Develop Reference

Multiple pins on Google Maps Android not working

I have been using a previous question and a Google Tutorial to attempt to add multiple pin images on a Google Map view when the current location of the user changes.
Each pin when tapped displays the Longitude and Latitude of the pin.
However currently my code only displays one pin and does not add another image when the location of the user changes. I am relatively new to Android and can't see why this code wouldn't work?
Map.java:
import java.util.List;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.MyLocationOverlay;
import com.google.android.maps.OverlayItem;
import android.util.Log;
public class Map extends MapActivity {
private MapView map;
private MapController controller;
private double lon, lat;
private Drawable drawable;
private MapOverlay itemizedoverlay;
private List<Overlay> mapOverlays;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.maps);
initMapView();
mapOverlays = map.getOverlays();
drawable = this.getResources().getDrawable(R.drawable.pin);
itemizedoverlay = new MapOverlay(drawable, this);
initMyLocation();
}
private void initMapView() {
map = (MapView) findViewById(R.id.map);
controller = map.getController();
map.setSatellite(true);
map.setBuiltInZoomControls(true);
}
private void initMyLocation() {
final MyLocationOverlay overlay = new MyLocationOverlay(this, map);
overlay.enableMyLocation();
overlay.enableCompass(); // wont work in emulator
overlay.runOnFirstFix(new Runnable() {
public void run() {
// Zoom in to current location - 1 is word view
controller.setZoom(20);
controller.animateTo(overlay.getMyLocation());
lon = overlay.getMyLocation().getLongitudeE6();
lat = overlay.getMyLocation().getLatitudeE6();
setLON(lon);
setLAT(lat);
//-0.959896
//51.742953
Log.w("test-lon", Double.toString(lon/1E6));
Log.w("test-lat", Double.toString(lat/1E6));
GeoPoint point = new GeoPoint((int)(lat),(int)(lon));
mapOverlays.add(itemizedoverlay);
test(point);
}
});
map.getOverlays().add(overlay);
}
public void setLON(double x){ //remove?
lon = x;
}
public void setLAT(double x){ //remove?
lat = x;
}
public void test(GeoPoint px){
OverlayItem overlayitem = new OverlayItem(px,"Test Point" , "Lat: " + Double.toString(lat/1E6) + "\nLon: " + Double.toString(lon/1E6) );
itemizedoverlay.addOverlay(overlayitem);
}
#Override
protected boolean isRouteDisplayed() {
// Required method from MapActivity
return false;
}
}
MapOverlay.java:
import java.util.ArrayList;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;
public class MapOverlay extends ItemizedOverlay {
private ArrayList<OverlayItem> mapOverlay = new ArrayList<OverlayItem>();
private Context mContext;
public MapOverlay (Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
mContext = context;
}
public MapOverlay(Drawable arg0) {
super(boundCenterBottom(arg0));
}
public void addOverlay(OverlayItem overlay) {
mapOverlay.add(overlay);
populate();
}
#Override
protected OverlayItem createItem(int i) {
return mapOverlay.get(i);
}
#Override
public int size() {
return mapOverlay.size();
}
#Override
protected boolean onTap(int index) {
OverlayItem item = mapOverlay.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
}

u need implements class LocationListener for listen our location changes and update on the map.
class LocationsListeners implements LocationListener {
#Override
public void onLocationChanged(Location location) {
setLAT(location.getLatitude());
setLON(location.getLongitude());
setGeoPoint(lat, lon);
mapOverlays.add(geoPoint);
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
u need method for calc the GeoPoint:
public GeoPoint setGeoPoint(double lat, double lon){
geoPoint = new GeoPoint((int) (lat * 1E6), (int)(lon * 1E6));
return geoPoint;
}
or using Little Fluffy Location - Its library that updates our location and notify u, is broadcast receiver, very simple and fast implementation:
try:
http://code.google.com/p/little-fluffy-location-library/

itemized overlay tutorial

I am trying to incorporate a map into an app I am developing, so I am learning how to use them with the ItemizedOverlay functionality. I went through the tutorial on dev-android, and everything went fine except this one line.
public class HelloMapViewActivity extends MapActivity {
#Override
protected boolean isRouteDisplayed()
{
return true;
}
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
MapView mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = this.getResources().getDrawable(R.drawable.androidmarker);
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable); //this is the error
GeoPoint point = new GeoPoint(19240000,-99120000);
OverlayItem overlayitem = new OverlayItem(point, "Hola, Mundo!", "I'm in Mexico City!");
itemizedoverlay.addOverlay(overlayitem);
mapOverlays.add(itemizedoverlay);
}
}
The problem says:
The constructor HelloItemizedOverlay(drawable) is undefined,
would anyone be able to tell me what im doing wrong? As well when I follow what Eclipse tells me to do and put null next to it in the parameters, it clears the problem but does not show up with the drawable over the map.

