/// <summary>
/// Initializes a new instance of the <see cref="ElementCollection"/> class.
/// </summary>
/// <param name="owner">The parent of this collection.</param>
public ElementCollection(IElementParent owner)
{
this.owner = owner;
if (owner is ElementBase e)
{
this.composite = new ObservableComposite <IList <Vertex> >(MakeVerticesObservable(e));
}
else
{
this.composite = new ObservableComposite <IList <Vertex> >(Observable.Never <IList <Vertex> >());
}
}
/// <inheritdoc />
public void Add(ElementBase element)
{
if (element.Parent != null)
{
throw new ArgumentException("Can't add element that already has a parent");
}
element.Parent = this.owner;
if (element is IElementParent parent)
{
composite.Add(parent.SubElements.composite);
removalCallbacks.Add(element, parent.SubElements.composite.Remove);
}
else
{
var leaf = new ObservableComposite <IList <Vertex> >(MakeVerticesObservable(element));
composite.Add(leaf);
removalCallbacks.Add(element, leaf.Remove);
}
}
