path: root/src/Scrollbar.c

/* MODIFIED ATHENA SCROLLBAR (USING ARROWHEADS AT ENDS OF TRAVEL) */
/* Modifications Copyright 1992 by Mitch Trachtenberg             */
/* Rights, permissions, and disclaimer of warranty are as in the  */
/* DEC and MIT notice below.                                      */

/***********************************************************

Copyright (c) 1987, 1988, 1994  X Consortium

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
X CONSORTIUM 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 X Consortium 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 X Consortium.


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.

******************************************************************/

/* ScrollBar.c */
/* created by weissman, Mon Jul  7 13:20:03 1986 */
/* converted by swick, Thu Aug 27 1987 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <X11/Xaw3d/Xaw3dP.h>

#include <X11/IntrinsicP.h>
#include <X11/StringDefs.h>

#include <X11/Xaw3d/XawInit.h>
#include <X11/Xaw3d/ScrollbarP.h>

#include <X11/Xmu/Drawing.h>

#include <stdint.h>

/* Private definitions. */

#ifdef XAW_ARROW_SCROLLBARS
static char defaultTranslations[] =
    "<Btn1Down>:   NotifyScroll()\n\
     <Btn2Down>:   MoveThumb() NotifyThumb() \n\
     <Btn3Down>:   NotifyScroll()\n\
     <Btn1Motion>: HandleThumb() \n\
     <Btn3Motion>: HandleThumb() \n\
     <Btn2Motion>: MoveThumb() NotifyThumb() \n\
     <BtnUp>:      EndScroll()";
#else
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()";
#ifdef bogusScrollKeys
    /* examples */
    "<KeyPress>f:  StartScroll(Forward) NotifyScroll(FullLength) EndScroll()"
    "<KeyPress>b:  StartScroll(Backward) NotifyScroll(FullLength) EndScroll()"
#endif
#endif

static float floatZero = 0.0;

#define Offset(field) XtOffsetOf(ScrollbarRec, field)

static XtResource resources[] = {
#ifdef XAW_ARROW_SCROLLBARS
/*  {XtNscrollCursor, XtCCursor, XtRCursor, sizeof(Cursor),
       Offset(scrollbar.cursor), XtRString, "crosshair"},*/
#else
  {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"},
#endif
  {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},
  {XtNpickTop, XtCPickTop, XtRBoolean, sizeof(Boolean),
       Offset(scrollbar.pick_top), XtRBoolean, (XtPointer) False},
  {XtNminimumThumb, XtCMinimumThumb, XtRDimension, sizeof(Dimension),
       Offset(scrollbar.min_thumb), XtRImmediate, (XtPointer) 7}
};
#undef Offset

static void ClassInitialize(void);
static void Initialize(Widget, Widget, ArgList, Cardinal *);
static void Destroy(Widget);
static void Realize(Widget, Mask *, XSetWindowAttributes *);
static void Resize(Widget);
static void Redisplay(Widget, XEvent *, Region);
static Boolean SetValues(Widget, Widget, Widget, ArgList, Cardinal *);

#ifdef XAW_ARROW_SCROLLBARS
static void HandleThumb(Widget, XEvent *, String *, Cardinal *);
#else
static void StartScroll(Widget, XEvent *, String *, Cardinal *);
#endif
static void MoveThumb(Widget, XEvent *, String *, Cardinal *);
static void NotifyThumb(Widget, XEvent *, String *, Cardinal *);
static void NotifyScroll(Widget, XEvent *, String *, Cardinal *);
static void EndScroll(Widget, XEvent *, String *, Cardinal *);

static XtActionsRec actions[] = {
#ifdef XAW_ARROW_SCROLLBARS
    {"HandleThumb",	HandleThumb},
#else
    {"StartScroll",     StartScroll},
#endif
    {"MoveThumb",	MoveThumb},
    {"NotifyThumb",	NotifyThumb},
    {"NotifyScroll",	NotifyScroll},
    {"EndScroll",	EndScroll}
};


