protected int LayoutTileColumn(int columnIndex, int startIndex, int maxVerticalCellCount, int maxHorizontalCellCount, ref int rowCount)
{
maxVerticalCellCount = Math.Max(2, maxVerticalCellCount);
int currentColumn = 0;
int currentRow = 0;
int rowSpan = 0;
rowCount = 0;
for (int i = startIndex; i < Children.Count; i++)
{
TileSize tileSize = VerticalTilePanel.GetTileSize(Children[i]);
int columnSpan = tileSize == TileSize.Small ? 1 : 2;
if (columnSpan > maxHorizontalCellCount)
{
return(-1);
}
if (currentColumn + columnSpan > maxHorizontalCellCount)
{
currentRow += rowSpan;
rowCount += rowSpan;
currentColumn = 0;
}
rowSpan = tileSize == TileSize.Large ? 2 : 1;
if (currentRow + rowSpan > maxVerticalCellCount)
{
return(i - 1);
}
VerticalTilePanel.SetColumn(Children[i], columnIndex + currentColumn);
VerticalTilePanel.SetRow(Children[i], currentRow);
currentColumn += columnSpan;
}
return(Children.Count - 1);
}
protected override Size MeasureOverride(Size availableSize)
{
int maxVerticalCellCount = Math.Max(1, (int)(double.IsInfinity(availableSize.Height) ? 100 : availableSize.Height / SmallTileHeight));
int startIndex = 0;
int columnIndex = 0;
int rowCount = 0;
while (startIndex != Children.Count)
{
int newIndex = LayoutTileColumn(columnIndex, startIndex, maxVerticalCellCount, 1, ref rowCount);
columnIndex++;
if (newIndex == -1)
{
newIndex = LayoutTileColumn(columnIndex - 1, startIndex, maxVerticalCellCount, 2, ref rowCount);
if (newIndex == -1)
{
throw new InvalidOperationException();
}
columnIndex++;
}
if (startIndex == 0)
{
maxVerticalCellCount = Math.Min(rowCount, maxVerticalCellCount);
}
startIndex = newIndex + 1;
}
foreach (UIElement child in Children)
{
TileSize tileSize = VerticalTilePanel.GetTileSize(child);
int rowSpan = tileSize == TileSize.Large ? 2 : 1;
int columnSpan = tileSize == TileSize.Small ? 1 : 2;
child.Measure(new Size(columnSpan * SmallTileWidth, rowSpan * SmallTileHeight));
}
return(new Size(SmallTileWidth * columnIndex, SmallTileHeight * maxVerticalCellCount));
}
protected override Size ArrangeOverride(Size finalSize)
{
foreach (UIElement child in Children)
{
TileSize tileSize = VerticalTilePanel.GetTileSize(child);
int rowSpan = tileSize == TileSize.Large ? 2 : 1;
int columnSpan = tileSize == TileSize.Small ? 1: 2;
child.Arrange(new Rect(VerticalTilePanel.GetColumn(child) * SmallTileWidth, VerticalTilePanel.GetRow(child) * SmallTileHeight, columnSpan * SmallTileWidth, rowSpan * SmallTileHeight));
}
return(finalSize);
}