgetClass)&simpleClassRec,	/* superclass */
+    "Scrollbar",			/* class_name */
+    sizeof(ScrollbarRec),		/* widget_size */
+    XawScrollbarClassInitialize,	/* class_initialize */
+    NULL,				/* class_part_init */
+    False,				/* class_inited */
+    XawScrollbarInitialize,		/* initialize */
+    NULL,				/* initialize_hook */
+    XawScrollbarRealize,		/* realize */
+    actions,				/* actions */
+    XtNumber(actions),			/* num_actions */
+    resources,				/* resources */
+    XtNumber(resources),		/* num_resources */
+    NULLQUARK,				/* xrm_class */
+    True,				/* compress_motion */
+    True,				/* compress_exposure */
+    True,				/* compress_enterleave */
+    False,				/* visible_interest */
+    XawScrollbarDestroy,		/* destroy */
+    XawScrollbarResize,			/* resize */
+    XawScrollbarRedisplay,		/* expose */
+    XawScrollbarSetValues,		/* set_values */
+    NULL,				/* set_values_hook */
+    XtInheritSetValuesAlmost,		/* set_values_almost */
+    NULL,				/* get_values_hook */
+    NULL,				/* accept_focus */
+    XtVersion,				/* version */
+    NULL,				/* callback_private */
+    defaultTranslations,		/* tm_table */
+    XtInheritQueryGeometry,		/* query_geometry */
+    XtInheritDisplayAccelerator,	/* display_accelerator */
+    NULL,				/* extension */
+  },
+  /* simple */
+  {
+    XtInheritChangeSensitive,		/* change_sensitive */
+  },
+  /* scrollbar */
+  {
+    NULL,				/* extension */
+  },
+};
+
+WidgetClass scrollbarWidgetClass = (WidgetClass)&scrollbarClassRec;
+
+/*
+ * Implementation
+ */
+static void
+XawScrollbarClassInitialize(void)
+{
+    XawInitializeWidgetSet();
+    XtAddConverter(XtRString, XtROrientation, XmuCvtStringToOrientation,
+		   NULL, 0);
+    XtSetTypeConverter(XtROrientation, XtRString, XmuCvtOrientationToString,
+		       NULL, 0, XtCacheNone, NULL);
+}
+
+/*
+ * Make sure the first number is within the range specified by the other
+ * two numbers.
+ */
+static int
+InRange(int num, int small, int big)
+{
+    return ((num < small) ? small : ((num > big) ? big : num));
+}
+
+/*
+ * Same as above, but for floating numbers
+ */
+static float
+FloatInRange(float num, float small, float big)
+{
+    return ((num < small) ? small : ((num > big) ? big : num));
+}
+
+/* Fill the area specified by top and bottom with the given pattern */
+static float
+FractionLoc(ScrollbarWidget w, int x, int y)
+{
+    float   result;
+
+    result = PICKLENGTH(w, x / (float)XtWidth(w), y / (float)XtHeight(w));
+
+    return (FloatInRange(result, 0.0, 1.0));
+}
+
+static void
+FillArea(ScrollbarWidget w, int top, int bottom, int thumb)
+{
+    Dimension length;
+
+    top = XawMax(1, top);
+    if (w->scrollbar.orientation == XtorientHorizontal) 
+    bottom = XawMin(bottom, XtWidth(w) - 1);
+    else
+    bottom = XawMin(bottom, XtHeight(w) - 1);
+
+    if (bottom <= top)
+	return;
+
+    length = bottom - top;
+
+    switch(thumb) {
+	/* Fill the new Thumb location */
+	case 1:
+	    if (w->scrollbar.orientation == XtorientHorizontal) 
+		XFillRectangle(XtDisplay(w), XtWindow(w), w->scrollbar.gc,
+			       top, 1, length, XtHeight(w) - 2);
+	    else
+		XFillRectangle(XtDisplay(w), XtWindow(w), w->scrollbar.gc,
