diff -r 000000000000 -r a41df078684a kernel/eka/euser/us_regn.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/euser/us_regn.cpp	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,1271 @@
+// Copyright (c) 1994-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the License "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+// e32\euser\us_regn.cpp
+// 
+//
+
+
+#include "us_std.h"
+
+NONSHARABLE_CLASS(TRectKey) : public TKey
+	{
+public:
+	TRectKey(const TRect *aRectList,const TPoint &aOffset);
+	virtual TInt Compare(TInt aLeft,TInt aRight) const;
+private:
+	const TRect *iRectList;
+	TBool iDown;
+	TBool iRight;
+	};
+
+NONSHARABLE_CLASS(TRectSwap) : public TSwap
+	{
+public:
+	inline TRectSwap(TRect *aRectList);
+	virtual void Swap(TInt aLeft,TInt aRight) const;
+private:
+	TRect *iRectList;
+	};
+
+inline TRectSwap::TRectSwap(TRect *aRectList)
+	{iRectList=aRectList;}
+
+enum {ERegionBufSize=8};
+
+EXPORT_C TRegion::TRegion(TInt aAllocedRects)
+//
+// Constructor.
+//
+	: iCount(0),iError(EFalse),iAllocedRects(aAllocedRects)
+	{}
+
+
+
+
+EXPORT_C TBool TRegion::IsEmpty() const
+/**
+Tests whether the region is empty.
+
+@return True, if the region is empty and its error flag is unset;
+        false, otherwise.
+*/
+	{
+
+	return(iCount==0 && !iError);
+	}
+
+
+
+
+#ifndef __REGIONS_MACHINE_CODED__
+EXPORT_C TRect TRegion::BoundingRect() const
+/**
+Gets the minimal rectangle that bounds the entire region.
+
+@return The region's minimal bounding rectangle.
+*/
+	{
+
+	TRect bounds;
+    const TRect *pRect;
+	const TRect *pEnd;
+	if (iCount>0)
+		{
+		pRect=RectangleList();
+		bounds=(*pRect++);
+		for (pEnd=pRect+(iCount-1);pRect<pEnd;pRect++)
+			{
+			if (pRect->iTl.iX<bounds.iTl.iX)
+				bounds.iTl.iX=pRect->iTl.iX;
+			if (pRect->iTl.iY<bounds.iTl.iY)
+				bounds.iTl.iY=pRect->iTl.iY;
+			if (pRect->iBr.iX>bounds.iBr.iX)
+				bounds.iBr.iX=pRect->iBr.iX;
+			if (pRect->iBr.iY>bounds.iBr.iY)
+				bounds.iBr.iY=pRect->iBr.iY;
+			}
+		}
+	return(bounds);
+	}	
+#endif
+
+
+
+
+EXPORT_C const TRect &TRegion::operator[](TInt aIndex) const
+/**
+Gets a rectangle from the region.
+
+@param aIndex The index of a rectangle within the region's array of rectangles. 
+              Indexes are relative to zero.
+              
+@return The specified rectangle.              
+              
+@panic USER 81, if aIndex is greater than or equal to the number 
+                of rectangles in the region.
+*/
+	{
+
+	__ASSERT_ALWAYS((TUint)aIndex<(TUint)iCount,Panic(ETRegionOutOfRange));
+    return(*(RectangleList()+aIndex));
+    }
+
+
+
+
+#ifndef __REGIONS_MACHINE_CODED__
+EXPORT_C TBool TRegion::IsContainedBy(const TRect &aRect) const
+/**
+Tests whether the region is fully enclosed within the specified rectangle.
+
+@param aRect The specified rectangle.
+ 
+@return True, if the region is fully enclosed within the rectangle (their sides 
+        may touch); false, otherwise.
+*/
+	{
+
+    const TRect *pRect1;
+    const TRect *pEnd1;
+	for (pRect1=RectangleList(),pEnd1=pRect1+iCount;pRect1<pEnd1;pRect1++)
+		{
+		if (pRect1->iTl.iX<aRect.iTl.iX || pRect1->iBr.iX>aRect.iBr.iX || pRect1->iTl.iY<aRect.iTl.iY || pRect1->iBr.iY>aRect.iBr.iY)
+			return(EFalse);
+		}
+	return(ETrue);
+	}
+
+
+
+
+EXPORT_C TBool TRegion::Intersects(const TRect &aRect) const
+/**
+Tests whether where there is any intersection between this region and the specified rectangle.
+
+@param aRect The specified rectangle.
+ 
+@return True, if there is an intersection; false, otherwise.
