Android Open Source - cheepcheep Home Timeline Activity

From Project

Back to project page cheepcheep.
License

The source code is released under:
Apache License
If you think the Android project cheepcheep listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
Java Source Code

package org.tarrio.cheepcheep;
/* www.j  a  v a2 s.c  om*/
import java.util.Date;
import java.util.List;

import org.tarrio.cheepcheep.R;
import org.tarrio.cheepcheep.dialog.NewTweetDialog;
import org.tarrio.cheepcheep.model.Preferences;
import org.tarrio.cheepcheep.model.Tweet;
import org.tarrio.cheepcheep.service.PreferencesProvider;
import org.tarrio.cheepcheep.service.TwitterStatusSaverService;
import org.tarrio.cheepcheep.task.AsyncTwitterTask;
import org.tarrio.cheepcheep.task.TaskCallback;
import org.tarrio.cheepcheep.task.UpdateTweetsTask;

import android.app.ListActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.AdapterContextMenuInfo;

public class HomeTimelineActivity extends ListActivity {

  // Time interval in ms during which two updates will turn the second update
  // into a full reload.
  private static final long RELOAD_INTERVAL = 5 * 1000;

  private List<Tweet> tweets;
  private TweetListAdapter tweetListAdapter;
  private PreferencesProvider preferencesProvider;
  private TwitterStatusSaverService twitterStatusSaver;
  private TweetListActions tweetListActions;

  private long lastUpdateTimestamp;

  /**
   * Returns the view's PreferencesProvider object.
   * 
   * @return a PreferencesProvider object.
   */
  public PreferencesProvider getPreferencesProvider() {
    return preferencesProvider;
  }

  /**
   * Called when the activity is first created.
   */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setupView();

    preferencesProvider = new PreferencesProvider(this);
    twitterStatusSaver = new TwitterStatusSaverService(this);
    tweets = twitterStatusSaver.loadTimeline();
    tweetListActions = new TweetListActions(this, preferencesProvider,
        tweets, new UpdateTweetsCallback(), new ReloadTweetsCallback());
    lastUpdateTimestamp = 0L;
    
    changeView();
    tweetListAdapter = new TweetListAdapter(this, tweets);
    setListAdapter(tweetListAdapter);
    updateTweets();
  }

  @Override
  public boolean onPrepareOptionsMenu(Menu menu) {
    menu.clear();
    getMenuInflater().inflate(R.menu.mainmenu, menu);
    if (hasCredentials(preferencesProvider.get())) {
      menu.removeItem(R.id.Signin);
      return true;
    } else {
      return false;
    }
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.NewTweet:
      newTweet();
      return true;
    case R.id.Update:
      updateTweets();
      return true;
    case R.id.Signin:
      signIn();
      return true;
    case R.id.Signout:
      signOut();
      return true;
    default:
      return super.onOptionsItemSelected(item);
    }
  }

  @Override
  public void onCreateContextMenu(ContextMenu menu, View v,
      ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    tweetListActions.createContextMenuForTweet(menu, menuInfo);
  }

  @Override
  public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
        .getMenuInfo();
    Tweet tweet = tweets.get((int) info.id);
    if (tweetListActions.processContextItemSelectedForTweets(item, tweet))
      return true;
    else
      return super.onContextItemSelected(item);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == Constants.RESULT_UPDATE)
      updateTweets();
    else if (resultCode == Constants.RESULT_RELOAD)
      reloadTweets();
  }

  @Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
    tweetListActions.createMenuForTweetAtPosition(position);
  }

  /**
   * Displays the dialog box for creating a new tweet.
   */
  private void newTweet() {
    new NewTweetDialog(this, preferencesProvider,
        new UpdateTweetsCallback(), null, null, 0L).show();
  }

  /**
   * Loads any new tweets, adds them to the current list of tweets, and
   * updates the displayed tweet list. If an update was done less than
   * RELOAD_INTERVAL milliseconds ago, it will be a full reload.
   */
  private void updateTweets() {
    long now = new Date().getTime();
    loadMoreTweets(now - lastUpdateTimestamp <= RELOAD_INTERVAL);
  }

  /**
   * Clears the caches and reloads all tweets.
   */
  private void reloadTweets() {
    loadMoreTweets(true);
  }

  /**
   * Loads tweets and updates the displayed tweet list.
   * 
   * @param reload
   *            if true, it will load new tweets to append to the current list
   *            of tweets; otherwise, it will clear the list and reload all
   *            tweets.
   */
  private void loadMoreTweets(final boolean reload) {
    long topId = (reload || tweets.isEmpty()) ? 0L : tweets.get(0).getId();

