BackgroundFetchTest.java

package com.codename1.test.bgfetch;


import com.codename1.background.BackgroundFetch;
import com.codename1.components.SpanLabel;
import com.codename1.ui.Display;
import com.codename1.ui.Form;
import com.codename1.ui.Dialog;
import com.codename1.ui.Label;
import com.codename1.ui.plaf.UIManager;
import com.codename1.ui.util.Resources;
import com.codename1.io.Log;
import com.codename1.ui.Toolbar;
import com.codename1.util.Callback;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;
import com.codename1.io.ConnectionRequest;
import com.codename1.io.NetworkManager;
import com.codename1.io.services.RSSService;
import java.util.List;
import com.codename1.ui.layouts.BoxLayout;
import com.codename1.io.services.RSSService;
import com.codename1.ui.Container;


/**
 * A simple demo showing the use of the Background Fetch API.  This demo will load
 * data from the Slashdot RSS feed while it is in the background.
 * 
 * To test it out, put the app into the background (or select Pause App in the simulator)
 * and wait 10 seconds.  Then open the app again. You should see that the data is loaded.
 */
public class BackgroundFetchTest implements BackgroundFetch {

    private Form current;
    private Resources theme;
    List<Map> records;
    
    // Container to hold the list of records.
    Container recordsContainer;

    public void init(Object context) {
        theme = UIManager.initFirstTheme("/theme");

        // Enable Toolbar on all Forms by default
        Toolbar.setGlobalToolbar(true);

        // Pro only feature, uncomment if you have a pro subscription
        // Log.bindCrashProtection(true);
    }
    
    public void start() {
        if(current != null){
            // Make sure we update the records as we are coming in from the 
            // background.
            updateRecords();
            current.show();
            return;
        }
        Display d = Display.getInstance();
        
        // This call is necessary to initialize background fetch
        d.setPreferredBackgroundFetchInterval(10);
        
        Form hi = new Form("Background Fetch Demo");
        hi.setLayout(new BoxLayout(BoxLayout.Y_AXIS));

        Label supported = new Label();
        if (d.isBackgroundFetchSupported()){
            supported.setText("Background Fetch IS Supported");
        } else {
            supported.setText("Background Fetch is NOT Supported");
        }
        
        hi.addComponent(new Label("Records:"));
        recordsContainer = new Container(new BoxLayout(BoxLayout.Y_AXIS));
        //recordsContainer.setScrollableY(true);
        hi.addComponent(recordsContainer);
        
        
        
        hi.addComponent(supported);
        updateRecords();
        hi.show();
    }

    /**
     * Update the UI with the records that are currently loaded.
     */
    private void updateRecords() {
        recordsContainer.removeAll();
        if (records != null) {
            for (Map m : records) {
                recordsContainer.addComponent(new SpanLabel((String)m.get("title")));
            }
        } else {
            recordsContainer.addComponent(new SpanLabel("Put the app in the background, wait 10 seconds, then open it again.  The app should background fetch some data from the Slashdot RSS feed and show it here."));
        }
        if (Display.getInstance().getCurrent() != null) {
            Display.getInstance().getCurrent().revalidate();
        }
    }
    
    public void stop() {
        current = Display.getInstance().getCurrent();
        if(current instanceof Dialog) {
            ((Dialog)current).dispose();
            current = Display.getInstance().getCurrent();
        }
    }
    
    public void destroy() {
    }

    /**
     * This method will be called in the background by the platform.  It will
     * load the RSS feed.  Note:  This only runs when the app is in the background.
     * @param deadline
     * @param onComplete 
     */
    @Override
    public void performBackgroundFetch(long deadline, Callback<Boolean> onComplete) {
        RSSService rss = new RSSService("http://rss.slashdot.org/Slashdot/slashdotMain");
        NetworkManager.getInstance().addToQueueAndWait(rss);
        records = rss.getResults();
        System.out.println(records);
        onComplete.onSucess(Boolean.TRUE);

    }

}