public void SetListener(PortfolioListener newListener)
{
if (newListener == null)
{
//we don't accept a null parameter. to delete the actual listener
//the RemoveListener method must be used
return;
}
//Set the listener
this.listener = newListener;
_log.Debug("Listener set on " + this.id);
//copy the actual listener to a constant that will be used
//by the asynchronous notification
PortfolioListener localListener = newListener;
//Clone the actual status of the portfolio, for use
//by the asynchronous notification
IDictionary currentStatus = (Hashtable)quantities.Clone();
//Create a task to asynchronously
//notify the listener of the actual status
executor.Add(delegate()
{
// call the onActualStatus on the listener;
// in case the listener has just been detached,
// the listener should detect the case
localListener.OnActualStatus(currentStatus);
});
}
private void Empty()
{
_log.Debug("Cleaning status " + this.id);
//remove all the quantities so that the portfolio will result empty
quantities.Clear();
if (this.listener != null)
{
//copy the actual listener to a constant that will be used
//by the asynchronous notification
PortfolioListener localListener = this.listener;
executor.Add(delegate()
{
// call the request on the listener;
// in case the listener has just been detached,
// the listener should detect the case
localListener.Empty();
});
}
}
public void RemoveListener()
{
//remove the listener
this.listener = null;
}
private void ChangeQty(string stock, int qty)
{
//Get the old quantity for the stock
Object oldQtyObject = quantities[stock];
int newQty;
int oldQty;
if (oldQtyObject == null)
{
//If oldQtyObject is null it means that we don't have that stock on our portfolio
if (qty <= 0)
{
//We can't sell something we don't have, warn and return.
_log.Warn(this.id + "|No stock to sell: " + stock);
return;
}
//Set oldQty to 0 to let the listener know that we previously didn't have such stock
oldQty = 0;
//The new quantity is equal to the bought value
newQty = qty;
}
else
{
oldQty = Convert.ToInt32(quantities[stock]);
Debug.Assert(oldQty > 0);
//The new quantity will be the value of the old quantity plus the qty value.
//If qty is a negative number than we are selling, in the other case we're buying
newQty = oldQty + qty;
// overflow check; just in case
if (qty > 0 && newQty <= qty)
{
newQty = oldQty;
_log.Warn(this.id + "|Quantity overflow; order ignored: " + stock);
return;
}
}
if (newQty < 0)
{
//We sold more than we had
_log.Warn(this.id + "|Not enough stock to sell: " + stock);
//We interpret this as "sell everything"
newQty = 0;
}
if (newQty == 0)
{
//If we sold everything we remove the stock from the internal structure
quantities.Remove(stock);
}
else
{
//Save the actual quantity in internal structure
quantities[stock] = newQty;
}
if (this.listener != null)
{
//copy the actual listener to a constant that will be used
//by the asynchronous notification
PortfolioListener localListener = this.listener;
//copy the values to constant to be used
//by the asynchronous notification
int newVal = newQty;
int oldVal = oldQty;
string stockId = stock;
//If we have a listener, create a task to asynchronously
//notify the listener of the actual status
executor.Add(delegate()
{
// call the update on the listener;
// in case the listener has just been detached,
// the listener should detect the case
localListener.Update(stockId, newVal, oldVal);
});
}
}
