DOP and DVMH

using System.Collections.Generic;

namespace Pfz.DistributableObservablePoco
{
	/// <summary>
	/// Represents a collection of the components available in a room.
	/// Using objects of this type it is possible to add and remove
	/// components to the room, as well as get their ID or enumerate them.
	/// </summary>
	public interface IDopRoomComponents:
		IEnumerable<object>
	{
		/// <summary>
		/// Tries to adds a component to the room and returns its ID.
		/// </summary>
		object Add(object component, out bool wasAdded, IDopCommunicationToParticipant owner=null);

		/// <summary>
		/// Tries to add a component to the room. This method returns true if the component
		/// was really added or false if such component was already in the room.
		/// </summary>
		bool Add(object component, IDopCommunicationToParticipant owner=null);

		/// <summary>
		/// Gets the owner of a component.
		/// The isValid out parameter returns true if the component is in this room,
		/// even if it doesn't has an owner, false if the component is not in this room.
		/// </summary>
		IDopCommunicationToParticipant TryGetOwner(object component, out bool isValid);

		/// <summary>
		/// Removes the given component from this room and returns the Id that was used
		/// by it. A return of null means that the component was not in the room to start with.
		/// </summary>
		object Remove(object component);

		/// <summary>
		/// Removes a component by its id and returns such removed component.
		/// A return of null means that a component with the given id doesn't exist.
		/// </summary>
		object RemoveById(object id);


		// Should support an input of null, returning null.
		/// <summary>
		/// Tries to get the ID of a component.
		/// This method returns null if the component is not part of the room.
		/// An input parameter of null also returns null.
		/// </summary>
		object TryGetId(object component);

		/// <summary>
		/// Tries to get a component by its ID.
		/// If a component with the given ID doesn't exist the return is null.
		/// An input parameter of null also returns null.
		/// </summary>
		object TryGetComponent(object id);
	}
}