Get center location of a map, using MapView.getMapCenter().

In the last exercise, Display a marker on MapView, using Overlays, a marker will be displayed in Mode 1 (with starting location) only. In this exercise, current center location of the Map in Mode 0 (without starting location) will be retrieved using the method MapView.getMapCenter(). Such that the appearance of both mode will be kept consistance.



To achieve it, AndroidMapView have to be modified, to add function in onCreate() to handle Mode 0.

package com.AndroidMapper;

import java.util.ArrayList;
import java.util.List;

import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.widget.CheckBox;
import android.widget.TextView;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.OverlayItem;

public class AndroidMapView extends MapActivity {

 private TextView myLongitude, myLatitude;
 private CheckBox mySatellite;

 private MapView myMapView;
 private MapController myMapController;

 private void SetSatellite()
 {
  myMapView.setSatellite(mySatellite.isChecked());
 };

@Override
protected void onCreate(Bundle icicle) {
 // TODO Auto-generated method stub
 super.onCreate(icicle);
 setContentView(R.layout.mymapview);

 Bundle bundle = this.getIntent().getExtras();
     int Mode = bundle.getInt("Mode");

 myMapView = (MapView)findViewById(R.id.mapview);
 myMapController = myMapView.getController();
 myMapView.setBuiltInZoomControls(true);

 myLongitude = (TextView)findViewById(R.id.longitude);
 myLatitude = (TextView)findViewById(R.id.latitude);
 mySatellite = (CheckBox)findViewById(R.id.satellite);
 mySatellite.setOnClickListener(mySatelliteOnClickListener);

 SetSatellite();

 if(Mode == 0)
 {
  GeoPoint initGeoPoint = myMapView.getMapCenter();
  CenterLocation(initGeoPoint);
 }
 else if(Mode == 1)
 {
  int intLatitude = bundle.getInt("Latitude");
  int intLongitude = bundle.getInt("Longitude");
  GeoPoint initGeoPoint = new GeoPoint(intLatitude, intLongitude);
  CenterLocation(initGeoPoint);
 }

}

private void placeMarker(int markerLatitude, int markerLongitude)
{
 Drawable marker=getResources().getDrawable(
   android.R.drawable.ic_menu_myplaces);
 marker.setBounds(0, 0, marker.getIntrinsicWidth(),
   marker.getIntrinsicHeight());
 myMapView.getOverlays().add(new InterestingLocations(marker,
   markerLatitude, markerLongitude));
}

@Override
protected boolean isRouteDisplayed() {
 // TODO Auto-generated method stub
 return false;
}

private void CenterLocation(GeoPoint centerGeoPoint)
{
 myMapController.animateTo(centerGeoPoint);

 myLongitude.setText("Longitude: "+
  String.valueOf((float)centerGeoPoint.getLongitudeE6()/1000000));
 myLatitude.setText("Latitude: "+
  String.valueOf((float)centerGeoPoint.getLatitudeE6()/1000000));
 placeMarker(centerGeoPoint.getLatitudeE6(),
   centerGeoPoint.getLongitudeE6());
};

private CheckBox.OnClickListener mySatelliteOnClickListener =
   new CheckBox.OnClickListener(){

    public void onClick(View v) {
     // TODO Auto-generated method stub
     SetSatellite();
    }
};

class InterestingLocations extends ItemizedOverlay<OverlayItem>{

 private List<OverlayItem> locations =
  new ArrayList<OverlayItem>();
 private Drawable marker;

 public InterestingLocations(Drawable defaultMarker,
   int LatitudeE6, int LongitudeE6) {
  super(defaultMarker);
  // TODO Auto-generated constructor stub
  this.marker=defaultMarker;
  // create locations of interest
  GeoPoint myPlace = new GeoPoint(LatitudeE6,LongitudeE6);
  locations.add(new OverlayItem(myPlace ,
    "My Place", "My Place"));
  populate();
 }

 @Override
 protected OverlayItem createItem(int i) {
  // TODO Auto-generated method stub
  return locations.get(i);
 }

 @Override
 public int size() {
  // TODO Auto-generated method stub
  return locations.size();
 }

 @Override
 public void draw(Canvas canvas, MapView mapView,
   boolean shadow) {
  // TODO Auto-generated method stub
  super.draw(canvas, mapView, shadow);
 
  boundCenterBottom(marker);
 }
}
}

Other files are same as previous exercise.

Download the files.