summaryrefslogtreecommitdiff
path: root/indra/llui/lllayoutstack.cpp
blob: 1aaba88c49c771501bccd66b34b5e8de8d49a842 (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
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
/** 
 * @file lllayoutstack.cpp
 * @brief LLLayout class - dynamic stacking of UI elements
 *
 * $LicenseInfo:firstyear=2001&license=viewergpl$
 * 
 * Copyright (c) 2001-2009, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

// Opaque view with a background and a border.  Can contain LLUICtrls.

#include "linden_common.h"

#include "lllayoutstack.h"

#include "lllocalcliprect.h"
#include "llpanel.h"
#include "llresizebar.h"
#include "llcriticaldamp.h"

static LLDefaultChildRegistry::Register<LLLayoutStack> register_layout_stack("layout_stack", &LLLayoutStack::fromXML);


//
// LLLayoutStack
//
struct LLLayoutStack::LayoutPanel
{
	LayoutPanel(LLPanel* panelp, ELayoutOrientation orientation, S32 min_width, S32 min_height, BOOL auto_resize, BOOL user_resize)	:	mPanel(panelp), 
		mMinWidth(min_width), 
		mMinHeight(min_height),
		mAutoResize(auto_resize),
		mUserResize(user_resize),
		mOrientation(orientation),
		mCollapsed(FALSE),
		mCollapseAmt(0.f),
		mVisibleAmt(1.f), // default to fully visible
		mResizeBar(NULL) 
	{
		LLResizeBar::Side side = (orientation == HORIZONTAL) ? LLResizeBar::RIGHT : LLResizeBar::BOTTOM;
		LLRect resize_bar_rect = panelp->getRect();

		S32 min_dim;
		if (orientation == HORIZONTAL)
		{
			min_dim = mMinHeight;
		}
		else
		{
			min_dim = mMinWidth;
		}
		LLResizeBar::Params p;
		p.name("resize");
			p.resizing_view(mPanel);
		p.min_size(min_dim);
		p.side(side);
		p.snapping_enabled(false);
		mResizeBar = LLUICtrlFactory::create<LLResizeBar>(p);
		// panels initialized as hidden should not start out partially visible
		if (!mPanel->getVisible())
		{
			mVisibleAmt = 0.f;
		}
	}

	~LayoutPanel()
	{
		// probably not necessary, but...
		delete mResizeBar;
		mResizeBar = NULL;
	}
	
	F32 getCollapseFactor()
	{
		if (mOrientation == HORIZONTAL)
		{
			F32 collapse_amt = 
				clamp_rescale(mCollapseAmt, 0.f, 1.f, 1.f, (F32)mMinWidth / (F32)llmax(1, mPanel->getRect().getWidth()));
			return mVisibleAmt * collapse_amt;
		}
		else
	{
			F32 collapse_amt = 
				clamp_rescale(mCollapseAmt, 0.f, 1.f, 1.f, llmin(1.f, (F32)mMinHeight / (F32)llmax(1, mPanel->getRect().getHeight())));
			return mVisibleAmt * collapse_amt;
		}
	}

	LLPanel* mPanel;
	S32 mMinWidth;
	S32 mMinHeight;
	BOOL mAutoResize;
	BOOL mUserResize;
	BOOL mCollapsed;
	LLResizeBar* mResizeBar;
	ELayoutOrientation mOrientation;
	F32 mVisibleAmt;
	F32 mCollapseAmt;
};

LLLayoutStack::Params::Params()
:	orientation("orientation", std::string("vertical")),
	animate("animate", true),
	clip("clip", true),
	border_size("border_size", LLCachedControl<S32>(*LLUI::sSettingGroups["config"], "UIResizeBarHeight", 0))
{
	name="stack";
}

