Android Open Source - android.app.niuz.io News Headers Activity

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License

The source code is released under:

GNU General Public License

Java Source Code

package io.niuz;
//from   w  w  w .  j  av  a  2  s .  co  m
import io.niuz.model.APIRetrievalStatus;
import io.niuz.model.News;
import io.niuz.services.NewsService;
import io.niuz.services.PhoneService;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import android.app.Activity;
import android.app.ListActivity;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class NewsHeadersActivity extends ListActivity {
  private NewsAdapter newsAdapter;
  private News[] objects;
  
  private Context context;
  
  private NewsHeadersRetrievalTask newsHeadersRetrievalTask;
  
  private void toast(String message) {
    PhoneService.toast(message, this);
  }
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_news_headers);
    this.context = this;
  }
  
  @Override
  protected void onPause() {
    super.onPause();
    if (newsHeadersRetrievalTask != null) {
      newsHeadersRetrievalTask.cancel(true);
    }
  }

  @Override
  protected void onResume() { 
    super.onResume();
    try {
      if (mustRenewObjects()) {
        toast("Retrieving news headers");
        if (newsHeadersRetrievalTask == null || newsHeadersRetrievalTask.getStatus() != AsyncTask.Status.RUNNING) {
          newsHeadersRetrievalTask = new NewsHeadersRetrievalTask();
          newsHeadersRetrievalTask.execute();
        }  
      }

    } catch (ParseException e) {
      toast("Error occurred while parsing dates");
    }
  }
  
  private boolean mustRenewObjects() throws ParseException {
    if (objects == null || objects.length == 0) {
      return true;

    } else {
      return NewsService.isNewsTooOld(objects[0]);
    }
  }
  
  private void sortAndShuffleNewsList(List<News> newsList) {
    if (newsList == null || newsList.size() <= 1) {
      return;
    }
    
    // Sorting descending
    Collections.sort(newsList, new Comparator<News>(){
      @Override
      public int compare(News arg0, News arg1) {        
        return (arg0.getSubcategoryWeight() == arg1.getSubcategoryWeight()
          ? 0
          : arg0.getSubcategoryWeight() > arg1.getSubcategoryWeight()
            ? -1
            : 1);
      }}
    );
    
    // Shuffling those with the same weight
    List<News> finalListToReturn = new ArrayList<News>(newsList.size());
    List<News> listToShuffle = new ArrayList<News>();
    Long lastItemWeight = null;
    
    // The algorithm below functions only if list is sorted in descending order
    for (int i=0 ; i<newsList.size() ; i++) {
      if (lastItemWeight == null 
          || newsList.get(i).getSubcategoryWeight() == lastItemWeight) {
        lastItemWeight = newsList.get(i).getSubcategoryWeight();
        listToShuffle.add(newsList.get(i));
        
        if (newsList.size() - 1 == i) {
          finalListToReturn.addAll(listToShuffle);
        }

      } else {
        Collections.shuffle(listToShuffle);
        finalListToReturn.addAll(listToShuffle);
        listToShuffle.clear();
        lastItemWeight = null;
      }
    }
    
    // Reinitializing the parameter list
    newsList.clear();
    newsList.addAll(finalListToReturn);
  }
  
  private void afterNewsRetrieval() {
    List<News> retrievedNewsFromTheServer = NewsService.getNewsList();

    if (retrievedNewsFromTheServer.size() == 0) {
      toast("Failed retrieving news list");
      
    } else {
      // Sorting for reading
      sortAndShuffleNewsList(retrievedNewsFromTheServer);

      // Initializing an array
      objects = new News[retrievedNewsFromTheServer.size()];
      for (int i=0 ; i<objects.length ; i++) {
        objects[i] = retrievedNewsFromTheServer.get(i);
      }
      
      // Initializing an adapter
      if (newsAdapter == null) {
        newsAdapter = new NewsAdapter(this, R.layout.view_news_header, objects);
        this.getListView().setAdapter(newsAdapter);
      }
      newsAdapter.notifyDataSetChanged();
      toast("News retrieval is complete");
    }
  }
  
  private class NewsHeadersRetrievalTask extends AsyncTask<Object, Object, APIRetrievalStatus> {
    @Override
    protected APIRetrievalStatus doInBackground(Object... arg0) {
      try {
        NewsService.initNewsList(context);
        return APIRetrievalStatus.SUCCESS;

      } catch (Exception e) {
        return APIRetrievalStatus.ERROR;
      }
    }
    
    @Override
    protected void onPostExecute(APIRetrievalStatus result) {
      switch (result) {
      case SUCCESS:
        afterNewsRetrieval();
        break;

      case ERROR:
        toast("Failed to retrieve news!");
      }
    }
  }
  
  private static class NewsHeaderRowHolder {
    TextView newsTitle;
    TextView newsSubcategoryName;
    TextView newsCompanyName;
  }
  
  private class NewsAdapter extends ArrayAdapter<News> {
    Context context;
    int resource;
    News[] objects;
    
    public NewsAdapter(Context context, int resource, News[] objects) {
      super(context, resource, objects);
      this.context = context;
      this.resource = resource;
      this.objects = objects;
    }
    
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
      View rowView = convertView;
      NewsHeaderRowHolder holder;
      
      // Init data object
      News dataObject = objects[position];
      
      // Creating row if it's not created
      if (rowView == null) {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        rowView = inflater.inflate(resource, null);
        
        holder = new NewsHeaderRowHolder();
        holder.newsTitle = (TextView)rowView.findViewById(R.id.news_header);
        holder.newsSubcategoryName = (TextView)rowView.findViewById(R.id.news_subcategory_name);
        holder.newsCompanyName = (TextView)rowView.findViewById(R.id.news_company);
        rowView.setTag(holder);
      } else {
        holder = (NewsHeaderRowHolder)rowView.getTag();  
      }
      
      // Populating data  
      holder.newsTitle.setText(dataObject.getTitle());
      holder.newsSubcategoryName.setText(dataObject.getSubcategoryName());
      holder.newsCompanyName.setText(dataObject.getNewsCompanyName());
      
      rowView.setOnClickListener(new OnNewsHeaderClickListener(dataObject));
      return rowView;
    }
    
    private class OnNewsHeaderClickListener implements View.OnClickListener {
      private News dataObject;
      
      OnNewsHeaderClickListener(News dataObject) {
        this.dataObject = dataObject;
      }
      
      @Override
      public void onClick(View view) {
        NewsReaderActivity.setNewsToRead(dataObject);
        startActivity(new Intent(context, NewsReaderActivity.class));
      }
    }
  }
  
  @Override
  public void onBackPressed() {
    startActivity(new Intent(context, PreMainActivity.class));
  }
}

Java Source Code List

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