/// <summary>
/// Adds references to existing features referenced by this observation.
/// <para/>
/// This should be called by implementations of <c>Operation.AddReferences</c>
/// (for each instance of Observation that the operation involves). This ensures
/// that the features utilized by observations are cross-referenced to the editing
/// operations that depend on them.
/// </summary>
/// <param name="op">The operation that makes use of this observation</param>
internal void AddReferences(Operation op)
{
Feature[] features = GetReferences();
foreach (Feature f in features)
f.AddOp(op);
}
/// <summary> /// Performs actions when the operation that uses this observation is marked /// for deletion as part of its rollback function. This cuts any reference from any /// previously existing feature that was cross-referenced to the operation (see /// calls made to AddOp). /// </summary> /// <param name="op">The operation that makes use of this observation.</param> internal abstract void OnRollback(Operation op);