Example of implementing OpenStreetMap on Android using osmdroid

Last article describe the preparation to using osmdroid on Android. It's time to implement a simple app to display OpenStreetMap on Android using osmdroid.

Make sure copy the requested JARs to libs folder, and edit manifest to add the permissions ~ refer last article.

Modify the main layout to add <org.osmdroid.views.MapView>.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:padding="@dimen/padding_medium"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />
    
    <org.osmdroid.views.MapView
        android:id="@+id/mapview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:clickable="true"/>

</RelativeLayout>

Modify the main activity:

package com.android_osmdroid;

import org.osmdroid.DefaultResourceProxyImpl;
import org.osmdroid.ResourceProxy;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapView;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.drawable.Drawable;

public class MainActivity extends Activity {
 
 MyItemizedOverlay myItemizedOverlay = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        
        Drawable marker=getResources().getDrawable(android.R.drawable.star_big_on);
        int markerWidth = marker.getIntrinsicWidth();
        int markerHeight = marker.getIntrinsicHeight();
        marker.setBounds(0, markerHeight, markerWidth, 0);
        
        ResourceProxy resourceProxy = new DefaultResourceProxyImpl(getApplicationContext());
        
        myItemizedOverlay = new MyItemizedOverlay(marker, resourceProxy);
        mapView.getOverlays().add(myItemizedOverlay);
        
        GeoPoint myPoint1 = new GeoPoint(0*1000000, 0*1000000);
        myItemizedOverlay.addItem(myPoint1, "myPoint1", "myPoint1");
        GeoPoint myPoint2 = new GeoPoint(50*1000000, 50*1000000);
        myItemizedOverlay.addItem(myPoint2, "myPoint2", "myPoint2");
        
    } 
    
}

Create a new class MyItemizedOverlay.java.

package com.android_osmdroid;

import java.util.ArrayList;

import org.osmdroid.ResourceProxy;
import org.osmdroid.api.IMapView;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.overlay.ItemizedOverlay;
import org.osmdroid.views.overlay.OverlayItem;

import android.graphics.Point;
import android.graphics.drawable.Drawable;

public class MyItemizedOverlay extends ItemizedOverlay<OverlayItem> {
 
 private ArrayList<OverlayItem> overlayItemList = new ArrayList<OverlayItem>();

 public MyItemizedOverlay(Drawable pDefaultMarker,
   ResourceProxy pResourceProxy) {
  super(pDefaultMarker, pResourceProxy);
  // TODO Auto-generated constructor stub
 }
 
 public void addItem(GeoPoint p, String title, String snippet){
  OverlayItem newItem = new OverlayItem(title, snippet, p);
  overlayItemList.add(newItem);
  populate(); 
 }

 @Override
 public boolean onSnapToItem(int arg0, int arg1, Point arg2, IMapView arg3) {
  // TODO Auto-generated method stub
  return false;
 }

 @Override
 protected OverlayItem createItem(int arg0) {
  // TODO Auto-generated method stub
  return overlayItemList.get(arg0);
 }

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

}

Compare with Google Map version with the same function.

Next: Display user location by adding MyLocationOverlay on org.osmdroid.views.MapView

---

Updated@2014-04-16: no map but saw this in my logcat: "Problem downloading MapTile: /0/0/0 HTTP response: HTTP/1.1 403 Forbidden"

The default Apache HttpClient user-agent was recently banned from accessing tile.openstreetmap.org (server returns 403). As a result, the Mapnik provider is no longer serving any tiles for osmdroid.

OpenStreetMap's tile usage policy ( http://wiki.openstreetmap.org/wiki/Tile_usage_policy ) says that a "Valid User-Agent identifying application" must be sent. The current user-agent osmdroid sends when it downloads a tile is "Apache-HttpClient/UNAVAILABLE (java 1.4)" which is pretty generic.

I've created a patch that will send a user-agent that is more compliant with OSM's tile usage policy. The new user-agent is "osmdroid ([package name])" where [package name] is the package name of the application using osmdroid.

The patch can be found here: http://pastebin.com/kxBh1gQ5

The patch is not very pretty, but it does its job.

reference: osmdroid Issue 515 : Send a better user-agent when downloading tiles

Thanks Lora Anneken comment.