Android Open Source - GeoTagger Map View

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Back to project page GeoTagger.
License

The source code is released under:
GNU General Public License
If you think the Android project GeoTagger 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 horizon.geotagger.view;
// w ww  .  j a v a 2s.c o  m
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Timer;
import java.util.TimerTask;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;

import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MyLocationOverlay;

import horizon.geotagger.AlertService;
import horizon.geotagger.R;
import horizon.geotagger.model.Tag;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MapView 
extends MapActivity
{
  private MyLocationOverlay myLocationOverlay;
  
  private TagOverlay tagOverlay;
  
  @Override
  public boolean onCreateOptionsMenu(Menu menu)
  {
    getMenuInflater().inflate(R.layout.mapview_menu, menu);
    return true;
  }
  
  private Timer timer;
  
  private class GetTask
  extends TimerTask
  {
    @Override
    public void run()
    {
      HttpClient client = new DefaultHttpClient();
      HttpGet get = new HttpGet("http://horizon-geotagger.appspot.com/tagsInBox?" +
          "north=90&south=-90&west=-180&east=180");
      HttpResponse response;
      try 
      {
        response = client.execute(get);
        StatusLine sl = response.getStatusLine();
        if(sl.getStatusCode() != HttpStatus.SC_OK)
        {
          get.abort();
          return;
        }
        
        HttpEntity entity = response.getEntity();
        if(entity == null)
          return;
                
        ObjectMapper mapper = new ObjectMapper();
        JsonNode node = mapper.readTree(EntityUtils.toString(entity, "UTF-8"));
        ArrayList<Tag> tags = new ArrayList<Tag>();
        
        if(!node.isArray() || node.isNull())
          return;
        
        for(Iterator<JsonNode> i = node.getElements(); i.hasNext(); )
          tags.add(mapper.treeToValue(i.next(), Tag.class));
        
        if(tags.size() == 0)
          return;
      
        com.google.android.maps.MapView mv = 
          (com.google.android.maps.MapView)findViewById(R.id.mapview);
        synchronized(mv.getOverlays())
        {
          if(tagOverlay != null)
            mv.getOverlays().remove(tagOverlay);
          tagOverlay = new TagOverlay(
              new BitmapDrawable(BitmapFactory.decodeResource(MapView.this.getResources(), R.drawable.icon)),
              tags);
          mv.getOverlays().add(tagOverlay);
        }
        mv.postInvalidate();
      }
      catch(Exception e)
      {
        e.printStackTrace();
      }
    }  
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item)
  {
    if(item.getItemId() == R.id.mapview_menu_exit)
    {
      exit();
      return true;
    }
    
    if(!isGpsEnabled())
    {
      displayGpsDisabledAlert();
      return true;
    }
    
    switch (item.getItemId())
    {
    case R.id.mapview_menu_mylocation:
      gotoMyLocation();
      return true;
    case R.id.mapview_menu_newtag:
      Intent i = new Intent("horizon.geotagger.ACTION_DO_GEOTAG");
      i.putExtra("location", myLocationOverlay.getLastFix());
      startActivity(i);
      return true;
    default:
      return false;
    }
  }

  @Override
  protected void onCreate(Bundle savedInstanceState) 
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mapview);
    com.google.android.maps.MapView mv = 
        (com.google.android.maps.MapView)findViewById(R.id.mapview);
    mv.setBuiltInZoomControls(true);
  }

  @Override
  protected void onPause()
  {
    super.onPause();
    myLocationOverlay.disableMyLocation();
    com.google.android.maps.MapView mv = 
        (com.google.android.maps.MapView)findViewById(R.id.mapview);
    synchronized(mv.getOverlays())
    {
      mv.getOverlays().remove(myLocationOverlay);
      if(tagOverlay != null)
        mv.getOverlays().remove(tagOverlay);
    }
    timer.cancel();
    timer = null;
  }
  
  @Override
  protected void onResume()
  {
    super.onResume();
    if(!isGpsEnabled())
      displayGpsDisabledAlert();
    
    com.google.android.maps.MapView mv = 
        (com.google.android.maps.MapView)findViewById(R.id.mapview);
    synchronized(mv.getOverlays())
    {
      if(myLocationOverlay == null)
        myLocationOverlay = new MyLocationOverlay(this, mv);
      myLocationOverlay.enableMyLocation();
      mv.getOverlays().add(myLocationOverlay);
    }
    mv.postInvalidate();
    
    timer = new Timer(true);
    timer.scheduleAtFixedRate(new GetTask(), 0, 60000);
  }
  
  @Override
  protected boolean isRouteDisplayed()
  {
    return false;
  }
  
  private void gotoMyLocation()
  {
    MapController mc = ((com.google.android.maps.MapView)
        findViewById(R.id.mapview)).getController();
    mc.animateTo(myLocationOverlay.getMyLocation());
  }
  
  private void displayGpsDisabledAlert()
  {
    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
    alertBuilder.setMessage(R.string.gps_disabled_warning)
        .setCancelable(true)
        .setNegativeButton(R.string.close_gps_disabled_warning, 
            new DialogInterface.OnClickListener()
        {
          @Override
          public void onClick(DialogInterface dialog, int which)
          {
            dialog.cancel();    
          }
        })
        .create()
        .show();      
  }
  
  private boolean isGpsEnabled()
  {
    LocationManager lm = (LocationManager)getSystemService(LOCATION_SERVICE);
    return lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
  }
  
  private void exit()
  {
    stopService(new Intent(getApplicationContext(), AlertService.class));
    finish();
  }
}
Java Source Code List