+			       1, top, XtWidth(w) - 2, length);
+	    break;
+	/* Clear the old Thumb location */
+	case 0:
+	    if (w->scrollbar.orientation == XtorientHorizontal) 
+		XClearArea(XtDisplay(w), XtWindow(w),
+			   top, 1, length, XtHeight(w) - 2, False);
+	    else
+		XClearArea(XtDisplay(w), XtWindow(w),
+			   1, top, XtWidth(w) - 2, length, False);
+	    break;
+    }
+}
+
+
+/* Paint the thumb in the area specified by w->top and
+   w->shown.  The old area is erased.  The painting and
+   erasing is done cleverly so that no flickering will occur. */
+static void
+PaintThumb(ScrollbarWidget w)
+{
+    Position oldtop, oldbot, newtop, newbot;
+
+    oldtop = w->scrollbar.topLoc;
+    oldbot = oldtop + w->scrollbar.shownLength;
+    newtop = w->scrollbar.length * w->scrollbar.top;
+    newbot = newtop + (int)(w->scrollbar.length * w->scrollbar.shown);
+    if (newbot < newtop + (int)w->scrollbar.min_thumb) 
+	newbot = newtop + w->scrollbar.min_thumb;
+    w->scrollbar.topLoc = newtop;
+    w->scrollbar.shownLength = newbot - newtop;
+
+    if (XtIsRealized((Widget)w)) {
+	if (newtop < oldtop)
+	    FillArea(w, newtop, XawMin(newbot, oldtop), 1);
+	if (newtop > oldtop)
+	    FillArea(w, oldtop, XawMin(newtop, oldbot), 0);
+	if (newbot < oldbot)
+	    FillArea(w, XawMax(newbot, oldtop), oldbot, 0);
+	if (newbot > oldbot)
+	    FillArea(w, XawMax(newtop, oldbot), newbot, 1);
+    }
+}
+
+static void
+SetDimensions(ScrollbarWidget w)
+{
+    if (w->scrollbar.orientation == XtorientVertical) {
+	w->scrollbar.length = XtHeight(w);
+	w->scrollbar.thickness = XtWidth(w);
+    }
+    else {
+	w->scrollbar.length = XtWidth(w);
+	w->scrollbar.thickness = XtHeight(w);
+    }
+}
+
+static void
+XawScrollbarDestroy(Widget w)
+{
+    ScrollbarWidget sbw = (ScrollbarWidget)w;
+    
+    XtReleaseGC(w, sbw->scrollbar.gc);
+}
+
+static void
+CreateGC(Widget w)
+{
+    ScrollbarWidget sbw = (ScrollbarWidget)w;
+    XGCValues gcValues;
+    XtGCMask mask;
+    unsigned int depth = 1;
+
+    if (sbw->scrollbar.thumb == XtUnspecifiedPixmap)
+	sbw->scrollbar.thumb = XmuCreateStippledPixmap(XtScreen(w),
+						       (Pixel)1, (Pixel)0,
+						       depth);
+    else if (sbw->scrollbar.thumb != None) {
+	Window root;
+	int x, y;
+	unsigned int width, height, bw;
+
+	XGetGeometry(XtDisplay(w), sbw->scrollbar.thumb, &root, &x, &y,
+		     &width, &height, &bw, &depth);
+    }
+
+    gcValues.foreground = sbw->scrollbar.foreground;
+    gcValues.background = sbw->core.background_pixel;
+    mask = GCForeground | GCBackground;
+
+    if (sbw->scrollbar.thumb != None) {
+	if (depth == 1) {
+	    gcValues.fill_style = FillOpaqueStippled;
+	    gcValues.stipple = sbw->scrollbar.thumb;
+	    mask |= GCFillStyle | GCStipple;
+	}
+	else {
+	    gcValues.fill_style = FillTiled;
+	    gcValues.tile = sbw->scrollbar.thumb;
+	    mask |= GCFillStyle | GCTile;
+	}
+    }
+    sbw->scrollbar.gc = XtGetGC(w, mask, &gcValues);
+}
+
+/* ARGSUSED */
+static void
+XawScrollbarInitialize(Widget request, Widget cnew,
+		       ArgList args, Cardinal *num_args)
+{
+    ScrollbarWidget w = (ScrollbarWidget)cnew;
+
+    CreateGC(cnew);
+
+    if (XtWidth(w) == 0)
+	XtWidth(w) = w->scrollbar.orientation == XtorientVertical ?
