summaryrefslogtreecommitdiff
path: root/miext/rootless/rootlessValTree.c
blob: 0ee4919e1d4d436f49d502fa8cd268333289fe39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
/*
 * Calculate window clip lists for rootless mode
 *
 * This file is very closely based on mivaltree.c.
 */

/*
 * mivaltree.c --
 *	Functions for recalculating window clip lists. Main function
 *	is miValidateTree.
 *

Copyright 1987, 1988, 1989, 1998  The Open Group

All Rights Reserved.

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, 1989 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.
 * 
 ******************************************************************/

/* The panoramix components contained the following notice */
/*****************************************************************

Copyright (c) 1991, 1997 Digital Equipment Corporation, Maynard, Massachusetts.

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.

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
DIGITAL EQUIPMENT CORPORATION BE LIABLE FOR ANY CLAIM, DAMAGES, INCLUDING,
BUT NOT LIMITED TO CONSEQUENTIAL OR INCIDENTAL 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 Digital Equipment Corporation
shall not be used in advertising or otherwise to promote the sale, use or other
dealings in this Software without prior written authorization from Digital
Equipment Corporation.

******************************************************************/
 /* 
  * Aug '86: Susan Angebranndt -- original code
  * July '87: Adam de Boor -- substantially modified and commented
  * Summer '89: Joel McCormack -- so fast you wouldn't believe it possible.
  *             In particular, much improved code for window mapping and
  *             circulating.
  *		Bob Scheifler -- avoid miComputeClips for unmapped windows,
  *				 valdata changes
  */
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <stddef.h> /* For NULL */
#include    <X11/X.h>
#include    "scrnintstr.h"
#include    "validate.h"
#include    "windowstr.h"
#include    "mi.h"
#include    "regionstr.h"
#include    "mivalidate.h"

#include    "globals.h"

int RootlessShapedWindowIn (ScreenPtr pScreen, RegionPtr universe,
			RegionPtr bounding, BoxPtr rect, int x, int y);

int RootlessMiValidateTree (WindowPtr pRoot, WindowPtr pChild, VTKind kind);

/*
 * Compute the visibility of a shaped window
 */
int
RootlessShapedWindowIn (ScreenPtr pScreen, RegionPtr universe,
			RegionPtr bounding, BoxPtr rect, int x, int y)
{
    BoxRec  box;
    register BoxPtr  boundBox;
    int	    nbox;
    Bool    someIn, someOut;
    register int t, x1, y1, x2, y2;

    nbox = REGION_NUM_RECTS (bounding);
    boundBox = REGION_RECTS (bounding);
    someIn = someOut = FALSE;
    x1 = rect->x1;
    y1 = rect->y1;
    x2 = rect->x2;
    y2 = rect->y2;
    while (nbox--)
    {
	if ((t = boundBox->x1 + x) < x1)
	    t = x1;
	box.x1 = t;
	if ((t = boundBox->y1 + y) < y1)
	    t = y1;
	box.y1 = t;
	if ((t = boundBox->x2 + x) > x2)
	    t = x2;
	box.x2 = t;
	if ((t = boundBox->y2 + y) > y2)
	    t = y2;
	box.y2 = t;
	if (box.x1 > box.x2)
	    box.x2 = box.x1;
	if (box.y1 > box.y2)
	    box.y2 = box.y1;
	switch (RECT_IN_REGION(pScreen, universe, &box))
	{
	case rgnIN:
	    if (someOut)
		return rgnPART;
	    someIn = TRUE;
	    break;
	case rgnOUT:
	    if (someIn)
		return rgnPART;
	    someOut = TRUE;
	    break;
	default:
	    return rgnPART;
	}
	boundBox++;
    }
    if (someIn)
	return rgnIN;
    return rgnOUT;
}

#define HasParentRelativeBorder(w) (!(w)->borderIsPixel && \
				    HasBorder(w) && \
				    (w)->backgroundState == ParentRelative)