+*/
+	{
+
+    const TRect *pRect1;
+    const TRect *pEnd1;
+	for (pRect1=RectangleList(),pEnd1=pRect1+iCount;pRect1<pEnd1;pRect1++)
+		{
+		if (aRect.Intersects(*pRect1))
+			return ETrue;
+		}
+	return EFalse;
+	}
+
+
+
+
+EXPORT_C void TRegion::Copy(const TRegion &aRegion)
+/**
+Copies another region to this region.
+
+The state of the specified region's error flag is also copied.
+
+@param aRegion The region to be copied.
+*/
+	{
+	if (aRegion.iError)
+		{
+		ForceError();
+		}
+	else
+		{
+		const TInt count = aRegion.iCount;
+		if (count == 0)
+			{ // release memory
+			Clear();
+			}
+		else
+			{
+			if (iError)
+				{
+				Clear();
+				}
+
+			if (SetListSize(count))
+				{
+				iCount = count;
+				Mem::Copy(RectangleListW(), aRegion.RectangleList(), sizeof(TRect)*count);
+				}
+			}
+		}
+	}
+
+
+
+
+EXPORT_C void TRegion::Offset(const TPoint &aOffset)
+/**
+Moves the region by adding a TPoint offset to the co-ordinates of its corners.
+	
+The size of the region is not changed.
+	
+@param aOffset The offset by which the region is moved. The region is moved 
+               horizontally by aOffset.iX pixels and vertically by aOffset.iY pixels.
+*/
+ 	{
+
+	TRect *pR=RectangleListW();
+	const TRect *pE=pR+iCount;
+	while (pR<pE)
+		{
+		pR->Move(aOffset);
+		pR++;
+		}
+	}
+
+
+
+
+EXPORT_C void TRegion::Offset(TInt aXoffset,TInt aYoffset)
+/**
+Moves the region by adding X and Y offsets to the co-ordinates of its corners.
+	
+The size of the region is not changed.
+	
+@param aXoffset The number of pixels by which to move the region horizontally. 
+                If negative, the region moves leftwards. 
+@param aYoffset The number of pixels by which to move the region vertically. 
+                If negative, the region moves upwards.
+*/
+	{
+
+	Offset(TPoint(aXoffset,aYoffset));
+	}
+
+
+
+
+EXPORT_C TBool TRegion::Contains(const TPoint &aPoint) const
+/**
+Tests whether a point is located within the region.
+
+If the point is located on the top or left hand side of any rectangle in the 
+region, it is considered to be within that rectangle and within the region. 
+
+If the point is located on the right hand side or bottom of a rectangle, it 
+is considered to be outside that rectangle, and may be outside the region.
+
+@param aPoint The specified point. 
+
+@return True, if the point is within the region; false, otherwise.
+*/
+	{
+	const TRect *pR=RectangleList();
+	const TRect *pE=pR+iCount;
+	while (pR<pE)
+		{
+		if (pR->Contains(aPoint))
+			return(ETrue);
+		pR++;
+		}
+	return(EFalse);
+	}
+
+
+
+
+EXPORT_C void TRegion::SubRect(const TRect &aRect,TRegion *aSubtractedRegion)
+/**
+Removes a rectangle from this region.
+
+If there is no intersection between the rectangle and this region, then this 
+region is unaffected. 
+
+@param aRect             The rectangular area to be removed from this region. 
+@param aSubtractedRegion A pointer to a region. If this is supplied, the
+                         removed rectangle is added to it. By default this
+                         pointer is NULL.
+*/
+	{
+	if (aRect.IsEmpty())
+		return;
+	TRect *prect=RectangleListW();
+	TInt limit=iCount;
+	for (TInt index=0;index<limit;)
+		{
+		if (prect->iBr.iX>aRect.iTl.iX && prect->iBr.iY>aRect.iTl.iY && prect->iTl.iX<aRect.iBr.iX && prect->iTl.iY<aRect.iBr.iY)
+			{
+			TRect rect(*prect);
+			TRect inter(aRect);
+			inter.Intersection(*prect);
+			DeleteRect(prect);
+			if (inter.iBr.iY!=rect.iBr.iY)
+				AppendRect(TRect(rect.iTl.iX,inter.iBr.iY,rect.iBr.iX,rect.iBr.iY));
+			if (inter.iTl.iY!=rect.iTl.iY)
+				AppendRect(TRect(rect.iTl.iX,rect.iTl.iY,rect.iBr.iX,inter.iTl.iY));
+			if (inter.iBr.iX!=rect.iBr.iX)
+				AppendRect(TRect(inter.iBr.iX,inter.iTl.iY,rect.iBr.iX,inter.iBr.iY));
+			if (inter.iTl.iX!=rect.iTl.iX)
+				AppendRect(TRect(rect.iTl.iX,inter.iTl.iY,inter.iTl.iX,inter.iBr.iY));
+			if (iError)
+				break;
+			if (aSubtractedRegion!=NULL)
+				aSubtractedRegion->AddRect(inter);
+			prect=RectangleListW()+index;		// List might have been re-allocated so re-get the pointer
+			limit--;
+			}
+		else
+			{
+			index++;
+			prect++;
+			}
+		}
+	}
+
+#endif
+
+
+
+
+/**
+Merges a rectangle with this region.
