/* $XConsortium: Box.c,v 1.47 91/10/16 22:19:07 eswu Exp $ */

/***********************************************************
Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
and the Massachusetts Institute of Technology, Cambridge, 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 names of Digital or MIT 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.

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

/* 
 * Box.c - Box composite widget
 * 
 */

#ifdef VMS
#   include <X11_DIRECTORY/IntrinsicP.h>
#   include <X11_DIRECTORY/StringDefs.h>
#   include <XMU_DIRECTORY/Misc.h>
#   include <XAW_DIRECTORY/XawInit.h>
#   include <XAW_DIRECTORY/BoxP.h>
#else
#   include <X11/IntrinsicP.h>
#   include <X11/StringDefs.h>
#   include <X11/Xmu/Misc.h>
#   include <X11/Xaw3d/XawInit.h>
#   include <X11/Xaw3d/BoxP.h>
#endif

/****************************************************************
 *
 * Box Resources
 *
 ****************************************************************/ 

static XtResource resources[] = {
    { XtNhSpace, XtCHSpace, XtRDimension, sizeof(Dimension),
		XtOffsetOf(BoxRec, box.h_space),
		XtRImmediate, (XtPointer)4 },
    { XtNvSpace, XtCVSpace, XtRDimension, sizeof(Dimension),
		XtOffsetOf(BoxRec, box.v_space),
		XtRImmediate, (XtPointer)4 },
    { XtNorientation, XtCOrientation, XtROrientation, sizeof(XtOrientation),
		XtOffsetOf(BoxRec, box.orientation),
		XtRImmediate, (XtPointer)XtorientVertical },
};

/****************************************************************
 *
 * Full class record constant
 *
 ****************************************************************/

static void ClassInitialize();
static void Initialize();
static void Realize();
static void Resize();
static Boolean SetValues();
static XtGeometryResult GeometryManager();
static void ChangeManaged();
static XtGeometryResult PreferredSize();

BoxClassRec boxClassRec = {
  {
/* core_class fields      */
    /* superclass         */    (WidgetClass) &compositeClassRec,
    /* class_name         */    "Box",
    /* widget_size        */    sizeof(BoxRec),
    /* class_initialize   */    ClassInitialize,
    /* class_part_init    */	NULL,
    /* class_inited       */	FALSE,
    /* initialize         */    Initialize,
    /* initialize_hook    */	NULL,
    /* realize            */    Realize,
    /* actions            */    NULL,
    /* num_actions	  */	0,
    /* resources          */    resources,
    /* num_resources      */    XtNumber(resources),
    /* xrm_class          */    NULLQUARK,
    /* compress_motion	  */	TRUE,
    /* compress_exposure  */	TRUE,
    /* compress_enterleave*/	TRUE,
    /* visible_interest   */    FALSE,
    /* destroy            */    NULL,
    /* resize             */    Resize,
    /* expose             */    NULL,
    /* 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           */    NULL,
    /* query_geometry     */	PreferredSize,
    /* display_accelerator*/	XtInheritDisplayAccelerator,
    /* extension          */	NULL
  },{
/* composite_class fields */
    /* geometry_manager   */    GeometryManager,
    /* change_managed     */    ChangeManaged,
    /* insert_child	  */	XtInheritInsertChild,
    /* delete_child	  */	XtInheritDeleteChild,
    /* extension          */	NULL
  },{
/* Box class fields */
    /* empty		  */	0,
  }
};

WidgetClass boxWidgetClass = (WidgetClass)&boxClassRec;

/****************************************************************
 *
 * Private Routines
 *
 ****************************************************************/

/*
 *
 * Do a layout, either actually assigning positions, or just calculating size.
 * Returns minimum width and height that will preserve the same layout.
 *
 */

static void DoLayout(bbw, width, height, reply_width, reply_height, position)
    BoxWidget	bbw;
    Dimension	width, height;
    Dimension	*reply_width, *reply_height; /* bounding box */
    Boolean	position;	/* actually reposition the windows? */
{
    Boolean vbox = (bbw->box.orientation == XtorientVertical);
    Cardinal  i;
    Dimension w, h;	/* Width and height needed for box 		*/
    Dimension lw, lh;	/* Width and height needed for current line 	*/
    Dimension bw, bh;	/* Width and height needed for current widget 	*/
    Dimension h_space;  /* Local copy of bbw->box.h_space 		*/
    register Widget widget;	/* Current widget 			*/
    int num_mapped_children = 0;
 
    /* Box width and height */
    h_space = bbw->box.h_space;
    w = h_space;
    h = bbw->box.v_space;
   