/*
 *-----------------------------------------------------------------------
 * RootlessComputeClips --
 *	Recompute the clipList, borderClip, exposed and borderExposed
 *	regions for pParent and its children. Only viewable windows are
 *	taken into account.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	clipList, borderClip, exposed and borderExposed are altered.
 *	A VisibilityNotify event may be generated on the parent window.
 *
 *-----------------------------------------------------------------------
 */
static void
RootlessComputeClips (WindowPtr pParent, ScreenPtr pScreen, 
		      RegionPtr universe, VTKind kind, RegionPtr exposed)
{
    int			dx,
			dy;
    RegionRec		childUniverse;
    register WindowPtr	pChild;
    int     	  	oldVis, newVis;
    BoxRec		borderSize;
    RegionRec		childUnion;
    Bool		overlap;
    RegionPtr		borderVisible;
    Bool		resized;
    /*
     * Figure out the new visibility of this window.
     * The extent of the universe should be the same as the extent of
     * the borderSize region. If the window is unobscured, this rectangle
     * will be completely inside the universe (the universe will cover it
     * completely). If the window is completely obscured, none of the
     * universe will cover the rectangle.
     */
    borderSize.x1 = pParent->drawable.x - wBorderWidth(pParent);
    borderSize.y1 = pParent->drawable.y - wBorderWidth(pParent);
    dx = (int) pParent->drawable.x + (int) pParent->drawable.width + wBorderWidth(pParent);
    if (dx > 32767)
	dx = 32767;
    borderSize.x2 = dx;
    dy = (int) pParent->drawable.y + (int) pParent->drawable.height + wBorderWidth(pParent);
    if (dy > 32767)
	dy = 32767;
    borderSize.y2 = dy;

    oldVis = pParent->visibility;
    switch (RECT_IN_REGION( pScreen, universe, &borderSize)) 
    {
    case rgnIN:
	    newVis = VisibilityUnobscured;
	    break;
	case rgnPART:
	    newVis = VisibilityPartiallyObscured;
	    {
		RegionPtr   pBounding;

		if ((pBounding = wBoundingShape (pParent)))
		{
		    switch (RootlessShapedWindowIn (pScreen, universe, 
						    pBounding, &borderSize,
						    pParent->drawable.x,
						    pParent->drawable.y))
		    {
		    case rgnIN:
			newVis = VisibilityUnobscured;
			break;
		    case rgnOUT:
			newVis = VisibilityFullyObscured;
			break;
		    }
		}
	    }
	    break;
	default:
	    newVis = VisibilityFullyObscured;
	    break;
    }

    pParent->visibility = newVis;
    if (oldVis != newVis &&
	((pParent->eventMask | wOtherEventMasks(pParent)) & VisibilityChangeMask))
	SendVisibilityNotify(pParent);

    dx = pParent->drawable.x - pParent->valdata->before.oldAbsCorner.x;
    dy = pParent->drawable.y - pParent->valdata->before.oldAbsCorner.y;

    /*
     * avoid computations when dealing with simple operations
     */

    switch (kind) {
    case VTMap:
    case VTStack:
    case VTUnmap:
	break;
    case VTMove:
	if ((oldVis == newVis) &&
	    ((oldVis == VisibilityFullyObscured) ||
	     (oldVis == VisibilityUnobscured)))
	{
	    pChild = pParent;
	    while (1)
	    {
		if (pChild->viewable)
		{
		    if (pChild->visibility != VisibilityFullyObscured)
		    {
			REGION_TRANSLATE( pScreen, &pChild->borderClip,
						      dx, dy);
			REGION_TRANSLATE( pScreen, &pChild->clipList,
						      dx, dy);
			pChild->drawable.serialNumber = NEXT_SERIAL_NUMBER;
			if (pScreen->ClipNotify)
			    (* pScreen->ClipNotify) (pChild, dx, dy);