+
+If requested it looks for a rectangle in the region that covers the new rectangle, if found method returns immediately.
+Otherwise, or if an enclosing rectangle is not found, the new aRect is subtracted from all intersecting rectangles,
+and then aRect is appended to the region.
+
+@param aRect             The rectangular area to be added to this region.
+@param aCovered          Whether to look for a rectangle in the region that covers the new aRect.
+*/
+void TRegion::MergeRect(const TRect &aRect, TBool aCovered)
+	{
+	TRect *prect=RectangleListW();
+	TInt limit=iCount;
+	TInt index=0;
+
+	while (aCovered && (index < limit) )
+		{
+		if (prect->iBr.iX<=aRect.iTl.iX || prect->iBr.iY<=aRect.iTl.iY || prect->iTl.iX>=aRect.iBr.iX || prect->iTl.iY>=aRect.iBr.iY)
+			{
+			index++;
+			prect++;
+			}
+		else
+			{
+			if (prect->iBr.iX>=aRect.iBr.iX && prect->iBr.iY>=aRect.iBr.iY && prect->iTl.iX<=aRect.iTl.iX && prect->iTl.iY<=aRect.iTl.iY)
+				{ // region rectangle covers new aRect
+				return;
+				}
+			break; // let the 2nd loop deal with this intersection
+			}
+		}
+
+	while (index < limit)
+		{
+		if (prect->iBr.iX<=aRect.iTl.iX || prect->iBr.iY<=aRect.iTl.iY || prect->iTl.iX>=aRect.iBr.iX || prect->iTl.iY>=aRect.iBr.iY)
+			{
+			index++;
+			prect++;
+			}
+		else
+			{
+			TRect rect(*prect);
+			TRect inter(aRect);
+			inter.Intersection(*prect);
+			DeleteRect(prect);
+			if (inter.iBr.iY!=rect.iBr.iY)
+				AppendRect(TRect(rect.iTl.iX,inter.iBr.iY,rect.iBr.iX,rect.iBr.iY));
+			if (inter.iTl.iY!=rect.iTl.iY)
+				AppendRect(TRect(rect.iTl.iX,rect.iTl.iY,rect.iBr.iX,inter.iTl.iY));
+			if (inter.iBr.iX!=rect.iBr.iX)
+				AppendRect(TRect(inter.iBr.iX,inter.iTl.iY,rect.iBr.iX,inter.iBr.iY));
+			if (inter.iTl.iX!=rect.iTl.iX)
+				AppendRect(TRect(rect.iTl.iX,inter.iTl.iY,inter.iTl.iX,inter.iBr.iY));
+			if (iError)
+				return;
+			prect=RectangleListW()+index;		// List might have been re-allocated so re-get the pointer
+			limit--;
+			}
+		}
+	AppendRect(aRect);
+	}
+
+
+
+EXPORT_C void TRegion::Union(const TRegion &aRegion)
+/**
+Replaces this region with the union of it and the specified region.
+
+Note that if the error flag of either this region or the specified region is
+set, then this region is cleared and its error flag is set. This frees up
+allocated memory.
+
+@param aRegion The region to be joined to this region.
+*/
+	{
+	if (aRegion.iError)
+		{
+		ForceError();
+		}
+	else if (!iError && (aRegion.iCount != 0))
+		{
+		if (iCount == 0)
+			{
+			Copy(aRegion);
+			}
+		else
+			{
+			RRegionBuf<ERegionBufSize> temp;
+			temp.Copy(aRegion);
+			if (temp.iCount>iCount)
+				{
+				temp.AppendRegion(*this);
+				Copy(temp);
+				}
+			else
+				{
+				AppendRegion(temp);
+				}
+			temp.Close();
+			}
+		}
+	}
+
+
+
+
+#ifndef __REGIONS_MACHINE_CODED__
+EXPORT_C void TRegion::Intersection(const TRegion &aRegion1,const TRegion &aRegion2)
+/**
+Replaces this region with the area of intersection between two specified regions.
+	
+Notes:
+	
+1. If the error flag of either of the two specified regions is set, then this 
+   region is cleared and its error flag is set. This frees up allocated memory.
