com.google.gwt.gdata.sample.hellogdata.client.MapsCreateMapDemo.java Source code

Introduction

Here is the source code for com.google.gwt.gdata.sample.hellogdata.client.MapsCreateMapDemo.java

Source

/*
 * Copyright 2008 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.google.gwt.gdata.sample.hellogdata.client;

import com.google.gwt.accounts.client.AuthSubStatus;
import com.google.gwt.accounts.client.User;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.gdata.client.GData;
import com.google.gwt.gdata.client.GDataSystemPackage;
import com.google.gwt.gdata.client.atom.Text;
import com.google.gwt.gdata.client.impl.CallErrorException;
import com.google.gwt.gdata.client.maps.MapEntry;
import com.google.gwt.gdata.client.maps.MapEntryCallback;
import com.google.gwt.gdata.client.maps.MapsService;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.Label;

/**
 * The following example demonstrates how to create a map.
 */
public class MapsCreateMapDemo extends GDataDemo {

    /**
     * This method is used by the main sample app to obtain
     * information on this sample and a sample instance.
     * 
     * @return An instance of this demo.
     */
    public static GDataDemoInfo init() {
        return new GDataDemoInfo() {

            @Override
            public GDataDemo createInstance() {
                return new MapsCreateMapDemo();
            }

            @Override
            public String getDescription() {
                return "<p>This sample demonstrates how to create and insert " + "a new map. The map feed post URL "
                        + "(http://maps.google.com/maps/feeds/maps/default/full) is used "
                        + "to insert a new map entry for the authenticated user.</p>";
            }

            @Override
            public String getName() {
                return "Maps - Creating a map";
            }
        };
    }

    private MapsService service;
    private FlexTable mainPanel;
    private final String scope = "http://maps.google.com/maps/feeds/maps/";

    /**
     * Setup the Google Maps service and create the main content panel.
     * If the user is not logged on to Google Maps display a message,
     * otherwise start the demo by creating a map.
     */
    public MapsCreateMapDemo() {
        mainPanel = new FlexTable();
        initWidget(mainPanel);
        if (!GData.isLoaded(GDataSystemPackage.MAPS)) {
            showStatus("Loading the GData Maps package...", false);
            GData.loadGDataApi(GDATA_API_KEY, new Runnable() {
                public void run() {
                    startDemo();
                }
            }, GDataSystemPackage.MAPS);
        } else {
            startDemo();
        }
    }

    /**
     * Create a map by inserting a map entry into
     * a maps feed.
     * Set the map's title and contents to an arbitrary string. Here
     * we prefix the title with 'GWT-Maps-Client' so that
     * we can identify which maps were created by this demo.
     * On success and failure, display a status message.
     * 
     * @param mapsFeedUri The uri of the maps feed into which to
     * insert the new map entry
     */
    private void createMap(String mapsFeedUri) {
        showStatus("Creating map...", false);
        MapEntry entry = MapEntry.newInstance();
        entry.setTitle(Text.newInstance());
        entry.getTitle().setText("GWT-Maps-Client - inserted map");
        service.insertEntry(mapsFeedUri, entry, new MapEntryCallback() {
            public void onFailure(CallErrorException caught) {
                showStatus("An error occurred while creating a map: " + caught.getMessage(), true);
            }

            public void onSuccess(MapEntry result) {
                showStatus("Created a map.", false);
            }
        });
    }

    /**
     * Displays a status message to the user.
     * 
     * @param message The message to display.
     * @param isError Indicates whether the status is an error status.
     */
    private void showStatus(String message, boolean isError) {
        mainPanel.clear();
        mainPanel.insertRow(0);
        mainPanel.addCell(0);
        Label msg = new Label(message);
        if (isError) {
            msg.setStylePrimaryName("hm-error");
        }
        mainPanel.setWidget(0, 0, msg);
    }

    /**
     * Starts this demo.
     */
    private void startDemo() {
        service = MapsService.newInstance("HelloGData_Maps_CreateMapDemo_v2.0");
        if (User.getStatus(scope) == AuthSubStatus.LOGGED_IN) {
            Button startButton = new Button("Create a map");
            startButton.addClickHandler(new ClickHandler() {
                public void onClick(ClickEvent event) {
                    createMap("http://maps.google.com/maps/feeds/maps/default/full");
                }
            });
            mainPanel.setWidget(0, 0, startButton);
        } else {
            showStatus("You are not logged on to Google Maps.", true);
        }
    }
}