ActivityComponent.java

/*
 * Copyright (C) 2012 Google Inc.
 *
 * Licensed 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 interactivespaces.activity.component;

import interactivespaces.activity.Activity;
import interactivespaces.configuration.Configuration;

import java.util.List;

/**
 * A component which provides functionality to an {@link Activity}.
 *
 * @author Keith M. Hughes
 */
public interface ActivityComponent {

  /**
   * Get the name of the component.
   *
   * @return the name of the component
   */
  String getName();

  /**
   * Get all base dependencies for this component.
   *
   * @return all base dependencies
   */
  List<String> getBaseDependencies();

  /**
   * Add more dependencies to this component.
   *
   * <p>
   * Be careful with this, it is possible to make the dependency graph for this
   * component unsatisfiable.
   *
   * @param dependencies
   *          the additional dependencies
   */
  void addDependency(String... dependencies);

  /**
   * Get all dependencies for this component.
   *
   * @return all dependencies
   */
  List<String> getDependencies();

  /**
   * Set the context for the component.
   *
   * @param componentContext
   *          the context the component is running in
   */
  void setComponentContext(ActivityComponentContext componentContext);

  /**
   * Start up the component.
   *
   * @param configuration
   *          the configuration containing parameters for the web server
   */
  void configureComponent(Configuration configuration);

  /**
   * Start up the component.
   */
  void startupComponent();

  /**
   * Shutdown the component.
   */
  void shutdownComponent();

  /**
   * Is the component running?
   *
   * @return {@code true} if the component is running.
   */
  boolean isComponentRunning();

  /**
   * Get the component context the component is running under.
   *
   * @return the component context
   */
  ActivityComponentContext getComponentContext();

  /**
   * Get the component status detail.
   *
   * @return the component status detail
   */
  String getComponentStatusDetail();

  /**
   * Get a description of the component.
   *
   * @return the description of the component
   */
  String getDescription();
}