+	
+2. If this region's error flag is already set, then the function has no effect.
+	
+@param aRegion1 The first region. 
+@param aRegion2 The second region.
+*/
+    {
+	if (aRegion1.iError || aRegion2.iError)
+		ForceError();
+	else
+		{
+		iCount=0;
+		const TRect *pRect1,*pEnd1;
+		const TRect *pRect2,*pEnd2;
+		for (pRect1=aRegion1.RectangleList(),pEnd1=pRect1+aRegion1.iCount;pRect1<pEnd1;pRect1++)
+			{
+			for (pRect2=aRegion2.RectangleList(),pEnd2=pRect2+aRegion2.iCount;pRect2<pEnd2;pRect2++)
+				{
+				if (pRect1->iBr.iX>pRect2->iTl.iX && pRect1->iBr.iY>pRect2->iTl.iY && pRect1->iTl.iX<pRect2->iBr.iX && pRect1->iTl.iY<pRect2->iBr.iY)
+					{
+					TRect rect(*pRect2);
+					rect.Intersection(*pRect1);
+					AppendRect(rect);
+					}
+				}
+			}
+		}
+	}
+#endif
+
+
+
+
+EXPORT_C void TRegion::Intersect(const TRegion &aRegion)
+/**
+Replaces this region with the area of intersection between it and the specified 
+region.
+
+Note that if the error flag of either this region or the specified region is
+set, then this region is cleared and its error flag is set. This frees up
+allocated memory.
+
+@param aRegion The region to be intersected with this region.
+*/
+	{
+	if (aRegion.iError)
+		{
+		ForceError();
+		}
+	else if (!iError && (iCount != 0))
+		{
+		if (aRegion.iCount == 0)
+			{
+			Clear();
+			}
+		else
+			{
+			RRegionBuf<ERegionBufSize> temp;
+			temp.Copy(*this);
+			Intersection(temp,aRegion);
+			temp.Close();
+			}
+		}
+	}
+
+
+
+
+EXPORT_C void TRegion::AddRect(const TRect &aRect)
+/**
+Adds a rectangle to this region.
+
+Notes:
+
+1. If this region's error flag is already set, this function has no effect.
+
+2. If the operation causes the capacity of this region to be exceeded, or if 
+   memory allocation fails, the region is cleared, freeing up any memory which 
+   has been allocated; its error flag is also set.
+
+@param aRect The rectangle to be added to this region.
+*/
+	{
+	if (!aRect.IsEmpty() && !iError)
+		{
+		TBool doAppend = ETrue;
+		if (iCount > 0)
+			{
+			TRect regRect = BoundingRect();
+			TRect inter(aRect);
+			inter.Intersection(regRect);
+
+			if (!inter.IsEmpty())
+				{
+				if ( inter == regRect )
+					{ // equivalent to IsContainedBy(aRect)
+					iCount=0;
+					}
+				else
+					{
+					TBool coversRect = (inter == aRect); // bounding rect of region includes all of aRect?
+					MergeRect(aRect, coversRect);
+					doAppend = EFalse;
+					}
+				}
+			}
+		if (doAppend)
+			{
+			AppendRect(aRect);
+			}
+
+		// RRegion could have unneeded memory that can be freed
+		if (!iError && (iAllocedRects > iCount))
+			{
+			ShrinkRegion();
+			}
+		}
+	}
+
+
+
+
+EXPORT_C void TRegion::SubRegion(const TRegion &aRegion,TRegion *aSubtractedRegion)
+/**
+Removes a region.
+
+If there is no area of intersection between the two regions, this region is 
+unaffected.
+
+@param aRegion           The region to be removed from this region.
+                         If aRegion's error flag is set, then this region is
+                         cleared, freeing up any allocated memory, and the
+                         error flag is set.
+@param aSubtractedRegion If specified, then on return contains the area removed 
+                         from this region.
+*/
+	{
+	SubtractRegion(aRegion, aSubtractedRegion);
+
+	// RRegion could have unneeded memory that can be freed
+	if (!iError && (iAllocedRects > iCount))
+		{
+		ShrinkRegion();
+		}
+	}
+
+
+/**
+Removes a region.
+
+If there is no area of intersection between the two regions, this region is 
+unaffected.
+
+@param aRegion           The region to be removed from this region.
+                         If aRegion's error flag is set, then this region is
+                         cleared, freeing up any allocated memory, and the
+                         error flag is set.
+@param aSubtractedRegion If specified, then on return contains the area removed 
+                         from this region.
