Android Open Source - android-002 Place View Activity

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License

The source code is released under:
Apache License
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Java Source Code

package course.labs.locationlab;
/*w  w w  .  j a  v  a 2s. c  o m*/
import static android.location.LocationManager.NETWORK_PROVIDER;
import android.app.ListActivity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ListView;
import android.widget.Toast;

public class PlaceViewActivity extends ListActivity implements LocationListener {
  private static final long FIVE_MINS = 5 * 60 * 1000;
  private static final String TAG = "Lab-Location";

  // Set to false if you don't have network access
//  public static boolean sHasNetwork = false;
  public static boolean sHasNetwork = true;

  private Location mLastLocationReading;
  private PlaceViewAdapter mAdapter;
  private LocationManager mLocationManager;
  private boolean mMockLocationOn = false;

  // default minimum time between new readings
  private long mMinTime = 5000;

  // default minimum distance between old and new readings.
  private float mMinDistance = 1000.0f;

  // A fake location provider used for testing
  private MockLocationProvider mMockLocationProvider;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Set up the app's user interface. This class is a ListActivity, 
    // so it has its own ListView. ListView's adapter should be a PlaceViewAdapter

    mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    ListView placesListView = getListView();

    // TODO - add a footerView to the ListView
    // You can use footer_view.xml to define the footer
    View footerView = getLayoutInflater().inflate(R.layout.footer_view, null);
    placesListView.addFooterView(footerView);
    
    mAdapter = new PlaceViewAdapter(getApplicationContext());
    setListAdapter(mAdapter);

    // TODO - footerView must respond to user clicks, handling 3 cases:

    // There is no current location - response is up to you. One good 
    // solution is to disable the footerView until you have acquired a
    // location.

    // There is a current location, but the user has already acquired a
    // PlaceBadge for this location. In this case issue a Toast message with the text -
    // "You already have this location badge." 
    // Use the PlaceRecord class' intersects() method to determine whether 
    // a PlaceBadge already exists for a given location.

    // There is a current location for which the user does not already have
    // a PlaceBadge. In this case download the information needed to make a new
    // PlaceBadge.

    footerView.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View arg0) {
        Log.i(TAG, "Entered footerView.OnClickListener.onClick()");
        
        if (mLastLocationReading == null) {
          CharSequence text = 
            "We have not yet determined your current location." 
                + " Try again later.";
          Toast.makeText(getApplicationContext(), 
                  text, 
                  Toast.LENGTH_SHORT)
            .show();
        } else {
          if ( mAdapter.intersects(mLastLocationReading) ) {
            CharSequence text = 
              "You already have this location badge.";
              Toast.makeText(getApplicationContext(), 
                      text, 
                      Toast.LENGTH_SHORT)
                .show();
          } else {
            Log.d(TAG, "Downloading place record for location " 
                + mLastLocationReading + " as a background task...");
            PlaceDownloaderTask downloaderTask = 
              new PlaceDownloaderTask(PlaceViewActivity.this, 
                          sHasNetwork);
            downloaderTask.execute(mLastLocationReading);
          }
        }
      }
    });
  }

  @Override
  protected void onResume() {
    super.onResume();

    startMockLocationManager();

    // TODO - Check NETWORK_PROVIDER for an existing location reading.
    // Only keep this last reading if it is fresh - less than 5 minutes old
    mLastLocationReading = 
      mLocationManager.getLastKnownLocation(NETWORK_PROVIDER);
    if (mLastLocationReading != null) {
      long locationAgeMs = ageInMilliseconds(mLastLocationReading);
      if (locationAgeMs > FIVE_MINS) {
        Log.d(TAG, "Discarding old last location " + mLastLocationReading 
              + "; it is " + locationAgeMs + " ms old");
        mLastLocationReading = null;
      }
    }
    
