com.taxigang.client.facebook.FacebookFactory.java Source code

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Here is the source code for com.taxigang.client.facebook.FacebookFactory.java

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/*
 * Copyright (C) 2010 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 com.taxigang.client.facebook;

import com.allen_sauer.gwt.log.client.Log;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.dom.client.ScriptElement;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.rpc.AsyncCallback;

/** Manages creating {@link FBConnection}s to receive messages from the server. */
public class FacebookFactory {

    private static final String FB_SRC = "http://connect.facebook.net/en_US/all.js";
    private static boolean scriptLoaded = false;
    private static AsyncCallback<ConnectState> thisCallback;

    public enum Action {
        WAIT, LOGIN
    };

    private static Command thisCommand;

    //public static FBConnection createFBConnection() {
    public static void createFBConnection(AsyncCallback<ConnectState> callback, Command command) {
        thisCallback = callback;
        thisCommand = command;
        Log.info("fb load begin: scriptLoaded=" + scriptLoaded);

        if (!scriptLoaded) {
            ScriptElement script = Document.get().createScriptElement();
            script.setSrc(FB_SRC);
            Document.get().getElementsByTagName("head").getItem(0).appendChild(script);
            addOnLoadHandler(script);
            waitAWhile(0, command);

        } else {
            Log.info("fbApiReady");
            fbApiReady();
        }

        //return createChannelImpl(channelId);
    }

    public static native void addOnLoadHandler(ScriptElement script)/*-{
                                                                    script.onload = function() {
                                                                    @com.taxigang.client.facebook.FacebookFactory::fbApiReady()();
                                                                    }
                                                                    // IE 6 & 7
                                                                    script.onreadystatechange = function() {
                                                                    if (this.readyState == 'complete') {
                                                                    @com.taxigang.client.facebook.FacebookFactory::fbApiReadyIE()();
                                                                    }
                                                                    }
                                                                        
                                                                    }-*/;

    public static void fbApiReadyIE() {
        Log.info("internet explorer fb api ready");
        fbApiReady();
    }

    public static void fbApiReady() {
        Log.info("fb api ready");
        scriptLoaded = true;

        thisCommand.execute();
        //FacebookApi.waitForAPI(new GetUserDetailsCallback());

    }

    private static void waitAWhile(final int counter, final Command command) {
        Timer timer = new Timer() {
            public void run() {
                Log.info("waitAWhile " + counter + " " + scriptLoaded);
                if (scriptLoaded) {
                    return;
                }
                int i = counter + 1;
                if (i > 8) {
                    Log.info("timed out " + scriptLoaded);
                    if (!scriptLoaded) {
                        createFBConnection(thisCallback, command);
                    }
                    return;
                }
                waitAWhile(i, command);
            }
        };
        timer.schedule(500);
    }

}