+*/
+void TRegion::SubtractRegion(const TRegion &aRegion,TRegion *aSubtractedRegion)
+	{
+	if (!iError)
+		{
+		if (aRegion.iError)
+			{
+			ForceError();
+			}
+		else if (iCount != 0)
+			{
+			const TRect *pR=aRegion.RectangleList();
+			const TRect *pE=pR+aRegion.iCount;
+			while (pR<pE && !iError)
+				{
+				SubRect(*pR++, aSubtractedRegion);
+				}
+			if (iError && aSubtractedRegion)
+				{
+				aSubtractedRegion->ForceError();
+				}
+			}
+		}
+	}
+
+
+
+
+#ifndef __REGIONS_MACHINE_CODED__
+EXPORT_C void TRegion::ClipRect(const TRect &aRect)
+/**
+Clips the region to the specified rectangle.
+
+The resulting region is the area of overlap between the region and the rectangle. 
+If there is no overlap, all rectangles within this region are deleted and 
+the resulting region is empty.
+
+@param aRect The rectangle to which this region is to be clipped.
+*/
+	{
+
+	for (TInt index=0;index<iCount;)
+		{
+		TRect *r2=RectangleListW()+index;
+		if (r2->iTl.iX<aRect.iTl.iX)
+			r2->iTl.iX=aRect.iTl.iX;
+		if (r2->iTl.iY<aRect.iTl.iY)
+			r2->iTl.iY=aRect.iTl.iY;
+		if (r2->iBr.iX>aRect.iBr.iX)
+			r2->iBr.iX=aRect.iBr.iX;
+		if (r2->iBr.iY>aRect.iBr.iY)
+			r2->iBr.iY=aRect.iBr.iY;
+		if (r2->IsEmpty())
+			DeleteRect(r2);
+		else
+			index++;
+		}
+	}
+#endif
+
+
+
+
+EXPORT_C void TRegion::Clear()
+/**
+Clears this region.
+
+This frees up any memory which has been allocated and unsets the error flag.
+*/
+	{
+
+	if (iAllocedRects>=0)
+		{
+		User::Free(((RRegion *)this)->iRectangleList);
+		((RRegion *)this)->iRectangleList=NULL;
+		iAllocedRects=0;
+		}
+	iCount=0;
+	iError=EFalse;
+	}
+
+
+
+
+
+EXPORT_C void TRegion::Tidy()
+/**
+Merges all rectangles within this region which share an adjacent edge of the 
+same length.
+
+The function subsequently checks for allocated but unused memory, if this memory is
+at least as large as the granularity it is released to the system.
+*/
+	{
+	TUint doMore = 2; // need 1 pass each of merging vertical & horizontal edges
+
+	while ( (iCount > 1) && doMore )
+		{
+		// make rows
+		--doMore;
+			{
+			TRect* pFirst = RectangleListW();
+			TRect* pLast = RectangleListW()+iCount-1;
+			TRect *pRect1 = pLast;
+			for (;pRect1 > pFirst; pRect1--)
+				{
+				TRect *pRect2 = pRect1-1;
+				const TInt top = pRect1->iTl.iY;
+				const TInt bottom = pRect1->iBr.iY;
+				for (;pRect2 >= pFirst; pRect2--)
+					{
+					if ( (top == pRect2->iTl.iY) && (bottom == pRect2->iBr.iY) )
+						{
+						if (pRect1->iBr.iX == pRect2->iTl.iX)
+							{
+							pRect2->iTl.iX = pRect1->iTl.iX;
+							}
+						else if (pRect1->iTl.iX == pRect2->iBr.iX)
+							{
+							pRect2->iBr.iX = pRect1->iBr.iX;
+							}
+						else
+							{
+							continue;
+							}
+						}
+					else
+						{
+						continue;
+						}
+					// remove merged and move last
+					if (pRect1 != pLast)
+						{
+						*pRect1 = *pLast;
+						}
+					--iCount;
+					--pLast;
+					doMore = 1;
+					break;
+					}
+				}
+			}
+
+		// make columns?
+		if (doMore)
+			{
+			--doMore;
+			TRect* pFirst = RectangleListW();
+			TRect* pLast = RectangleListW()+iCount-1;
+			TRect *pRect1 = pLast;
+			for (;pRect1 > pFirst; pRect1--)
+				{
+				TRect *pRect2 = pRect1-1;
+				const TInt left = pRect1->iTl.iX;
+				const TInt right = pRect1->iBr.iX;
+
+				for (;pRect2 >= pFirst; pRect2--)
+					{
+					if ( (left == pRect2->iTl.iX) && (right == pRect2->iBr.iX) )
+						{
+						if (pRect1->iBr.iY == pRect2->iTl.iY)
+							{
+							pRect2->iTl.iY = pRect1->iTl.iY;
+							}
+						else if (pRect1->iTl.iY == pRect2->iBr.iY)
+							{
+							pRect2->iBr.iY = pRect1->iBr.iY;
+							}
+						else
+							{
+							continue;
+							}
+						}
+					else
+						{
+						continue;
+						}
+					// remove merged
+					if (pRect1 != pLast)
+						{
+						*pRect1 = *pLast;
+						}
+					--iCount;
+					--pLast;
+					doMore = 1;
+					break;
+					}
+				}
+			}
+		}
+
+	// free space
+	if (iAllocedRects>iCount)
+		{
+		ShrinkRegion();
+		}
+	}
+
+
+
+EXPORT_C TInt TRegion::Sort()
+/**
+Sorts the region's array of rectangles according to their vertical position 
+on the screen.
