Question

This is a ListView I get to display with the cities and places available. I want to show the distance from the current point to the listed places.

eg:

+++++++++++++++++++++++++
Name :Hotel Hilton
Category :hotel
distance:1km
+++++++++++++++++++++++++

How do I calculate and display each distance value on the list?

ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();

            JSONArray jsonArray = new JSONArray(response);

            if (jsonArray != null) {
                for (int i = 0; i < jsonArray.length(); i++) {
                    JSONObject object = (JSONObject) jsonArray.get(i);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_Name, object.getString("name"));
                    map.put(TAG_Category, object.getString("category"));
                    map.put(TAG_Lat, object.getString("lat"));
                    map.put(TAG_Lng, object.getString("lng"));

                    contactList.add(map);

                }
            }

            ListAdapter adapter = new SimpleAdapter(this, contactList,
                    R.layout.menu_list_row, new String[] { TAG_Name,
                    TAG_Category }, new int[] { R.id.LR_Name,
                            R.id.LR_date });
            list.setAdapter(adapter);
        }

Current position is identified from GPS and stors as lat,lng.

Answer 1

You can use:

float[] res = new float[3];
Location.distanceBetween(object.getDouble("lat"), object.getDouble("lng"), lat,lng, res);

given that first two parameters are doubles, representing your object’s position, while lat and lng variables contain your current position.

Result, expressed in meters, will be at res[0]