    TaskCallback callback = new TaskCallback() {
      @Override
      public void onSuccess(AsyncTwitterTask t) {
        UpdateTweetsTask task = (UpdateTweetsTask) t;
        long minKeepId = 0L;

        if (reload) {
          tweets.clear();
          twitterStatusSaver.clear();
          changeView();
        }

        List<Tweet> newTweets = task.getNewTweets();
        if ((newTweets != null) && (newTweets.size() > 0)) {
          tweets.addAll(0, newTweets);
          if (tweets.size() > Constants.HOME_MAX_TWEETS) {
            minKeepId = tweets.get(Constants.HOME_MAX_TWEETS - 1)
                .getId();
          }
          twitterStatusSaver.appendToTimeline(newTweets, minKeepId);
          while (tweets.size() > Constants.HOME_MAX_TWEETS)
            tweets.remove(tweets.size() - 1);
        }
        lastUpdateTimestamp = new Date().getTime();
        tweetListAdapter.notifyDataSetChanged();
      }

      @Override
      public void onFailure(int statusCode, AsyncTwitterTask task) {
        lastUpdateTimestamp = new Date().getTime();
        tweetListAdapter.notifyDataSetChanged();
      }
    };
    new UpdateTweetsTask(this, preferencesProvider.get(), callback, topId)
        .run();
  }

  private void clearTweets() {
    tweets.clear();
    twitterStatusSaver.clear();
    changeView();
    tweetListAdapter.notifyDataSetChanged();
  }

  /**
   * Signs in to Twitter using OAuth
   */
  private void signIn() {
    Intent i = new Intent(Constants.ACTION_OAUTH, Uri.parse(""), this,
        OAuthActivity.class);
    startActivityForResult(i, Constants.DO_OAUTH);
  }

  /**
   * Deletes the OAuth credentials
   */
  private void signOut() {
    Preferences pref = preferencesProvider.get();
    clearCredentials(pref);
    preferencesProvider.save(pref);
    clearTweets();
  }

  /**
   * Returns whether the given preferences object has some (presumably valid)
   * credentials.
   * 
   * @param pref
   *            a preferences object.
   * @return whether the given preferences object has some (presumably valid)
   *         credentials.
   */
  private boolean hasCredentials(Preferences pref) {
    return !"".equals(pref.getConsumerToken());
  }

  /**
   * Clears the credentials from the given preferences object.
   * 
   * @param pref
   *            the preferences object.
   */
  private void clearCredentials(Preferences pref) {
    pref.setUsername("");
    pref.setConsumerToken("");
    pref.setConsumerSecret("");
  }

  /**
   * Sets the activity's view up.
   */
  private void setupView() {
    setContentView(R.layout.hometimeline);
    String appName = getString(R.string.app_name);
    String noAuthText = String.format(getString(R.string.noauth_text),
        appName);
    ((TextView) findViewById(R.id.NoAuthText)).setText(noAuthText);
    registerForContextMenu(getListView());
  }

  /**
   * Changes the view in the window depending on whether the user is
   * authenticated or not.
   */
  private void changeView() {
    Preferences prefs = preferencesProvider.get();
    String appName = getString(R.string.app_name);

    if (hasCredentials(prefs)) {
      String userName = prefs.getUsername();
      String titleFormat = getString(R.string.home_timeline_title);
      setTitle(String.format(titleFormat, appName, userName));
      findViewById(R.id.NoAuthTextLayout).setVisibility(View.GONE);
      findViewById(android.R.id.list).setVisibility(View.VISIBLE);
      registerForContextMenu(findViewById(android.R.id.list));
    } else {
      setTitle(appName);
      Button signinButton = (Button) findViewById(R.id.Signin);
      signinButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
          signIn();
        }
      });
      findViewById(R.id.NoAuthTextLayout).setVisibility(View.VISIBLE);
      findViewById(android.R.id.list).setVisibility(View.GONE);
    }
  }

  private class UpdateTweetsCallback implements TaskCallback {
    /**
     * Updates the tweets after posting a tweet.
     */
    @Override
    public void onSuccess(AsyncTwitterTask task) {
      updateTweets();
    }

    /**
     * Does nothing if posting fails.
     */
    @Override
    public void onFailure(int statusCode, AsyncTwitterTask task) {
    }
  }

  private class ReloadTweetsCallback implements TaskCallback {
    /**
     * Reloads all tweets after deleting a tweet.
     */
    @Override
    public void onSuccess(AsyncTwitterTask task) {
      reloadTweets();
    }

    /**
     * Does nothing if deleting a tweet fails.
     */
    @Override
    public void onFailure(int statusCode, AsyncTwitterTask task) {
    }
  }

}
Java Source Code List