    // TODO - register to receive location updates from NETWORK_PROVIDER
    mLocationManager.requestLocationUpdates(NETWORK_PROVIDER, 
                        mMinTime, 
                        mMinDistance, 
                        this);
  }

  @Override
  protected void onPause() {

    // TODO - unregister for location updates
    mLocationManager.removeUpdates(this);
    
    shutdownMockLocationManager();
    super.onPause();
  }

  // Callback method used by PlaceDownloaderTask
  public void addNewPlace(PlaceRecord place) {
    Log.i(TAG, "Entered addNewPlace()");

    // TODO - Attempt to add place to the adapter, considering the following cases
    
    // The place is null. In this case issue a Toast message with the text
    // "PlaceBadge could not be acquired"
    // Do not add the PlaceBadge to the adapter
    if (place == null) {
      CharSequence text = "PlaceBadge could not be acquired";
      Toast.makeText(getApplicationContext(), 
              text, 
              Toast.LENGTH_SHORT)
        .show();
      return;
    }

    // A PlaceBadge for this location already exists. In this case issue a Toast message
    // with the text - "You already have this location badge." Use the PlaceRecord 
    // class' intersects() method to determine whether a PlaceBadge already exists
    // for a given location. Do not add the PlaceBadge to the adapter
    for ( PlaceRecord placeRecord : mAdapter.getList() ) {
      if ( placeRecord.intersects( place.getLocation() ) ) {
        CharSequence text = 
          "You already have this location badge.";
        Toast.makeText(getApplicationContext(), 
                text, 
                Toast.LENGTH_SHORT)
          .show();
      }
    }
    
    // The place has no country name. In this case issue a Toast message
    // with the text - "There is no country at this location". 
    // Do not add the PlaceBadge to the adapter
    if (place.getCountryName() == null 
        || "".equals(place.getCountryName() )) {
      Log.w(TAG, "Attempt to add a place with no country: " + place);
      CharSequence text = "There is no country at this location";
      Toast.makeText(getApplicationContext(), 
              text, 
              Toast.LENGTH_SHORT)
        .show();
      return;
    }
    
    // Otherwise - add the PlaceBadge to the adapter
    Log.d(TAG, "Adding new place: " + place);
    mAdapter.add(place);
  }

  // LocationListener methods
  @Override
  public void onLocationChanged(Location currentLocation) {

    // TODO - Update last location considering the following cases.
    // 1) If there is no last location, set the last location to the current
    // location.
    // 2) If the current location is older than the last location, ignore
    // the current location
    // 3) If the current location is newer than the last locations, keep the
    // current location.
    if (mLastLocationReading == null 
        || currentLocation.getTime() > mLastLocationReading.getTime() ) {
      mLastLocationReading = currentLocation;
    }
  }

  @Override
  public void onProviderDisabled(String provider) {
    // not implemented
  }

  @Override
  public void onProviderEnabled(String provider) {
    // not implemented
  }

  @Override
  public void onStatusChanged(String provider, int status, Bundle extras) {
    // not implemented
  }

  // Returns age of location in milliseconds
  private long ageInMilliseconds(Location location) {
    return System.currentTimeMillis() - location.getTime();
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return true;
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.delete_badges:
      mAdapter.removeAllViews();
      return true;
    case R.id.place_one:
      mMockLocationProvider.pushLocation(37.422, -122.084);
      return true;
    case R.id.place_no_country:
      mMockLocationProvider.pushLocation(0, 0);
      return true;
    case R.id.place_two:
      mMockLocationProvider.pushLocation(38.996667, -76.9275);
      return true;
    default:
      return super.onOptionsItemSelected(item);
    }
  }

  private void shutdownMockLocationManager() {
    if (mMockLocationOn) {
      mMockLocationProvider.shutdown();
    }
  }

  private void startMockLocationManager() {
    if (!mMockLocationOn) {
      mMockLocationProvider = new MockLocationProvider(
          LocationManager.NETWORK_PROVIDER, this);
    }
  }
}
Java Source Code List
