Merge branch 'release/maint-b' into pipewire-linux-volume-catcher

1 files changed, 800 insertions, 797 deletions

diff --git a/indra/llui/lllayoutstack.cpp b/indra/llui/lllayoutstack.cpp
index 7e4e828a88..13d6faa673 100644
--- a/indra/llui/lllayoutstack.cpp
+++ b/indra/llui/lllayoutstack.cpp
@@ -1,25 +1,25 @@
-/** 
+/**
  * @file lllayoutstack.cpp
  * @brief LLLayout class - dynamic stacking of UI elements
  *
  * $LicenseInfo:firstyear=2001&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, Linden Research, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- * 
+ *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
+ *
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
@@ -45,159 +45,159 @@ static LLLayoutStack::LayoutStackRegistry::Register<LLLayoutPanel> register_layo
 //
 // LLLayoutPanel
 //
-LLLayoutPanel::Params::Params()	
-:	expanded_min_dim("expanded_min_dim", 0),
-	min_dim("min_dim", -1),
-	user_resize("user_resize", false),
-	auto_resize("auto_resize", true)
-{
-	addSynonym(min_dim, "min_width");
-	addSynonym(min_dim, "min_height");
-}
-
-LLLayoutPanel::LLLayoutPanel(const Params& p)	
-:	LLPanel(p),
-	mExpandedMinDim(p.expanded_min_dim.isProvided() ? p.expanded_min_dim : p.min_dim),
- 	mMinDim(p.min_dim), 
- 	mAutoResize(p.auto_resize),
- 	mUserResize(p.user_resize),
-	mCollapsed(FALSE),
-	mCollapseAmt(0.f),
-	mVisibleAmt(1.f), // default to fully visible
-	mResizeBar(NULL),
-	mFractionalSize(0.f),
-	mTargetDim(0),
-	mIgnoreReshape(false),
-	mOrientation(LLLayoutStack::HORIZONTAL)
-{
-	// panels initialized as hidden should not start out partially visible
-	if (!getVisible())
-	{
-		mVisibleAmt = 0.f;
-	}
+LLLayoutPanel::Params::Params()
+:   expanded_min_dim("expanded_min_dim", 0),
+    min_dim("min_dim", -1),
+    user_resize("user_resize", false),
+    auto_resize("auto_resize", true)
+{
+    addSynonym(min_dim, "min_width");
+    addSynonym(min_dim, "min_height");
+}
+
+LLLayoutPanel::LLLayoutPanel(const Params& p)
+:   LLPanel(p),
+    mExpandedMinDim(p.expanded_min_dim.isProvided() ? p.expanded_min_dim : p.min_dim),
+    mMinDim(p.min_dim),
+    mAutoResize(p.auto_resize),
+    mUserResize(p.user_resize),
+    mCollapsed(FALSE),
+    mCollapseAmt(0.f),
+    mVisibleAmt(1.f), // default to fully visible
+    mResizeBar(NULL),
+    mFractionalSize(0.f),
+    mTargetDim(0),
+    mIgnoreReshape(false),
+    mOrientation(LLLayoutStack::HORIZONTAL)
+{
+    // panels initialized as hidden should not start out partially visible
+    if (!getVisible())
+    {
+        mVisibleAmt = 0.f;
+    }
 }
 
 void LLLayoutPanel::initFromParams(const Params& p)
 {
-	LLPanel::initFromParams(p);
-	setFollowsNone();
+    LLPanel::initFromParams(p);
+    setFollowsNone();
 }
 
 
 LLLayoutPanel::~LLLayoutPanel()
 {
-	// probably not necessary, but...
-	delete mResizeBar;
-	mResizeBar = NULL;
+    // probably not necessary, but...
+    delete mResizeBar;
+    mResizeBar = NULL;
 
     gFocusMgr.removeKeyboardFocusWithoutCallback(this);
 }
 
 F32 LLLayoutPanel::getAutoResizeFactor() const
 {
-	return mVisibleAmt * (1.f - mCollapseAmt);
+    return mVisibleAmt * (1.f - mCollapseAmt);
 }
- 
+
 F32 LLLayoutPanel::getVisibleAmount() const
 {
-	return mVisibleAmt;
+    return mVisibleAmt;
 }
 
 S32 LLLayoutPanel::getLayoutDim() const
 {
-	return ll_round((F32)((mOrientation == LLLayoutStack::HORIZONTAL)
-					? getRect().getWidth()
-					: getRect().getHeight()));
+    return ll_round((F32)((mOrientation == LLLayoutStack::HORIZONTAL)
+                    ? getRect().getWidth()
+                    : getRect().getHeight()));
 }
 
 S32 LLLayoutPanel::getTargetDim() const
 {
-	return mTargetDim;
+    return mTargetDim;
 }
 
 void LLLayoutPanel::setTargetDim(S32 value)
 {
-	LLRect new_rect(getRect());
-	if (mOrientation == LLLayoutStack::HORIZONTAL)
-	{
-		new_rect.mRight = new_rect.mLeft + value;
-	}
-	else
-	{
-		new_rect.mTop = new_rect.mBottom + value;
-	}
-	setShape(new_rect, true);
+    LLRect new_rect(getRect());
+    if (mOrientation == LLLayoutStack::HORIZONTAL)
+    {
+        new_rect.mRight = new_rect.mLeft + value;
+    }
+    else
+    {
+        new_rect.mTop = new_rect.mBottom + value;
+    }
+    setShape(new_rect, true);
 }
 
 S32 LLLayoutPanel::getVisibleDim() const
 {
-	F32 min_dim = getRelevantMinDim();
-	return ll_round(mVisibleAmt
-					* (min_dim
-						+ (((F32)mTargetDim - min_dim) * (1.f - mCollapseAmt))));
+    F32 min_dim = getRelevantMinDim();
+    return ll_round(mVisibleAmt
+                    * (min_dim
+                        + (((F32)mTargetDim - min_dim) * (1.f - mCollapseAmt))));
 }
- 
+
 void LLLayoutPanel::setOrientation( LLView::EOrientation orientation )
 {
-	mOrientation = orientation;
-	S32 layout_dim = ll_round((F32)((mOrientation == LLLayoutStack::HORIZONTAL)
-		? getRect().getWidth()
-		: getRect().getHeight()));
-
-	if (mAutoResize == FALSE 
-		&& mUserResize == TRUE 
-		&& mMinDim == -1 )
-	{
-		setMinDim(layout_dim);
-	}
-	mTargetDim = llmax(layout_dim, getMinDim());
+    mOrientation = orientation;
+    S32 layout_dim = ll_round((F32)((mOrientation == LLLayoutStack::HORIZONTAL)
+        ? getRect().getWidth()
+        : getRect().getHeight()));
+
+    if (mAutoResize == FALSE
+        && mUserResize == TRUE
+        && mMinDim == -1 )
+    {
+        setMinDim(layout_dim);
+    }
+    mTargetDim = llmax(layout_dim, getMinDim());
 }
- 
+
 void LLLayoutPanel::setVisible( BOOL visible )
 {
-	if (visible != getVisible())
-	{
-		LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
-		if (stackp)
-		{
-			stackp->mNeedsLayout = true;
-		}
-	}
-	LLPanel::setVisible(visible);
+    if (visible != getVisible())
+    {
+        LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
+        if (stackp)
+        {
+            stackp->mNeedsLayout = true;
+        }
+    }
+    LLPanel::setVisible(visible);
 }
 
 void LLLayoutPanel::reshape( S32 width, S32 height, BOOL called_from_parent /*= TRUE*/ )
 {
-	if (width == getRect().getWidth() && height == getRect().getHeight() && !LLView::sForceReshape) return;
+    if (width == getRect().getWidth() && height == getRect().getHeight() && !LLView::sForceReshape) return;
 
