public override void PrepareLayout()
{
base.PrepareLayout();
calculatedAttributes.Clear();
contentWidth = CollectionView.Frame.Width;
nfloat columnWidth = contentWidth / NumberOfColumns;
nfloat height = columnWidth * 1.25f; // Our cells height is a 25% greater than their width
for (int i = 0; i < columnsXOffset.Length; i++)
{
columnsXOffset[i] = i * columnWidth;
}
for (int i = 0; i < columnsYOffset.Length; i++)
{
columnsYOffset[i] = 0;
}
UICollectionViewLayoutAttributes attribute1 = UICollectionViewLayoutAttributes.CreateForCell(NSIndexPath.FromItemSection(0, 0));
attribute1.Frame = new CGRect(columnsXOffset[1], 0, columnWidth, buttonHeight);
calculatedAttributes.Add(attribute1);
columnsYOffset[1] = buttonHeight; // Second column has a vertical offset (due to sell button height)
int column = 0;
for (int i = 0; i < CollectionView.NumberOfItemsInSection(1); i++)
{
var indexPath = NSIndexPath.FromItemSection(i, 1);
var frame = new CGRect(columnsXOffset[column], columnsYOffset[column], columnWidth, height);
var insetFrame = RectangleFExtensions.Inset(frame, 0f, 0f);
UICollectionViewLayoutAttributes attribute = UICollectionViewLayoutAttributes.CreateForCell(indexPath);
attribute.Frame = insetFrame;
calculatedAttributes.Add(attribute);
contentHeight = System.NMath.Max(contentHeight, RectangleFExtensions.GetMaxY(frame));
columnsYOffset[column] = columnsYOffset[column] + height;
column = column >= (NumberOfColumns - 1) ? 0 : ++column;
}
}