ScrollbarClassRec scrollbarClassRec = {
  { /* core fields */
    /* superclass       */	(WidgetClass) &threeDClassRec,
    /* class_name       */	"Scrollbar",
    /* size             */	sizeof(ScrollbarRec),
    /* class_initialize	*/	ClassInitialize,
    /* class_part_init  */	NULL,
    /* class_inited	*/	FALSE,
    /* initialize       */	Initialize,
    /* initialize_hook  */	NULL,
    /* realize          */	Realize,
    /* actions          */	actions,
    /* num_actions	*/	XtNumber(actions),
    /* resources        */	resources,
    /* num_resources    */	XtNumber(resources),
    /* xrm_class        */	NULLQUARK,
    /* compress_motion	*/	TRUE,
    /* compress_exposure*/	TRUE,
    /* compress_enterleave*/	TRUE,
    /* visible_interest */	FALSE,
    /* destroy          */	Destroy,
    /* resize           */	Resize,
    /* expose           */	Redisplay,
    /* set_values       */	SetValues,
    /* set_values_hook  */	NULL,
    /* set_values_almost */	XtInheritSetValuesAlmost,
    /* get_values_hook  */	NULL,
    /* accept_focus     */	NULL,
    /* version          */	XtVersion,
    /* callback_private */	NULL,
    /* tm_table         */	defaultTranslations,
    /* query_geometry	*/	XtInheritQueryGeometry,
    /* display_accelerator*/	XtInheritDisplayAccelerator,
    /* extension        */	NULL
  },
  { /* simple fields */
    /* change_sensitive	*/	XtInheritChangeSensitive
  },
  { /* threeD fields */
    /* shadowdraw	*/	XtInheritXaw3dShadowDraw /*,*/
    /* shadowboxdraw	*/	/*XtInheritXaw3dShadowBoxDraw*/
  },
  { /* scrollbar fields */
    /* ignore		*/	0
  }

};

WidgetClass scrollbarWidgetClass = (WidgetClass)&scrollbarClassRec;

#define NoButton -1
#define PICKLENGTH(widget, x, y) \
    ((widget->scrollbar.orientation == XtorientHorizontal) ? x : y)
#define MIN(x,y)	((x) < (y) ? (x) : (y))
#define MAX(x,y)	((x) > (y) ? (x) : (y))

static void
ClassInitialize(void)
{
    XawInitializeWidgetSet();
    XtAddConverter( XtRString, XtROrientation, XmuCvtStringToOrientation,
		    (XtConvertArgList)NULL, (Cardinal)0 );
}

#ifdef XAW_ARROW_SCROLLBARS
/* CHECKIT #define MARGIN(sbw) (sbw)->scrollbar.thickness + (sbw)->threeD.shadow_width */
#define MARGIN(sbw) (sbw)->scrollbar.thickness
#else
#define MARGIN(sbw) (sbw)->threeD.shadow_width
#endif

/*
 The original Xaw Scrollbar's FillArea *really* relied on the fact that the
 server was going to clip at the window boundaries; so the logic was really
 rather sloppy.  To avoid drawing over the shadows and the arrows requires
 some extra care...  Hope I didn't make any mistakes.
*/
static void
FillArea (ScrollbarWidget sbw, Position top, Position bottom, int fill)
{
    int tlen = bottom - top;	/* length of thumb in pixels */
    int sw, margin, floor;
    int lx, ly, lw, lh;

    if (bottom <= 0 || bottom <= top)
	return;
    if ((sw = sbw->threeD.shadow_width) < 0)
	sw = 0;
    margin = MARGIN (sbw);
    floor = sbw->scrollbar.length - margin;

    if (sbw->scrollbar.orientation == XtorientHorizontal) {
	lx = ((top < margin) ? margin : top);
	ly = sw;
	lw = ((bottom > floor) ? floor - top : tlen);
/* CHECKIT	lw = (((top + tlen) > floor) ? floor - top : tlen); */
	lh = sbw->core.height - 2 * sw;
    } else {
	lx = sw;
	ly = ((top < margin) ? margin : top);
	lw = sbw->core.width - 2 * sw;
/* CHECKIT	lh = (((top + tlen) > floor) ? floor - top : tlen); */
	lh = ((bottom > floor) ? floor - top : tlen);
    }
    if (lh <= 0 || lw <= 0) return;
    if (fill) {
	XFillRectangle(XtDisplay((Widget) sbw), XtWindow((Widget) sbw),
			sbw->scrollbar.gc,
			lx, ly, (unsigned int) lw, (unsigned int) lh);
    } else {
	XClearArea (XtDisplay((Widget) sbw), XtWindow((Widget) sbw),
			lx, ly, (unsigned int) lw, (unsigned int) lh,
			FALSE);
    }
}