LLLayoutStack::LLLayoutStack(const LLLayoutStack::Params& p) 
:	LLView(p),
	mMinWidth(0),
	mMinHeight(0),
	mPanelSpacing(p.border_size),
	mOrientation((p.orientation() == "vertical") ? VERTICAL : HORIZONTAL),
	mAnimate(p.animate),
	mAnimatedThisFrame(false),
	mClip(p.clip)
{}

LLLayoutStack::~LLLayoutStack()
{
	e_panel_list_t panels = mPanels; // copy list of panel pointers
	mPanels.clear(); // clear so that removeChild() calls don't cause trouble
	std::for_each(panels.begin(), panels.end(), DeletePointer());
}

void LLLayoutStack::draw()
{
	updateLayout();

	e_panel_list_t::iterator panel_it;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		// clip to layout rectangle, not bounding rectangle
		LLRect clip_rect = (*panel_it)->mPanel->getRect();
		// scale clipping rectangle by visible amount
		if (mOrientation == HORIZONTAL)
		{
			clip_rect.mRight = clip_rect.mLeft + llround((F32)clip_rect.getWidth() * (*panel_it)->getCollapseFactor());
		}
		else
		{
			clip_rect.mBottom = clip_rect.mTop - llround((F32)clip_rect.getHeight() * (*panel_it)->getCollapseFactor());
		}

		LLPanel* panelp = (*panel_it)->mPanel;

		LLLocalClipRect clip(clip_rect, mClip);
		// only force drawing invisible children if visible amount is non-zero
		drawChild(panelp, 0, 0, !clip_rect.isEmpty());
	}
	mAnimatedThisFrame = false;
}

void LLLayoutStack::removeChild(LLView* view)
{
	LayoutPanel* embedded_panelp = findEmbeddedPanel(dynamic_cast<LLPanel*>(view));

	if (embedded_panelp)
	{
		mPanels.erase(std::find(mPanels.begin(), mPanels.end(), embedded_panelp));
		delete embedded_panelp;
	}

	// need to update resizebars

	calcMinExtents();

	LLView::removeChild(view);
}

BOOL LLLayoutStack::postBuild()
{
	updateLayout();
	return TRUE;
}

static void get_attribute_s32_and_write(LLXMLNodePtr node,
										const char* name,
										S32 *value,
										S32 default_value,
										LLXMLNodePtr output_child)
{
	BOOL has_attr = node->getAttributeS32(name, *value);
	if (has_attr && *value != default_value && output_child)
	{
		// create an attribute child node
		LLXMLNodePtr child_attr = output_child->createChild(name, TRUE);
		child_attr->setIntValue(*value);
	}
}

static void get_attribute_bool_and_write(LLXMLNodePtr node,
										const char* name,
										BOOL *value,
										BOOL default_value,
										LLXMLNodePtr output_child)
{
	BOOL has_attr = node->getAttributeBOOL(name, *value);
	if (has_attr && *value != default_value && output_child)
	{
		LLXMLNodePtr child_attr = output_child->createChild(name, TRUE);
		child_attr->setBoolValue(*value);
	}
}
//static 
LLView* LLLayoutStack::fromXML(LLXMLNodePtr node, LLView *parent, LLXMLNodePtr output_node)
{
	LLLayoutStack::Params p(LLUICtrlFactory::getDefaultParams<LLLayoutStack>());
	LLXUIParser::instance().readXUI(node, p, LLUICtrlFactory::getInstance()->getCurFileName());