I think this is a good basic source to learn http://developer.android.com/resources/tutorials/views/hello-mapview.html

Here is an example how my HelloItemizedOverlay was when I was working with Google Maps :
import java.util.ArrayList;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;
#SuppressWarnings("rawtypes")
public class HelloItemizedOverlay extends ItemizedOverlay {
private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
Context mContext;
public HelloItemizedOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
}
public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
mContext = context;
}
#Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
#Override
public int size() {
return mOverlays.size();
}
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
#Override
protected boolean onTap(int index) {
OverlayItem item = mOverlays.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
}

HelloitemizedOverlay konstructor also needs the context.

How to add a marker when I touch the map in android ?

I have a map activity which displays the map, I want to add a marker when I touch on the screen ..
This is my Activity ...
package com.adhamenaya.android;
import java.util.List;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.MotionEvent;
import android.widget.Toast;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
public class MapApp extends MapActivity {
private MapView mapView;
private MapController mapController;
private LocationManager locationManager;
private Context context;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
context=this;
initLayout();
initMap();
}
private void initLayout(){
mapView = (MapView) findViewById(R.id.mapview);
//blueIcon = (Drawable)this.getResources().getDrawable(R.drawable.blueicon);
}
private void initMap(){
mapView.setBuiltInZoomControls(true);
mapView.setStreetView(true);
mapController=mapView.getController();
mapController.setZoom(10);// 1 is world view
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0, 0, new GeoUpdateHandler());
}
#Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
class GeoUpdateHandler implements LocationListener {
#Override
public void onLocationChanged(Location location) {
int lat=(int)(location.getLatitude()*1E6);
int lng=(int)(location.getLongitude()*1E6);
GeoPoint point=new GeoPoint(lat,lng);
//GeoPoint point = new GeoPoint(19240000,-99120000);
mapController.animateTo(point);
mapController.setCenter(point);
Drawable redIcon = context.getResources().getDrawable(R.drawable.redicon);
List<Overlay> mapOverlays = mapView.getOverlays();
MyItemizedOverlay itemizedoverlay = new MyItemizedOverlay(redIcon);
OverlayItem overlayitem = new OverlayItem(point, "Hello !", "I'm here");
itemizedoverlay.addOverlay(overlayitem);
mapOverlays.add(itemizedoverlay);
}
#Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
public boolean onTouchEvent(MotionEvent event){
int x=(int)event.getX();
int y=(int)event.getY();
Toast.makeText(context, x, Toast.LENGTH_LONG).show();
GeoPoint point = mapView.getProjection().fromPixels(x, y);
Drawable redIcon = context.getResources().getDrawable(R.drawable.blueicon);
List<Overlay> mapOverlays = mapView.getOverlays();
MyItemizedOverlay itemizedoverlay = new MyItemizedOverlay(redIcon);
OverlayItem overlayitem = new OverlayItem(point, "New Place", "I clicked here !");
itemizedoverlay.addOverlay(overlayitem);
mapOverlays.add(itemizedoverlay);
return false;
}
}
}
Edit : This is the class for ItemizedOverlay, where I have implemented onTap() method , but nothing happens ...
package com.adhamenaya.android;
import java.util.ArrayList;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.view.MotionEvent;
import android.widget.Toast;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.MapView;
import com.google.android.maps.OverlayItem;
public class MyItemizedOverlay extends ItemizedOverlay{
private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
private Context mContext;
public MyItemizedOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
}
public MyItemizedOverlay(Drawable defaultMarker, Context context) {
super(defaultMarker);
mContext = context;
}
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
#Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
#Override
public int size() {
return mOverlays.size();
}
#Override
protected boolean onTap(int index) {
OverlayItem item = mOverlays.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
#Override
public boolean onTouchEvent(MotionEvent event, MapView mapView) {
int x=(int)event.getX();
int y=(int)event.getY();
Toast.makeText(mContext, x, Toast.LENGTH_LONG).show();
return super.onTouchEvent(event, mapView);
}
}

Hello, MapView! tutorial covers showing markers on MapView. In the tutorial markers are added as soon as the activity starts, but you can also add markers at later time, for example, when user touches screen. If you try this approach, you'll likely want to override onTap in your subclass of ItemizedOverlay.
Update:
If you follow the tutorial, you'll have your own subclass of ItemizedOverlay. onTap is one of its methods. Now that I look at the documentation, unfortunately onTap(GeoPoint p, MapView mapView) is not public or protected so you cannot override it.
What you can do, is have another overlay, solely for detecting taps. Instead of subclassing ItemizedOverlay, subclass Overlay.
private class TapOverlay extends Overlay {
public boolean onTap(GeoPoint p, MapView mapView) {
// code that adds item in your ItemizedOverlay
// goes here
return true;
}
}

