/// <summary>
/// Arranges the content of the <see cref="DataGridRowsPresenter"/>.
/// </summary>
/// <returns>
/// The actual size used by the <see cref="DataGridRowsPresenter"/>.
/// </returns>
/// <param name="finalSize">
/// The final area within the parent that this element should use to arrange itself and its children.
/// </param>
protected override Size ArrangeOverride(Size finalSize)
{
if (finalSize.Height == 0 || this.OwningGrid == null)
{
return(base.ArrangeOverride(finalSize));
}
this.OwningGrid.OnFillerColumnWidthNeeded(finalSize.Width);
double rowDesiredWidth = this.OwningGrid.ColumnsInternal.VisibleEdgedColumnsWidth + this.OwningGrid.ColumnsInternal.FillerColumn.FillerWidth;
double topEdge = -this.OwningGrid.NegVerticalOffset;
foreach (UIElement element in this.OwningGrid.DisplayData.GetScrollingElements())
{
DataGridRow row = element as DataGridRow;
if (row != null)
{
DiagnosticsDebug.Assert(row.Index != -1, "Expected Index other than -1."); // A displayed row should always have its index
// Visibility for all filler cells needs to be set in one place. Setting it individually in
// each CellsPresenter causes an NxN layout cycle (see DevDiv Bugs 211557)
row.EnsureFillerVisibility();
row.Arrange(new Rect(-this.OwningGrid.HorizontalOffset, topEdge, rowDesiredWidth, element.DesiredSize.Height));
}
else
{
DataGridRowGroupHeader groupHeader = element as DataGridRowGroupHeader;
if (groupHeader != null)
{
double leftEdge = this.OwningGrid.AreRowGroupHeadersFrozen ? 0 : -this.OwningGrid.HorizontalOffset;
groupHeader.Arrange(new Rect(leftEdge, topEdge, rowDesiredWidth - leftEdge, element.DesiredSize.Height));
}
}
topEdge += element.DesiredSize.Height;
}
double finalHeight = Math.Max(topEdge + this.OwningGrid.NegVerticalOffset, finalSize.Height);
// Clip the RowsPresenter so rows cannot overlap other elements in certain styling scenarios
RectangleGeometry rg = new RectangleGeometry();
rg.Rect = new Rect(0, 0, finalSize.Width, finalHeight);
this.Clip = rg;
return(new Size(finalSize.Width, finalHeight));
}