/* Paint the thumb in the area specified by sbw->top and
   sbw->shown.  The old area is erased.  The painting and
   erasing is done cleverly so that no flickering will occur. */

static void
PaintThumb (ScrollbarWidget sbw, XEvent *event)
{
    Dimension s                   = sbw->threeD.shadow_width;
    Position  oldtop              = sbw->scrollbar.topLoc;
    Position  oldbot              = oldtop + sbw->scrollbar.shownLength;
    Dimension margin              = MARGIN (sbw);
    Dimension tzl                 = sbw->scrollbar.length - margin - margin;
    Position newtop, newbot;
    Position  floor               = sbw->scrollbar.length - margin;

    newtop = margin + (int)(tzl * sbw->scrollbar.top);
    newbot = newtop + (int)(tzl * sbw->scrollbar.shown);
    if (sbw->scrollbar.shown < 1.) newbot++;
    if (newbot < newtop + (int)sbw->scrollbar.min_thumb +
                        2 * (int)sbw->threeD.shadow_width)
      newbot = newtop + sbw->scrollbar.min_thumb +
                        2 * sbw->threeD.shadow_width;
    if ( newbot >= floor ) {
	newtop = floor-(newbot-newtop)+1;
	newbot = floor;
    }

    sbw->scrollbar.topLoc = newtop;
    sbw->scrollbar.shownLength = newbot - newtop;
    if (XtIsRealized ((Widget) sbw)) {
      /*  3D thumb wanted ?
       */
      if (s)
	  {
          if (newtop < oldtop) FillArea(sbw, oldtop, oldtop + s, 0);
          if (newtop > oldtop) FillArea(sbw, oldtop, MIN(newtop, oldbot), 0);
          if (newbot < oldbot) FillArea(sbw, MAX(newbot, oldtop), oldbot, 0);
          if (newbot > oldbot) FillArea(sbw, oldbot - s, oldbot, 0);

          if (sbw->scrollbar.orientation == XtorientHorizontal)
	      {
	      _ShadowSurroundedBox((Widget)sbw, (ThreeDWidget)sbw,
		  newtop, s, newbot, sbw->core.height - s,
		  sbw->threeD.relief, TRUE);
	      }
	  else
	      {
	      _ShadowSurroundedBox((Widget)sbw, (ThreeDWidget)sbw,
		  s, newtop, sbw->core.width - s, newbot,
		  sbw->threeD.relief, TRUE);
	      }
	  }
      else
	  {
	  /*
	    Note to Mitch: FillArea is (now) correctly implemented to
	    not draw over shadows or the arrows. Therefore setting clipmasks
	    doesn't seem to be necessary.  Correct me if I'm wrong!
	  */
          if (newtop < oldtop) FillArea(sbw, newtop, MIN(newbot, oldtop), 1);
          if (newtop > oldtop) FillArea(sbw, oldtop, MIN(newtop, oldbot), 0);
          if (newbot < oldbot) FillArea(sbw, MAX(newbot, oldtop), oldbot, 0);
          if (newbot > oldbot) FillArea(sbw, MAX(newtop, oldbot), newbot, 1);
	  }
    }
}

#ifdef XAW_ARROW_SCROLLBARS
static void
PaintArrows (ScrollbarWidget sbw)
{
    XPoint    pt[20];
    Dimension s   = sbw->threeD.shadow_width;
    Dimension t   = sbw->scrollbar.thickness;
    Dimension l   = sbw->scrollbar.length;
    Dimension tms = t - s, lms = l - s;
    Dimension tm1 = t - 1;
    Dimension lmt = l - t;
    Dimension lp1 = lmt + 1;
    Dimension sm1 = s - 1;
    Dimension t2  = t / 2;
    Dimension sa30 = (Dimension)(1.732 * s );  /* cotangent of 30 deg */
    Display   *dpy = XtDisplay (sbw);
    Window    win = XtWindow (sbw);
    GC        top = sbw->threeD.top_shadow_GC;
    GC        bot = sbw->threeD.bot_shadow_GC;


    if (XtIsRealized ((Widget) sbw)) {
	/* 3D arrows?
         */
	if (s) {
	    /* upper/right arrow */
	    pt[0].x = sm1;         pt[0].y = tm1;
	    pt[1].x = t2;          pt[1].y = sm1;
	    pt[2].x = t2;          pt[2].y = s + sa30;
	    pt[3].x = sm1 + sa30;  pt[3].y = tms - 1;

	    pt[4].x = sm1;         pt[4].y = tm1;
	    pt[5].x = tms;         pt[5].y = tm1;
	    pt[6].x = t2;          pt[6].y = sm1;
	    pt[7].x = t2;          pt[7].y = s + sa30;
	    pt[8].x = tms - sa30;  pt[8].y = tms - 1;
	    pt[9].x = sm1 + sa30;  pt[9].y = tms - 1;