    /* Line width and height */
    lh = 0;
    lw = h_space;
  
    for (i = 0; i < bbw->composite.num_children; i++) {
	widget = bbw->composite.children[i];
	if (widget->core.managed) {
	    if (widget->core.mapped_when_managed) num_mapped_children++;
	    /* Compute widget width */
	    bw = widget->core.width + 2*widget->core.border_width + h_space;
	    if ((Dimension)(lw + bw) > width) {
		if (lw > h_space) {
		    /* At least one widget on this line, and
		     * can't fit any more.  Start new line if vbox.
		     */
		    AssignMax(w, lw);
		    if (vbox) {
			h += lh + bbw->box.v_space;
			lh = 0;
			lw = h_space;
		    }
		}
		else if (!position) {
		    /* too narrow for this widget; we'll assume we can grow */
		    DoLayout(bbw, lw + bw, height, reply_width,
			     reply_height, position);
		    return;
		}
	    }
	    if (position && (lw != widget->core.x || h != widget->core.y)) {
		/* It would be nice to use window gravity, but there isn't
		 * sufficient fine-grain control to nicely handle all
		 * situations (e.g. when only the height changes --
		 * a common case).  Explicit unmapping is a cheap hack
		 * to speed things up & avoid the visual jitter as
		 * things slide around.
		 *
		 * %%% perhaps there should be a client resource to
		 * control this.  If so, we'll have to optimize to
		 * perform the moves from the correct end so we don't
		 * force extra exposures as children occlude each other.
		 */
		if (XtIsRealized(widget) && widget->core.mapped_when_managed)
		    XUnmapWindow( XtDisplay(widget), XtWindow(widget) );
		XtMoveWidget(widget, (int)lw, (int)h);
	    }
	    lw += bw;
	    bh = widget->core.height + 2*widget->core.border_width;
	    AssignMax(lh, bh);
	} /* if managed */
    } /* for */

    if (!vbox && width && lw > width && lh < height) {
	/* reduce width if too wide and height not filled */
	Dimension sw = lw, sh = lh;
	Dimension width_needed;
	XtOrientation orientation = bbw->box.orientation;
	bbw->box.orientation = XtorientVertical;
	while (sh < height && sw > width) {
	    width_needed = sw;
	    DoLayout(bbw, sw-1, height, &sw, &sh, False);
	}
	if (sh < height) width_needed = sw;
	if (width_needed != lw) {
	    DoLayout(bbw,width_needed,height,reply_width,reply_height,position);
	    bbw->box.orientation = orientation;
	    return;
	}
	bbw->box.orientation = orientation;
    }

    if (position && XtIsRealized((Widget)bbw)) {
	if (bbw->composite.num_children == num_mapped_children)
	    XMapSubwindows( XtDisplay((Widget)bbw), XtWindow((Widget)bbw) );
	else {
	    int i = bbw->composite.num_children;
	    register Widget *childP = bbw->composite.children;
	    for (; i > 0; childP++, i--)
		if (XtIsRealized(*childP) && XtIsManaged(*childP) &&
		    (*childP)->core.mapped_when_managed)
		    XtMapWidget(*childP);
	}
    }

    /* Finish off last line */
    if (lw > h_space) {
	AssignMax(w, lw);
        h += lh + bbw->box.v_space;
    }

    *reply_width = Max(w, 1);
    *reply_height = Max(h, 1);
}

/*
 *
 * Calculate preferred size, given constraining box, caching it in the widget.
 *
 */

static XtGeometryResult PreferredSize(widget, constraint, preferred)
    Widget widget;
    XtWidgetGeometry *constraint, *preferred;
{
    BoxWidget w = (BoxWidget)widget;
    Dimension width /*, height */;
    Dimension preferred_width = w->box.preferred_width;
    Dimension preferred_height = w->box.preferred_height;

    constraint->request_mode &= CWWidth | CWHeight;

    if (constraint->request_mode == 0) {
	/* parent isn't going to change w or h, so nothing to re-compute */
	return XtGeometryYes;
    }

    if (constraint->request_mode == w->box.last_query_mode &&
	(!(constraint->request_mode & CWWidth) ||
	 constraint->width == w->box.last_query_width) &&
	(!(constraint->request_mode & CWHeight) ||
	 constraint->height == w->box.last_query_height)) {
	/* same query; current preferences are still valid */
	preferred->request_mode = CWWidth | CWHeight;
	preferred->width = preferred_width;
	preferred->height = preferred_height;
	if (constraint->request_mode == (CWWidth | CWHeight) &&
	    constraint->width == preferred_width &&
	    constraint->height == preferred_height) {
	    return XtGeometryYes;
        }
	else return XtGeometryAlmost;
    }
	