-	if (!mIgnoreReshape && mAutoResize == false)
-	{
-		mTargetDim = (mOrientation == LLLayoutStack::HORIZONTAL) ? width : height;
-		LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
-		if (stackp)
-		{
-			stackp->mNeedsLayout = true;
-		}
-	}
-	LLPanel::reshape(width, height, called_from_parent);
+    if (!mIgnoreReshape && mAutoResize == false)
+    {
+        mTargetDim = (mOrientation == LLLayoutStack::HORIZONTAL) ? width : height;
+        LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
+        if (stackp)
+        {
+            stackp->mNeedsLayout = true;
+        }
+    }
+    LLPanel::reshape(width, height, called_from_parent);
 }
 
 void LLLayoutPanel::handleReshape(const LLRect& new_rect, bool by_user)
 {
-	LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
-	if (stackp)
-	{
-		if (by_user)
-		{	// tell layout stack to account for new shape
-			
-			// make sure that panels have already been auto resized
-			stackp->updateLayout();
-			// now apply requested size to panel
-			stackp->updatePanelRect(this, new_rect);
-		}
-		stackp->mNeedsLayout = true;
-	}
-	LLPanel::handleReshape(new_rect, by_user);
+    LLLayoutStack* stackp = dynamic_cast<LLLayoutStack*>(getParent());
+    if (stackp)
+    {
+        if (by_user)
+        {   // tell layout stack to account for new shape
+
+            // make sure that panels have already been auto resized
+            stackp->updateLayout();
+            // now apply requested size to panel
+            stackp->updatePanelRect(this, new_rect);
+        }
+        stackp->mNeedsLayout = true;
+    }
+    LLPanel::handleReshape(new_rect, by_user);
 }
 
 //
@@ -205,85 +205,85 @@ void LLLayoutPanel::handleReshape(const LLRect& new_rect, bool by_user)
 //
 
 LLLayoutStack::Params::Params()
-:	orientation("orientation"),
-	animate("animate", true),
-	clip("clip", true),
-	open_time_constant("open_time_constant", 0.02f),
-	close_time_constant("close_time_constant", 0.03f),
-	resize_bar_overlap("resize_bar_overlap", 1),
-	border_size("border_size", LLCachedControl<S32>(*LLUI::getInstance()->mSettingGroups["config"], "UIResizeBarHeight", 0)),
-	show_drag_handle("show_drag_handle", false),
-	drag_handle_first_indent("drag_handle_first_indent", 0),
-	drag_handle_second_indent("drag_handle_second_indent", 0),
-	drag_handle_thickness("drag_handle_thickness", 5),
-	drag_handle_shift("drag_handle_shift", 2),
+:   orientation("orientation"),
+    animate("animate", true),
+    clip("clip", true),
+    open_time_constant("open_time_constant", 0.02f),
+    close_time_constant("close_time_constant", 0.03f),
+    resize_bar_overlap("resize_bar_overlap", 1),
+    border_size("border_size", LLCachedControl<S32>(*LLUI::getInstance()->mSettingGroups["config"], "UIResizeBarHeight", 0)),
+    show_drag_handle("show_drag_handle", false),
+    drag_handle_first_indent("drag_handle_first_indent", 0),
+    drag_handle_second_indent("drag_handle_second_indent", 0),
+    drag_handle_thickness("drag_handle_thickness", 5),
+    drag_handle_shift("drag_handle_shift", 2),
     drag_handle_color("drag_handle_color", LLUIColorTable::instance().getColor("ResizebarBody"))
 {
-	addSynonym(border_size, "drag_handle_gap");
-}
-
-LLLayoutStack::LLLayoutStack(const LLLayoutStack::Params& p) 
-:	LLView(p),
-	mPanelSpacing(p.border_size),
-	mOrientation(p.orientation),
-	mAnimate(p.animate),
-	mAnimatedThisFrame(false),
-	mNeedsLayout(true),
-	mClip(p.clip),
-	mOpenTimeConstant(p.open_time_constant),
-	mCloseTimeConstant(p.close_time_constant),
-	mResizeBarOverlap(p.resize_bar_overlap),
-	mShowDragHandle(p.show_drag_handle),
-	mDragHandleFirstIndent(p.drag_handle_first_indent),
-	mDragHandleSecondIndent(p.drag_handle_second_indent),
-	mDragHandleThickness(p.drag_handle_thickness),
-	mDragHandleShift(p.drag_handle_shift),
+    addSynonym(border_size, "drag_handle_gap");
+}
+
+LLLayoutStack::LLLayoutStack(const LLLayoutStack::Params& p)
+:   LLView(p),
+    mPanelSpacing(p.border_size),
+    mOrientation(p.orientation),
+    mAnimate(p.animate),
+    mAnimatedThisFrame(false),
+    mNeedsLayout(true),
+    mClip(p.clip),
+    mOpenTimeConstant(p.open_time_constant),
+    mCloseTimeConstant(p.close_time_constant),
+    mResizeBarOverlap(p.resize_bar_overlap),
+    mShowDragHandle(p.show_drag_handle),
+    mDragHandleFirstIndent(p.drag_handle_first_indent),
+    mDragHandleSecondIndent(p.drag_handle_second_indent),
+    mDragHandleThickness(p.drag_handle_thickness),
+    mDragHandleShift(p.drag_handle_shift),
     mDragHandleColor(p.drag_handle_color())
 {
 }
 
 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());
+    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();
-
-	// always clip to stack itself
-	LLLocalClipRect clip(getLocalRect());
-	for (LLLayoutPanel* panelp : mPanels)
-	{
-		if ((!panelp->getVisible() || panelp->mCollapsed)
-			&& (panelp->mVisibleAmt < 0.001f || !mAnimate))
-		{
-			// essentially invisible
-			continue;
-		}
-		// clip to layout rectangle, not bounding rectangle
-		LLRect clip_rect = panelp->getRect();
-		// scale clipping rectangle by visible amount
-		if (mOrientation == HORIZONTAL)
-		{
-			clip_rect.mRight = clip_rect.mLeft + panelp->getVisibleDim();
-		}
-		else
-		{
-			clip_rect.mBottom = clip_rect.mTop - panelp->getVisibleDim();
-		}
-
-		{LLLocalClipRect clip(clip_rect, mClip);
-			// only force drawing invisible children if visible amount is non-zero
-			drawChild(panelp, 0, 0, !clip_rect.isEmpty());
-		}
-		if (panelp->getResizeBar()->getVisible())
-		{
-			drawChild(panelp->getResizeBar());
-		}
-	}
+    updateLayout();
+
+    // always clip to stack itself
+    LLLocalClipRect clip(getLocalRect());
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if ((!panelp->getVisible() || panelp->mCollapsed)
+            && (panelp->mVisibleAmt < 0.001f || !mAnimate))
+        {
+            // essentially invisible
+            continue;
+        }
+        // clip to layout rectangle, not bounding rectangle
+        LLRect clip_rect = panelp->getRect();
+        // scale clipping rectangle by visible amount
+        if (mOrientation == HORIZONTAL)
+        {
+            clip_rect.mRight = clip_rect.mLeft + panelp->getVisibleDim();
+        }
+        else
+        {
+            clip_rect.mBottom = clip_rect.mTop - panelp->getVisibleDim();
+        }
+
+        {LLLocalClipRect clip(clip_rect, mClip);
+            // only force drawing invisible children if visible amount is non-zero
+            drawChild(panelp, 0, 0, !clip_rect.isEmpty());
+        }
+        if (panelp->getResizeBar()->getVisible())
+        {
+            drawChild(panelp->getResizeBar());
+        }
+    }
 }
 
 void LLLayoutStack::deleteAllChildren()
@@ -299,15 +299,15 @@ void LLLayoutStack::deleteAllChildren()
 
 void LLLayoutStack::removeChild(LLView* view)
 {
-	LLLayoutPanel* embedded_panelp = findEmbeddedPanel(dynamic_cast<LLPanel*>(view));
+    LLLayoutPanel* embedded_panelp = findEmbeddedPanel(dynamic_cast<LLPanel*>(view));
 
-	if (embedded_panelp)
-	{
-		mPanels.erase(std::find(mPanels.begin(), mPanels.end(), embedded_panelp));
+    if (embedded_panelp)
+    {
+        mPanels.erase(std::find(mPanels.begin(), mPanels.end(), embedded_panelp));
         LLView::removeChild(view);
-		updateFractionalSizes();
-		mNeedsLayout = true;
-	}
+        updateFractionalSizes();
+        mNeedsLayout = true;
+    }
     else
     {
         LLView::removeChild(view);
@@ -316,213 +316,215 @@ void LLLayoutStack::removeChild(LLView* view)
 