+
+The sort uses the bottom right hand corner co-ordinates of the rectangles.
+The co-ordinates of the top and left hand sides are irrelevant 
+to the sort operation.
+
+Higher rectangles take precedence over lower ones. For rectangles at the same 
+vertical position, the leftmost takes priority.
+
+Note that the sort order may need to be different from the default if, for example, 
+a region is moved downwards so that lower non-overlapping rectangles need 
+to be redrawn (and sorted) before higher ones. In this case, use the second 
+overload of this function.
+
+@return KErrNone, if the operation is successful; KErrGeneral, otherwise.
+*/
+	{
+
+	return Sort(TPoint(-1,-1));
+	}
+
+
+
+
+EXPORT_C TInt TRegion::Sort(const TPoint &aOffset)
+//
+// Sort the region for copying to the same display.
+//
+/**
+Sorts the region's array of rectangles according to a specified sort order.
+
+The sort uses the bottom right hand co-ordinates of the rectangles.
+The co-ordinates of the top and left hand sides are irrelevant 
+to the sort operation
+
+The order of the sort is determined by whether the iX and iY members of aOffset 
+are positive, or zero or less. If aOffset.iY is greater than zero,
+lower rectangles take precedence over higher rectangles in the list order.
+Otherwise, higher rectangles take precedence. For rectangles of equal height,
+aOffset.iX becomes relevant to the sort.
+If is greater than zero, rightmost rectangles
+take precedence. Otherwise, leftmost rectangles take precedence.
+
+Note that the sort order may need to be different from the default if,
+for example, a region is moved downwards so that lower non-overlapping
+rectangles need to be redrawn (and sorted) before higher ones.
+
+@param aOffset A point whose iX and iY members determine the order of the 
+               sort. 
+
+@return KErrNone, if the operation is successful; KErrGeneral, otherwise.
+*/
+	{
+	TRectKey key(RectangleList(),aOffset);
+	TRectSwap swap(RectangleListW());
+	return(User::QuickSort(iCount,key,swap));
+	}
+
+
+
+
+EXPORT_C TRect *TRegion::RectangleListW()
+//
+// Return a writeable rectangle list.
+//
+	{
+	if (iAllocedRects>=0)
+		return(((RRegion *)this)->iRectangleList);
+	else if (iAllocedRects&ERRegionBuf)
+		return((TRect *)(this+1));
+	return((TRect *)(((RRegion *)this)+1));
+	}
+
+
+/** Ensure that the region is big enough to hold aCount rectangles.
+
+@param aCount number of rectangles the region is expected to hold
+@return ETrue if region is big enough, EFalse if fixed size region is too small or alloc failed.
+*/
+TBool TRegion::SetListSize(TInt aCount)
+	{
+	TInt newAlloc = 0;
+	if (iAllocedRects < 0)
+		{
+		if (aCount > (-(iAllocedRects|ERRegionBuf)))
+			{
+			if (iAllocedRects & ERRegionBuf)
+				{ // TRegionFixed
+				ForceError();
+				return EFalse;
+				}
+			// successful alloc will change RRegionBuf into RRegion
+			newAlloc = Max(aCount, ((RRegion *)this)->iGranularity);
+			}
+		}
+	else if (aCount > iAllocedRects)
+		{
+		newAlloc = Max(aCount, iAllocedRects + ((RRegion *)this)->iGranularity);
+		}
+
+	if (newAlloc > 0)
+		{
+		TRect *newList = (TRect *)User::ReAlloc(((RRegion *)this)->iRectangleList, newAlloc*sizeof(TRect));
+		if (newList == NULL)
+			{
+			ForceError();
+			return EFalse;
+			}
+		((RRegion *)this)->iRectangleList = newList;
+		iAllocedRects = newAlloc;
+		}
+	return ETrue;
+	}
+
+/** Ensure that the region is big enough to hold aCount rectangles.
+Any allocation increase is for at least the granularity count of rectangles.