	    /* lower/left arrow */
	    pt[10].x = tms;        pt[10].y = lp1;
	    pt[11].x = s;          pt[11].y = lp1;
	    pt[12].x = t2;         pt[12].y = lms;
	    pt[13].x = t2;         pt[13].y = lms - sa30;
	    pt[14].x = s + sa30;   pt[14].y = lmt + s + 1;
	    pt[15].x = tms - sa30; pt[15].y = lmt + s + 1;

	    pt[16].x = tms;        pt[16].y = lp1;
	    pt[17].x = t2;         pt[17].y = lms;
	    pt[18].x = t2;         pt[18].y = lms - sa30;
	    pt[19].x = tms - sa30; pt[19].y = lmt + s + 1;

	    /* horizontal arrows require that x and y coordinates be swapped */
	    if (sbw->scrollbar.orientation == XtorientHorizontal) {
		int n;
		int swap;
		for (n = 0; n < 20; n++) {
		    swap = pt[n].x;
		    pt[n].x = pt[n].y;
		    pt[n].y = swap;
		}
	    }
	    XFillPolygon (dpy, win, top, pt, 4, Complex, CoordModeOrigin);
	    XFillPolygon (dpy, win, bot, pt + 4, 6, Complex, CoordModeOrigin);
	    XFillPolygon (dpy, win, top, pt + 10, 6, Complex, CoordModeOrigin);
	    XFillPolygon (dpy, win, bot, pt + 16, 4, Complex, CoordModeOrigin);

	} else {
	    pt[0].x = 0;      pt[0].y = tm1;
	    pt[1].x = t;      pt[1].y = tm1;
	    pt[2].x = t2;     pt[2].y = 0;

	    pt[3].x = 0;      pt[3].y = lp1;
	    pt[4].x = t;      pt[4].y = lp1;
	    pt[5].x = t2;     pt[5].y = l;

	    /* horizontal arrows require that x and y coordinates be swapped */
	    if (sbw->scrollbar.orientation == XtorientHorizontal) {
		int n;
		int swap;
		for (n = 0; n < 6; n++) {
		    swap = pt[n].x;
		    pt[n].x = pt[n].y;
		    pt[n].y = swap;
		}
	    }
	    /* draw the up/left arrow */
	    XFillPolygon (dpy, win, sbw->scrollbar.gc,
			  pt, 3,
			  Convex, CoordModeOrigin);
	    /* draw the down/right arrow */
	    XFillPolygon (dpy, win, sbw->scrollbar.gc,
			  pt+3, 3,
			  Convex, CoordModeOrigin);
	}
    }
}
#endif

/*	Function Name: Destroy
 *	Description: Called as the scrollbar is going away...
 *	Arguments: w - the scrollbar.
 *	Returns: nonw
 */
static void
Destroy (Widget w)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
#ifdef XAW_ARROW_SCROLLBARS
    if(sbw->scrollbar.timer_id != (XtIntervalId) 0)
	XtRemoveTimeOut (sbw->scrollbar.timer_id);
#endif
    XtReleaseGC (w, sbw->scrollbar.gc);
}

/*	Function Name: CreateGC
 *	Description: Creates the GC.
 *	Arguments: w - the scrollbar widget.
 *	Returns: none.
 */

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;
	if (XGetGeometry (XtDisplay(w), sbw->scrollbar.thumb, &root, &x, &y,
			 &width, &height, &bw, &depth) == 0) {
	    XtAppError (XtWidgetToApplicationContext (w),
	       "Scrollbar Widget: Could not get geometry of thumb pixmap.");
	}
    }

