View.java

/**
 * 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.client.wavepanel.view;

/**
 * Base interface for all views of wave panel components.
 *
 */
public interface View {

  //
  // The engineering intent of this enum is to encourage new view types to be
  // added only with a full understanding of what it means to add a new view
  // type, including implications for paging, server-side rendering, client-side
  // stitching, etc. Adding new view types is not be done lightly.
  //
  // As the universe of view objects grows, this set should be modularized for
  // ease of maintenance. However, a global set of all kinds still needs exist
  // somewhere, e.g., for disambiguation on even handling.
  //

  /**
   * View grammar:
   *
   * <pre>
   *   Wave ::= Conversation*
   *   Conversation ::= Participants RootThread
   *   Participants ::= Participant* Add
   *   RootThread ::= Blip*
   *   Blip ::= Meta Anchor* Conversation*
   *   Meta ::= MenuItem* DOM Anchor*
   *   Anchor ::= [ InlineThread ]
   *   InlineThread ::= Toggle Blip*
   * </pre>
   */
  enum Type {
    WAVE,
    ROOT_CONVERSATION,
    INLINE_CONVERSATION,
    ROOT_THREAD,
    REPLY_BOX,
    INLINE_THREAD,
    CONTINUATION_INDICATOR,
    TOGGLE,
    BLIP,
    META,
    MENU_ITEM,
    ANCHOR,
    PARTICIPANT,
    PARTICIPANTS,
    ADD_PARTICIPANT,
    NEW_WAVE_WITH_PARTICIPANTS,
  }

  Type getType();

  /**
   * Remove this view from the parent, if it has one.
   */
  void remove();
}