+			w->scrollbar.thickness : w->scrollbar.length;
+
+    if (XtHeight(w) == 0)
+	XtHeight(w) = w->scrollbar.orientation == XtorientHorizontal ?
+			w->scrollbar.thickness : w->scrollbar.length;
+
+    SetDimensions(w);
+    w->scrollbar.direction = 0;
+    w->scrollbar.topLoc = 0;
+    w->scrollbar.shownLength = w->scrollbar.min_thumb;
+}
+
+static void
+XawScrollbarRealize(Widget gw, Mask *valueMask,
+		    XSetWindowAttributes *attributes)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+
+    w->scrollbar.inactiveCursor = w->scrollbar.orientation == XtorientVertical ?
+		w->scrollbar.verCursor : w->scrollbar.horCursor;
+
+    XtVaSetValues(gw, XtNcursor, w->scrollbar.inactiveCursor, NULL);
+
+    /* 
+     * The Simple widget actually stuffs the value in the valuemask
+     */
+    (*scrollbarWidgetClass->core_class.superclass->core_class.realize)
+	(gw, valueMask, attributes);
+}
+
+/*ARGSUSED*/
+static Boolean 
+XawScrollbarSetValues(Widget current, Widget request, Widget desired,
+		      ArgList args, Cardinal *num_args)
+{
+    ScrollbarWidget w = (ScrollbarWidget)current;
+    ScrollbarWidget dw = (ScrollbarWidget)desired;
+    Boolean redraw = False;
+
+    /*
+     * If these values are outside the acceptable range ignore them...
+     */
+    if (dw->scrollbar.top < 0.0 || dw->scrollbar.top > 1.0)
+	dw->scrollbar.top = w->scrollbar.top;
+
+    if (dw->scrollbar.shown < 0.0 || dw->scrollbar.shown > 1.0)
+	dw->scrollbar.shown = w->scrollbar.shown;
+
+    if (XtIsRealized (desired)) {
+	if (w->scrollbar.foreground != dw->scrollbar.foreground ||
+	    w->core.background_pixel != dw->core.background_pixel ||
+	    w->scrollbar.thumb != dw->scrollbar.thumb) {
+	    XtReleaseGC((Widget)dw, w->scrollbar.gc);
+	    CreateGC((Widget)dw);
+	    redraw = True;
+	}
+	if (w->scrollbar.top != dw->scrollbar.top ||
+	    w->scrollbar.shown != dw->scrollbar.shown)
+	    redraw = True;
+    }
+
+    return (redraw);
+}
+
+static void
+XawScrollbarResize(Widget gw)
+{
+    /* ForgetGravity has taken care of background, but thumb may
+     * have to move as a result of the new size. */
+    SetDimensions((ScrollbarWidget)gw);
+    XawScrollbarRedisplay(gw, NULL, NULL);
+}
+
+/*ARGSUSED*/
+static void
+XawScrollbarRedisplay(Widget gw, XEvent *event, Region region)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+    int x, y;
+    unsigned int width, height;
+
+    if (Superclass->core_class.expose)
+	(*Superclass->core_class.expose)(gw, event, region);
+
+    if (w->scrollbar.orientation == XtorientHorizontal) {
+	x = w->scrollbar.topLoc;
+	y = 1;
+	width = w->scrollbar.shownLength;
+	height = XtHeight(w) - 2;
+    }
+    else {
+	x = 1;
+	y = w->scrollbar.topLoc;
+	width = XtWidth(w) - 2;
+	height = w->scrollbar.shownLength;
+    }
+
+    if (region == NULL ||
+	XRectInRegion(region, x, y, width, height) != RectangleOut) {
+	/* Forces entire thumb to be painted */
+	w->scrollbar.topLoc = -(w->scrollbar.length + 1);
+	PaintThumb(w);
+    }
+}
+
+/*ARGSUSED*/
+static void
+StartScroll(Widget gw, XEvent *event, String *params, Cardinal *num_params)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+    Cursor cursor;
+    char direction;
+
+    if (w->scrollbar.direction != 0)	/* if we're already scrolling */
+	return;
+    if (*num_params > 0)
+	direction = *params[0];
+    else
+	direction = 'C';
+
+    w->scrollbar.direction = direction;
+
+    switch(direction) {
+	case 'B':
+	case 'b':
+	    cursor = w->scrollbar.orientation == XtorientVertical ?