+Similar to SetListSize, but always preserves existing iCount rectangles.
+
+@param aCount number of rectangles the region is expected to hold
+@return NULL if region is not big enough, otherwise pointer to the Rect array.
+*/
+TRect* TRegion::ExpandRegion(TInt aCount)
+	{
+	TRect *prects=NULL;
+	if (!iError)
+		{
+		if (iAllocedRects & ERRegionBuf)
+			{							// TRegionFix
+			if (aCount > -iAllocedRects)
+				{						// Can't expand a TRegionFix
+				ForceError();
+				return NULL;
+				}
+			prects=(TRect *)(this+1);
+			}
+		else if (iAllocedRects < 0)
+			{							// RRegionBuf
+			prects = (TRect *)(((RRegion *)this)+1);
+			if (aCount > (-(iAllocedRects|ERRegionBuf)))
+				{
+				RRegion *pr = (RRegion *)this;
+				TUint newCount = Max(aCount, iCount + pr->iGranularity);
+				TRect *newList = (TRect *)User::Alloc(newCount * sizeof(TRect));
+				if (newList == NULL)
+					{
+					ForceError();
+					return NULL;
+					}
+				iAllocedRects = newCount;
+				pr->iRectangleList = newList;
+				if (iCount > 0)
+					{
+					Mem::Copy(pr->iRectangleList, prects, sizeof(TRect)*iCount);
+					}
+				prects = pr->iRectangleList;
+				}
+			}
+		else
+			{
+			RRegion *pr = (RRegion *)this;
+			prects = pr->iRectangleList;
+			if (iAllocedRects < aCount)
+				{
+				TUint newCount = Max(aCount, iAllocedRects + pr->iGranularity);
+				prects=(TRect *)User::ReAlloc(prects, newCount*sizeof(TRect));
+				if (prects == NULL)
+					{
+					ForceError();
+					return NULL;
+					}
+				iAllocedRects = newCount;
+				pr->iRectangleList = prects;
+				}
+			}
+		}
+
+	return prects;
+	}
+
+
+/**
+After an RRegion's iCount has reduced try to release some memory.
+Hysteresis rule: reduce allocated memory to iCount, but only if 
+the released memory will also be at least the granularity.
+*/
+void TRegion::ShrinkRegion()
+	{
+	ASSERT(iAllocedRects > iCount);
+	// must be an RRegion
+	RRegion *pr=(RRegion *)this;
+	if (iAllocedRects >= (iCount + pr->iGranularity) )
+		{
+		TRect *newList = NULL;
+		if (iCount == 0)
+			{
+			User::Free(pr->iRectangleList);
+			}
+		else
+			{
+			newList = (TRect *)User::ReAlloc(pr->iRectangleList, iCount*sizeof(TRect));
+			if (newList == NULL)
+				{
+				ForceError();
+				return;
+				}
+			}
+		iAllocedRects = iCount;
+		pr->iRectangleList = newList;
+		}
+	}
+
+
+void TRegion::AppendRect(const TRect &aRect)
+//
+// Add a rectangle to the list.
+//
+	{
+	TRect *prects = ExpandRegion(iCount+1);
+	if (prects)
+		{
+		*(prects+iCount)=aRect;
+		iCount++;
+		}
+	}
+
+
+#ifndef __REGIONS_MACHINE_CODED__
+
+
+EXPORT_C void TRegion::ForceError()
+/**
+Sets the error flag, and clears the region.
+
+This frees up memory allocated to the region.
+*/
+	{
+
+	Clear();
+	iError=ETrue;
+	}
+
+void TRegion::DeleteRect(TRect *aRect)
+//
+// Delete a specific rectangle in the list.
+//
+	{
+
+	iCount--;
+	Mem::Copy(aRect,aRect+1,((TUint8 *)(RectangleList()+iCount))-((TUint8 *)aRect));
+	}
+#endif
+
+void TRegion::AppendRegion(TRegion &aRegion)
+//
+// Append all the rectangles from aRegion to this.
+//
+	{
+	aRegion.SubtractRegion(*this);
+	if (aRegion.iError)
+		{
+		ForceError();
+		}
+	else if (aRegion.iCount > 0)
+		{
+		// alloc enough memory, then memcpy
+		const TInt newCount = iCount + aRegion.iCount;
+		if (ExpandRegion(newCount))
+			{
+			TRect* pDest = RectangleListW() + iCount;
+			const TRect* pSource = aRegion.RectangleList();
+			Mem::Copy(pDest, pSource, aRegion.iCount * sizeof(TRect));
+			iCount = newCount;
+			}
+		}
+	}
+
+
+
+EXPORT_C RRegion::RRegion()
+	: TRegion(0), iGranularity(EDefaultGranularity), iRectangleList(NULL)
+/**
+Default constructor.