 BOOL LLLayoutStack::postBuild()
 {
-	updateLayout();
-	return TRUE;
+    updateLayout();
+    return TRUE;
 }
 
 bool LLLayoutStack::addChild(LLView* child, S32 tab_group)
 {
-	LLLayoutPanel* panelp = dynamic_cast<LLLayoutPanel*>(child);
-	if (panelp)
-	{
-		panelp->setOrientation(mOrientation);
-		mPanels.push_back(panelp);
-		createResizeBar(panelp);
-		mNeedsLayout = true;
-	}
-	BOOL result = LLView::addChild(child, tab_group);
+    LLLayoutPanel* panelp = dynamic_cast<LLLayoutPanel*>(child);
+    if (panelp)
+    {
+        panelp->setOrientation(mOrientation);
+        mPanels.push_back(panelp);
+        createResizeBar(panelp);
+        mNeedsLayout = true;
+    }
+    BOOL result = LLView::addChild(child, tab_group);
 
-	updateFractionalSizes();
-	return result;
+    updateFractionalSizes();
+    return result;
 }
 
 void LLLayoutStack::addPanel(LLLayoutPanel* panel, EAnimate animate)
 {
-	addChild(panel);
+    addChild(panel);
 
-	// panel starts off invisible (collapsed)
-	if (animate == ANIMATE)
-	{
-		panel->mVisibleAmt = 0.f;
-		panel->setVisible(TRUE);
-	}
+    // panel starts off invisible (collapsed)
+    if (animate == ANIMATE)
+    {
+        panel->mVisibleAmt = 0.f;
+        panel->setVisible(TRUE);
+    }
 }
 
 void LLLayoutStack::collapsePanel(LLPanel* panel, BOOL collapsed)
 {
-	LLLayoutPanel* panel_container = findEmbeddedPanel(panel);
-	if (!panel_container) return;
+    LLLayoutPanel* panel_container = findEmbeddedPanel(panel);
+    if (!panel_container) return;
 
-	panel_container->mCollapsed = collapsed;
-	mNeedsLayout = true;
+    panel_container->mCollapsed = collapsed;
+    mNeedsLayout = true;
 }
 
 class LLImagePanel : public LLPanel
 {
 public:
-	struct Params :	public LLInitParam::Block<Params, LLPanel::Params>
-	{
-		Optional<bool> horizontal;
-		Params() : horizontal("horizontal", false) {}
-	};
-	LLImagePanel(const Params& p) : LLPanel(p), mHorizontal(p.horizontal) {}
-	virtual ~LLImagePanel() {}
-
-	void draw()
-	{
-		const LLRect& parent_rect = getParent()->getRect();
-		const LLRect& rect = getRect();
-		LLRect clip_rect( -rect.mLeft, parent_rect.getHeight() - rect.mBottom - 2
-			, parent_rect.getWidth() - rect.mLeft - (mHorizontal ? 2 : 0), -rect.mBottom);
-		LLLocalClipRect clip(clip_rect);
-		LLPanel::draw();
-	}
+    struct Params : public LLInitParam::Block<Params, LLPanel::Params>
+    {
+        Optional<bool> horizontal;
+        Params() : horizontal("horizontal", false) {}
+    };
+    LLImagePanel(const Params& p) : LLPanel(p), mHorizontal(p.horizontal) {}
+    virtual ~LLImagePanel() {}
+
+    void draw()
+    {
+        const LLRect& parent_rect = getParent()->getRect();
+        const LLRect& rect = getRect();
+        LLRect clip_rect( -rect.mLeft, parent_rect.getHeight() - rect.mBottom - 2
+            , parent_rect.getWidth() - rect.mLeft - (mHorizontal ? 2 : 0), -rect.mBottom);
+        LLLocalClipRect clip(clip_rect);
+        LLPanel::draw();
+    }
 
 private:
-	bool mHorizontal;
+    bool mHorizontal;
 };
 
 void LLLayoutStack::updateLayout()
-{	
+{
     LL_PROFILE_ZONE_SCOPED_CATEGORY_UI;
 