	// Export must happen before setupParams() mungles rectangles and before
	// this item gets added to parent (otherwise screws up last_child_rect
	// logic). JC
	if (output_node)
	{
		Params output_params(p);
		setupParamsForExport(output_params, parent);
		LLLayoutStack::Params default_params(LLUICtrlFactory::getDefaultParams<LLLayoutStack>());
		output_node->setName(node->getName()->mString);
		LLXUIParser::instance().writeXUI(
			output_node, output_params, &default_params);
	}

	p.from_xui = true;
	applyXUILayout(p, parent);
	LLLayoutStack* layout_stackp = LLUICtrlFactory::create<LLLayoutStack>(p);

	if (parent && layout_stackp)
	{
		S32 tab_group = p.tab_group.isProvided() ? p.tab_group() : parent->getLastTabGroup();

		parent->addChild(layout_stackp, tab_group);
	}

	for (LLXMLNodePtr child_node = node->getFirstChild(); child_node.notNull(); child_node = child_node->getNextSibling())
	{
		const S32 DEFAULT_MIN_WIDTH = 0;
		const S32 DEFAULT_MIN_HEIGHT = 0;
		const BOOL DEFAULT_AUTO_RESIZE = TRUE;

		S32 min_width = DEFAULT_MIN_WIDTH;
		S32 min_height = DEFAULT_MIN_HEIGHT;
		BOOL auto_resize = DEFAULT_AUTO_RESIZE;

		LLXMLNodePtr output_child;
		if (output_node) 
		{
			output_child = output_node->createChild("", FALSE);
		}

		// Layout stack allows child nodes to acquire additional attributes,
		// such as "min_width" in:  <button label="Foo" min_width="100"/>
		// If these attributes exist and have non-default values, write them
		// to the output node.
		get_attribute_s32_and_write(child_node, "min_width", &min_width,
			DEFAULT_MIN_WIDTH, output_child);
		get_attribute_s32_and_write(child_node, "min_height", &min_height,
			DEFAULT_MIN_HEIGHT, output_child);
		get_attribute_bool_and_write(child_node, "auto_resize", &auto_resize,
			DEFAULT_AUTO_RESIZE, output_child);

		if (child_node->hasName("layout_panel"))
		{
			BOOL user_resize = TRUE;
			get_attribute_bool_and_write(child_node, "user_resize", &user_resize,
				TRUE, output_child);
			LLPanel* panelp = (LLPanel*)LLPanel::fromXML(child_node, layout_stackp, output_child);
			if (panelp)
			{
				panelp->setFollowsNone();
				layout_stackp->addPanel(panelp, min_width, min_height, auto_resize, user_resize);
			}
		}
		else
		{
			BOOL user_resize = FALSE;
			get_attribute_bool_and_write(child_node, "user_resize", &user_resize,
				FALSE, output_child);

			LLPanel::Params p;
			p.mouse_opaque(false);
			LLPanel* panelp = LLUICtrlFactory::create<LLPanel>(p);
			LLView* new_child = LLUICtrlFactory::getInstance()->createFromXML(child_node, panelp, LLStringUtil::null, LLPanel::child_registry_t::instance(), output_child);
			if (new_child)
			{
				// put child in new embedded panel
				layout_stackp->addPanel(panelp, min_width, min_height, auto_resize, user_resize);
				// resize panel to contain widget and move widget to be contained in panel
				panelp->setRect(new_child->getRect());
				new_child->setOrigin(0, 0);
			}
			else
			{
				panelp->die();
			}
		}
		
		if (output_child && !output_child->mChildren && output_child->mAttributes.empty() && output_child->getValue().empty())
		{
			output_node->deleteChild(output_child);
		}
	}

	if (!layout_stackp->postBuild())
	{
		delete layout_stackp;
		return NULL;
	}

	return layout_stackp;
}

S32 LLLayoutStack::getDefaultHeight(S32 cur_height)
{
	// if we are spanning our children (crude upward propagation of size)
	// then don't enforce our size on our children
	if (mOrientation == HORIZONTAL)
	{
		cur_height = llmax(mMinHeight, getRect().getHeight());
	}

	return cur_height;
}

S32 LLLayoutStack::getDefaultWidth(S32 cur_width)
{
	// if we are spanning our children (crude upward propagation of size)
	// then don't enforce our size on our children
	if (mOrientation == VERTICAL)
	{
		cur_width = llmax(mMinWidth, getRect().getWidth());
	}