+
+Initialises its granularity to five.
+*/
+	{}
+
+
+
+
+EXPORT_C RRegion::RRegion(TInt aGran)
+	: TRegion(0), iGranularity(aGran), iRectangleList(NULL)
+/**
+Constructs the object with the specified granularity.
+
+@param aGran The initial value for the region's granularity.
+             This value must not be negative.
+*/
+	{}
+
+
+
+
+EXPORT_C RRegion::RRegion(const TRect &aRect, TInt aGran)
+	: TRegion(0), iGranularity(aGran), iRectangleList(NULL)
+/**
+Constructs the object with the specified rectangle and granularity.
+
+The resulting region consists of the specified single rectangle.
+
+@param aRect The single rectangle with which to initialise the region 
+@param aGran The initial value for the region's granularity. By default, 
+             this is five.
+*/
+	{
+
+	if (!aRect.IsEmpty())
+		AppendRect(aRect);
+	}
+
+
+
+
+EXPORT_C RRegion::RRegion(const RRegion &aRegion)
+/**
+Copy constructor.
+
+Constructs a new region from an existing one by performing a bit-wise copy.  Both the new and
+existing regions are left containing pointers to the same data, so Close() must only be called on
+one of them.
+
+Use of this method is not recommended.
+
+@param aRegion The region to be copied.
+*/
+	{
+	*this=aRegion;
+	}
+
+
+
+
+EXPORT_C RRegion::RRegion(TInt aBuf, TInt aGran)
+//
+// Constructor.
+//
+	: TRegion(aBuf), iGranularity(aGran), iRectangleList(NULL)
+	{}
+
+
+
+
+EXPORT_C RRegion::RRegion(TInt aCount,TRect* aRectangleList,TInt aGran/*=EDefaultGranularity*/)
+/**
+Constructor that takes ownership of an already created rectangle list.
+
+@param aCount         The number of rectangles in the region.
+@param aRectangleList A pointer to the set of rectangles.
+@param aGran          The region's granularity.
+*/
+	: TRegion(aCount), iGranularity(aGran), iRectangleList(aRectangleList)
+	{
+	iCount=aCount;
+	}
+
+
+
+
+EXPORT_C void RRegion::Close()
+/**
+Closes the region.
+
+Frees up any memory which has been allocated, and unsets the error flag, if 
+set. 
+
+The region can be re-used after calling this method.  Its granularity is preserved.
+*/
+	{
+
+	Clear();
+	}
+
+
+
+
+EXPORT_C void RRegion::Destroy()
+//
+// Destroy
+//
+/**
+Deletes the region.
+
+Frees all memory.
+
+Note this method will delete the RRegion object and therefore it should not be 
+invoked on RRegion objects that are not allocated on the heap.  RRegion::Close()
+should be used for RRegion objects stored on the stack.
+
+@panic USER 42 if the RRegion object is stored on the stack.
+*/
+	{
+
+	Clear();
+	delete this;
+	}
+
+
+
+
+TInt TRectKey::Compare(TInt aLeft,TInt aRight) const
+//
+// Compares two rectangles for partial ordering.
+//
+	{
+
+	if (aLeft==aRight)
+		return(0);
+	const TRect *r1=&iRectList[aLeft];
+	const TRect *r2=&iRectList[aRight];
+	if (r2->iBr.iY<=r1->iTl.iY)
+		return(iDown ? -1 : 1);
+	if (r1->iBr.iY<=r2->iTl.iY)
+		return(iDown ? 1 : -1);
+	if (r2->iBr.iX<=r1->iTl.iX)
+		return(iRight ? -1 : 1);
+	__ASSERT_DEBUG(r1->iBr.iX<=r2->iTl.iX,Panic(ETRegionInvalidRegionInSort));
+	return(iRight ? 1 : -1);
+	}
+
+void TRectSwap::Swap(TInt aLeft,TInt aRight) const
+//
+// Swap two rectangles.
+//
+	{
+
+	TRect tmp(iRectList[aLeft]);
+	iRectList[aLeft]=iRectList[aRight];
+	iRectList[aRight]=tmp;
+	}
+
+TRectKey::TRectKey(const TRect *aRectList,const TPoint &aOffset)
+//
+// Rectangle key constructor
+//
+	{
+
+	iRectList=aRectList;
+	if(aOffset.iX>0)
+		iRight=ETrue;
+	else
+		iRight=EFalse;
+	if(aOffset.iY>0)
+		iDown=ETrue;
+	else
+		iDown=EFalse;
+	}