+		w->scrollbar.downCursor : w->scrollbar.rightCursor;
+	    break;
+	case 'F':
+	case 'f':
+	    cursor = w->scrollbar.orientation == XtorientVertical ?
+		w->scrollbar.upCursor : w->scrollbar.leftCursor;
+	    break;
+	case 'C':
+	case 'c':
+	     cursor = w->scrollbar.orientation == XtorientVertical ?
+		w->scrollbar.rightCursor : w->scrollbar.upCursor;
+	     break;
+	default:
+	     return;	/* invalid invocation */
+    }
+
+    XtVaSetValues(gw, XtNcursor, cursor, NULL);
+
+    XFlush(XtDisplay(w));
+}
+
+static Boolean
+CompareEvents(XEvent *oldEvent, XEvent *newEvent)
+{
+#define Check(field) if (newEvent->field != oldEvent->field) return (False)
+
+    Check(xany.display);
+    Check(xany.type);
+    Check(xany.window);
+
+    switch(newEvent->type) {
+	case MotionNotify:
+	    Check(xmotion.state);
+	    break;
+	case ButtonPress:
+	case ButtonRelease:
+	    Check(xbutton.state);
+	    Check(xbutton.button);
+	    break;
+	case KeyPress:
+	case KeyRelease:
+	    Check(xkey.state);
+	    Check(xkey.keycode);
+	    break;
+	case EnterNotify:
+	case LeaveNotify:
+	    Check(xcrossing.mode);
+	    Check(xcrossing.detail);
+	    Check(xcrossing.state);
+	    break;
+    }
+#undef Check
+
+    return (True);
+}
+
+struct EventData {
+    XEvent *oldEvent;
+    int count;
+};
+
+static Bool
+PeekNotifyEvent(Display *dpy, XEvent *event, char *args)
+{
+    struct EventData *eventData = (struct EventData*)args;
+
+    return (++eventData->count == QLength(dpy)	/* since PeekIf blocks */
+	    || CompareEvents(event, eventData->oldEvent));
+}
+
+static Bool
+LookAhead(Widget w, XEvent *event)
+{
+    XEvent newEvent;
+    struct EventData eventData;
+
+    if (QLength(XtDisplay(w)) == 0)
+	return (False);
+
+    eventData.count = 0;
+    eventData.oldEvent = event;
+
+    XPeekIfEvent(XtDisplay(w), &newEvent, PeekNotifyEvent, (char*)&eventData);
+
+    if (CompareEvents(event, &newEvent))
+	return (True);
+
+    return (False);
+}
+
+static void
+ExtractPosition(XEvent *event, Position *x, Position *y)
+{
+    switch(event->type) {
+	case MotionNotify:
+	    *x = event->xmotion.x;
+	    *y = event->xmotion.y;
+	    break;
+	case ButtonPress:
+	case ButtonRelease:
+	    *x = event->xbutton.x;
+	    *y = event->xbutton.y;
+	    break;
+	case KeyPress:
+	case KeyRelease:
+	    *x = event->xkey.x;
+	    *y = event->xkey.y;
+	    break;
+	case EnterNotify:
+	case LeaveNotify:
+	    *x = event->xcrossing.x;
+	    *y = event->xcrossing.y;
+	    break;
+	default:
+	    *x = 0;
+	    *y = 0;
+	    break;
+    }
+}
+
+static void
+NotifyScroll(Widget gw, XEvent *event, String *params, Cardinal *num_params)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+    long call_data = 0;
+    char style;
+    Position x, y;
+
+    if (w->scrollbar.direction == 0)	/* if no StartScroll */
