protected override bool CanPasteIntoItem(IPasteResult pasteResult, AssetCompositeItemViewModel item, out string error)
{
// try to paste as hierarchy
var hierarchy = pasteResult.Items[0].Data as AssetCompositeHierarchyData <UIElementDesign, UIElement>;
if (hierarchy != null)
{
var contentControl = item as ContentControlViewModel;
if (contentControl != null && hierarchy.RootParts.Count > 1)
{
error = $"({contentControl.Name}) can only have one child as content. {hierarchy.RootParts.Count} elements can't be pasted into it.";
return(false);
}
}
return(base.CanPasteIntoItem(pasteResult, item, out error));
}
private static void ExpandElementRecursively([NotNull] TreeView treeView, AssetCompositeItemViewModel item)
{
// Since treeview can have virtualization and also a lot of items, we dispatch the recursive expansion amongst successive frames
treeView.Dispatcher.BeginInvoke(new Action(() =>
{
var viewItem = treeView.GetTreeViewItemFor(item);
if (viewItem == null)
{
return;
}
viewItem.IsExpanded = true;
foreach (var child in item.EnumerateChildren())
{
ExpandElementRecursively(treeView, child);
}
}), DispatcherPriority.ApplicationIdle);
}