		    }
		    if (pChild->valdata)
		    {
			REGION_NULL(pScreen,
				    &pChild->valdata->after.borderExposed);
			if (HasParentRelativeBorder(pChild))
			  {
			    REGION_SUBTRACT(pScreen,
					 &pChild->valdata->after.borderExposed,
					 &pChild->borderClip,
					 &pChild->winSize);
			}
			REGION_NULL(pScreen, &pChild->valdata->after.exposed);
		    }
		    if (pChild->firstChild)
		    {
			pChild = pChild->firstChild;
			continue;
		    }
		}
		while (!pChild->nextSib && (pChild != pParent))
		    pChild = pChild->parent;
		if (pChild == pParent)
		    break;
		pChild = pChild->nextSib;
	    }
	    return;
	}
	/* fall through */
    default:
    	/*
     	 * To calculate exposures correctly, we have to translate the old
     	 * borderClip and clipList regions to the window's new location so there
     	 * is a correspondence between pieces of the new and old clipping regions.
     	 */
    	if (dx || dy) 
    	{
	    /*
	     * We translate the old clipList because that will be exposed or copied
	     * if gravity is right.
	     */
	    REGION_TRANSLATE( pScreen, &pParent->borderClip, dx, dy);
	    REGION_TRANSLATE( pScreen, &pParent->clipList, dx, dy);
    	} 
	break;
    case VTBroken:
	REGION_EMPTY (pScreen, &pParent->borderClip);
	REGION_EMPTY (pScreen, &pParent->clipList);
	break;
    }

    borderVisible = pParent->valdata->before.borderVisible;
    resized = pParent->valdata->before.resized;
    REGION_NULL(pScreen, &pParent->valdata->after.borderExposed);
    REGION_NULL(pScreen, &pParent->valdata->after.exposed);

    /*
     * Since the borderClip must not be clipped by the children, we do
     * the border exposure first...
     *
     * 'universe' is the window's borderClip. To figure the exposures, remove
     * the area that used to be exposed from the new.
     * This leaves a region of pieces that weren't exposed before.
     */

    if (HasBorder (pParent))
    {
    	if (borderVisible)
    	{
	    /*
	     * when the border changes shape, the old visible portions
	     * of the border will be saved by DIX in borderVisible --
	     * use that region and destroy it
	     */
	    REGION_SUBTRACT( pScreen, exposed, universe, borderVisible);
	    REGION_DESTROY( pScreen, borderVisible);
    	}
    	else
    	{
	    REGION_SUBTRACT( pScreen, exposed, universe, &pParent->borderClip);
    	}
	if (HasParentRelativeBorder(pParent) && (dx || dy)) {
	    REGION_SUBTRACT( pScreen, &pParent->valdata->after.borderExposed,
				  universe,
				  &pParent->winSize);
	} else {
	    REGION_SUBTRACT( pScreen, &pParent->valdata->after.borderExposed,
			       exposed, &pParent->winSize);
	}

    	REGION_COPY( pScreen, &pParent->borderClip, universe);
    
    	/*
     	 * To get the right clipList for the parent, and to make doubly sure
     	 * that no child overlaps the parent's border, we remove the parent's
     	 * border from the universe before proceeding.
     	 */
    
    	REGION_INTERSECT( pScreen, universe, universe, &pParent->winSize);
    }
    else
    	REGION_COPY( pScreen, &pParent->borderClip, universe);
    