	return cur_width;
}

void LLLayoutStack::addPanel(LLPanel* panel, S32 min_width, S32 min_height, BOOL auto_resize, BOOL user_resize, EAnimate animate, S32 index)
{
	// panel starts off invisible (collapsed)
	if (animate == ANIMATE)
	{
		panel->setVisible(FALSE);
	}
	LayoutPanel* embedded_panel = new LayoutPanel(panel, mOrientation, min_width, min_height, auto_resize, user_resize);
	
	mPanels.insert(mPanels.begin() + llclamp(index, 0, (S32)mPanels.size()), embedded_panel);
	
	if (panel->getParent() != this) 
	{
		addChild(panel);
	}
	addChild(embedded_panel->mResizeBar);

	// bring all resize bars to the front so that they are clickable even over the panels
	// with a bit of overlap
	for (e_panel_list_t::iterator panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		LLResizeBar* resize_barp = (*panel_it)->mResizeBar;
		sendChildToFront(resize_barp);
	}

	// start expanding panel animation
	if (animate == ANIMATE)
	{
		panel->setVisible(TRUE);
	}
}

void LLLayoutStack::removePanel(LLPanel* panel)
{
	removeChild(panel);
}

void LLLayoutStack::collapsePanel(LLPanel* panel, BOOL collapsed)
{
	LayoutPanel* panel_container = findEmbeddedPanel(panel);
	if (!panel_container) return;

	panel_container->mCollapsed = collapsed;
}

void LLLayoutStack::updatePanelAutoResize(const std::string& panel_name, BOOL auto_resize)
{
	LayoutPanel* panel = findEmbeddedPanelByName(panel_name);

	if (panel)
	{
		panel->mAutoResize = auto_resize;
	}
}

void LLLayoutStack::setPanelUserResize(const std::string& panel_name, BOOL user_resize)
{
	LayoutPanel* panel = findEmbeddedPanelByName(panel_name);

	if (panel)
	{
		panel->mUserResize = user_resize;
	}
}

bool LLLayoutStack::getPanelMinSize(const std::string& panel_name, S32* min_widthp, S32* min_heightp)
{
	LayoutPanel* panel = findEmbeddedPanelByName(panel_name);

	if (panel)
	{
		if (min_widthp) *min_widthp = panel->mMinWidth;
		if (min_heightp) *min_heightp = panel->mMinHeight;
	}

	return NULL != panel;
}

static LLFastTimer::DeclareTimer FTM_UPDATE_LAYOUT("Update LayoutStacks");
void LLLayoutStack::updateLayout(BOOL force_resize)
{
	LLFastTimer ft(FTM_UPDATE_LAYOUT);
	static LLUICachedControl<S32> resize_bar_overlap ("UIResizeBarOverlap", 0);
	calcMinExtents();

	// calculate current extents
	S32 total_width = 0;
	S32 total_height = 0;

	const F32 ANIM_OPEN_TIME = 0.02f;
	const F32 ANIM_CLOSE_TIME = 0.03f;

	e_panel_list_t::iterator panel_it;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end();	++panel_it)
	{
		LLPanel* panelp = (*panel_it)->mPanel;
		if (panelp->getVisible()) 
		{
			if (mAnimate)
			{
				if (!mAnimatedThisFrame)
				{
					(*panel_it)->mVisibleAmt = lerp((*panel_it)->mVisibleAmt, 1.f, LLCriticalDamp::getInterpolant(ANIM_OPEN_TIME));
					if ((*panel_it)->mVisibleAmt > 0.99f)
					{
						(*panel_it)->mVisibleAmt = 1.f;
					}
				}
			}
			else
			{
				(*panel_it)->mVisibleAmt = 1.f;
			}
		}
		else // not visible
		{
			if (mAnimate)
			{
				if (!mAnimatedThisFrame)
				{
					(*panel_it)->mVisibleAmt = lerp((*panel_it)->mVisibleAmt, 0.f, LLCriticalDamp::getInterpolant(ANIM_CLOSE_TIME));
					if ((*panel_it)->mVisibleAmt < 0.001f)
					{
						(*panel_it)->mVisibleAmt = 0.f;
					}
				}
			}
			else
			{
				(*panel_it)->mVisibleAmt = 0.f;
			}
		}

