/// <summary>
/// Specify a function that extracts a sortable key from object instances, that can be used to order items in the view.
///
/// The ordering of the view will be checked whenever one of the items raises a property changed event
/// (see <see cref="INotifyPropertyChanged"/>) for one of a set of specified properties. Only the position of the element
/// raising the event will be considered.
///
/// When new items are added to the collection, the function will be used to select an appropriate position
/// in the view.
/// </summary>
/// <param name="function">The function that gets the sort key from an instance of <see cref="T"/>.</param>
/// <param name="orderCheckPropertyNames">The names of the properties that should trigger a check.</param>
public void OrderBy <TKey>(Func <T, TKey> function, IEnumerable <string> orderCheckPropertyNames, bool orderDescending) where TKey : IComparable
{
if (_mediator == null)
{
throw new MediatorNotSetException();
}
if (_collectionOrder != null)
{
_collectionOrder.Detach();
}
var order = new CollectionOrder <T, TKey>(function, View, _dispatcher, orderCheckPropertyNames, orderDescending);
order.LoadKeysAndTriggerArrange(_target, _mediator);
_collectionOrder = order;
}
/// <summary>
/// Specify a function that extracts a sortable key from object instances, that can be used to order items in the view.
///
/// The ordering of the view will be checked whenever one of the items raises a property changed event
/// (see <see cref="INotifyPropertyChanged"/>) for one of a set of specified properties. Only the position of the element
/// raising the event will be considered.
///
/// When new items are added to the collection, the function will be used to select an appropriate position
/// in the view.
/// </summary>
/// <param name="function">The function that gets the sort key from an instance of <see cref="T"/>.</param>
/// <param name="orderCheckPropertyNames">The names of the properties that should trigger a check.</param>
/// <param name="orderDescending">True if the sort order is to be descending instead of ascending</param>
public void OrderBy <TKey>(Func <TItem, TKey> function, IEnumerable <string> orderCheckPropertyNames, bool orderDescending) where TKey : IComparable
{
_log.LazyAdd("Set Order {0}", new Lazy <string>(function.ToString), new Lazy <string>(() => orderCheckPropertyNames.Aggregate((t, i) => t + "," + i)));
if (_mediator == null)
{
throw new MediatorNotSetException();
}
if (_collectionOrder != null)
{
_collectionOrder.Detach();
}
var order = new CollectionOrder <TItem, TKey>(function, View, _dispatcher, orderCheckPropertyNames, orderDescending);
order.LoadKeysAndTriggerArrange(View, _mediator);
_collectionOrder = order;
}
