internal SourceItemCollections(
IViewModel selectionVM,
Func <TItemSource, bool> isActiveFilter
)
{
IEnumerable <TItemSource> allItems = SelectionHelpers
.GetAllSourceItems <TItemSource>(selectionVM);
IEnumerable <TItemSource> selectedItems = SelectionHelpers
.GetSelectedSourceItems <TItemSource>(selectionVM);
AllSourceItems = new HashSet <TItemSource>(allItems);
IEnumerable <TItemSource> selectableItems = allItems;
if (isActiveFilter != null)
{
selectableItems = selectableItems.Where(isActiveFilter);
}
if (selectedItems != null && selectedItems.Any())
{
// Add items that are either inactive but currently selected or do
// are not contained in the all items at all.
selectableItems = selectableItems.Union(selectedItems);
}
SelectableItems = selectableItems.ToList();
}
public SelectableItemsCollection <TItemSource> GetSelectableItems(IBehaviorContext context)
{
SelectableItemsCollection <TItemSource> items;
if (!context.FieldValues.TryGetValue(_items, out items))
{
var source = ((IHasSourceObject <TSourceObject>)context.VM).Source;
Func <TItemSource, bool> reducedFilter = null;
if (IsActiveFilter != null)
{
reducedFilter = item => IsActiveFilter(source, item);
}
items = new SelectableItemsCollection <TItemSource>(
SelectionHelpers.GetAllSourceItems <TItemSource>(context.VM),
SelectionHelpers.GetSelectedSourceItems <TItemSource>(context.VM),
reducedFilter
);
context.FieldValues.SetValue(_items, items);
}
return(items);
}