How do I set streetView in my mapview

I an working on an android project whereby i need to set my map to zoom in and show a more detailed view of my map, like the streets of where i want my coordinates to triangulate. The problem is in Mapview class, setStreetView is deprecated, wat is the alternative?
This is how setStreetView looks when i use it.
package com.HelloMapView;
import java.util.List;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.LinearLayout;
public class HelloMapView extends MapActivity {
MapView mapview;
LinearLayout linearlayout;
List<Overlay> mapOverlay;
Drawable drawable;
HelloItemizedOverlay itemizedOverlay;
#SuppressWarnings("deprecation")
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapview=(MapView)findViewById(R.id.mapview);
mapview.setBuiltInZoomControls(true);
mapview.setStreetView(true);
mapOverlay=mapview.getOverlays();
drawable=this.getResources().getDrawable(R.drawable.androidmarker);
itemizedOverlay=new HelloItemizedOverlay(drawable);
GeoPoint geoPoint=new GeoPoint(19240000,-99120000);
OverlayItem overlayitem=new OverlayItem(geoPoint,"","");
itemizedOverlay.addoverlay(overlayitem);
mapOverlay.add(itemizedOverlay);
}
#Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
}
this does not work it only shows square boxes with no map at all

Use setStreetView(boolean) of MapView.

myMapView.setStreetView(true);

public class ABC extends MapActivity {
private static MapController myMapController = null;
private static GeoPoint geoPoint = new GeoPoint
(
(int) (25.24243399999999 * 1E6), (int) (55.30611937301637 * 1E6));
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.contact_us_layout);
MapView mapView = (MapView) findViewById(R.id.mapview);
mapView.displayZoomControls(false);
mapView.setBuiltInZoomControls(true);
mapView.setFocusable(true);
myMapController = mapView.getController();
myMapController.animateTo(geoPoint);
myMapController.setZoom(15);
// mapView.invalidate();
// mapView.setFocusable(true);
myMapController.setCenter(geoPoint);
List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = this.getResources().getDrawable(
R.drawable.mapmarker);
HelloItemizedOverlay itemizedOverlay = new HelloItemizedOverlay(
drawable, this);
OverlayItem overlayItem = new OverlayItem(geoPoint,
"abc");
itemizedOverlay.addOverlay(overlayItem);
mapOverlays.add(itemizedOverlay);
//mapView.setSatellite(true);
**mapView.setStreetView(true);**
public class HelloItemizedOverlay extends ItemizedOverlay {
private ArrayList mOverlays = new ArrayList();
private Context mContext;
public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
mContext = context;
}
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
#Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
#Override
public int size() {
return mOverlays.size();
}
#Override
protected boolean onTap(int index) {
OverlayItem item = mOverlays.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
}
}
Hello,,,
I have posted the working code for what u desire...
If your map isn't displaying anything. Your api key is not signed properly..Please sign it again and provide it in mapView.
If you want streetView of map use:
mapView.setStreetView(true)
If you want satelliteView of map use:
mapView.setSatellite(true)

Android Google Map view returns error when onTap() is used - Alertdialog is supposed to be displayed

I currently have modified 'Google Map View' code (found below) but when the map loads and you click on the item on the map it returns an error.
I believe it has something to do with the null value for mContext but I'm not sure, I would really appreciate it if anyone could help me out with this:
protected boolean onTap(int index) {
OverlayItem item = mOverlays.get(index);
Context mContext = null;
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
My Map class:
package testing.map;
import java.util.List;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
public class Mapview extends MapActivity {
/** Called when the activity is first created. */
protected boolean isRouteDisplayed(){
return false;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mapview);
MapView mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = this.getResources().getDrawable(R.drawable.jd_sports_logo);
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable);
//Declared longitude/latitude as doubles as GeoPoint only uses 'int' - converted to microdegrees
double latitude = 51.545538;
double longitude = -0.477247;
GeoPoint point = new GeoPoint((int)(latitude * 1e6), (int)(longitude * 1e6));
OverlayItem overlayitem = new OverlayItem(point, "Hola, Mundo!", "I'm in Mexico City!");
itemizedoverlay.addOverlay(overlayitem);
mapOverlays.add(itemizedoverlay);
}
}
My HelloItemizedOverlay class:
package testing.map;
import java.util.ArrayList;
import android.graphics.drawable.Drawable;
import android.app.AlertDialog;
import android.content.Context;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;
public class HelloItemizedOverlay extends ItemizedOverlay {
private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
public HelloItemizedOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
}
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
super(defaultMarker);
Context mContext = context;
}
#Override
protected OverlayItem createItem(int i) {
// TODO Auto-generated method stub
return mOverlays.get(i);
}
#Override
public int size() {
// TODO Auto-generated method stub
return mOverlays.size();
}
#Override
protected boolean onTap(int index) {
OverlayItem item = mOverlays.get(index);
Context mContext = null;
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
}

You are missing the Context in the main class.
Add this :
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable, mContext);
where mContext = this;
instead of this:
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable);

Change two places:
1.
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable, this);
2.
public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
mContext = context;
}

I also found that the HelloGoogleMaps tutorial code failed with a npe when you tap the marker.
If you pass this (from an instance that extends MapActivity) the dialog shows.
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable, this);
Constructor required:
public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
super(defaultMarker);
mContext = context;
}

you can pass context like this, here is the pseudo code:
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(this,drawable);