-	if (!mNeedsLayout) return;
-
-	bool continue_animating = animatePanels();
-	F32 total_visible_fraction = 0.f;
-	S32 space_to_distribute = (mOrientation == HORIZONTAL)
-							? getRect().getWidth()
-							: getRect().getHeight();
-
-	// first, assign minimum dimensions
-	LLLayoutPanel* panelp = NULL;
-	BOOST_FOREACH(panelp, mPanels)
-	{
-		if (panelp->mAutoResize)
-		{
-			panelp->mTargetDim = panelp->getRelevantMinDim();
-		}
-		space_to_distribute -= panelp->getVisibleDim() + ll_round((F32)mPanelSpacing * panelp->getVisibleAmount());
-		total_visible_fraction += panelp->mFractionalSize * panelp->getAutoResizeFactor();
-	}
-
-	llassert(total_visible_fraction < 1.05f);
-
-	// don't need spacing after last panel
-	space_to_distribute += panelp ? ll_round((F32)mPanelSpacing * panelp->getVisibleAmount()) : 0;
-
-	S32 remaining_space = space_to_distribute;
-	if (space_to_distribute > 0 && total_visible_fraction > 0.f)
-	{	// give space proportionally to visible auto resize panels
-		BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-		{
-			if (panelp->mAutoResize)
-			{
-				F32 fraction_to_distribute = (panelp->mFractionalSize * panelp->getAutoResizeFactor()) / (total_visible_fraction);
-				S32 delta = ll_round((F32)space_to_distribute * fraction_to_distribute);
-				panelp->mTargetDim += delta;
-				remaining_space -= delta;
-			}
-		}
-	}
-
-	// distribute any left over pixels to non-collapsed, visible panels
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (remaining_space == 0) break;
-
-		if (panelp->mAutoResize 
-			&& !panelp->mCollapsed 
-			&& panelp->getVisible())
-		{
-			S32 space_for_panel = remaining_space > 0 ? 1 : -1;
-			panelp->mTargetDim += space_for_panel;
-			remaining_space -= space_for_panel;
-		}
-	}
-
-	F32 cur_pos = (mOrientation == HORIZONTAL) ? 0.f : (F32)getRect().getHeight();
-
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		F32 panel_dim = llmax(panelp->getExpandedMinDim(), panelp->mTargetDim);
-
-		LLRect panel_rect;
-		if (mOrientation == HORIZONTAL)
-		{
-			panel_rect.setLeftTopAndSize(ll_round(cur_pos),
-										getRect().getHeight(),
-										ll_round(panel_dim),
-										getRect().getHeight());
-		}
-		else
-		{
-			panel_rect.setLeftTopAndSize(0,
-										ll_round(cur_pos),
-										getRect().getWidth(),
-										ll_round(panel_dim));
-		}
-
-		LLRect resize_bar_rect(panel_rect);
-		F32 panel_spacing = (F32)mPanelSpacing * panelp->getVisibleAmount();
-		F32 panel_visible_dim = panelp->getVisibleDim();
-		S32 panel_spacing_round = (S32)(ll_round(panel_spacing));
-
-		if (mOrientation == HORIZONTAL)
-		{
-			cur_pos += panel_visible_dim + panel_spacing;
-
-			if (mShowDragHandle && panel_spacing_round > mDragHandleThickness)
-			{
-				resize_bar_rect.mLeft = panel_rect.mRight + mDragHandleShift;
-				resize_bar_rect.mRight = resize_bar_rect.mLeft + mDragHandleThickness;
-			}
-			else
-			{
-				resize_bar_rect.mLeft = panel_rect.mRight - mResizeBarOverlap;
-				resize_bar_rect.mRight = panel_rect.mRight + panel_spacing_round + mResizeBarOverlap;
-			}
-
-			if (mShowDragHandle)
-			{
-				resize_bar_rect.mBottom += mDragHandleSecondIndent;
-				resize_bar_rect.mTop -= mDragHandleFirstIndent;
-			}
-
-		}
-		else //VERTICAL
-		{
-			cur_pos -= panel_visible_dim + panel_spacing;
-
-			if (mShowDragHandle && panel_spacing_round > mDragHandleThickness)
-			{
-				resize_bar_rect.mTop = panel_rect.mBottom - mDragHandleShift;
-				resize_bar_rect.mBottom = resize_bar_rect.mTop - mDragHandleThickness;
-			}
-			else
-			{
-				resize_bar_rect.mTop = panel_rect.mBottom + mResizeBarOverlap;
-				resize_bar_rect.mBottom = panel_rect.mBottom - panel_spacing_round - mResizeBarOverlap;
-			}
-
-			if (mShowDragHandle)
-			{
-				resize_bar_rect.mLeft += mDragHandleFirstIndent;
-				resize_bar_rect.mRight -= mDragHandleSecondIndent;
-			}
-		}
-
-		panelp->setIgnoreReshape(true);
-		panelp->setShape(panel_rect);
-		panelp->setIgnoreReshape(false);
-		panelp->mResizeBar->setShape(resize_bar_rect);
-	}
-
-	updateResizeBarLimits();
-
-	// clear animation flag at end, since panel resizes will set it
-	// and leave it set if there is any animation in progress
-	mNeedsLayout = continue_animating;
+    if (!mNeedsLayout) return;
+
+    bool continue_animating = animatePanels();
+    F32 total_visible_fraction = 0.f;
+    S32 space_to_distribute = (mOrientation == HORIZONTAL)
+                            ? getRect().getWidth()
+                            : getRect().getHeight();
+
+    // first, assign minimum dimensions
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (panelp->mAutoResize)
+        {
+            panelp->mTargetDim = panelp->getRelevantMinDim();
+        }
+        space_to_distribute -= panelp->getVisibleDim() + ll_round((F32)mPanelSpacing * panelp->getVisibleAmount());
+        total_visible_fraction += panelp->mFractionalSize * panelp->getAutoResizeFactor();
+    }
+
+    llassert(total_visible_fraction < 1.05f);
+
+    // don't need spacing after last panel
+    if (!mPanels.empty())
+    {
+        space_to_distribute += ll_round(F32(mPanelSpacing) * mPanels.back()->getVisibleAmount());
+    }
+
+    S32 remaining_space = space_to_distribute;
+    if (space_to_distribute > 0 && total_visible_fraction > 0.f)
+    {   // give space proportionally to visible auto resize panels
+        for (LLLayoutPanel* panelp : mPanels)
+        {
+            if (panelp->mAutoResize)
+            {
+                F32 fraction_to_distribute = (panelp->mFractionalSize * panelp->getAutoResizeFactor()) / (total_visible_fraction);
+                S32 delta = ll_round((F32)space_to_distribute * fraction_to_distribute);
+                panelp->mTargetDim += delta;
+                remaining_space -= delta;
+            }
+        }
+    }
+
+    // distribute any left over pixels to non-collapsed, visible panels
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (remaining_space == 0) break;
+
+        if (panelp->mAutoResize
+            && !panelp->mCollapsed
+            && panelp->getVisible())
+        {
+            S32 space_for_panel = remaining_space > 0 ? 1 : -1;
+            panelp->mTargetDim += space_for_panel;
+            remaining_space -= space_for_panel;
+        }
+    }
+
+    F32 cur_pos = (mOrientation == HORIZONTAL) ? 0.f : (F32)getRect().getHeight();
+
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        F32 panel_dim = llmax(panelp->getExpandedMinDim(), panelp->mTargetDim);
+
+        LLRect panel_rect;
+        if (mOrientation == HORIZONTAL)
+        {
+            panel_rect.setLeftTopAndSize(ll_round(cur_pos),
+                                        getRect().getHeight(),
+                                        ll_round(panel_dim),
+                                        getRect().getHeight());
+        }
+        else
+        {
+            panel_rect.setLeftTopAndSize(0,
+                                        ll_round(cur_pos),
+                                        getRect().getWidth(),
+                                        ll_round(panel_dim));
+        }
+
+        LLRect resize_bar_rect(panel_rect);
+        F32 panel_spacing = (F32)mPanelSpacing * panelp->getVisibleAmount();
+        F32 panel_visible_dim = panelp->getVisibleDim();
+        S32 panel_spacing_round = (S32)(ll_round(panel_spacing));
+
+        if (mOrientation == HORIZONTAL)
+        {
+            cur_pos += panel_visible_dim + panel_spacing;
+
+            if (mShowDragHandle && panel_spacing_round > mDragHandleThickness)
+            {
+                resize_bar_rect.mLeft = panel_rect.mRight + mDragHandleShift;
+                resize_bar_rect.mRight = resize_bar_rect.mLeft + mDragHandleThickness;
+            }
+            else
+            {
+                resize_bar_rect.mLeft = panel_rect.mRight - mResizeBarOverlap;
+                resize_bar_rect.mRight = panel_rect.mRight + panel_spacing_round + mResizeBarOverlap;
+            }
+
+            if (mShowDragHandle)
+            {
+                resize_bar_rect.mBottom += mDragHandleSecondIndent;
+                resize_bar_rect.mTop -= mDragHandleFirstIndent;
+            }
+
+        }
+        else //VERTICAL
+        {
+            cur_pos -= panel_visible_dim + panel_spacing;
+
+            if (mShowDragHandle && panel_spacing_round > mDragHandleThickness)
+            {
+                resize_bar_rect.mTop = panel_rect.mBottom - mDragHandleShift;
+                resize_bar_rect.mBottom = resize_bar_rect.mTop - mDragHandleThickness;
+            }
+            else
+            {
+                resize_bar_rect.mTop = panel_rect.mBottom + mResizeBarOverlap;
+                resize_bar_rect.mBottom = panel_rect.mBottom - panel_spacing_round - mResizeBarOverlap;
+            }
+
+            if (mShowDragHandle)
+            {
+                resize_bar_rect.mLeft += mDragHandleFirstIndent;
+                resize_bar_rect.mRight -= mDragHandleSecondIndent;
+            }
+        }
+
+        panelp->setIgnoreReshape(true);
+        panelp->setShape(panel_rect);
+        panelp->setIgnoreReshape(false);
+        panelp->mResizeBar->setShape(resize_bar_rect);
+    }
+
+    updateResizeBarLimits();
+
+    // clear animation flag at end, since panel resizes will set it
+    // and leave it set if there is any animation in progress
+    mNeedsLayout = continue_animating;
 } // end LLLayoutStack::updateLayout
 
 void LLLayoutStack::setPanelSpacing(S32 val)
@@ -536,486 +538,487 @@ void LLLayoutStack::setPanelSpacing(S32 val)
 
 LLLayoutPanel* LLLayoutStack::findEmbeddedPanel(LLPanel* panelp) const
 {
-	if (!panelp) return NULL;
+    if (!panelp) return NULL;
 
-	BOOST_FOREACH(LLLayoutPanel* p, mPanels)
-	{
-		if (p == panelp)
-		{
-			return p;
-		}
-	}
-	return NULL;
+    for (LLLayoutPanel* p : mPanels)
+    {
+        if (p == panelp)
+        {
+            return p;
+        }
+    }
+    return NULL;
 }
 
 LLLayoutPanel* LLLayoutStack::findEmbeddedPanelByName(const std::string& name) const
 {
-	LLLayoutPanel* result = NULL;
+    LLLayoutPanel* result = NULL;
 
-	BOOST_FOREACH(LLLayoutPanel* p, mPanels)
-	{
-		if (p->getName() == name)
-		{
-			result = p;
-			break;
-		}
-	}
+    for (LLLayoutPanel* p : mPanels)
+    {
+        if (p->getName() == name)
+        {
+            result = p;
+            break;
+        }
+    }
 
