/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.waveprotocol.wave.model.conversation;
import java.util.Collection;
/**
* A forest of {@link Conversation} trees, usually viewed under some filter such
* as participation.
*
* @author anorth@google.com (Alex North)
*/
public interface ConversationView {
/**
* Gets the globally unique identifier of this group of conversations.
*
* @return the globally unique identifier of this group of conversations.
*/
String getId();
/**
* Gets a view of the conversations in this view. The collection is not
* modifiable.
*/
Collection<? extends Conversation> getConversations();
/**
* Retrieves a Conversation from the Conversation view by id.
*
* @param conversationId id of Conversation to return
* @return the Conversation with the given id, or null if no such conversation exists.
*/
Conversation getConversation(String conversationId);
// TODO(anorth/zdwang): remove the concept of a distinguished root.
/**
* Gets the root conversation from this view, if one exists.
*
* @return a conversation, or null
*/
Conversation getRoot();
/**
* Creates a root conversation in this view.
*
* @return the created conversation
* @throws IllegalStateException if this view already has a root conversation
*/
Conversation createRoot();
/**
* Creates a new conversation in this view.
*/
Conversation createConversation();
}