    /* else gotta do it the long way...
       I have a preference for tall and narrow, so if my width is
       constrained, I'll accept it; otherwise, I'll compute the minimum
       width that will fit me within the height constraint */

    w->box.last_query_mode = constraint->request_mode;
    w->box.last_query_width = constraint->width;
    w->box.last_query_height= constraint->height;

    if (constraint->request_mode & CWWidth)
	width = constraint->width;
    else /* if (constraint->request_mode & CWHeight) */ {
	 /* let's see if I can become any narrower */
	width = 0;
	constraint->width = 65535;
    }

    /* height is currently ignored by DoLayout.
       height = (constraint->request_mode & CWHeight) ? constraint->height
		       : *preferred_height;
     */
    DoLayout(w, width, (Dimension)0,
	     &preferred_width, &preferred_height, FALSE);

    if (constraint->request_mode & CWHeight &&
	preferred_height > constraint->height) {
	/* find minimum width for this height */
	if (preferred_width > constraint->width) {
	    /* punt; over-constrained */
	}
	else {
	    width = preferred_width;
	    do { /* find some width big enough to stay within this height */
		width *= 2;
		if (width > constraint->width) width = constraint->width;
		DoLayout(w, width, 0, &preferred_width, &preferred_height, FALSE);
	    } while (preferred_height > constraint->height &&
		     width < constraint->width);
	    if (width != constraint->width) {
		do { /* find minimum width */
		    width = preferred_width;
		    DoLayout(w, preferred_width-1, 0,
			     &preferred_width, &preferred_height, FALSE);
		} while (preferred_height < constraint->height);
		/* one last time */
		DoLayout(w, width, 0, &preferred_width, &preferred_height, FALSE);
	    }
	}
    }

    preferred->request_mode = CWWidth | CWHeight;
    preferred->width = w->box.preferred_width = preferred_width;
    preferred->height = w->box.preferred_height = preferred_height;

    if (constraint->request_mode == (CWWidth|CWHeight)
	&& constraint->width == preferred_width
	&& constraint->height == preferred_height) {
	return XtGeometryYes;
    }
    else return XtGeometryAlmost;
}

/*
 *
 * Actually layout the box
 *
 */

static void Resize(w)
    Widget	w;
{
    Dimension junk;
    DoLayout((BoxWidget)w, w->core.width, w->core.height, &junk, &junk, TRUE);
} /* Resize */

/*
 *
 * Try to do a new layout within the current width and height;
 * if that fails try to resize and do it within the box returne
 * by PreferredSize.
 *
 * TryNewLayout just says if it's possible, and doesn't actually move the kids
 */

static Boolean TryNewLayout(bbw)
    BoxWidget	bbw;
{
    Dimension 	preferred_width, preferred_height;
    Dimension	proposed_width, proposed_height;
    int		iterations;

    DoLayout( bbw, bbw->core.width, bbw->core.height,
	      &preferred_width, &preferred_height, FALSE );

    /* at this point, preferred_width is guaranteed to not be greater
       than bbw->core.width unless some child is larger, so there's no
       point in re-computing another layout */

    if ((bbw->core.width == preferred_width) &&
	(bbw->core.height == preferred_height)) {
        /* Same size */
	return (TRUE);
    }

    /* let's see if our parent will go for a new size. */
    iterations = 0;
    proposed_width = preferred_width;
    proposed_height = preferred_height;
    do {
	switch (XtMakeResizeRequest((Widget)bbw,proposed_width,proposed_height,
				     &proposed_width, &proposed_height))
	{
	    case XtGeometryYes:
		return (TRUE);

	    case XtGeometryNo:
		if (iterations > 0)
		    /* protect from malicious parents who change their minds */
		    DoLayout( bbw, bbw->core.width, bbw->core.height,
			      &preferred_width, &preferred_height, FALSE );
		if ((preferred_width <= bbw->core.width) &&
		    (preferred_height <= bbw->core.height)) {
		    return (TRUE);
                }
		else {
		    return (FALSE);
                }
	    case XtGeometryAlmost:
		if (proposed_height >= preferred_height &&
		    proposed_width >= preferred_width) {

