/// <inheritdoc/>
protected override bool CanReplaceItem(IObjectNode collection, NodeIndex index, object newItem)
{
if (collection.Type != typeof(EntityComponentCollection))
{
return(base.CanReplaceItem(collection, index, newItem));
}
if (newItem == null)
{
return(false);
}
var componentType = newItem.GetType();
// Cannot replace the transform component by another type of component
if (collection.IndexedTarget(index).Type == typeof(TransformComponent) && componentType != typeof(TransformComponent))
{
return(false);
}
if (!EntityComponentAttributes.Get(componentType).AllowMultipleComponents)
{
// Cannot replace components that disallow multiple components, unless it is that specific component we're replacing
var components = (EntityComponentCollection)collection.Retrieve();
if (components.Where((x, i) => x.GetType() == componentType && i != index.Int).Any())
{
return(false);
}
}
return(base.CanReplaceItem(collection, index, newItem));
}
/// <summary>
/// Indicates whether the target node of the item corresponding to the given index in the collection contained in the given node should be visited or not.
/// </summary>
/// <param name="collectionNode">The node to evaluate.</param>
/// <param name="index">The index of the item to evaluate.</param>
/// <returns>True if the node of the item corresponding to the given index in the collection contained in the given node should be visited, false otherwise.</returns>
/// <remarks>This method is invoked only when the given <see cref="IObjectNode"/> contains a collection with items being references.</remarks>
protected internal virtual bool ShouldVisitTargetItem([NotNull] IObjectNode collectionNode, NodeIndex index)
{
if (collectionNode == null)
{
throw new ArgumentNullException(nameof(collectionNode));
}
var target = collectionNode.IndexedTarget(index);
return(!visitedNodes.Contains(target));
}
public override void AddItem(object value)
{
if (Container.IndexedTarget(Index) == null || !Container.IndexedTarget(Index).IsEnumerable)
{
throw new NodePresenterException($"{nameof(MemberNodePresenter)}.{nameof(AddItem)} cannot be invoked on members that are not collection.");
}
try
{
Container.IndexedTarget(Index).Add(value);
}
catch (Exception e)
{
throw new NodePresenterException("An error occurred while adding an item to the node, see the inner exception for more information.", e);
}
}
/// <inheritdoc/>
protected override void ReplaceItem(IObjectNode collection, NodeIndex index, object newItem)
{
// If we're replacing the transform component, only manually copy allowed properties to the existing one.
if (collection.Type == typeof(EntityComponentCollection) && newItem is TransformComponent newTransform)
{
var node = collection.IndexedTarget(index);
node[nameof(TransformComponent.Position)].Update(newTransform.Position);
node[nameof(TransformComponent.Rotation)].Update(newTransform.Rotation);
node[nameof(TransformComponent.Scale)].Update(newTransform.Scale);
return;
}
base.ReplaceItem(collection, index, newItem);
}