Android Open Source - SandB-Android Article List Fragment

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License

The source code is released under:

GNU General Public License

Java Source Code

package edu.grinnell.sandb;
/*w w w  .ja v  a 2 s.  c  o  m*/
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.TextView;

import com.actionbarsherlock.app.SherlockListFragment;

import edu.grinnell.sandb.data.Article;
import edu.grinnell.sandb.data.ArticleTable;

public class ArticleListFragment extends SherlockListFragment {

  public static String ARTICLE_CATEGORY_KEY = "category";
  // LinkedHashMap retains insertion ordering
  public static final Map<String, String> titleToKey = new LinkedHashMap<String, String>();

  public static final String[] CATEGORIES;

  // Fill in the a map to correspond to section tabs for the article list
  static {
    titleToKey.put("All", null);
    titleToKey.put("News", "News");
    titleToKey.put("Arts", "Arts");
    titleToKey.put("Community", "Community");
    titleToKey.put("Features", "Features");
    titleToKey.put("Opinion", "Opinion");
    titleToKey.put("Sports", "Sports");

    CATEGORIES = titleToKey.keySet().toArray(new String[0]);
  }

  public String mCategory;

  public static final String UPDATE = "edu.grinnell.sandb.UPDATE";
  private static final String STATE_ACTIVATED_POSITION = "activated_position";

  private Callbacks mCallbacks = sDummyCallbacks;
  private int mActivatedPosition = ListView.INVALID_POSITION;

  private ArticleListAdapter mAdapter;
  private List<Article> mData;
  private SwipeRefreshLayout pullToRefresh;
  private static final String TAG = "ArticleListFragment";

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
    // TODO restore from instance state
    Bundle b = getArguments();

    mCategory = null;
    if (b != null)
      mCategory = titleToKey.get(b.getString(ARTICLE_CATEGORY_KEY));

    // Retrieve the articles for the selected category
    mData = loadDataFromCache(mCategory);
    Log.i(TAG, "Loading data for the '" + mCategory + "' category..");

    if (mData == null)
      mData = new ArrayList<Article>();

    mAdapter = new ArticleListAdapter((MainActivity) getSherlockActivity(),
        R.layout.articles_row, mData);
  }

  // Retrieve the articles for a given category from the sqlite database 
  private List<Article> loadDataFromCache(String category) {
    ArticleTable table = new ArticleTable(getActivity());
    table.open();
    List<Article> data;
    data = table.findByCategory(category);
    table.close();
    return data;
  }

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {

    // Create new view and store inflated layout in a View.
    View rootView = inflater.inflate(R.layout.fragment_article_list,
        container, false);

    // Add Swipe-down to refresh functionality
    pullToRefresh = (SwipeRefreshLayout) rootView
        .findViewById(R.id.swipeRefresh);
    pullToRefresh.setOnRefreshListener(mRefresh);
    pullToRefresh.setColorScheme(R.color.gred,
      R.color.DarkGray, R.color.black,R.color.gred );
    return rootView;
  }

  
  // Set OnRefreshListener 
  OnRefreshListener mRefresh = new OnRefreshListener(){
    @Override
    public void onRefresh() {
      // Update the article list. 
      update();
      pullToRefresh.setRefreshing(true);
            Log.d("Swipe", "Refreshing Number");
            ( new Handler()).postDelayed(new Runnable() {
                @Override
                public void run() {
                    pullToRefresh.setRefreshing(false);
                    
                }
            }, 1500);
      // Stop the refreshing after list is updated
      //pullToRefresh.setRefreshing(false);
    }
  };
  
  @Override
  public void onActivityCreated(Bundle ofJoy) {
    super.onActivityCreated(ofJoy);
  }

  @Override
  public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    setListAdapter(mAdapter);

    if (savedInstanceState != null
        && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
      // setActivatedPosition(savedInstanceState.getInt(STATE_ACTIVATED_POSITION));
    }
  }

  /* Update the article list */
  public void update() {
    mData = loadDataFromCache(mCategory);
    mAdapter.clear();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
      mAdapter.addAll(mData);
    } else {
      for (Article a : mData) {
        mAdapter.add(a);
      }
    }

    mAdapter.notifyDataSetChanged();
  }

  /* If no articles are available, notify the user */
  public void setEmptyText(String text) {
    TextView empty = (TextView) getListView().getEmptyView();
    empty.setText(text);
  }

  @Override
  public void onDetach() {
    super.onDetach();
    mCallbacks = sDummyCallbacks;
  }

  /* Open the ArticleDetailActivity when a list item is selected */
  @Override
  public void onListItemClick(ListView listView, View view, int position,
      long id) {
    super.onListItemClick(listView, view, position, id);
    mCallbacks.onItemSelected(position);
    Intent detailIntent = new Intent(getSherlockActivity(),
        ArticleDetailActivity.class);
    detailIntent.putExtra(ArticleDetailFragment.ARTICLE_ID_KEY,
        mData.get(position).getId());
    detailIntent.putExtra(ArticleDetailActivity.COMMENTS_FEED,
        mData.get(position).getComments());
    startActivity(detailIntent);
    // Add a smooth animation
    getSherlockActivity().overridePendingTransition(R.anim.slide_in,
        R.anim.slide_out);
  }

  @Override
  public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    if (mActivatedPosition != ListView.INVALID_POSITION) {
      outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
    }
  }

  public void setActivateOnItemClick(boolean activateOnItemClick) {
    getListView().setChoiceMode(
        activateOnItemClick ? ListView.CHOICE_MODE_SINGLE
            : ListView.CHOICE_MODE_NONE);
  }

  public void setActivatedPosition(int position) {
    if (position == ListView.INVALID_POSITION) {
      getListView().setItemChecked(mActivatedPosition, false);
    } else {
      getListView().setItemChecked(position, true);
    }

    mActivatedPosition = position;
  }

  public interface Callbacks {
    public void onItemSelected(int position);

    public void setListActivateState();
  }

  private static Callbacks sDummyCallbacks = new Callbacks() {
    @Override
    public void onItemSelected(int position) {
    }

    @Override
    public void setListActivateState() {
    }
  };

  @Override
  public void onAttach(Activity activity) {
    super.onAttach(activity);
    if (!(activity instanceof Callbacks)) {
      throw new IllegalStateException(
          "Activity must implement fragment's callbacks.");
    }
    mCallbacks = (Callbacks) activity;
  }

}

Java Source Code List

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