protected override Size MeasureOverride()

in XamlControlsGallery/Common/VariedImageSizeLayout.cs [29:85]
46 lines of code
9 McCabe index (conditional complexity)

        protected override Size MeasureOverride(VirtualizingLayoutContext context, Size availableSize)
        {
            var viewport = context.RealizationRect;

            if (availableSize.Width != m_lastAvailableWidth || cachedBoundsInvalid)
            {
                UpdateCachedBounds(availableSize);
                m_lastAvailableWidth = availableSize.Width;
            }

            // Initialize column offsets
            int numColumns = (int)(availableSize.Width / Width);
            if (m_columnOffsets.Count == 0)
            {
                for (int i = 0; i < numColumns; i++)
                {
                    m_columnOffsets.Add(0);
                }
            }

            m_firstIndex = GetStartIndex(viewport);
            int currentIndex = m_firstIndex;
            double nextOffset = -1.0;

            // Measure items from start index to when we hit the end of the viewport.
            while (currentIndex < context.ItemCount && nextOffset < viewport.Bottom)
            {
                var child = context.GetOrCreateElementAt(currentIndex);
                child.Measure(new Size(Width, availableSize.Height));

                if (currentIndex >= m_cachedBounds.Count)
                {
                    // We do not have bounds for this index. Lay it out and cache it.
                    int columnIndex = GetIndexOfLowestColumn(m_columnOffsets, out nextOffset);
                    m_cachedBounds.Add(new Rect(columnIndex * Width, nextOffset, Width, child.DesiredSize.Height));
                    m_columnOffsets[columnIndex] += child.DesiredSize.Height;
                }
                else
                {
                    if (currentIndex + 1 == m_cachedBounds.Count)
                    {
                        // Last element. Use the next offset.
                        GetIndexOfLowestColumn(m_columnOffsets, out nextOffset);
                    }
                    else
                    {
                        nextOffset = m_cachedBounds[currentIndex + 1].Top;
                    }
                }

                m_lastIndex = currentIndex;
                currentIndex++;
            }

            var extent = GetExtentSize(availableSize);
            return extent;
        }