Sort Location By Distance Maps Android

Question

I have various location names and their latitude and longitude coming from server side. I am putting them in a list view using custom adapter. In the adapter, I have written the code to calculate the distance of the location from my current location. Every thing is working fine, But I want to sort my list by distance. I am unable to figure out how to do it.

My Activity code is:

    List<String> Names = new ArrayList<String>();
    List<String> MinLevel = new ArrayList<String>();

    Names=db.getId();
    MinLevel=db.getMinLevel();

    MapAdapter ad=new MapAdapter(this, Names,MinLevel);
    lv.setAdapter(ad);

The MapAdapter

private final Context context;
private List<String>Name=new ArrayList<String>();
private List<String>Min=new ArrayList<String>();
PharmacyDB db;
public MapAdapter(Context context,List<String>phname,List<String>phmin) {
    super();
    this.context = context;

    this.Name=phname;
    this.Min=phmin;

}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {


    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View v = inflater.inflate(R.layout.test_adapter,parent, false);
    db=new PharmacyDB(context);
    final TextView pharname = (TextView)v.findViewById(R.id.test_ad_name);
    final TextView distance = (TextView)v.findViewById(R.id.test_ad_dist);
    final TextView rad_min = (TextView)v.findViewById(R.id.test_rad);
    final RelativeLayout det=(RelativeLayout)v.findViewById(R.id.details);



    pharname.setText(db.getPharmacyName(Name.get(position)));
  if(!Min.get(position).equals("null")&&!Min.get(position).equals(null)){
      rad_min.setText(Min.get(position));
  }
  else{
      rad_min.setText("NA");
  }
  if(!db.getLat(Name.get(position)).equals("") && !db.getLat(Name.get(position)).contains("null") && !db.getLat(Name.get(position)).equals(null)&&!db.getLat(Name.get(position)).startsWith("0")){
  float dis= distFrom((float)MapTest.mLatitude, (float)MapTest.mLongitude, Float.parseFloat(db.getLat(Name.get(position))), Float.parseFloat(db.getLong(Name.get(position))));
  int d=Math.round(dis);


  if(d<1000){
  distance.setText(String.valueOf(d)+ " Meters");
  }
  else{
      if((d/1000)<50)
      distance.setText(String.valueOf(d/1000)+ " Kms");
      else
          distance.setText("NA");
  }
    }
    else{
        distance.setText("NA");
    }


   return v;
}


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

@Override
public Object getItem(int arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public long getItemId(int arg0) {
    return 0;
}
public static float distFrom(float lat1, float lng1, float lat2, float lng2) {
    double earthRadius = 6371000; //meters
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
               Math.cos(Math.toRadians(lat1)) *   Math.cos(Math.toRadians(lat2)) *
               Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    float dist = (float) (earthRadius * c);

    return dist;
    }

score 0 · Answer 1 · answered Jul 24 '15 at 06:28

0

I suggest You to not calculate distance in Adapter insted create a Simple bean class for all the feilds and implement Comparator or Comparable and Override CompareTo() method according to distance.

Create a List of that object, and call list.sort();

You will get sorted List then pass this list to Adapter

answered Jul 24 '15 at 06:28

Gaurav

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can you help me with it?.. I din't get it.. Ive seen this process though – Prakhar Jul 24 '15 at 06:33
first Create a bean class let say `class ABC{ String name; float distance; //contructor and getter setter }` – Gaurav Jul 24 '15 at 09:09
then `class ABC implements Comparator` you can refer this ans http://stackoverflow.com/questions/14154127/collections-sortlistt-comparator-super-t-method-example – Gaurav Jul 24 '15 at 09:10

Sort Location By Distance Maps Android

1 Answers1