WebSocket.java

/*
 * Copyright 2009 Mark Renouf
 * 
 * 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, WITHDIR
 * 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.google.gwt.nextgen.websocket.client;

import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.dom.client.ErrorEvent;
import com.google.gwt.event.dom.client.ErrorHandler;
import com.google.gwt.event.dom.client.HasErrorHandlers;
import com.google.gwt.event.shared.EventBus;
import com.google.gwt.event.shared.EventHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.event.shared.SimpleEventBus;
import com.google.gwt.nextgen.websocket.client.event.CloseEvent;
import com.google.gwt.nextgen.websocket.client.event.CloseHandler;
import com.google.gwt.nextgen.websocket.client.event.HasCloseHandlers;
import com.google.gwt.nextgen.websocket.client.event.HasMessageHandlers;
import com.google.gwt.nextgen.websocket.client.event.HasOpenHandlers;
import com.google.gwt.nextgen.websocket.client.event.MessageEvent;
import com.google.gwt.nextgen.websocket.client.event.MessageHandler;
import com.google.gwt.nextgen.websocket.client.event.OpenEvent;
import com.google.gwt.nextgen.websocket.client.event.OpenHandler;

public class WebSocket implements HasOpenHandlers, HasCloseHandlers,
    HasErrorHandlers, HasMessageHandlers {

  public static final int CONNECTING = 0;
  public static final int OPEN = 1;
  public static final int CLOSING = 2;
  public static final int CLOSED = 3;

  private WebSocketImpl socket;

  public static native boolean available() /*-{
    return !!$wnd.WebSocket;
  }-*/;

  /**
   * Requests a new WebSocket connection to the specified URL. The connection
   * is opened asynchronously. You must add an OpenListener immediately after
   * (before the next browser event loop), in order to ensure no events are
   * missed.
   *
   * @param url The websocket url to connect to, the protocol must be ws:// or wss://
   */
  public WebSocket(String url) {
    this.socket = WebSocketImpl.create(this, url);
  }

  public String getProtocol() {
    return socket.getProtocol();
  }

  public int getReadyState() {
    return socket.getReadyState();
  }

  public long getBufferedAmount() {
    return (long) socket.getBufferedAmount();
  }

  public void send(String message) {
    socket.send(message);
  }

  public void close() {
    socket.close();
  }

  private EventBus eventBus;

  void handleOpenEvent(NativeEvent e) {
    OpenEvent.fireNativeEvent(e, this);
  }

  void handleMessageEvent(NativeEvent e) {
    MessageEvent.fireNativeEvent(e, this);
  }

  void handleErrorEvent(NativeEvent e) {
    ErrorEvent.fireNativeEvent(e, this);
  }

  void handleCloseEvent(NativeEvent e) {
    CloseEvent.fireNativeEvent(e, this);
  }

  @Override
  public HandlerRegistration addMessageHandler(MessageHandler handler) {
    return ensureHandlers().addHandler(MessageEvent.getType(), handler);
  }

  @Override
  public HandlerRegistration addErrorHandler(ErrorHandler handler) {
    return ensureHandlers().addHandler(ErrorEvent.getType(), handler);
  }

  @Override
  public HandlerRegistration addCloseHandler(CloseHandler handler) {
    return ensureHandlers().addHandler(CloseEvent.getType(), handler);
  }

  @Override
  public HandlerRegistration addOpenHandler(OpenHandler handler) {
    return ensureHandlers().addHandler(OpenEvent.getType(), handler);
  }

  /**
   * Adds this handler to the widget.
   *
   * @param <H>
   *    the type of handler to add
   * @param type
   *    the event type
   * @param handler
   *    the handler
   * @return {@link HandlerRegistration} used to remove the handler
   */
  public final <H extends EventHandler> HandlerRegistration addHandler(
    final H handler, GwtEvent.Type<H> type) {
    return ensureHandlers().addHandler(type, handler);
  }

  /**
   * Ensures the existence of the handler manager.
   *
   * @return the handler manager
   */
  EventBus ensureHandlers() {
    return eventBus == null ? eventBus = createEventBus() : eventBus;
  }

  /**
   * Creates the {@link EventBus} used by this Widget. You can override this
   * method to create a custom {@link EventBus}.
   *
   * @return the {@link EventBus} you want to use
   */
  protected EventBus createEventBus() {
    return new SimpleEventBus();
  }

  public void fireEvent(GwtEvent<?> event) {
    if (eventBus != null) {
      eventBus.fireEvent(event);
    }
  }
}