private void OnHeaderToggled(HeaderItem <TItem> headerItem)
{
// Doesn't seem to be any difference in the behavior for clicking the Header vs the checkmark in the header.
//does selection contain this item already?
if (Selection.SelectedItems.Contains(headerItem.Item))
{
//deselect it and all children
var items = SubGroupSelector(headerItem.Item)?.RecursiveSelect <TItem, TItem>(r => SubGroupSelector(r), i => i).Append(headerItem.Item);
SelectionZone.RemoveItems(items);
}
else
{
//select it and all children
var items = SubGroupSelector(headerItem.Item)?.RecursiveSelect <TItem, TItem>(r => SubGroupSelector(r), i => i).Append(headerItem.Item);
SelectionZone.AddItems(items);
}
}
protected override async Task OnParametersSetAsync()
{
if (SubGroupSelector != null)
{
//if (ItemsSource != null && !ItemsSource.Equals(_itemsSource))
//if (RootGroup != null && !RootGroup.Equals(_rootGroup))
if (ItemsSource != null && !ItemsSource.Equals(_itemsSource))
{
//dispose old subscriptions
_transformedDisposable?.Dispose();
_itemsSource = ItemsSource;
//_rootGroup = RootGroup;
if (_itemsSource != null)
//if (_rootGroup != null)
{
//var list = new System.Collections.Generic.List<TItem>();
//list.Add(_rootGroup);
var changeSet = _itemsSource.AsObservableChangeSet();
System.Collections.Generic.List <HeaderItem <TItem> > headersList = new System.Collections.Generic.List <HeaderItem <TItem> >();
Dictionary <int, int> depthIndex = new Dictionary <int, int>();
var rootIndex = 0;
var transformedChangeSet = changeSet.TransformMany <GroupedListItem <TItem>, TItem>((x) =>
{
var header = new HeaderItem <TItem>(x, null, rootIndex++, 0, GroupTitleSelector);
headersList.Add(header);
var children = SubGroupSelector(x).RecursiveSelect <TItem, GroupedListItem <TItem> >(
r => SubGroupSelector(r),
(s, index, depth) =>
{
if (!depthIndex.ContainsKey(depth))
{
depthIndex[depth] = 0;
}
var parent = headersList.FirstOrDefault(header => header.Depth == depth - 1 && SubGroupSelector(header.Item).Contains(s));
if (SubGroupSelector(s) == null || SubGroupSelector(s).Count() == 0)
{
var item = new PlainItem <TItem>(s, parent, index, depth);
parent?.Children.Add(item);
return(item);
}
else
{
var header = new HeaderItem <TItem>(s, parent, index, depth, GroupTitleSelector);
headersList.Add(header);
parent?.Children.Add(header);
return(header);
}
},
1);
return(Enumerable.Repeat(header, 1).Concat(children));
});
_transformedDisposable = transformedChangeSet
.AutoRefreshOnObservable(x => x.IsVisibleObservable)
.Filter(x => x.IsVisible)
.Sort(new GroupedListItemComparer <TItem>())
.Bind(out dataItems)
.Subscribe();
}
}
}
if (SelectionMode == SelectionMode.Single && Selection.SelectedItems.Count() > 1)
{
SelectionZone.ClearSelection();
}
else if (SelectionMode == SelectionMode.None && Selection.SelectedItems.Count() > 0)
{
Selection.ClearSelection();
}
else
{
bool hasChanged = false;
//make a copy of list
var selected = Selection.SelectedItems.ToList();
//check to see if a header needs to be turned OFF because all of its children are *not* selected.
restart:
var headers = selected.Where(x => SubGroupSelector(x) != null && SubGroupSelector(x).Count() > 0).ToList();
foreach (var header in headers)
{
if (SubGroupSelector(header).Except(selected).Count() > 0)
{
hasChanged = true;
selected.Remove(header);
//start loop over again, simplest way to start over is a goto statement. This is needed when a header turns off, but it's parent header needs to turn off, too.
goto restart;
}
}
//check to see if a header needs to be turned ON because all of its children *are* selected.
var potentialHeaders = dataItems.Where(x => selected.Contains(x.Item)).Select(x => x.Parent).Where(x => x != null).Distinct().ToList();
foreach (var header in potentialHeaders)
{
if (header.Children.Select(x => x.Item).Except(selected).Count() == 0)
{
if (!selected.Contains(header.Item))
{
selected.Add(header.Item);
hasChanged = true;
}
}
}
if (hasChanged)
{
SelectionZone.AddAndRemoveItems(selected.Except(Selection.SelectedItems).ToList(), Selection.SelectedItems.Except(selected).ToList());
}
}
await base.OnParametersSetAsync();
}