-	return result;
+    return result;
 }
 
 void LLLayoutStack::createResizeBar(LLLayoutPanel* panelp)
 {
-	BOOST_FOREACH(LLLayoutPanel* lp, mPanels)
-	{
-		if (lp->mResizeBar == NULL)
-		{
-			LLResizeBar::Params resize_params;
-			resize_params.name("resize");
-			resize_params.resizing_view(lp);
-			resize_params.min_size(lp->getRelevantMinDim());
-			resize_params.side((mOrientation == HORIZONTAL) ? LLResizeBar::RIGHT : LLResizeBar::BOTTOM);
-			resize_params.snapping_enabled(false);
-			LLResizeBar* resize_bar = LLUICtrlFactory::create<LLResizeBar>(resize_params);
-			lp->mResizeBar = resize_bar;
-
-			if (mShowDragHandle)
-			{
-				LLPanel::Params resize_bar_bg_panel_p;
-				resize_bar_bg_panel_p.name = "resize_handle_bg_panel";
-				resize_bar_bg_panel_p.rect = lp->mResizeBar->getLocalRect();
-				resize_bar_bg_panel_p.follows.flags = FOLLOWS_ALL;
-				resize_bar_bg_panel_p.tab_stop = false;
-				resize_bar_bg_panel_p.background_visible = true;
-				resize_bar_bg_panel_p.bg_alpha_color = mDragHandleColor;
-				resize_bar_bg_panel_p.has_border = true;
-				resize_bar_bg_panel_p.border.border_thickness = 1;
-				resize_bar_bg_panel_p.border.highlight_light_color = LLUIColorTable::instance().getColor("ResizebarBorderLight");
-				resize_bar_bg_panel_p.border.shadow_dark_color = LLUIColorTable::instance().getColor("ResizebarBorderDark");
-
-				LLPanel* resize_bar_bg_panel = LLUICtrlFactory::create<LLPanel>(resize_bar_bg_panel_p);
-
-				LLIconCtrl::Params icon_p;
-				icon_p.name = "resize_handle_image";
-				icon_p.rect = lp->mResizeBar->getLocalRect();
-				icon_p.follows.flags = FOLLOWS_ALL;
-				icon_p.image = LLUI::getUIImage(mOrientation == HORIZONTAL ? "Vertical Drag Handle" : "Horizontal Drag Handle");
-				resize_bar_bg_panel->addChild(LLUICtrlFactory::create<LLIconCtrl>(icon_p));
-
-				lp->mResizeBar->addChild(resize_bar_bg_panel);
-			}
-
-			/*if (mShowDragHandle)
-			{
-				LLViewBorder::Params border_params;
-				border_params.border_thickness = 1;
-				border_params.highlight_light_color = LLUIColorTable::instance().getColor("ResizebarBorderLight");
-				border_params.shadow_dark_color = LLUIColorTable::instance().getColor("ResizebarBorderDark");
-
-				addBorder(border_params);
-				setBorderVisible(TRUE);
-
-				LLImagePanel::Params image_panel;
-				mDragHandleImage = LLUI::getUIImage(LLResizeBar::RIGHT == mSide ? "Vertical Drag Handle" : "Horizontal Drag Handle");
-				image_panel.bg_alpha_image = mDragHandleImage;
-				image_panel.background_visible = true;
-				image_panel.horizontal = (LLResizeBar::BOTTOM == mSide);
-				mImagePanel = LLUICtrlFactory::create<LLImagePanel>(image_panel);
-				setImagePanel(mImagePanel);
-			}*/
-
-			//if (mShowDragHandle)
-			//{
-			//	setBackgroundVisible(TRUE);
-			//	setTransparentColor(LLUIColorTable::instance().getColor("ResizebarBody"));
-			//}
-
-			/*if (mShowDragHandle)
-			{
-			S32 image_width = mDragHandleImage->getTextureWidth();
-			S32 image_height = mDragHandleImage->getTextureHeight();
-			const LLRect& panel_rect = getRect();
-			S32 image_left = (panel_rect.getWidth() - image_width) / 2 - 1;
-			S32 image_bottom = (panel_rect.getHeight() - image_height) / 2;
-			mImagePanel->setRect(LLRect(image_left, image_bottom + image_height, image_left + image_width, image_bottom));
-			}*/
-			LLView::addChild(resize_bar, 0);
-		}
-	}
-	// 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);
-	}
+    for (LLLayoutPanel* lp : mPanels)
+    {
+        if (lp->mResizeBar == NULL)
+        {
+            LLResizeBar::Params resize_params;
+            resize_params.name("resize");
+            resize_params.resizing_view(lp);
+            resize_params.min_size(lp->getRelevantMinDim());
+            resize_params.side((mOrientation == HORIZONTAL) ? LLResizeBar::RIGHT : LLResizeBar::BOTTOM);
+            resize_params.snapping_enabled(false);
+            LLResizeBar* resize_bar = LLUICtrlFactory::create<LLResizeBar>(resize_params);
+            lp->mResizeBar = resize_bar;
+
+            if (mShowDragHandle)
+            {
+                LLPanel::Params resize_bar_bg_panel_p;
+                resize_bar_bg_panel_p.name = "resize_handle_bg_panel";
+                resize_bar_bg_panel_p.rect = lp->mResizeBar->getLocalRect();
+                resize_bar_bg_panel_p.follows.flags = FOLLOWS_ALL;
+                resize_bar_bg_panel_p.tab_stop = false;
+                resize_bar_bg_panel_p.background_visible = true;
+                resize_bar_bg_panel_p.bg_alpha_color = mDragHandleColor;
+                resize_bar_bg_panel_p.has_border = true;
+                resize_bar_bg_panel_p.border.border_thickness = 1;
+                resize_bar_bg_panel_p.border.highlight_light_color = LLUIColorTable::instance().getColor("ResizebarBorderLight");
+                resize_bar_bg_panel_p.border.shadow_dark_color = LLUIColorTable::instance().getColor("ResizebarBorderDark");
+
+                LLPanel* resize_bar_bg_panel = LLUICtrlFactory::create<LLPanel>(resize_bar_bg_panel_p);
+
+                LLIconCtrl::Params icon_p;
+                icon_p.name = "resize_handle_image";
+                icon_p.rect = lp->mResizeBar->getLocalRect();
+                icon_p.follows.flags = FOLLOWS_ALL;
+                icon_p.image = LLUI::getUIImage(mOrientation == HORIZONTAL ? "Vertical Drag Handle" : "Horizontal Drag Handle");
+                resize_bar_bg_panel->addChild(LLUICtrlFactory::create<LLIconCtrl>(icon_p));
+
+                lp->mResizeBar->addChild(resize_bar_bg_panel);
+            }
+
+            /*if (mShowDragHandle)
+            {
+                LLViewBorder::Params border_params;
+                border_params.border_thickness = 1;
+                border_params.highlight_light_color = LLUIColorTable::instance().getColor("ResizebarBorderLight");
+                border_params.shadow_dark_color = LLUIColorTable::instance().getColor("ResizebarBorderDark");
+
+                addBorder(border_params);
+                setBorderVisible(TRUE);
+
+                LLImagePanel::Params image_panel;
+                mDragHandleImage = LLUI::getUIImage(LLResizeBar::RIGHT == mSide ? "Vertical Drag Handle" : "Horizontal Drag Handle");
+                image_panel.bg_alpha_image = mDragHandleImage;
+                image_panel.background_visible = true;
+                image_panel.horizontal = (LLResizeBar::BOTTOM == mSide);
+                mImagePanel = LLUICtrlFactory::create<LLImagePanel>(image_panel);
+                setImagePanel(mImagePanel);
+            }*/
+
+            //if (mShowDragHandle)
+            //{
+            //  setBackgroundVisible(TRUE);
+            //  setTransparentColor(LLUIColorTable::instance().getColor("ResizebarBody"));
+            //}
+
+            /*if (mShowDragHandle)
+            {
+            S32 image_width = mDragHandleImage->getTextureWidth();
+            S32 image_height = mDragHandleImage->getTextureHeight();
+            const LLRect& panel_rect = getRect();
+            S32 image_left = (panel_rect.getWidth() - image_width) / 2 - 1;
+            S32 image_bottom = (panel_rect.getHeight() - image_height) / 2;
+            mImagePanel->setRect(LLRect(image_left, image_bottom + image_height, image_left + image_width, image_bottom));
+            }*/
+            LLView::addChild(resize_bar, 0);
+        }
+    }
+    // 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);
+    }
 }
 