		    /*
		     * Take it, and assume the parent knows what it is doing.
		     *
		     * The parent must accept this since it was returned in
		     * almost.
		     *
		     */
		    (void) XtMakeResizeRequest( (Widget)bbw,
				       proposed_width, proposed_height,
				       &proposed_width, &proposed_height);
		    return(TRUE);
		}
		else if (proposed_width != preferred_width) {
		    /* recalc bounding box; height might change */
		    DoLayout(bbw, proposed_width, 0,
			     &preferred_width, &preferred_height, FALSE);
		    proposed_height = preferred_height;
		}
		else { /* proposed_height != preferred_height */
		    XtWidgetGeometry constraints, reply;
		    constraints.request_mode = CWHeight;
		    constraints.height = proposed_height;
		    (void)PreferredSize((Widget)bbw, &constraints, &reply);
		    proposed_width = preferred_width;
		}
	}
	iterations++;
    } while (iterations < 10);
    return (FALSE);
}

/*
 *
 * Geometry Manager
 *
 * 'reply' is unused; we say only yeay or nay, never almost.
 *
 */

/*ARGSUSED*/
static XtGeometryResult GeometryManager(w, request, reply)
    Widget		w;
    XtWidgetGeometry	*request;
    XtWidgetGeometry	*reply;	/* RETURN */

{
    Dimension	width, height, borderWidth;
    BoxWidget bbw;

    /* Position request always denied */
    if ((request->request_mode & CWX && request->x != w->core.x) ||
	(request->request_mode & CWY && request->y != w->core.y)) {
        return (XtGeometryNo);
    }
    /* Size changes must see if the new size can be accomodated */
    if (request->request_mode & (CWWidth | CWHeight | CWBorderWidth)) {

	/* Make all three fields in the request valid */
	if ((request->request_mode & CWWidth) == 0)
	    request->width = w->core.width;
	if ((request->request_mode & CWHeight) == 0)
	    request->height = w->core.height;
        if ((request->request_mode & CWBorderWidth) == 0)
	    request->border_width = w->core.border_width;

	/* Save current size and set to new size */
	width = w->core.width;
	height = w->core.height;
	borderWidth = w->core.border_width;
	w->core.width = request->width;
	w->core.height = request->height;
	w->core.border_width = request->border_width;

	/* Decide if new layout works: (1) new widget is smaller,
	   (2) new widget fits in existing Box, (3) Box can be
	   expanded to allow new widget to fit */

	bbw = (BoxWidget) w->core.parent;

/* whenever a child changes his geometry, we attempt to
 * change ours to be the minimum enclosing size...
	if (((request->width + request->border_width <= width + borderWidth) &&
	    (request->height + request->border_width <= height + borderWidth))
	|| bbw->box.preferred_width < bbw->core.width
	|| bbw->box.preferred_height < bbw->core.height
	|| TryNewLayout(bbw)) {
 */
	if (TryNewLayout(bbw)) {
	    /* Fits in existing or new space, relayout */
	    (*XtClass((Widget)bbw)->core_class.resize)((Widget)bbw);
	    return (XtGeometryYes);
	} else {
	    /* Cannot satisfy request, change back to original geometry */
	    w->core.width = width;
	    w->core.height = height;
	    w->core.border_width = borderWidth;
	    return (XtGeometryNo);
	}
    }; /* if any size changes requested */

    /* Any stacking changes don't make a difference, so allow if that's all */
    return (XtGeometryYes);
}

static void ChangeManaged(w)
    Widget w;
{
    /* Reconfigure the box */
    (void) TryNewLayout((BoxWidget)w);
    Resize(w);
}

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

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

    newbbw->box.last_query_mode = CWWidth | CWHeight;
    newbbw->box.last_query_width = newbbw->box.last_query_height = 0;
    newbbw->box.preferred_width = Max(newbbw->box.h_space, 1);
    newbbw->box.preferred_height = Max(newbbw->box.v_space, 1);

    if (newbbw->core.width == 0)
        newbbw->core.width = newbbw->box.preferred_width;

    if (newbbw->core.height == 0)
	newbbw->core.height = newbbw->box.preferred_height;

} /* Initialize */

static void Realize(w, valueMask, attributes)
    register Widget w;
    Mask *valueMask;
    XSetWindowAttributes *attributes;
{
    attributes->bit_gravity = NorthWestGravity;
    *valueMask |= CWBitGravity;

    XtCreateWindow( w, (unsigned)InputOutput, (Visual *)CopyFromParent,
		    *valueMask, attributes);
} /* Realize */

/* ARGSUSED */
static Boolean SetValues(current, request, new, args, num_args)
    Widget current, request, new;
    ArgList args;
    Cardinal *num_args;
{
   /* need to relayout if h_space or v_space change */
    return False;
}