		if ((*panel_it)->mCollapsed)
		{
			(*panel_it)->mCollapseAmt = lerp((*panel_it)->mCollapseAmt, 1.f, LLCriticalDamp::getInterpolant(ANIM_CLOSE_TIME));
		}
		else
		{
			(*panel_it)->mCollapseAmt = lerp((*panel_it)->mCollapseAmt, 0.f, LLCriticalDamp::getInterpolant(ANIM_CLOSE_TIME));
		}

		if (mOrientation == HORIZONTAL)
		{
			// enforce minimize size constraint by default
			if (panelp->getRect().getWidth() < (*panel_it)->mMinWidth)
			{
				panelp->reshape((*panel_it)->mMinWidth, panelp->getRect().getHeight());
			}
        	total_width += llround(panelp->getRect().getWidth() * (*panel_it)->getCollapseFactor());
        	// want n-1 panel gaps for n panels
			if (panel_it != mPanels.begin())
			{
				total_width += mPanelSpacing;
			}
		}
		else //VERTICAL
		{
			// enforce minimize size constraint by default
			if (panelp->getRect().getHeight() < (*panel_it)->mMinHeight)
			{
				panelp->reshape(panelp->getRect().getWidth(), (*panel_it)->mMinHeight);
			}
			total_height += llround(panelp->getRect().getHeight() * (*panel_it)->getCollapseFactor());
			if (panel_it != mPanels.begin())
			{
				total_height += mPanelSpacing;
			}
		}
	}

	S32 num_resizable_panels = 0;
	S32 shrink_headroom_available = 0;
	S32 shrink_headroom_total = 0;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		// panels that are not fully visible do not count towards shrink headroom
		if ((*panel_it)->getCollapseFactor() < 1.f) 
		{
			continue;
		}

		// if currently resizing a panel or the panel is flagged as not automatically resizing
		// only track total available headroom, but don't use it for automatic resize logic
		if ((*panel_it)->mResizeBar->hasMouseCapture() 
			|| (!(*panel_it)->mAutoResize 
				&& !force_resize))
		{
			if (mOrientation == HORIZONTAL)
			{
				shrink_headroom_total += (*panel_it)->mPanel->getRect().getWidth() - (*panel_it)->mMinWidth;
			}
			else //VERTICAL
			{
				shrink_headroom_total += (*panel_it)->mPanel->getRect().getHeight() - (*panel_it)->mMinHeight;
			}
		}
		else
		{
			num_resizable_panels++;
			if (mOrientation == HORIZONTAL)
			{
				shrink_headroom_available += (*panel_it)->mPanel->getRect().getWidth() - (*panel_it)->mMinWidth;
				shrink_headroom_total += (*panel_it)->mPanel->getRect().getWidth() - (*panel_it)->mMinWidth;
			}
			else //VERTICAL
			{
				shrink_headroom_available += (*panel_it)->mPanel->getRect().getHeight() - (*panel_it)->mMinHeight;
				shrink_headroom_total += (*panel_it)->mPanel->getRect().getHeight() - (*panel_it)->mMinHeight;
			}
		}
	}

	// calculate how many pixels need to be distributed among layout panels
	// positive means panels need to grow, negative means shrink
	S32 pixels_to_distribute;
	if (mOrientation == HORIZONTAL)
	{
		pixels_to_distribute = getRect().getWidth() - total_width;
	}
	else //VERTICAL
	{
		pixels_to_distribute = getRect().getHeight() - total_height;
	}

