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PORedraw/refresh Itemizedoverlay? (android/google maps api)
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  1. PORedraw/refresh Itemizedoverlay? (android/google maps api)
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    copied!<p>I am making a GPS tracker using google maps API and displaying the users current position on a map using ItemizedOverylay. As the users position changes regularly, I've set up a CountDownTimer to delete the current Itemizedoverlay and add a new one at the new position every 5 seconds (there is no way of changing an itemizedOverlay's position) but the screen isn't drawing the new positions unless i physically touch the screen! Here is the code for my itemized overlay:</p> <pre><code>import java.util.ArrayList; import java.util.List; import android.app.AlertDialog; import android.content.Context; import android.graphics.drawable.Drawable; import android.widget.Toast; import com.google.android.maps.ItemizedOverlay; import com.google.android.maps.OverlayItem; public class HelloItemizedOverlay extends ItemizedOverlay{ private ArrayList&lt;OverlayItem&gt; mOverlays = new ArrayList&lt;OverlayItem&gt;(); Context mContext; public HelloItemizedOverlay(Drawable defaultMarker) { /*This passes the defaultMarker up to the default constructor * to bound its coordinates and then initialize mContext with the given Context.*/ super(boundCenterBottom(defaultMarker)); } public HelloItemizedOverlay(Drawable defaultMarker, Context context) { /*This passes the defaultMarker up to the default constructor * to bound its coordinates and then initialize mContext with the given Context.*/ super(boundCenterBottom(defaultMarker)); mContext = context; } @Override protected boolean onTap(int index) { /*This uses the member android.content.Context to create * a new AlertDialog.Builder and uses the tapped OverlayItem's title * and snippet for the dialog's title and message text. (You'll see the * OverlayItem title and snippet defined when you create it below.)*/ OverlayItem item = mOverlays.get(index); AlertDialog.Builder dialog = new AlertDialog.Builder(mContext); dialog.setTitle(item.getTitle()); dialog.setMessage(item.getSnippet()); dialog.show(); return true; } public void addOverlay(OverlayItem overlay) { mOverlays.add(overlay); /*Each time you add a new OverlayItem to the ArrayList, you must * call populate() for the ItemizedOverlay, which will read each * of the OverlayItems and prepare them to be drawn.*/ populate(); } public void addOverlayList(List&lt;OverlayItem&gt; overlayitems) { Object temp[] = overlayitems.toArray(); try{ for(int i = 0;i&lt;temp.length;i++) { mOverlays.add((OverlayItem)temp[i]); } }catch(Error e) { Toast.makeText(mContext, "Something happened when adding the overlays:"+e.getMessage() , Toast.LENGTH_LONG).show(); } populate(); } public void removeOverlayList(List&lt;OverlayItem&gt; overlayitems) { Object temp[] = overlayitems.toArray(); try{ for(int i = 0;i&lt;temp.length;i++) { mOverlays.remove((OverlayItem)temp[i]); } }catch(Error e) { Toast.makeText(mContext, "Something happened when adding the overlays:"+e.getMessage() , Toast.LENGTH_LONG).show(); } populate(); } public void removeOverlay(OverlayItem overlay){ mOverlays.remove(overlay); populate(); } public void doPopulate() { populate(); } @Override protected OverlayItem createItem(int i) { // TODO Auto-generated method stub return mOverlays.get(i); } @Override public int size() { /*You must also override the size() method to return the current * number of items in the ArrayList:*/ return mOverlays.size(); } } </code></pre> <p>Does anyone know if there is a method or something I can call to force a redraw/refresh when I put the new items in?</p> <p>EDIT: Here is a snippet of the MapsActivity:</p> <pre><code>public class HelloGoogleMaps extends MapActivity { /*************************** * map stuff *****/ HelloItemizedOverlay myPosition; MapView mapView; MapController mapController; List&lt;Overlay&gt; mapOverlays; OverlayItem myPositionOverlayItem; public double myLatitude = 0; public double myLongitude = 0; public double myCoarseLatitude = 0; public double myCoarseLongitude = 0; public boolean isGPS; public boolean isGPSFix; public boolean useGPSLocation; public boolean useNetworkLocation; public long mLastLocationMillis;//system time of last gps contact /*boolean so when gps gets your location it will zoom to where you are, * but will only do this once (once it's set to true)*/ boolean pickedUpLocation; public MyCount counter;//for timing events /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.mymapview); pickedUpLocation = false; mapView = (MapView) findViewById(R.id.mapview); mapView.setBuiltInZoomControls(true); mapView.setStreetView(true); /*mapcontroller controls zoom etc*/ mapController = mapView.getController(); mapOverlays = mapView.getOverlays(); Drawable my_icon = this.getResources().getDrawable(R.drawable.androidmarker_teacher); myPosition = new HelloItemizedOverlay(my_icon, this); itemizedoverlay = new HelloItemizedOverlay(drawable, this); /*All overlay elements on a map are held by the MapView, so when you * want to add some, you have to get a list from the getOverlays() method. * Then instantiate the Drawable used for the map marker, which was saved in * the res/drawable/ directory. The constructor for HelloItemizedOverlay * (your custom ItemizedOverlay) takes the Drawable in order to set the * default marker for all overlay items.