/// <summary>
/// Replaces a cell at the given colomn and row with the given cell.
/// not tested, this will crash if the row and or colomn are out of bounds..
/// </summary>
/// <param name="x">colomn</param>
/// <param name="y">row</param>
/// <param name="cell">cell</param>
public void SetCellItem(int x, int y, ItemGridDataCell cell)
{
_grid[y].AddCell(cell);
cell.PropertyChanged += cell_PropertyChanged;
}