 // 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 
+//static
 void LLLayoutStack::updateClass()
 {
-	for (auto& layout : instance_snapshot())
-	{
-		layout.updateLayout();
-		layout.mAnimatedThisFrame = false;
-	}
+    for (auto& layout : instance_snapshot())
+    {
+        layout.updateLayout();
+        layout.mAnimatedThisFrame = false;
+    }
 }
 
 void LLLayoutStack::updateFractionalSizes()
 {
-	F32 total_resizable_dim = 0.f;
+    F32 total_resizable_dim = 0.f;
 
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (panelp->mAutoResize)
-		{
-			total_resizable_dim += llmax(MIN_FRACTIONAL_SIZE, (F32)(panelp->getLayoutDim() - panelp->getRelevantMinDim()));
-		}
-	}
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (panelp->mAutoResize)
+        {
+            total_resizable_dim += llmax(MIN_FRACTIONAL_SIZE, (F32)(panelp->getLayoutDim() - panelp->getRelevantMinDim()));
+        }
+    }
 
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (panelp->mAutoResize)
-		{
-			F32 panel_resizable_dim = llmax(MIN_FRACTIONAL_SIZE, (F32)(panelp->getLayoutDim() - panelp->getRelevantMinDim()));
-			panelp->mFractionalSize = panel_resizable_dim > 0.f 
-				? llclamp(panel_resizable_dim / total_resizable_dim, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE)
-				: MIN_FRACTIONAL_SIZE;
-			llassert(!llisnan(panelp->mFractionalSize));
-		}
-	}
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (panelp->mAutoResize)
+        {
+            F32 panel_resizable_dim = llmax(MIN_FRACTIONAL_SIZE, (F32)(panelp->getLayoutDim() - panelp->getRelevantMinDim()));
+            panelp->mFractionalSize = panel_resizable_dim > 0.f
+                ? llclamp(panel_resizable_dim / total_resizable_dim, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE)
+                : MIN_FRACTIONAL_SIZE;
+            llassert(!llisnan(panelp->mFractionalSize));
+        }
+    }
 
-	normalizeFractionalSizes();
+    normalizeFractionalSizes();
 }
 
 
 void LLLayoutStack::normalizeFractionalSizes()
 {
-	S32 num_auto_resize_panels = 0;
-	F32 total_fractional_size = 0.f;
-	
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (panelp->mAutoResize)
-		{
-			total_fractional_size += panelp->mFractionalSize;
-			num_auto_resize_panels++;
-		}
-	}
-
-	if (total_fractional_size == 0.f)
-	{ // equal distribution
-		BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-		{
-			if (panelp->mAutoResize)
-			{
-				panelp->mFractionalSize = MAX_FRACTIONAL_SIZE / (F32)num_auto_resize_panels;
-			}
-		}
-	}
-	else
-	{ // renormalize
-		BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-		{
-			if (panelp->mAutoResize)
-			{
-				panelp->mFractionalSize /= total_fractional_size;
-			}
-		}
-	}
+    S32 num_auto_resize_panels = 0;
+    F32 total_fractional_size = 0.f;
+
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (panelp->mAutoResize)
+        {
+            total_fractional_size += panelp->mFractionalSize;
+            num_auto_resize_panels++;
+        }
+    }
+
+    if (total_fractional_size == 0.f)
+    { // equal distribution
+        for (LLLayoutPanel* panelp : mPanels)
+        {
+            if (panelp->mAutoResize)
+            {
+                panelp->mFractionalSize = MAX_FRACTIONAL_SIZE / (F32)num_auto_resize_panels;
+            }
+        }
+    }
+    else
+    { // renormalize
+        for (LLLayoutPanel* panelp : mPanels)
+        {
+            if (panelp->mAutoResize)
+            {
+                panelp->mFractionalSize /= total_fractional_size;
+            }
+        }
+    }
 }
 
 bool LLLayoutStack::animatePanels()
 {
-	bool continue_animating = false;
-	
-	//
-	// animate visibility
-	//
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (panelp->getVisible())
-		{
-			if (mAnimate && panelp->mVisibleAmt < 1.f)
-			{
-				if (!mAnimatedThisFrame)
-				{
-					panelp->mVisibleAmt = lerp(panelp->mVisibleAmt, 1.f, LLSmoothInterpolation::getInterpolant(mOpenTimeConstant));
-					if (panelp->mVisibleAmt > 0.99f)
-					{
-						panelp->mVisibleAmt = 1.f;
-					}
-				}
-				
-				mAnimatedThisFrame = true;
-				continue_animating = true;
-			}
-			else
-			{
-				if (panelp->mVisibleAmt != 1.f)
-				{
-					panelp->mVisibleAmt = 1.f;
-					mAnimatedThisFrame = true;
-				}
-			}
-		}
-		else // not visible
-		{
-			if (mAnimate && panelp->mVisibleAmt > 0.f)
-			{
-				if (!mAnimatedThisFrame)
-				{
-					panelp->mVisibleAmt = lerp(panelp->mVisibleAmt, 0.f, LLSmoothInterpolation::getInterpolant(mCloseTimeConstant));
-					if (panelp->mVisibleAmt < 0.001f)
-					{
-						panelp->mVisibleAmt = 0.f;
-					}
-				}
-
-				continue_animating = true;
-				mAnimatedThisFrame = true;
-			}
-			else
-			{
-				if (panelp->mVisibleAmt != 0.f)
-				{
-					panelp->mVisibleAmt = 0.f;
-					mAnimatedThisFrame = true;
-				}
-			}
-		}
-
-		F32 collapse_state = panelp->mCollapsed ? 1.f : 0.f;
-		if (panelp->mCollapseAmt != collapse_state)
-		{
-			if (mAnimate)
-			{
-				if (!mAnimatedThisFrame)
-				{
-					panelp->mCollapseAmt = lerp(panelp->mCollapseAmt, collapse_state, LLSmoothInterpolation::getInterpolant(mCloseTimeConstant));
-				}
-			
-				if (llabs(panelp->mCollapseAmt - collapse_state) < 0.001f)
-				{
-					panelp->mCollapseAmt = collapse_state;
-				}
-
-				mAnimatedThisFrame = true;
-				continue_animating = true;
-			}
-			else
-			{
-				panelp->mCollapseAmt = collapse_state;
-				mAnimatedThisFrame = true;
-			}
-		}
-	}
-
-	if (mAnimatedThisFrame) mNeedsLayout = true;
-	return continue_animating;
+    bool continue_animating = false;
+
+    //
+    // animate visibility
+    //
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (panelp->getVisible())
+        {
+            if (mAnimate && panelp->mVisibleAmt < 1.f)
+            {
+                if (!mAnimatedThisFrame)
+                {
+                    panelp->mVisibleAmt = lerp(panelp->mVisibleAmt, 1.f, LLSmoothInterpolation::getInterpolant(mOpenTimeConstant));
+                    if (panelp->mVisibleAmt > 0.99f)
+                    {
+                        panelp->mVisibleAmt = 1.f;
+                    }
+                }
+
+                mAnimatedThisFrame = true;
+                continue_animating = true;
+            }
+            else
+            {
+                if (panelp->mVisibleAmt != 1.f)
+                {
+                    panelp->mVisibleAmt = 1.f;
+                    mAnimatedThisFrame = true;
+                }
+            }
+        }
+        else // not visible
+        {
+            if (mAnimate && panelp->mVisibleAmt > 0.f)
+            {
+                if (!mAnimatedThisFrame)
+                {
+                    panelp->mVisibleAmt = lerp(panelp->mVisibleAmt, 0.f, LLSmoothInterpolation::getInterpolant(mCloseTimeConstant));
+                    if (panelp->mVisibleAmt < 0.001f)
+                    {
+                        panelp->mVisibleAmt = 0.f;
+                    }
+                }
+
+                continue_animating = true;
+                mAnimatedThisFrame = true;
+            }
+            else
+            {
+                if (panelp->mVisibleAmt != 0.f)
+                {
+                    panelp->mVisibleAmt = 0.f;
+                    mAnimatedThisFrame = true;
+                }
+            }
+        }
+
+        F32 collapse_state = panelp->mCollapsed ? 1.f : 0.f;
+        if (panelp->mCollapseAmt != collapse_state)
+        {
+            if (mAnimate)
+            {
+                if (!mAnimatedThisFrame)
+                {
+                    panelp->mCollapseAmt = lerp(panelp->mCollapseAmt, collapse_state, LLSmoothInterpolation::getInterpolant(mCloseTimeConstant));
+                }
+
+                if (llabs(panelp->mCollapseAmt - collapse_state) < 0.001f)
+                {
+                    panelp->mCollapseAmt = collapse_state;
+                }
+
+                mAnimatedThisFrame = true;
+                continue_animating = true;
+            }
+            else
+            {
+                panelp->mCollapseAmt = collapse_state;
+                mAnimatedThisFrame = true;
+            }
+        }
+    }
+
+    if (mAnimatedThisFrame) mNeedsLayout = true;
+    return continue_animating;
 }
 