	// now we distribute the pixels...
	S32 cur_x = 0;
	S32 cur_y = getRect().getHeight();

	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		LLPanel* panelp = (*panel_it)->mPanel;

		S32 cur_width = panelp->getRect().getWidth();
		S32 cur_height = panelp->getRect().getHeight();
		S32 new_width = llmax((*panel_it)->mMinWidth, cur_width);
		S32 new_height = llmax((*panel_it)->mMinHeight, cur_height); 

		S32 delta_size = 0;

		// if panel can automatically resize (not animating, and resize flag set)...
		if ((*panel_it)->getCollapseFactor() == 1.f 
			&& (force_resize || (*panel_it)->mAutoResize) 
			&& !(*panel_it)->mResizeBar->hasMouseCapture()) 
		{
			if (mOrientation == HORIZONTAL)
			{
				// if we're shrinking
				if (pixels_to_distribute < 0)
				{
					// shrink proportionally to amount over minimum
					// so we can do this in one pass
					delta_size = (shrink_headroom_available > 0) ? llround((F32)pixels_to_distribute * ((F32)(cur_width - (*panel_it)->mMinWidth) / (F32)shrink_headroom_available)) : 0;
					shrink_headroom_available -= (cur_width - (*panel_it)->mMinWidth);
				}
				else
				{
					// grow all elements equally
					delta_size = llround((F32)pixels_to_distribute / (F32)num_resizable_panels);
					num_resizable_panels--;
				}
				pixels_to_distribute -= delta_size;
				new_width = llmax((*panel_it)->mMinWidth, cur_width + delta_size);
			}
			else
			{
				new_width = getDefaultWidth(new_width);
			}

			if (mOrientation == VERTICAL)
			{
				if (pixels_to_distribute < 0)
				{
					// shrink proportionally to amount over minimum
					// so we can do this in one pass
					delta_size = (shrink_headroom_available > 0) ? llround((F32)pixels_to_distribute * ((F32)(cur_height - (*panel_it)->mMinHeight) / (F32)shrink_headroom_available)) : 0;
					shrink_headroom_available -= (cur_height - (*panel_it)->mMinHeight);
				}
				else
				{
					delta_size = llround((F32)pixels_to_distribute / (F32)num_resizable_panels);
					num_resizable_panels--;
				}
				pixels_to_distribute -= delta_size;
				new_height = llmax((*panel_it)->mMinHeight, cur_height + delta_size);
			}
			else
			{
				new_height = getDefaultHeight(new_height);
			}
		}
		else
		{
			if (mOrientation == HORIZONTAL)
			{
				new_height = getDefaultHeight(new_height);
			}
			else // VERTICAL
			{
				new_width = getDefaultWidth(new_width);
			}
		}

		// adjust running headroom count based on new sizes
		shrink_headroom_total += delta_size;

		LLRect panel_rect;
		panel_rect.setLeftTopAndSize(cur_x, cur_y, new_width, new_height);
		panelp->setShape(panel_rect);

		LLRect resize_bar_rect = panel_rect;
		if (mOrientation == HORIZONTAL)
		{
			resize_bar_rect.mLeft = panel_rect.mRight - resize_bar_overlap;
			resize_bar_rect.mRight = panel_rect.mRight + mPanelSpacing + resize_bar_overlap;
		}
		else
		{
			resize_bar_rect.mTop = panel_rect.mBottom + resize_bar_overlap;
			resize_bar_rect.mBottom = panel_rect.mBottom - mPanelSpacing - resize_bar_overlap;
		}
		(*panel_it)->mResizeBar->setRect(resize_bar_rect);

		if (mOrientation == HORIZONTAL)
		{
			cur_x += llround(new_width * (*panel_it)->getCollapseFactor()) + mPanelSpacing;
		}
		else //VERTICAL
		{
			cur_y -= llround(new_height * (*panel_it)->getCollapseFactor()) + mPanelSpacing;
		}
	}

