LoadMoreAsyncTask.java

package com.oreilly.android.otweet.tasks;

import java.util.ArrayList;

import android.os.AsyncTask;
import twitter4j.Paging;
import twitter4j.Twitter;
import twitter4j.TwitterException;

public class LoadMoreAsyncTask extends AsyncTask<Void, Void, LoadMoreAsyncTask.LoadMoreStatusesResult> {
  
  private long targetId;
  private boolean newerThanId;
  private Twitter twitter;
  private LoadMoreStatusesResponder responder;
  
  public interface LoadMoreStatusesResponder {
    public void loadingMoreStatuses();
    public void statusesLoaded(LoadMoreStatusesResult result);
  }
  
  public class LoadMoreStatusesResult {
    public ArrayList<twitter4j.Status> statuses;
    public boolean newer;
    public LoadMoreStatusesResult(ArrayList<twitter4j.Status> statuses, boolean newer) {
      super();
      this.statuses = statuses;
      this.newer = newer;
    }
  }
  
  public LoadMoreAsyncTask(
      LoadMoreStatusesResponder responder,
      Twitter twitter,
      long targetId,
      boolean newerThanId) {
    super();
    this.responder = responder;
    this.targetId = targetId;
    this.twitter = twitter;
    this.newerThanId = newerThanId;
  }

  @Override
  protected LoadMoreAsyncTask.LoadMoreStatusesResult doInBackground(Void...params) {
    ArrayList<twitter4j.Status> statii = null;
    try {
      if (newerThanId) {
          statii = twitter.getHomeTimeline(new Paging().sinceId(targetId));
      } else {
        statii = twitter.getHomeTimeline(new Paging().maxId(targetId));
      }
    } catch (TwitterException e) {
      throw new RuntimeException("Unable to load timeline", e);
    }
    
    return new LoadMoreStatusesResult(statii, newerThanId);
  }

  @Override
  public void onPreExecute() {
    responder.loadingMoreStatuses();
  }
  
  @Override
  public void onPostExecute(LoadMoreStatusesResult result) {
    responder.statusesLoaded(result);
  }


}