*/ /*Initialise GPS*/ try{ LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); LocationListener mlocListener = new MyLocationListener(); //get fine location mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener); //get coarse location mlocManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 0, 0, mlocListener); boolean isGPS = mlocManager.isProviderEnabled (LocationManager.GPS_PROVIDER); MyGPSListener myGPSListener = new MyGPSListener(); mlocManager.addGpsStatusListener(myGPSListener); } catch(Error e) { Toast.makeText( getApplicationContext(),"Error!"+e.getMessage(),Toast.LENGTH_SHORT).show(); } GeoPoint point = new GeoPoint((int)(myCoarseLatitude * 1e6),(int) (myCoarseLongitude* 1e6)); myPositionOverlayItem = new OverlayItem(point, "Evening guvna!", "This is where i am"); /*All that's left is to add this OverlayItem to your collection in the * HelloItemizedOverlay instance, then add the HelloItemizedOverlay to the MapView: */ myPosition.addOverlay(myPositionOverlayItem); mapOverlays.add(myPosition); /*begin counting 5 seconds to update positions*/ counter = new MyCount(5000,1000); counter.start(); } @Override protected boolean isRouteDisplayed() { // TODO Auto-generated method stub return false; } public void updateMyPosition() { /*remove my guy*/ mapView.getOverlays().remove(myPosition); myPosition.removeOverlay(myPositionOverlayItem); myPosition.doPopulate(); GeoPoint point; if(useGPSLocation) { point = new GeoPoint((int)(myLatitude * 1e6),(int) (myLongitude* 1e6)); } else { point = new GeoPoint((int)(myCoarseLatitude * 1e6),(int) (myCoarseLongitude* 1e6)); } myPositionOverlayItem = new OverlayItem(point, "You are here", "Awww yeah!"); myPosition.addOverlay(myPositionOverlayItem); myPosition.doPopulate(); mapOverlays.add(myPosition); } public void clearTheMap() { mapView.getOverlays().clear(); myPosition.doPopulate(); } /******************************************************* * GPS!!!!!!!! * This method gets the location of you from gps * ************************************************/ public class MyLocationListener implements LocationListener { public void onLocationChanged(Location loc) { String provider = loc.getProvider(); if(provider.equals(LocationManager.GPS_PROVIDER)) { myLatitude = loc.getLatitude(); myLongitude = loc.getLongitude(); mLastLocationMillis = SystemClock.elapsedRealtime(); if((!pickedUpLocation)&amp;&amp;(myLatitude!=0)) { mapController.animateTo(new GeoPoint((int)(myLatitude * 1e6),(int) (myLongitude* 1e6))); pickedUpLocation = true; } } else { myCoarseLatitude = loc.getLatitude(); myCoarseLongitude = loc.getLongitude(); if((!pickedUpLocation)&amp;&amp;(myCoarseLatitude!=0)) { //Toast.makeText(getBaseContext(), "picked up Location with network - "+myCoarseLatitude+" "+myCoarseLongitude, Toast.LENGTH_LONG).show(); mapController.animateTo(new GeoPoint((int)(myCoarseLatitude * 1e6),(int) (myCoarseLongitude* 1e6))); pickedUpLocation = true; } } /*first time it picks up your location it will animate to where you are*/ /* String Text = "My current location is: "+ "Latitud = " + loc.getLatitude()+ "Longitud = " + loc.getLongitude(); Toast.makeText( getApplicationContext(),Text,Toast.LENGTH_SHORT).show(); */ } public void onProviderDisabled(String provider) { Toast.makeText( getApplicationContext(),"Gps Disabled",Toast.LENGTH_SHORT ).show(); myLatitude = -1; myLongitude = -1; } public void onProviderEnabled(String provider) { Toast.makeText( getApplicationContext(),"Gps Enabled",Toast.LENGTH_SHORT).show(); myLatitude = 0; myLongitude = 0; } public void onStatusChanged(String provider, int status, Bundle extras) { } } /*********************************************** * -GPS Status monitor- * Will see if the sattelites are still fixed to your phone * If satellites arent available, it takes network (coarse) location * If a fix is aquired it will use GPS (fine) location * **********************************/ private class MyGPSListener implements GpsStatus.Listener { public void onGpsStatusChanged(int event) { switch (event) { case GpsStatus.GPS_EVENT_SATELLITE_STATUS: if (myLatitude != 0) isGPSFix = (SystemClock.elapsedRealtime() - mLastLocationMillis) &lt; 3000; if (isGPSFix) { // A fix has been acquired. useGPSLocation = true; useNetworkLocation = false; } else { // The fix has been lost. useGPSLocation = false; useNetworkLocation = true; } break; case GpsStatus.GPS_EVENT_FIRST_FIX: // Do something. isGPSFix = true; useGPSLocation = true; useNetworkLocation = false; break; } } } /************************************************************* * Counter class for timing events **********/ public class MyCount extends CountDownTimer{ public MyCount(long millisInFuture, long countDownInterval) { super(millisInFuture, countDownInterval); } @Override public void onFinish() { clearTheMap(); updateMyPosition();//redraw my guy myPosition.doPopulate(); //Toast.makeText( getApplicationContext(),"Sent my position - used ",Toast.LENGTH_SHORT).show(); resetTimer(); } public void resetTimer() { counter = new MyCount(5000,1000); counter.start(); } @Override public void onTick(long millisUntilFinished) { /*tv.setText(”Left: ” + millisUntilFinished/1000);*/ } } } </code></pre>
 

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