	// update resize bars with new limits
	LLResizeBar* last_resize_bar = NULL;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		LLPanel* panelp = (*panel_it)->mPanel;

		if (mOrientation == HORIZONTAL)
		{
			(*panel_it)->mResizeBar->setResizeLimits(
				(*panel_it)->mMinWidth, 
				(*panel_it)->mMinWidth + shrink_headroom_total);
		}
		else //VERTICAL
		{
			(*panel_it)->mResizeBar->setResizeLimits(
				(*panel_it)->mMinHeight, 
				(*panel_it)->mMinHeight + shrink_headroom_total);
		}

		// toggle resize bars based on panel visibility, resizability, etc
		BOOL resize_bar_enabled = panelp->getVisible() && (*panel_it)->mUserResize;
		(*panel_it)->mResizeBar->setVisible(resize_bar_enabled);

		if (resize_bar_enabled)
		{
			last_resize_bar = (*panel_it)->mResizeBar;
		}
	}

	// hide last resize bar as there is nothing past it
	// resize bars need to be in between two resizable panels
	if (last_resize_bar)
	{
		last_resize_bar->setVisible(FALSE);
	}

	// not enough room to fit existing contents
	if (force_resize == FALSE
		// layout did not complete by reaching target position
		&& ((mOrientation == VERTICAL && cur_y != -mPanelSpacing)
			|| (mOrientation == HORIZONTAL && cur_x != getRect().getWidth() + mPanelSpacing)))
	{
		// do another layout pass with all stacked elements contributing
		// even those that don't usually resize
		llassert_always(force_resize == FALSE);
		updateLayout(TRUE);
	}

	 mAnimatedThisFrame = true;
} // end LLLayoutStack::updateLayout


LLLayoutStack::LayoutPanel* LLLayoutStack::findEmbeddedPanel(LLPanel* panelp) const
{
	if (!panelp) return NULL;

	e_panel_list_t::const_iterator panel_it;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		if ((*panel_it)->mPanel == panelp)
		{
			return *panel_it;
		}
	}
	return NULL;
}

LLLayoutStack::LayoutPanel* LLLayoutStack::findEmbeddedPanelByName(const std::string& name) const
{
	LayoutPanel* result = NULL;

	for (e_panel_list_t::const_iterator panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		LayoutPanel* p = *panel_it;

		if (p->mPanel->getName() == name)
		{
			result = p;
			break;
		}
	}

	return result;
}

// Compute sum of min_width or min_height of children
void LLLayoutStack::calcMinExtents()
{
	mMinWidth = 0;
	mMinHeight = 0;

	e_panel_list_t::iterator panel_it;
	for (panel_it = mPanels.begin(); panel_it != mPanels.end(); ++panel_it)
	{
		if (mOrientation == HORIZONTAL)
		{
			mMinHeight = llmax(	mMinHeight, 
								(*panel_it)->mMinHeight);
            mMinWidth += (*panel_it)->mMinWidth;
			if (panel_it != mPanels.begin())
			{
				mMinWidth += mPanelSpacing;
			}
		}
		else //VERTICAL
		{
	        mMinWidth = llmax(	mMinWidth, 
								(*panel_it)->mMinWidth);
			mMinHeight += (*panel_it)->mMinHeight;
			if (panel_it != mPanels.begin())
			{
				mMinHeight += mPanelSpacing;
			}
		}
	}
}

// update layout stack animations, etc. once per frame
// NOTE: we use this to size world view based on animating UI, *before* we draw the UI
// we might still need to call updateLayout during UI draw phase, in case UI elements
// are resizing themselves dynamically
//static 
void LLLayoutStack::updateClass()
{
	for (LLLayoutStack::instance_iter it = beginInstances(); it != endInstances(); ++it)
	{
		it->updateLayout();
	}
}