    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;
	}
    }
    /* the creation should be non-caching, because */
    /* we now set and clear clip masks on the gc returned */
    sbw->scrollbar.gc = XtGetGC (w, mask, &gcValues);
}

static void
SetDimensions (ScrollbarWidget sbw)
{
    if (sbw->scrollbar.orientation == XtorientVertical) {
	sbw->scrollbar.length = sbw->core.height;
	sbw->scrollbar.thickness = sbw->core.width;
    } else {
	sbw->scrollbar.length = sbw->core.width;
	sbw->scrollbar.thickness = sbw->core.height;
    }
}

/* ARGSUSED */
static void
Initialize(Widget request, Widget new, ArgList args, Cardinal *num_args)
{
    ScrollbarWidget sbw = (ScrollbarWidget) new;

    CreateGC (new);

    if (sbw->core.width == 0)
	sbw->core.width = (sbw->scrollbar.orientation == XtorientVertical)
	    ? sbw->scrollbar.thickness : sbw->scrollbar.length;

    if (sbw->core.height == 0)
	sbw->core.height = (sbw->scrollbar.orientation == XtorientHorizontal)
	    ? sbw->scrollbar.thickness : sbw->scrollbar.length;

    SetDimensions (sbw);
#ifdef XAW_ARROW_SCROLLBARS
    sbw->scrollbar.scroll_mode = 0;
    sbw->scrollbar.timer_id = (XtIntervalId)0;
#else
    sbw->scrollbar.direction = 0;
#endif
    sbw->scrollbar.topLoc = 0;
    sbw->scrollbar.shownLength = sbw->scrollbar.min_thumb;
}

static void
Realize(Widget w, Mask *valueMask, XSetWindowAttributes *attributes)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
#ifdef XAW_ARROW_SCROLLBARS
    if(sbw->simple.cursor_name == NULL)
	XtVaSetValues(w, XtNcursorName, "crosshair", NULL);
    /* dont set the cursor of the window to anything */
    *valueMask &= ~CWCursor;
#else
    sbw->scrollbar.inactiveCursor =
      (sbw->scrollbar.orientation == XtorientVertical)
	? sbw->scrollbar.verCursor
	: sbw->scrollbar.horCursor;

    XtVaSetValues (w, XtNcursor, sbw->scrollbar.inactiveCursor, NULL);
#endif
    /*
     * The Simple widget actually stuffs the value in the valuemask.
     */

    (*scrollbarWidgetClass->core_class.superclass->core_class.realize)
	(w, valueMask, attributes);
}

/* ARGSUSED */
static Boolean
SetValues(Widget current, Widget request, Widget desired, ArgList args, Cardinal *num_args)
{
    ScrollbarWidget sbw = (ScrollbarWidget) current;
    ScrollbarWidget dsbw = (ScrollbarWidget) desired;
    Boolean redraw = FALSE;

/*
 * If these values are outside the acceptable range ignore them...
 */

    if (dsbw->scrollbar.top < 0.0 || dsbw->scrollbar.top > 1.0)
        dsbw->scrollbar.top = sbw->scrollbar.top;

    if (dsbw->scrollbar.shown < 0.0 || dsbw->scrollbar.shown > 1.0)
        dsbw->scrollbar.shown = sbw->scrollbar.shown;

/*
 * Change colors and stuff...
 */
    if (XtIsRealized (desired)) {
	if (sbw->scrollbar.foreground != dsbw->scrollbar.foreground ||
	    sbw->core.background_pixel != dsbw->core.background_pixel ||
	    sbw->scrollbar.thumb != dsbw->scrollbar.thumb) {
	    XtReleaseGC (desired, sbw->scrollbar.gc);
	    CreateGC (desired);
	    redraw = TRUE;
	}
	if (sbw->scrollbar.top != dsbw->scrollbar.top ||
	    sbw->scrollbar.shown != dsbw->scrollbar.shown)
	    redraw = TRUE;
    }
    return redraw;
}

static void
Resize (Widget w)
{
    /* ForgetGravity has taken care of background, but thumb may
     * have to move as a result of the new size. */
    SetDimensions ((ScrollbarWidget) w);
    Redisplay (w, (XEvent*) NULL, (Region)NULL);
}


/* ARGSUSED */
static void
Redisplay(Widget w, XEvent *event, Region region)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
    ScrollbarWidgetClass swclass = (ScrollbarWidgetClass) XtClass (w);
    int x, y;
    unsigned int width, height;

