public void ResetLayout()
        {
            if (this.UseNewLayoutSystem)
            {
                this.InvalidateMeasure();
                this.InvalidateArrange();
            }
            else
            {
                IRadScrollViewport scrollViewport = this.viewport as IRadScrollViewport;
                if (scrollViewport != null)
                {
                    scrollViewport.InvalidateViewport();
                }

                if (this.viewport == null)
                {
                    this.horizontalScrollBar.Visibility = ElementVisibility.Collapsed;
                    this.verticalScrollBar.Visibility   = ElementVisibility.Collapsed;
                    return;
                }

                // Init size members (clientSize, viewportSize, extentSize)
                this.clientSize = this.Parent.FieldSize;
                Size preferredViewportSize = this.viewport.GetPreferredSize(this.clientSize);
                this.extentSize = this.UsePhysicalScrolling ? preferredViewportSize :
                                  ((IRadScrollViewport)this.viewport).GetExtentSize();
                ScrollFlags sf             = GetScrollingNeeds(this.extentSize, this.clientSize);
                Size        scrollBarsSize = GetScrollBarsSize(sf);
                this.viewportSize = Size.Subtract(this.clientSize, scrollBarsSize);

                // Viewport
                Point     startPoint   = new Point(base.RightToLeft ? scrollBarsSize.Width : 0, 0);
                Rectangle viewportRect = new Rectangle(startPoint,
                                                       this.UsePhysicalScrolling ? this.extentSize : this.viewportSize);
                this.viewport.SetBounds(viewportRect);

                ResetScrollState(sf);
                ResetScrollPos();

                OnSizeHScroll(this.clientSize);
                OnSizeVScroll(this.clientSize);
                OnSizeBlankSpot(this.clientSize);
            }
        }
        protected override SizeF ArrangeOverride(SizeF finalSize)
        {
            IRadScrollViewport scrollViewport = this.viewport as IRadScrollViewport;

            if (scrollViewport != null)
            {
                scrollViewport.InvalidateViewport();
            }

            if (this.viewport == null)
            {
                base.ArrangeOverride(finalSize);

                this.horizontalScrollBar.Visibility = ElementVisibility.Collapsed;
                this.verticalScrollBar.Visibility   = ElementVisibility.Collapsed;

                return(finalSize);
            }

            // Init size members (clientSize, viewportSize, extentSize)
            this.clientSize = Size.Round(finalSize);
            //TODO:
            //changed this.viewport.DesiziredSize to this.viewport.Size
            //MUST be tested
            Size preferredViewportSize = Size.Round(this.viewport.DesiredSize);

            this.extentSize = this.UsePhysicalScrolling ? preferredViewportSize :
                              ((IRadScrollViewport)this.viewport).GetExtentSize();
            ScrollFlags sf             = GetScrollingNeeds(this.extentSize, this.clientSize);
            Size        scrollBarsSize = GetScrollBarsSize(sf);

            this.viewportSize = Size.Subtract(this.clientSize, scrollBarsSize);

            // Sets Visibility and Enabled properties of the scrollbars and the blankspot
            ResetScrollState(sf);

            // !!! blankSpotSize is non-empty ONLY when both scrollbars are visible
            Size blankSpotSize = Size.Empty;

            if (this.BlankSpot.Visibility == ElementVisibility.Visible)
            {
                blankSpotSize = scrollBarsSize;
            }

            float viewportLeftPos         = this.RightToLeft ? scrollBarsSize.Width : 0;
            float horizontalScrollLeftPos = this.RightToLeft ? scrollBarsSize.Width : 0;
            float verticalScrollLeftPos   = this.RightToLeft ? 0 : finalSize.Width - scrollBarsSize.Width;
            float blankSpotLeftPos        = this.RightToLeft ? 0 : finalSize.Width - blankSpotSize.Width;

            RectangleF viewportRect = new RectangleF(
                viewportLeftPos, 0,
                this.viewportSize.Width, this.viewportSize.Height);
            RectangleF vertScrollRect = new RectangleF(
                verticalScrollLeftPos, 0,
                scrollBarsSize.Width, Math.Max(0, finalSize.Height - scrollBarsSize.Height));
            RectangleF horizScrollRect = new RectangleF(
                horizontalScrollLeftPos, finalSize.Height - scrollBarsSize.Height,
                Math.Max(0, finalSize.Width - scrollBarsSize.Width), scrollBarsSize.Height);
            RectangleF blankSpotRectRect = new RectangleF(
                blankSpotLeftPos, finalSize.Height - blankSpotSize.Height,
                blankSpotSize.Width, blankSpotSize.Height);

            this.viewport.Arrange(viewportRect);
            this.VerticalScrollBar.Arrange(vertScrollRect);
            this.HorizontalScrollBar.Arrange(horizScrollRect);
            this.BlankSpot.Arrange(blankSpotRectRect);

            ResetScrollPos();

            return(finalSize);
        }