//--------------------------------------------------------------------------
#region ** implementation
// when the current quarter changes, update filters, total sales, and goals
void _quarters_CurrentChanged(object sender, EventArgs e)
{
// update filters
SalesByCustomer.Refresh();
SalesByCategory.Refresh();
// calculate sales for this quarter and for the previous quarter
var qtrList = _quarters.Source as IList;
var qtrThis = Quarters.CurrentItem as string;
var qtrPrev = Quarters.CurrentPosition < qtrList.Count - 1
? qtrList[Quarters.CurrentPosition + 1] as string
: string.Empty;
_quarterSales = 0;
decimal _prevQuarterSales = 0;
foreach (Order o in _orders)
{
if (o.Quarter == qtrThis)
{
_quarterSales += o.Amount;
}
else if (o.Quarter == qtrPrev)
{
_prevQuarterSales += o.Amount;
}
}
// compute sales goals (2% gold, 15% platinum)
_goalGold = _prevQuarterSales * (decimal)1.02;
_goalPlat = _prevQuarterSales * (decimal)1.15;
// raise PropertyChanged event to update bindings
OnPropertyChanged();
}
// create SalesByCustomer collection (filtered by Quarter)
void CreateSalesByCustomer()
{
var lsc = new List <SalesByCustomer>();
// group by quarter
var qByQtr =
from o in _orders
group o by o.Quarter into g
select new { Quarter = g.Key, Orders = g };
foreach (var oq in qByQtr)
{
// group by customer
var qByCust =
from o in oq.Orders
group o by o.Customer into g
select new { Customer = g.Key, Quarter = oq.Quarter, Orders = g };
foreach (var oc in qByCust)
{
var sbc = new SalesByCustomer();
sbc.Customer = oc.Customer;
sbc.Quarter = oc.Quarter;
sbc.Amount = (from o in oc.Orders select o.Amount).Sum();
sbc.Scale = Math.Max(1, Math.Sqrt((double)sbc.Amount / 1000.0));
lsc.Add(sbc);
}
}
// create ICollectionView
_salesByCustomer = new CollectionViewSource();
_salesByCustomer.Source = lsc;
// sort by customer name
var sd = new SortDescription("Customer.CompanyName", ListSortDirection.Ascending);
SalesByCustomer.SortDescriptions.Add(sd);
// filter by current Quarter
SalesByCustomer.Filter = (item) =>
{
var sbc = item as SalesByCustomer;
return(string.Equals(sbc.Quarter, (string)Quarters.CurrentItem));
};
}
