protected override Size MeasureOverride()

in ApplicationUnderTests/AppUIBasics/Common/WrapPanel.cs [234:302]


        protected override Size MeasureOverride(Size constraint)
        {
            // Variables tracking the size of the current line, the total size
            // measured so far, and the maximum size available to fill.  Note
            // that the line might represent a row or a column depending on the
            // orientation.
            Orientation o = Orientation;
            OrientedSize lineSize = new OrientedSize(o);
            OrientedSize totalSize = new OrientedSize(o);
            OrientedSize maximumSize = new OrientedSize(o, constraint.Width, constraint.Height);

            // Determine the constraints for individual items
            double itemWidth = ItemWidth;
            double itemHeight = ItemHeight;
            bool hasFixedWidth = !double.IsNaN(itemWidth);
            bool hasFixedHeight = !double.IsNaN(itemHeight);
            Size itemSize = new Size(
                hasFixedWidth ? itemWidth : constraint.Width,
                hasFixedHeight ? itemHeight : constraint.Height);

            // Measure each of the Children
            foreach (UIElement element in Children)
            {
                // Determine the size of the element
                element.Measure(itemSize);
                OrientedSize elementSize = new OrientedSize(
                    o,
                    hasFixedWidth ? itemWidth : element.DesiredSize.Width,
                    hasFixedHeight ? itemHeight : element.DesiredSize.Height);

                // If this element falls of the edge of the line
                if (NumericExtensions.IsGreaterThan(lineSize.Direct + elementSize.Direct, maximumSize.Direct))
                {
                    // Update the total size with the direct and indirect growth
                    // for the current line
                    totalSize.Direct = Math.Max(lineSize.Direct, totalSize.Direct);
                    totalSize.Indirect += lineSize.Indirect;

                    // Move the element to a new line
                    lineSize = elementSize;

                    // If the current element is larger than the maximum size,
                    // place it on a line by itself
                    if (NumericExtensions.IsGreaterThan(elementSize.Direct, maximumSize.Direct))
                    {
                        // Update the total size for the line occupied by this
                        // single element
                        totalSize.Direct = Math.Max(elementSize.Direct, totalSize.Direct);
                        totalSize.Indirect += elementSize.Indirect;

                        // Move to a new line
                        lineSize = new OrientedSize(o);
                    }
                }
                else
                {
                    // Otherwise just add the element to the end of the line
                    lineSize.Direct += elementSize.Direct;
                    lineSize.Indirect = Math.Max(lineSize.Indirect, elementSize.Indirect);
                }
            }

            // Update the total size with the elements on the last line
            totalSize.Direct = Math.Max(lineSize.Direct, totalSize.Direct);
            totalSize.Indirect += lineSize.Indirect;

            // Return the total size required as an un-oriented quantity
            return new Size(totalSize.Width, totalSize.Height);
        }