    (*swclass->threeD_class.shadowdraw) (w, event, region, sbw->threeD.relief, FALSE);

    if (sbw->scrollbar.orientation == XtorientHorizontal) {
	x = sbw->scrollbar.topLoc;
	y = 1;
	width = sbw->scrollbar.shownLength;
	height = sbw->core.height - 2;
    } else {
	x = 1;
	y = sbw->scrollbar.topLoc;
	width = sbw->core.width - 2;
	height = sbw->scrollbar.shownLength;
    }
    if (region == NULL ||
	XRectInRegion (region, x, y, width, height) != RectangleOut) {
	/* Forces entire thumb to be painted. */
	sbw->scrollbar.topLoc = -(sbw->scrollbar.length + 1);
	PaintThumb (sbw, event);
    }
#ifdef XAW_ARROW_SCROLLBARS
    /* we'd like to be region aware here!!!! */
    PaintArrows (sbw);
#endif

}


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 Boolean
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);

    return CompareEvents (event, &newEvent);
}


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;
    }
}

#ifdef XAW_ARROW_SCROLLBARS
/* ARGSUSED */
static void
HandleThumb(Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    Position x,y;
    ScrollbarWidget sbw = (ScrollbarWidget) w;

    ExtractPosition( event, &x, &y );
    /* if the motion event puts the pointer in thumb, call Move and Notify */
    /* also call Move and Notify if we're already in continuous scroll mode */
    if (sbw->scrollbar.scroll_mode == 2 ||
	(PICKLENGTH (sbw,x,y) >= sbw->scrollbar.topLoc &&
	PICKLENGTH (sbw,x,y) <= sbw->scrollbar.topLoc + sbw->scrollbar.shownLength)){
	XtCallActionProc(w, "MoveThumb", event, params, *num_params);
	XtCallActionProc(w, "NotifyThumb", event, params, *num_params);
    }
}

static void
RepeatNotify(XtPointer client_data, XtIntervalId *idp)
{
#define A_FEW_PIXELS 5
    ScrollbarWidget sbw = (ScrollbarWidget) client_data;
    intptr_t call_data;
    if (sbw->scrollbar.scroll_mode != 1 && sbw->scrollbar.scroll_mode != 3) {
	sbw->scrollbar.timer_id = (XtIntervalId) 0;
	return;
    }
    call_data = MAX (A_FEW_PIXELS, sbw->scrollbar.length / 20);
    if (sbw->scrollbar.scroll_mode == 1)
	call_data = -call_data;
    XtCallCallbacks((Widget)sbw, XtNscrollProc, (XtPointer) call_data);
    sbw->scrollbar.timer_id =
    XtAppAddTimeOut(XtWidgetToApplicationContext((Widget)sbw),
		    (unsigned long) 150,
		    RepeatNotify,
		    client_data);
}

#else /* XAW_ARROW_SCROLLBARS */
/* ARGSUSED */
static void
StartScroll (Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
    Cursor cursor;
    char direction;

    if (sbw->scrollbar.direction != 0) return; /* if we're already scrolling */
    if (*num_params > 0)
	direction = *params[0];
    else
	direction = 'C';

    sbw->scrollbar.direction = direction;

    switch (direction) {
    case 'B':
    case 'b':
	cursor = (sbw->scrollbar.orientation == XtorientVertical)
			? sbw->scrollbar.downCursor
			: sbw->scrollbar.rightCursor;
	break;
    case 'F':
    case 'f':
	cursor = (sbw->scrollbar.orientation == XtorientVertical)
			? sbw->scrollbar.upCursor
			: sbw->scrollbar.leftCursor;
	break;
    case 'C':
    case 'c':
	cursor = (sbw->scrollbar.orientation == XtorientVertical)
			? sbw->scrollbar.rightCursor
			: sbw->scrollbar.upCursor;
	break;
    default:
	return; /* invalid invocation */
    }
    XtVaSetValues (w, XtNcursor, cursor, NULL);
    XFlush (XtDisplay (w));
}
#endif /* XAW_ARROW_SCROLLBARS */

/*
 * Make sure the first number is within the range specified by the other
 * two numbers.
 */

#ifndef XAW_ARROW_SCROLLBARS
static int
InRange(int num, int small, int big)
{
    return (num < small) ? small : ((num > big) ? big : num);
}
#endif