 void LLLayoutStack::updatePanelRect( LLLayoutPanel* resized_panel, const LLRect& new_rect )
 {
-	S32 new_dim = (mOrientation == HORIZONTAL)
-					? new_rect.getWidth()
-					: new_rect.getHeight();
-	S32 delta_panel_dim = new_dim - resized_panel->getVisibleDim();
-	if (delta_panel_dim == 0) return;
-
-	F32 total_visible_fraction = 0.f;
-	F32 delta_auto_resize_headroom = 0.f;
-	F32 old_auto_resize_headroom = 0.f;
-
-	LLLayoutPanel* other_resize_panel = NULL;
-	LLLayoutPanel* following_panel = NULL;
-
-	BOOST_REVERSE_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (panelp->mAutoResize)
-		{
-			old_auto_resize_headroom += (F32)(panelp->mTargetDim - panelp->getRelevantMinDim());
-			if (panelp->getVisible() && !panelp->mCollapsed)
-			{
-				total_visible_fraction += panelp->mFractionalSize;
-			}
-		}
-
-		if (panelp == resized_panel)
-		{
-			other_resize_panel = following_panel;
-		}
-
-		if (panelp->getVisible() && !panelp->mCollapsed)
-		{
-			following_panel = panelp;
-		}
-	}
-
-	if (resized_panel->mAutoResize)
-	{
-		if (!other_resize_panel || !other_resize_panel->mAutoResize)
-		{
-			delta_auto_resize_headroom += delta_panel_dim;	
-		}
-	}
-	else 
-	{
-		if (!other_resize_panel || other_resize_panel->mAutoResize)
-		{
-			delta_auto_resize_headroom -= delta_panel_dim;
-		}
-	}
-
-	F32 fraction_given_up = 0.f;
-	F32 fraction_remaining = 1.f;
-	F32 new_auto_resize_headroom = old_auto_resize_headroom + delta_auto_resize_headroom;
-
-	enum
-	{
-		BEFORE_RESIZED_PANEL,
-		RESIZED_PANEL,
-		NEXT_PANEL,
-		AFTER_RESIZED_PANEL
-	} which_panel = BEFORE_RESIZED_PANEL;
-
-	BOOST_FOREACH(LLLayoutPanel* panelp, mPanels)
-	{
-		if (!panelp->getVisible() || panelp->mCollapsed) 
-		{
-			if (panelp->mAutoResize) 
-			{
-				fraction_remaining -= panelp->mFractionalSize;
-			}
-			continue;
-		}
-
-		if (panelp == resized_panel)
-		{
-			which_panel = RESIZED_PANEL;
-		}
-
-		switch(which_panel)
-		{
-		case BEFORE_RESIZED_PANEL:
-			if (panelp->mAutoResize)
-			{	// freeze current size as fraction of overall auto_resize space
-				F32 fractional_adjustment_factor = new_auto_resize_headroom == 0.f
-													? 1.f
-													: old_auto_resize_headroom / new_auto_resize_headroom;
-				F32 new_fractional_size = llclamp(panelp->mFractionalSize * fractional_adjustment_factor,
-													MIN_FRACTIONAL_SIZE,
-													MAX_FRACTIONAL_SIZE);
-				fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
-				fraction_remaining -= panelp->mFractionalSize;
-				panelp->mFractionalSize = new_fractional_size;
-				llassert(!llisnan(panelp->mFractionalSize));
-			}
-			else
-			{
-				// leave non auto-resize panels alone
-			}
-			break;
-		case RESIZED_PANEL:
-			if (panelp->mAutoResize)
-			{	// freeze new size as fraction
-				F32 new_fractional_size = (new_auto_resize_headroom == 0.f)
-					? MAX_FRACTIONAL_SIZE
-					: llclamp(total_visible_fraction * (F32)(new_dim - panelp->getRelevantMinDim()) / new_auto_resize_headroom, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE);
-				fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
-				fraction_remaining -= panelp->mFractionalSize;
-				panelp->mFractionalSize = new_fractional_size;
-				llassert(!llisnan(panelp->mFractionalSize));
-			}
-			else
-			{	// freeze new size as original size
-				panelp->mTargetDim = new_dim;
-			}
-			which_panel = NEXT_PANEL;
-			break;
-		case NEXT_PANEL:
-			if (panelp->mAutoResize)
-			{
-				fraction_remaining -= panelp->mFractionalSize;
-				if (resized_panel->mAutoResize)
-				{
-					panelp->mFractionalSize = llclamp(panelp->mFractionalSize + fraction_given_up, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE);
-					fraction_given_up = 0.f;
-				}
-				else
-				{
-					if (new_auto_resize_headroom < 1.f)
-					{
-						new_auto_resize_headroom = 1.f;
-					}
-
-					F32 new_fractional_size = llclamp(total_visible_fraction * (F32)(panelp->mTargetDim - panelp->getRelevantMinDim() + delta_auto_resize_headroom) 
-														/ new_auto_resize_headroom,
-													MIN_FRACTIONAL_SIZE,
-													MAX_FRACTIONAL_SIZE);
-					fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
-					panelp->mFractionalSize = new_fractional_size;
-				}
-			}
-			else
-			{
-				panelp->mTargetDim -= delta_panel_dim;
-			}
-			which_panel = AFTER_RESIZED_PANEL;
-			break;
-		case AFTER_RESIZED_PANEL:
-			if (panelp->mAutoResize && fraction_given_up != 0.f)
-			{
-				panelp->mFractionalSize = llclamp(panelp->mFractionalSize + (panelp->mFractionalSize / fraction_remaining) * fraction_given_up,
-												MIN_FRACTIONAL_SIZE,
-												MAX_FRACTIONAL_SIZE);
-			}
-		default:
-			break;
-		}
-	}
-	updateLayout();
-	//normalizeFractionalSizes();
+    S32 new_dim = (mOrientation == HORIZONTAL)
+                    ? new_rect.getWidth()
+                    : new_rect.getHeight();
+    S32 delta_panel_dim = new_dim - resized_panel->getVisibleDim();
+    if (delta_panel_dim == 0) return;
+
+    F32 total_visible_fraction = 0.f;
+    F32 delta_auto_resize_headroom = 0.f;
+    F32 old_auto_resize_headroom = 0.f;
+
+    LLLayoutPanel* other_resize_panel = NULL;
+    LLLayoutPanel* following_panel = NULL;
+
+    BOOST_REVERSE_FOREACH(LLLayoutPanel* panelp, mPanels) // Should replace this when C++20 reverse view adaptor becomes available...
+    {
+        if (panelp->mAutoResize)
+        {
+            old_auto_resize_headroom += (F32)(panelp->mTargetDim - panelp->getRelevantMinDim());
+            if (panelp->getVisible() && !panelp->mCollapsed)
+            {
+                total_visible_fraction += panelp->mFractionalSize;
+            }
+        }
+
+        if (panelp == resized_panel)
+        {
+            other_resize_panel = following_panel;
+        }
+
+        if (panelp->getVisible() && !panelp->mCollapsed)
+        {
+            following_panel = panelp;
+        }
+    }
+
+    if (resized_panel->mAutoResize)
+    {
+        if (!other_resize_panel || !other_resize_panel->mAutoResize)
+        {
+            delta_auto_resize_headroom += delta_panel_dim;
+        }
+    }
+    else
+    {
+        if (!other_resize_panel || other_resize_panel->mAutoResize)
+        {
+            delta_auto_resize_headroom -= delta_panel_dim;
+        }
+    }
+
+    F32 fraction_given_up = 0.f;
+    F32 fraction_remaining = 1.f;
+    F32 new_auto_resize_headroom = old_auto_resize_headroom + delta_auto_resize_headroom;
+
+    enum
+    {
+        BEFORE_RESIZED_PANEL,
+        RESIZED_PANEL,
+        NEXT_PANEL,
+        AFTER_RESIZED_PANEL
+    } which_panel = BEFORE_RESIZED_PANEL;
+
+    for (LLLayoutPanel* panelp : mPanels)
+    {
+        if (!panelp->getVisible() || panelp->mCollapsed)
+        {
+            if (panelp->mAutoResize)
+            {
+                fraction_remaining -= panelp->mFractionalSize;
+            }
+            continue;
+        }
+
+        if (panelp == resized_panel)
+        {
+            which_panel = RESIZED_PANEL;
+        }
+
+        switch(which_panel)
+        {
+        case BEFORE_RESIZED_PANEL:
+            if (panelp->mAutoResize)
+            {   // freeze current size as fraction of overall auto_resize space
+                F32 fractional_adjustment_factor = new_auto_resize_headroom == 0.f
+                                                    ? 1.f
+                                                    : old_auto_resize_headroom / new_auto_resize_headroom;
+                F32 new_fractional_size = llclamp(panelp->mFractionalSize * fractional_adjustment_factor,
+                                                    MIN_FRACTIONAL_SIZE,
+                                                    MAX_FRACTIONAL_SIZE);
+                fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
+                fraction_remaining -= panelp->mFractionalSize;
+                panelp->mFractionalSize = new_fractional_size;
+                llassert(!llisnan(panelp->mFractionalSize));
+            }
+            else
+            {
+                // leave non auto-resize panels alone
+            }
+            break;
+        case RESIZED_PANEL:
+            if (panelp->mAutoResize)
+            {   // freeze new size as fraction
+                F32 new_fractional_size = (new_auto_resize_headroom == 0.f)
+                    ? MAX_FRACTIONAL_SIZE
+                    : llclamp(total_visible_fraction * (F32)(new_dim - panelp->getRelevantMinDim()) / new_auto_resize_headroom, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE);
+                fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
+                fraction_remaining -= panelp->mFractionalSize;
+                panelp->mFractionalSize = new_fractional_size;
+                llassert(!llisnan(panelp->mFractionalSize));
+            }
+            else
+            {   // freeze new size as original size
+                panelp->mTargetDim = new_dim;
+            }
+            which_panel = NEXT_PANEL;
+            break;
+        case NEXT_PANEL:
+            if (panelp->mAutoResize)
+            {
+                fraction_remaining -= panelp->mFractionalSize;
+                if (resized_panel->mAutoResize)
+                {
+                    panelp->mFractionalSize = llclamp(panelp->mFractionalSize + fraction_given_up, MIN_FRACTIONAL_SIZE, MAX_FRACTIONAL_SIZE);
+                    fraction_given_up = 0.f;
+                }
+                else
+                {
+                    if (new_auto_resize_headroom < 1.f)
+                    {
+                        new_auto_resize_headroom = 1.f;
+                    }
+
+                    F32 new_fractional_size = llclamp(total_visible_fraction * (F32)(panelp->mTargetDim - panelp->getRelevantMinDim() + delta_auto_resize_headroom)
+                                                        / new_auto_resize_headroom,
+                                                    MIN_FRACTIONAL_SIZE,
+                                                    MAX_FRACTIONAL_SIZE);
+                    fraction_given_up -= new_fractional_size - panelp->mFractionalSize;
+                    panelp->mFractionalSize = new_fractional_size;
+                }
+            }
+            else
+            {
+                panelp->mTargetDim -= delta_panel_dim;
+            }
+            which_panel = AFTER_RESIZED_PANEL;
+            break;
+        case AFTER_RESIZED_PANEL:
+            if (panelp->mAutoResize && fraction_given_up != 0.f)
+            {
+                panelp->mFractionalSize = llclamp(panelp->mFractionalSize + (panelp->mFractionalSize / fraction_remaining) * fraction_given_up,
+                                                MIN_FRACTIONAL_SIZE,
+                                                MAX_FRACTIONAL_SIZE);
+            }
+            break;
+        default:
+            break;
+        }
+    }
+    updateLayout();
+    //normalizeFractionalSizes();
 }
 
