EXP-1424 FIX Floaters open on top of one another in default position with no offset

EXP-1412 FIX Additional Inventory windows are opened directly on top of each after opening additional inventory windows and closing the first time
also made sidepanel floaters reuse the existing instances, saving state

3 files changed, 22 insertions, 4 deletions

diff --git a/indra/llui/llfloater.cpp b/indra/llui/llfloater.cpp
index 3085921e04..29d05b8002 100644
--- a/indra/llui/llfloater.cpp
+++ b/indra/llui/llfloater.cpp
@@ -165,6 +165,7 @@ LLFloater::Params::Params()
 :	title("title"),
 	short_title("short_title"),
 	single_instance("single_instance", false),
+	reuse_instance("reuse_instance", false),
 	can_resize("can_resize", false),
 	can_minimize("can_minimize", true),
 	can_close("can_close", true),
@@ -239,6 +240,7 @@ LLFloater::LLFloater(const LLSD& key, const LLFloater::Params& p)
 	mTitle(p.title),
 	mShortTitle(p.short_title),
 	mSingleInstance(p.single_instance),
+	mReuseInstance(p.reuse_instance.isProvided() ? p.reuse_instance : p.single_instance), // reuse single-instance floaters by default
 	mKey(key),
 	mCanTearOff(p.can_tear_off),
 	mCanMinimize(p.can_minimize),
@@ -776,12 +778,19 @@ void LLFloater::closeFloater(bool app_quitting)
 			else
 			{
 				setVisible(FALSE);
+				if (!mReuseInstance)
+				{
+					destroy();
+				}
 			}
 		}
 		else
 		{
 			setVisible(FALSE); // hide before destroying (so handleVisibilityChange() gets called)
-			destroy();
+			if (!mReuseInstance)
+			{
+				destroy();
+			}
 		}
 	}
 }
@@ -861,9 +870,15 @@ bool LLFloater::applyRectControl()
 {
 	bool saved_rect = false;
 
-	// If we have a saved rect, use it
-	if (mRectControl.size() > 1)
+	if (LLFloaterReg::getLastFloaterInGroup(mInstanceName))
+	{
+		// other floaters in our group, position ourselves relative to them and don't save the rect
+		mRectControl.clear();
+		mOpenPositioning = LLFloaterEnums::OPEN_POSITIONING_CASCADING;
+	}
+	else if (mRectControl.size() > 1)
 	{
+		// If we have a saved rect, use it
 		const LLRect& rect = getControlGroup()->getRect(mRectControl);
 		saved_rect = rect.notEmpty();
 		if (saved_rect)
@@ -2949,6 +2964,7 @@ void LLFloater::initFromParams(const LLFloater::Params& p)
 	mHeaderHeight = p.header_height;
 	mLegacyHeaderHeight = p.legacy_header_height;
 	mSingleInstance = p.single_instance;
+	mReuseInstance = p.reuse_instance.isProvided() ? p.reuse_instance : p.single_instance;
 
 	mOpenPositioning = p.open_positioning;
 	mSpecifiedLeft = p.specified_left;
@@ -3230,7 +3246,6 @@ void LLFloater::stackWith(LLFloater& other)
 
 	next_rect.setLeftTopAndSize(next_rect.mLeft, next_rect.mTop, getRect().getWidth(), getRect().getHeight());
 	
-	mRectControl.clear(); // don't save rect of stacked floaters
 	setShape(next_rect);
 }
 
diff --git a/indra/llui/llfloater.h b/indra/llui/llfloater.h
index f610b04e35..f384e64e53 100644
--- a/indra/llui/llfloater.h
+++ b/indra/llui/llfloater.h
@@ -120,6 +120,7 @@ public:
 								short_title;
 		
 		Optional<bool>			single_instance,
+								reuse_instance,
 								can_resize,
 								can_minimize,
 								can_close,
@@ -409,6 +410,7 @@ private:
 	LLUIString		mShortTitle;
 	
 	BOOL			mSingleInstance;	// TRUE if there is only ever one instance of the floater
+	bool			mReuseInstance;		// true if we want to hide the floater when we close it instead of destroying it
 	std::string		mInstanceName;		// Store the instance name so we can remove ourselves from the list
 	
 	BOOL			mCanTearOff;
diff --git a/indra/llui/llfloaterreg.cpp b/indra/llui/llfloaterreg.cpp
index df3cff9968..e144b68f5e 100644
--- a/indra/llui/llfloaterreg.cpp
+++ b/indra/llui/llfloaterreg.cpp
@@ -167,6 +167,7 @@ LLFloater* LLFloaterReg::getInstance(const std::string& name, const LLSD& key)
 				res->setInstanceName(name);
 
 				LLFloater *last_floater = (list.empty() ? NULL : list.back());
+
 				res->applyControlsAndPosition(last_floater);
 
 				gFloaterView->adjustToFitScreen(res, false);