Question

I have code written by Hesham Saeed. I want to put the direction function in AsyncTask as it is using Network. How can i do that as i m new to Android.
I need to move direction in AsyncTask..

Main Activity Code.

package com.example.googlemaptst;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;

import android.app.ProgressDialog;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;

public class MapsActivity extends MapActivity
{    

/** Called when the activity is first created. */
Button b;
private ProgressDialog pDialog;
private  Route directions(final GeoPoint start, final GeoPoint dest)  {
   Parser parser;
    String jsonURL = "http://maps.google.com/maps/api/directions/json?";
    final StringBuffer sBuf = new StringBuffer(jsonURL);
    sBuf.append("origin=");
    sBuf.append(start.getLatitudeE6()/1E6);
    sBuf.append(',');
    sBuf.append(start.getLongitudeE6()/1E6);
    sBuf.append("&destination=");
    sBuf.append(dest.getLatitudeE6()/1E6);
    sBuf.append(',');
    sBuf.append(dest.getLongitudeE6()/1E6);
    sBuf.append("&sensor=true&mode=driving");
    Log.v("I came in URL", sBuf.toString());
    parser = new GoogleParser(sBuf.toString());
    Route r =  parser.parse();
    return r;
}

@Override
public void onCreate(Bundle savedInstanceState)
{
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_map);
     MapView mapView = (MapView) findViewById(R.id.mapView); //or you can declare it directly with the API key
     Route route = directions(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));
     RouteOverlay routeOverlay = new RouteOverlay(route, Color.BLUE);
     mapView.getOverlays().add(routeOverlay);

}

@Override
protected boolean isRouteDisplayed() {

    return false;
}
}

Answer 1

Ok, here’s what you have to do:

    MapView mapView = null;
@Override
public void onCreate(Bundle savedInstanceState)
{
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_map);
     mapView = (MapView) findViewById(R.id.mapView); //or you can declare it directly with the API key
     DirectionsTask getDirectionsTask = new DirectionsTask();
     getDirectionsTask.execute(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));

}

private class DirectionsTask extends AsyncTask<GeoPoint, Void, Route> {

    protected Route doInBackground(GeoPoint... geoPointParams) {
        GeoPoint start = geoPointParams[0];
        GeoPoint dest = geoPoint[1];

           Parser parser;
            String jsonURL = "http://maps.google.com/maps/api/directions/json?";
            final StringBuffer sBuf = new StringBuffer(jsonURL);
            sBuf.append("origin=");
            sBuf.append(start.getLatitudeE6()/1E6);
            sBuf.append(',');
            sBuf.append(start.getLongitudeE6()/1E6);
            sBuf.append("&destination=");
            sBuf.append(dest.getLatitudeE6()/1E6);
            sBuf.append(',');
            sBuf.append(dest.getLongitudeE6()/1E6);
            sBuf.append("&sensor=true&mode=driving");
            Log.v("I came in URL", sBuf.toString());
            parser = new GoogleParser(sBuf.toString());
            Route r =  parser.parse();
            return r;
    }


}

protected void onPostExecute(Route route) {
    RouteOverlay routeOverlay = new RouteOverlay(route, Color.BLUE);
     mapView.getOverlays().add(routeOverlay);
}

A couple of comments. Put mapView outside of OnCreate so onPostExecute has access to it. Note that onPostExecute gets called in the UI thread so that’s ok.