 void LLLayoutStack::reshape(S32 width, S32 height, BOOL called_from_parent)
 {
-	mNeedsLayout = true;
-	LLView::reshape(width, height, called_from_parent);
+    mNeedsLayout = true;
+    LLView::reshape(width, height, called_from_parent);
 }
 
 void LLLayoutStack::updateResizeBarLimits()
 {
-	LLLayoutPanel* previous_visible_panelp = NULL;
-	BOOST_REVERSE_FOREACH(LLLayoutPanel* visible_panelp, mPanels)
-	{
-		if (!visible_panelp->getVisible() || visible_panelp->mCollapsed)
-		{
-			visible_panelp->mResizeBar->setVisible(FALSE);
-			continue;
-		}
-
-		// toggle resize bars based on panel visibility, resizability, etc
-		if (previous_visible_panelp
-			&& (visible_panelp->mUserResize || previous_visible_panelp->mUserResize)				// one of the pair is user resizable
-			&& (visible_panelp->mAutoResize || visible_panelp->mUserResize)							// current panel is resizable
-			&& (previous_visible_panelp->mAutoResize || previous_visible_panelp->mUserResize))		// previous panel is resizable
-		{
-			visible_panelp->mResizeBar->setVisible(TRUE);
-			S32 previous_panel_headroom = previous_visible_panelp->getVisibleDim() - previous_visible_panelp->getRelevantMinDim();
-			visible_panelp->mResizeBar->setResizeLimits(visible_panelp->getRelevantMinDim(), 
-														visible_panelp->getVisibleDim() + previous_panel_headroom);
-		}
-		else
-		{
-			visible_panelp->mResizeBar->setVisible(FALSE);
-		}
-
-		previous_visible_panelp = visible_panelp;
-	}
+    LLLayoutPanel* previous_visible_panelp{ nullptr };
+    BOOST_REVERSE_FOREACH(LLLayoutPanel* visible_panelp, mPanels) // Should replace this when C++20 reverse view adaptor becomes available...
+    {
+        if (!visible_panelp->getVisible() || visible_panelp->mCollapsed)
+        {
+            visible_panelp->mResizeBar->setVisible(FALSE);
+            continue;
+        }
+
+        // toggle resize bars based on panel visibility, resizability, etc
+        if (previous_visible_panelp
+            && (visible_panelp->mUserResize || previous_visible_panelp->mUserResize)                // one of the pair is user resizable
+            && (visible_panelp->mAutoResize || visible_panelp->mUserResize)                         // current panel is resizable
+            && (previous_visible_panelp->mAutoResize || previous_visible_panelp->mUserResize))      // previous panel is resizable
+        {
+            visible_panelp->mResizeBar->setVisible(TRUE);
+            S32 previous_panel_headroom = previous_visible_panelp->getVisibleDim() - previous_visible_panelp->getRelevantMinDim();
+            visible_panelp->mResizeBar->setResizeLimits(visible_panelp->getRelevantMinDim(),
+                                                        visible_panelp->getVisibleDim() + previous_panel_headroom);
+        }
+        else
+        {
+            visible_panelp->mResizeBar->setVisible(FALSE);
+        }
+
+        previous_visible_panelp = visible_panelp;
+    }
 }