    if ((pChild = pParent->firstChild) && pParent->mapped)
    {
	REGION_NULL(pScreen, &childUniverse);
	REGION_NULL(pScreen, &childUnion);
	if ((pChild->drawable.y < pParent->lastChild->drawable.y) ||
	    ((pChild->drawable.y == pParent->lastChild->drawable.y) &&
	     (pChild->drawable.x < pParent->lastChild->drawable.x)))
	{
	    for (; pChild; pChild = pChild->nextSib)
	    {
		if (pChild->viewable)
		    REGION_APPEND( pScreen, &childUnion, &pChild->borderSize);
	    }
	}
	else
	{
	    for (pChild = pParent->lastChild; pChild; pChild = pChild->prevSib)
	    {
		if (pChild->viewable)
		    REGION_APPEND( pScreen, &childUnion, &pChild->borderSize);
	    }
	}
	REGION_VALIDATE( pScreen, &childUnion, &overlap);

	for (pChild = pParent->firstChild;
	     pChild;
	     pChild = pChild->nextSib)
 	{
	    if (pChild->viewable) {
		/*
		 * If the child is viewable, we want to remove its extents
		 * from the current universe, but we only re-clip it if
		 * it's been marked.
		 */
		if (pChild->valdata) {
		    /*
		     * Figure out the new universe from the child's
		     * perspective and recurse.
		     */
		    REGION_INTERSECT( pScreen, &childUniverse,
					    universe,
					    &pChild->borderSize);
		    RootlessComputeClips (pChild, pScreen, &childUniverse, 
					  kind, exposed);
		}
		/*
		 * Once the child has been processed, we remove its extents
		 * from the current universe, thus denying its space to any
		 * other sibling.
		 */
		if (overlap)
		    REGION_SUBTRACT( pScreen, universe, universe,
					  &pChild->borderSize);
	    }
	}
	if (!overlap)
	    REGION_SUBTRACT( pScreen, universe, universe, &childUnion);
	REGION_UNINIT( pScreen, &childUnion);
	REGION_UNINIT( pScreen, &childUniverse);
    } /* if any children */

    /*
     * 'universe' now contains the new clipList for the parent window.
     *
     * To figure the exposure of the window we subtract the old clip from the
     * new, just as for the border.
     */

    if (oldVis == VisibilityFullyObscured ||
	oldVis == VisibilityNotViewable)
    {
	REGION_COPY( pScreen, &pParent->valdata->after.exposed, universe);
    }
    else if (newVis != VisibilityFullyObscured &&
	     newVis != VisibilityNotViewable)
    {
    	REGION_SUBTRACT( pScreen, &pParent->valdata->after.exposed,
			       universe, &pParent->clipList);
    }

    /*
     * One last thing: backing storage. We have to try to save what parts of
     * the window are about to be obscured. We can just subtract the universe
     * from the old clipList and get the areas that were in the old but aren't
     * in the new and, hence, are about to be obscured.
     */
    if (pParent->backStorage && !resized)
    {
	REGION_SUBTRACT( pScreen, exposed, &pParent->clipList, universe);
	(* pScreen->SaveDoomedAreas)(pParent, exposed, dx, dy);
    }
    
    /* HACK ALERT - copying contents of regions, instead of regions */
    {
	RegionRec   tmp;

	tmp = pParent->clipList;
	pParent->clipList = *universe;
	*universe = tmp;
    }

#ifdef NOTDEF
    REGION_COPY( pScreen, &pParent->clipList, universe);
#endif

    pParent->drawable.serialNumber = NEXT_SERIAL_NUMBER;

    if (pScreen->ClipNotify)
	(* pScreen->ClipNotify) (pParent, dx, dy);
}

static void
RootlessTreeObscured(WindowPtr pParent)
{
    register WindowPtr pChild;
    register int    oldVis;

    pChild = pParent;
    while (1)
    {
	if (pChild->viewable)
	{
	    oldVis = pChild->visibility;
	    if (oldVis != (pChild->visibility = VisibilityFullyObscured) &&
		((pChild->eventMask | wOtherEventMasks(pChild)) & VisibilityChangeMask))
		SendVisibilityNotify(pChild);
	    if (pChild->firstChild)
	    {
		pChild = pChild->firstChild;
		continue;
	    }
	}
	while (!pChild->nextSib && (pChild != pParent))
	    pChild = pChild->parent;
	if (pChild == pParent)
	    break;
	pChild = pChild->nextSib;
    }
}

