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

Introduction

Here is the source code for com.google.gwt.gdata.sample.hellogdata.client.GDataPackagesDemo.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.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.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Label;

/**
 * The following example demonstrates how to load individual
 * GData packages.
 */
public class GDataPackagesDemo 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 GDataPackagesDemo();
            }

            @Override
            public String getDescription() {
                return "<p>This sample demonstrates how to load individual GData "
                        + "packages. In your GData apps you can enhance performance by "
                        + "loading only the GData packages that are used.</p>";
            }

            @Override
            public String getName() {
                return "API - Loading GData packages";
            }
        };
    }

    private FlexTable mainPanel;

    /**
     * Create the main content panel for this demo and call
     * showPackageStatus to display the load status
     * for each GData system package.
     */
    public GDataPackagesDemo() {
        mainPanel = new FlexTable();
        mainPanel.setCellPadding(4);
        mainPanel.setCellSpacing(0);
        initWidget(mainPanel);
        startDemo();
    }

    /**
     * Refreshes this demo by clearing the contents of
     * the main panel and calling showPackageStatus to
     * display the load status for each GData system package.
     */
    private void refreshDemo() {
        mainPanel.clear();
        showPackageStatus();
    }

    /**
     * Display the GData package statuses in a
     * tabular fashion with the help of a GWT FlexTable widget.
     * We initialize an array containing the name, icon
     * and url for each of the supported GData packages.
     * For each package a table row is added displaying the name,
     * page, link and icon, in addition to the load status.
     * The GData class contains the isLoaded method which is used
     * to retrieve the load status for a given package.
     */
    private void showPackageStatus() {
        String[][] systems = new String[][] {
                new String[] { "Google Analytics", "ANALYTICS", "gdata-analytics.png",
                        "http://code.google.com/apis/analytics/" },
                new String[] { "Google Base", "GBASE", "gdata-base.png", "http://code.google.com/apis/base/" },
                new String[] { "Google Blogger", "BLOGGER", "gdata-blogger.png",
                        "http://code.google.com/apis/blogger/" },
                new String[] { "Google Calendar", "CALENDAR", "gdata-calendar.png",
                        "http://code.google.com/apis/calendar/" },
                new String[] { "Google Contacts", "CONTACTS", "gdata-contacts.png",
                        "http://code.google.com/apis/contacts/" },
                new String[] { "Google Finance", "FINANCE", "gdata-finance.png",
                        "http://code.google.com/apis/finance/" },
                new String[] { "Google Maps", "MAPS", "gdata-maps.png",
                        "http://code.google.com/apis/maps/documentation/mapsdata/" },
                new String[] { "Google Sidewiki", "SIDEWIKI", "gdata-sidewiki.png",
                        "http://code.google.com/apis/sidewiki/" } };
        for (int i = 0; i < systems.length; i++) {
            String[] sys = systems[i];
            final String identifier = sys[1];
            mainPanel.insertRow(i);
            mainPanel.addCell(i);
            mainPanel.addCell(i);
            mainPanel.addCell(i);
            mainPanel.addCell(i);
            Image icon = new Image(sys[2]);
            mainPanel.setWidget(i, 0, icon);
            Label name = new HTML("<a href=\"" + sys[3] + "\">" + sys[0] + "</a>");
            mainPanel.setWidget(i, 1, name);
            Label statusLabel = new Label();
            Anchor actionLink = new Anchor();
            if (GData.isLoaded(GDataSystemPackage.valueOf(identifier))) {
                statusLabel.setText("Loaded");
            } else {
                statusLabel.setText("Not loaded");
                actionLink.setText("Load");
                actionLink.addClickHandler(new ClickHandler() {
                    public void onClick(ClickEvent event) {
                        GData.loadGDataApi(GDATA_API_KEY, new Runnable() {
                            public void run() {
                                refreshDemo();
                            }
                        }, GDataSystemPackage.valueOf(identifier));
                    }
                });
            }
            mainPanel.setWidget(i, 2, statusLabel);
            mainPanel.setWidget(i, 3, actionLink);
        }
    }

    /**
     * Starts this demo.
     */
    private void startDemo() {
        showPackageStatus();
    }
}