/*
 * Same as above, but for floating numbers.
 */

static float
FloatInRange(float num, float small, float big)
{
    return (num < small) ? small : ((num > big) ? big : num);
}


#ifdef XAW_ARROW_SCROLLBARS
static void
NotifyScroll (Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
    intptr_t call_data;
    Position x, y;

    if (sbw->scrollbar.scroll_mode == 2  /* if scroll continuous */
	|| LookAhead (w, event))
	return;

    ExtractPosition (event, &x, &y);

    if (PICKLENGTH (sbw,x,y) < sbw->scrollbar.thickness) {
	/* handle first arrow zone */
	call_data = -MAX (A_FEW_PIXELS, sbw->scrollbar.length / 20);
	XtCallCallbacks (w, XtNscrollProc, (XtPointer)(call_data));
	/* establish autoscroll */
	sbw->scrollbar.timer_id =
	    XtAppAddTimeOut (XtWidgetToApplicationContext (w),
				(unsigned long) 300, RepeatNotify, (XtPointer)w);
	sbw->scrollbar.scroll_mode = 1;
    } else if (PICKLENGTH (sbw,x,y) > sbw->scrollbar.length - sbw->scrollbar.thickness) {
	/* handle last arrow zone */
	call_data = MAX (A_FEW_PIXELS, sbw->scrollbar.length / 20);
	XtCallCallbacks (w, XtNscrollProc, (XtPointer)(call_data));
	/* establish autoscroll */
	sbw->scrollbar.timer_id =
	    XtAppAddTimeOut (XtWidgetToApplicationContext (w),
				(unsigned long) 300, RepeatNotify, (XtPointer)w);
	sbw->scrollbar.scroll_mode = 3;
    } else if (PICKLENGTH (sbw, x, y) < sbw->scrollbar.topLoc) {
	/* handle zone "above" the thumb */
	call_data = - sbw->scrollbar.length;
	XtCallCallbacks (w, XtNscrollProc, (XtPointer)(call_data));
    } else if (PICKLENGTH (sbw, x, y) > sbw->scrollbar.topLoc + sbw->scrollbar.shownLength) {
	/* handle zone "below" the thumb */
	call_data = sbw->scrollbar.length;
	XtCallCallbacks (w, XtNscrollProc, (XtPointer)(call_data));
    } else
	{
	/* handle the thumb in the motion notify action */
	}
    return;
}
#else /* XAW_ARROW_SCROLLBARS */
static void
NotifyScroll (Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
    intptr_t call_data = 0;
    char style;
    Position x, y;

    if (sbw->scrollbar.direction == 0) return; /* if no StartScroll */
    if (LookAhead (w, 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 (sbw, x, y), 0, (int) sbw->scrollbar.length);
	break;

    case 'F':    /* FullLength */
    case 'f':
	call_data = sbw->scrollbar.length;
	break;
    }
    switch (sbw->scrollbar.direction) {
    case 'B':
    case 'b':
	call_data = -call_data;
	/* fall through */

    case 'F':
    case 'f':
	XtCallCallbacks (w, XtNscrollProc, (XtPointer)call_data);
	break;

    case 'C':
    case 'c':
	/* NotifyThumb has already called the thumbProc(s) */
	break;
    }
}
#endif /* XAW_ARROW_SCROLLBARS */

/* ARGSUSED */
static void
EndScroll(Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;

#ifdef XAW_ARROW_SCROLLBARS
    sbw->scrollbar.scroll_mode = 0;
    /* no need to remove any autoscroll timeout; it will no-op */
    /* because the scroll_mode is 0 */
    /* but be sure to remove timeout in destroy proc */
#else
    XtVaSetValues (w, XtNcursor, sbw->scrollbar.inactiveCursor, NULL);
    XFlush (XtDisplay (w));
    sbw->scrollbar.direction = 0;
#endif
}

static float
FractionLoc (ScrollbarWidget sbw, int x, int y)
{
    float   result;
    int margin;
    float   height, width;

    margin = MARGIN (sbw);
    x -= margin;
    y -= margin;
    height = sbw->core.height - 2 * margin;
    width = sbw->core.width - 2 * margin;
    result = PICKLENGTH (sbw, x / width, y / height);
    return FloatInRange(result, 0.0, 1.0);
}


static void
MoveThumb (Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;
    Position x, y;
    float loc, s;
#ifdef XAW_ARROW_SCROLLBARS
    float t;
#endif

