Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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 com.vaadin.shared.communication; import java.io.Serializable; import java.util.HashMap; import java.util.Map; import java.util.Set; import com.vaadin.shared.Connector; import com.vaadin.shared.annotations.NoLayout; /** * Interface to be implemented by all shared state classes used to communicate * basic information about a {@link Connector} from server to client. * * Shared state classes have to be declared in shared package to be accessible * both for server and client code. * * Shared state objects are only sent from the server to the client, and any * modifications from the client should be performed via an RPC call that * modifies the authoritative state on the server. * * A shared state class should be a bean with getters and setters for each * field. Supported data types are simple Java types, other beans and maps and * arrays of these. * * On the client side the connector should override * {@link com.vaadin.client.ui.AbstractConnector#getState()} to return the * correct state type. This automatically causes a correct state object to be * created. * * Subclasses of a {@link Connector} using shared state should also provide a * subclass of the shared state class of the parent class to extend the state. A * single {@link Connector} can only have one shared state object. * * @since 7.0 */ public class SharedState implements Serializable { /** * The automatically managed resources used by the connector. * * @see com.vaadin.server.AbstractClientConnector#setResource(String, * com.vaadin.server.Resource) * @see com.vaadin.client.ui.AbstractConnector#getResourceUrl(String) */ public Map<String, URLReference> resources = new HashMap<>(); public boolean enabled = true; /** * A set of event identifiers with registered listeners. */ @NoLayout public Set<String> registeredEventListeners; }