Android Open Source - NearestRestaurants Nearest Restaurants List Fragment

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Back to project page NearestRestaurants.

License

The source code is released under:

Apache License

Java Source Code

package com.jiahaoliuliu.nearestrestaurants;
//w  w  w. j  a va  2  s.  c o m
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnScrollChangedListener;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.TextView;
import android.widget.Toast;

import com.actionbarsherlock.app.SherlockListFragment;
import com.google.android.gms.maps.model.LatLng;
import com.jiahaoliuliu.nearestrestaurants.interfaces.OnPositionRequestedListener;
import com.jiahaoliuliu.nearestrestaurants.interfaces.OnProgressBarShowRequestListener;
import com.jiahaoliuliu.nearestrestaurants.interfaces.OnRefreshRequestedListener;
import com.jiahaoliuliu.nearestrestaurants.interfaces.OnUpdatePositionListener;
import com.jiahaoliuliu.nearestrestaurants.interfaces.RequestRestaurantsCallback;
import com.jiahaoliuliu.nearestrestaurants.models.Restaurant;
import com.jiahaoliuliu.nearestrestaurants.session.ErrorHandler;
import com.jiahaoliuliu.nearestrestaurants.session.Session;
import com.jiahaoliuliu.nearestrestaurants.session.ErrorHandler.RequestStatus;

/**
 * The fragment used to show the list of the restaurants when the users position
 * is known.
 * @author Jiahao Liu
 */
public class NearestRestaurantsListFragment extends SherlockListFragment
    implements OnUpdatePositionListener, OnScrollListener, OnRefreshRequestedListener {

    private static final String LOG_TAG = NearestRestaurantsListFragment.class.getSimpleName();

    // Interfaces
    private OnPositionRequestedListener onPositionRequestedListener;
    private OnProgressBarShowRequestListener onProgressBarShowRequestListener;

    private Context context;
    private Session session;

    // The list adapter
    private RestaurantListAdapter restaurantListAdapter;

    // The user position
    private LatLng myActualPosition; 

    // The token for the next page
    private String nextPageToken;
    
    // Set if the list is loading or not
    private boolean isLoadingMoreRestaurants = false;;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        this.context = activity;
        session = Session.getCurrentSession(context);

        // Check the onPositionRequestedListener
        try {
            onPositionRequestedListener = (OnPositionRequestedListener)activity;
            myActualPosition = onPositionRequestedListener.requestPosition();
            updateRestaurants();
        } catch (ClassCastException classCastException) {
            Log.e(LOG_TAG, "The attached activity must implements the OnPositionRequestedListener", classCastException);
        }

        // Check the onProgressBarShowRequestListener
        try {
          onProgressBarShowRequestListener = (OnProgressBarShowRequestListener) activity;
        } catch (ClassCastException classCastException) {
          Log.e(LOG_TAG, "The attached activity must implements the OnProgressBarShowRequestListener", classCastException);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,  
        Bundle savedInstanceState) {
        return super.onCreateView(inflater, container, savedInstanceState);
    }

    @Override
    public void onActivityCreated(Bundle arg0) {
        super.onActivityCreated(arg0);
        getListView().setOnScrollListener(this);
    }

    @Override
    public void updatePosition(LatLng newPosition) {
        myActualPosition = newPosition;
        updateRestaurants();
    }

    /**
     * Update the list of the restaurants based on the position of the user
     */
    private void updateRestaurants() {
        if (myActualPosition == null) {
            Log.e(LOG_TAG, "Trying to update the list of the restaurants when the position of the user is unknown.");
            return;
        }

        if (session == null) {
          Log.w(LOG_TAG, "Trying to upate the list of the restaurants when the session is not ready");
          return;
        }

        session.getRestaurantsNearby(myActualPosition, new RequestRestaurantsCallback() {

            @Override
            public void done(List<Restaurant> restaurants,
                             String newNextPageToken,
                             String errorMessage,
                             RequestStatus requestStatus) {
                if (!ErrorHandler.isError(requestStatus)) {
                    Log.v(LOG_TAG, "List of the restaurants returned correctly");
                    nextPageToken = newNextPageToken;
                    showRestaurantList(restaurants);
                } else {
                    Toast.makeText(context, errorMessage, Toast.LENGTH_LONG).show();

                    // Remove the next page token saved
                    nextPageToken = null;
                    // If there is any error about Internet connection but the list of
                    // restaurants has been retrieved offline, draw them on the map
                    if (requestStatus == RequestStatus.ERROR_REQUEST_NOK_HTTP_NO_CONNECTION
                        && restaurants != null) {
                      showRestaurantList(restaurants);
                    }

                }
            }
        });
    }

    /**
     * Show the list of restaurants as list
     * @param restaurants
     */
    private void showRestaurantList(List<Restaurant> restaurants) {
        // Check if the restaurant list adapter exists before
        // If not
        if (restaurantListAdapter == null) {
            restaurantListAdapter = new RestaurantListAdapter(context, restaurants);
            setListAdapter(restaurantListAdapter);
        } else {
            restaurantListAdapter.setRestaurants(restaurants);
        }
    }

  @Override
  public void onScroll(AbsListView view, int firstVisibleItem,
      int visibleItemCount, int totalItemCount) {
    
    boolean loadMoreRestaurants =
        firstVisibleItem + visibleItemCount >= totalItemCount;

    boolean moreDataAvailable =
        (nextPageToken != null && !nextPageToken.equalsIgnoreCase(""));

    if (loadMoreRestaurants && moreDataAvailable && !isLoadingMoreRestaurants) {
      Log.v(LOG_TAG, "Load more restaurants request send and more restaurants are available. Loading.");
      // Show the progress bar
      onProgressBarShowRequestListener.showProgressBar();
      
      isLoadingMoreRestaurants = true;
      // The app is requesting for more data and there is more data available.
      // Requesting them
      Toast.makeText(context, R.string.loading_new_restaurants, Toast.LENGTH_LONG).show();
      session.getRestaurantsNearbyNextPage(nextPageToken, new RequestRestaurantsCallback() {
        
        @Override
        public void done(List<Restaurant> newRestaurants, String newNextPageToken,
            String errorMessage, RequestStatus requestStatus) {
          isLoadingMoreRestaurants = false;
          // Disable the progress bar
          onProgressBarShowRequestListener.hidePorgressBar();

          if (!ErrorHandler.isError(requestStatus)) {
            nextPageToken = newNextPageToken;
            restaurantListAdapter.addMoreRestaurants(newRestaurants);
          } else {
            Toast.makeText(context, errorMessage, Toast.LENGTH_LONG).show();

                      // Remove the next page token saved
                      nextPageToken = null;

                      // If there is any error about Internet connection but the list of
                      // restaurants has been retrieved offLine, reset the list
                      if (requestStatus == RequestStatus.ERROR_REQUEST_NOK_HTTP_NO_CONNECTION
                          && newRestaurants != null) {
                        showRestaurantList(newRestaurants);
                      }
          }
        }
      });
    }
  }

  @Override
  public void onScrollStateChanged(AbsListView view, int scrollState) {
    // Do nothing
  }

  @Override
  public void refresh() {
    Log.v(LOG_TAG, "Refresh received");
    updateRestaurants();
  }
}

Java Source Code List

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