title: Why aren't all my listeners registered?
body: <pre><code>public interface DownloadListener {
      public void onDownloaded();
  }
  
  public class DownloadManager {
  
      private static DownloadManager instance;
  
      private DownloadListener mDownloadListener;
  
      public static synchronized DownloadManager getInstance(){
          if(instance == null)
              instance = new DownloadManager();
          return instance;
      }
  
  
      private DownloadManager() {
          myHandler.sendEmptyMessageDelayed(29, 3 * 1000);
      }
  
      public void registerDownloadListener(DownloadListener downloadListener) {
          mDownloadListener = downloadListener;
      }
  
      Handler myHandler = new Handler(new Handler.Callback() {
          @Override
          public boolean handleMessage(Message msg) {
              if (msg.what == 29) {
                  mDownloadListener.onDownloaded();
                  return true;
              }
              return false;
          }
      });
  }
  
  public class I implements DownloadListener {
  
      public I() {
          DownloadManager.getInstance().registerDownloadListener(this);
      }
  
      @Override
      public void onDownloaded() {
          Log.e("TAG", "I onDownloaded");
      }
  }
  
  public class You implements DownloadListener {
  
      public You() {
          DownloadManager.getInstance().registerDownloadListener(this);
      }
  
      @Override
      public void onDownloaded() {
          Log.e("TAG", "You onDownloaded");
      }
  
  }
  
  public class PATTERNSActivity extends Activity implements DownloadListener {
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);
  
          new I();
          new You();
  
          DownloadManager.getInstance().registerDownloadListener(this);
      }
  
      @Override
      public void onDownloaded() {
          Log.e("TAG","PATTERNSActivity onDownloaded");
      }
  
  }
  </code></pre>
  
  <p>I am expecting to get:</p>
  
  <blockquote>
    <p>I onDownloaded </p>
    
    <p>You onDownloaded </p>
    
    <p>PATTERNSActivity onDownloaded</p>
  </blockquote>
  
  <p>But I am getting only:</p>
  
  <blockquote>
    <p>PATTERNSActivity onDownloaded</p>
  </blockquote>
  
  <p>What could it be the problem?</p>