+	return;
+
+    if (LookAhead(gw, event))
+	return;
+
+    if (*num_params > 0)
+	style = *params[0];
+    else
+	style = 'P';
+
+    switch(style) {
+	case 'P':    /* Proportional */
+	case 'p':
+	    ExtractPosition(event, &x, &y);
+	    call_data = InRange(PICKLENGTH(w, x, y), 0, (int)w->scrollbar.length);
+	    break;
+	case 'F':    /* FullLength */
+	case 'f':
+	    call_data = w->scrollbar.length;
+	    break;
+    }
+
+    switch(w->scrollbar.direction) {
+	case 'B':
+	case 'b':
+	    call_data = -call_data;
+	    /*FALLTHROUGH*/
+	case 'F':
+	case 'f':
+	    XtCallCallbacks(gw, XtNscrollProc, (XtPointer)call_data);
+	    break;
+	case 'C':
+	case 'c':    /* NotifyThumb has already called the thumbProc(s) */
+	    break;
+    }
+}
+
+/*ARGSUSED*/
+static void
+EndScroll(Widget gw, XEvent *event, String *params, Cardinal *num_params)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+
+    XtVaSetValues(gw, XtNcursor, w->scrollbar.inactiveCursor, NULL);
+    XFlush(XtDisplay(w));		/* make sure it get propogated */
+
+    w->scrollbar.direction = 0;
+}
+
+/*ARGSUSED*/
+static void
+MoveThumb(Widget gw, XEvent *event, String *params, Cardinal *num_params)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+    Position x, y;
+
+    if (w->scrollbar.direction == 0)	/* if no StartScroll */
+	return;
+
+    if (LookAhead(gw, event))
+	return;
+
+    if (!event->xmotion.same_screen)
+	return;
+
+    ExtractPosition(event, &x, &y);
+    w->scrollbar.top = FractionLoc(w, x, y);
+}
+
+/*ARGSUSED*/
+static void
+NotifyThumb(Widget gw, XEvent *event, String *params, Cardinal *num_params)
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+    union {
+	XtPointer xtp;
+	float xtf;
+    } xtpf;
+
+    if (w->scrollbar.direction == 0)	/* if no StartScroll */
+	return;
+
+    if (LookAhead(gw, event))
+	return;
+
+    /* thumbProc is not pretty, but is necessary for backwards
+       compatibility on those architectures for which it work{s,ed};
+       the intent is to pass a (truncated) float by value. */
+    xtpf.xtf = w->scrollbar.top;
+    XtCallCallbacks(gw, XtNthumbProc, xtpf.xtp);
+    XtCallCallbacks(gw, XtNjumpProc, (XtPointer)&w->scrollbar.top);
+
+    PaintThumb(w);
+}
+
+/*
+ *  Public routines
+ */
+/* Set the scroll bar to the given location. */
+void
+XawScrollbarSetThumb(Widget gw,
+#if NeedWidePrototypes
+		     double top, double shown
+#else
+		     float top, float shown
+#endif
+		     )
+{
+    ScrollbarWidget w = (ScrollbarWidget)gw;
+
+    if (w->scrollbar.direction == 'c')	/* if still thumbing */
+	return;
+
+    w->scrollbar.top = top > 1.0 ? 1.0 : top >= 0.0 ? top : w->scrollbar.top;
+
+    w->scrollbar.shown = shown > 1.0 ? 1.0 : shown >= 0.0 ?
+				shown : w->scrollbar.shown;
+    PaintThumb(w);
+}