/*
 *-----------------------------------------------------------------------
 * RootlessMiValidateTree --
 *	Recomputes the clip list for pParent and all its inferiors.
 *
 * Results:
 *	Always returns 1.
 *
 * Side Effects:
 *	The clipList, borderClip, exposed, and borderExposed regions for
 *	each marked window are altered.
 *
 * Notes:
 *	This routine assumes that all affected windows have been marked
 *	(valdata created) and their winSize and borderSize regions
 *	adjusted to correspond to their new positions. The borderClip and
 *	clipList regions should not have been touched.
 *
 *	The top-most level is treated differently from all lower levels
 *	because pParent is unchanged. For the top level, we merge the
 *	regions taken up by the marked children back into the clipList
 *	for pParent, thus forming a region from which the marked children
 *	can claim their areas. For lower levels, where the old clipList
 *	and borderClip are invalid, we can't do this and have to do the
 *	extra operations done in miComputeClips, but this is much faster
 *	e.g. when only one child has moved...
 *
 *-----------------------------------------------------------------------
 */
/* 
   Quartz version: used for validate from root in rootless mode.
   We need to make sure top-level windows don't clip each other, 
   and that top-level windows aren't clipped to the root window.
*/
/*ARGSUSED*/
// fixme this is ugly
// Xprint/ValTree.c doesn't work, but maybe that method can?
int
RootlessMiValidateTree (WindowPtr pRoot, /* Parent to validate */
			WindowPtr pChild, /* First child of pRoot that was
					   * affected */
			VTKind kind /* What kind of configuration caused call */)
{
    RegionRec	  	childClip;  /* The new borderClip for the current
				     * child */
    RegionRec		exposed;    /* For intermediate calculations */
    register ScreenPtr	pScreen;
    register WindowPtr	pWin;

    pScreen = pRoot->drawable.pScreen;
    if (pChild == NullWindow)
	pChild = pRoot->firstChild;

    REGION_NULL(pScreen, &childClip);
    REGION_NULL(pScreen, &exposed);

    if (REGION_BROKEN (pScreen, &pRoot->clipList) &&
	!REGION_BROKEN (pScreen, &pRoot->borderClip))
    {
        // fixme this might not work, but hopefully doesn't happen anyway.
        kind = VTBroken;
        REGION_EMPTY (pScreen, &pRoot->clipList);
        ErrorF("ValidateTree: BUSTED!\n");
    }

    /* 
     * Recursively compute the clips for all children of the root. 
     * They don't clip against each other or the root itself, so 
     * childClip is always reset to that child's size.
     */

    for (pWin = pChild;
	 pWin != NullWindow;
	 pWin = pWin->nextSib)
    {
        if (pWin->viewable) {
            if (pWin->valdata) {
                REGION_COPY( pScreen, &childClip, &pWin->borderSize);
                RootlessComputeClips (pWin, pScreen, &childClip, kind, &exposed);
            } else if (pWin->visibility == VisibilityNotViewable) {
                RootlessTreeObscured(pWin);
            }
        } else {
            if (pWin->valdata) {
                REGION_EMPTY( pScreen, &pWin->clipList);
                if (pScreen->ClipNotify)
                    (* pScreen->ClipNotify) (pWin, 0, 0);
                REGION_EMPTY( pScreen, &pWin->borderClip);
                pWin->valdata = NULL;
            }
        }
    }

    REGION_UNINIT(pScreen, &childClip);

    /* The root is never clipped by its children, so nothing on the root 
       is ever exposed by moving or mapping its children. */
    REGION_NULL(pScreen, &pRoot->valdata->after.exposed);
    REGION_NULL(pScreen, &pRoot->valdata->after.borderExposed);

    return 1;
}