#ifndef XAW_ARROW_SCROLLBARS
    if (sbw->scrollbar.direction == 0) return; /* if no StartScroll */
#endif

    if (LookAhead (w, event)) return;

    if (!event->xmotion.same_screen) return;

    ExtractPosition (event, &x, &y);
    loc = FractionLoc (sbw, x, y);
    s = sbw->scrollbar.shown;
#ifdef XAW_ARROW_SCROLLBARS
    t = sbw->scrollbar.top;
    if (sbw->scrollbar.scroll_mode != 2 )
      /* initialize picked position */
      sbw->scrollbar.picked = (FloatInRange( loc, t, t + s ) - t);
#else
    sbw->scrollbar.picked = 0.5 * s;
#endif
    if (sbw->scrollbar.pick_top)
      sbw->scrollbar.top = loc;
    else {
      sbw->scrollbar.top = loc - sbw->scrollbar.picked;
      if (sbw->scrollbar.top < 0.0) sbw->scrollbar.top = 0.0;
    }

#if 0
    /* this breaks many text-line scrolls */
    if (sbw->scrollbar.top + sbw->scrollbar.shown > 1.0)
      sbw->scrollbar.top = 1.0 - sbw->scrollbar.shown;
#endif
#ifdef XAW_ARROW_SCROLLBARS
    sbw->scrollbar.scroll_mode = 2; /* indicate continuous scroll */
#endif
    PaintThumb (sbw, event);
    XFlush (XtDisplay (w));	/* re-draw it before Notifying */
}


/* ARGSUSED */
static void
NotifyThumb (Widget w, XEvent *event, String *params, Cardinal *num_params)
{
    register ScrollbarWidget sbw = (ScrollbarWidget) w;
    float top = sbw->scrollbar.top;

#ifndef XAW_ARROW_SCROLLBARS
    if (sbw->scrollbar.direction == 0) return; /* if no StartScroll */
#endif

    if (LookAhead (w, 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. */
/* #ifdef XAW_ARROW_SCROLLBARS */
    /* This corrects for rounding errors: If the thumb is moved to the end of
       the scrollable area sometimes the last line/column is not displayed.
       This can happen when the integer number of the top line or leftmost
       column to be be displayed is calculated from the float value
       sbw->scrollbar.top. The numerical error of this rounding problem is
       very small. We therefore add a small value which then forces the
       next line/column (the correct one) to be used. Since we can expect
       that the resolution of display screens will not be higher then
       10000 text lines/columns we add 1/10000 to the top position. The
       intermediate variable `top' is used to avoid erroneous summing up
       corrections (can this happen at all?). If the arrows are not displayed
       there is no problem since in this case there is always a constant
       integer number of pixels the thumb must be moved in order to scroll
       to the next line/column. */
    /* Removed the dependancy on scrollbar arrows. Xterm as distributed in
       X11R6.6 by The XFree86 Project wants this correction, with or without
       the arrows. */
    top += 0.0001;
/* #endif */
    XtCallCallbacks (w, XtNthumbProc, *(XtPointer*)&top);
    XtCallCallbacks (w, XtNjumpProc, (XtPointer)&top);
}



/************************************************************
 *
 *  Public routines.
 *
 ************************************************************/

/* Set the scroll bar to the given location. */

void XawScrollbarSetThumb (Widget w,
#if NeedWidePrototypes
			double top, double shown)
#else
			float top, float shown)
#endif
{
    ScrollbarWidget sbw = (ScrollbarWidget) w;

#ifdef WIERD
    fprintf(stderr,"< XawScrollbarSetThumb w=%p, top=%f, shown=%f\n",
	    w,top,shown);
#endif

#ifdef XAW_ARROW_SCROLLBARS
    if (sbw->scrollbar.scroll_mode == (char) 2) return; /* if still thumbing */
#else
    if (sbw->scrollbar.direction == 'c') return; /* if still thumbing */
#endif

    sbw->scrollbar.top = (top > 1.0) ? 1.0 :
				(top >= 0.0) ? top : sbw->scrollbar.top;

    sbw->scrollbar.shown = (shown > 1.0) ? 1.0 :
				(shown >= 0.0) ? shown : sbw->scrollbar.shown;

    PaintThumb (sbw, NULL);
}