Hi guys! im working with google places and i'm currently able to show 20 markers on the map. I have a FloatingActionButton on my map screen and once the user presses/clicks on it it should display the markers based on the next_page_token. Currently ive hard coded one in for testing and it works but im confused on how to implement it so that when the user clicks on the button then it finds new ones each time.
My Maps class:
package com.example.test.outandabout;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
import org.json.JSONObject;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnInfoWindowClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements LocationListener {
GoogleMap mMap;
double mLatitude = 0;
double mLongitude = 0;
HashMap<String, String> mMarkerPlaceLink = new HashMap<String, String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mMap = mapFragment.getMap();
// Enabling MyLocation in Google Map
mMap.setMyLocationEnabled(true);
mMap.getUiSettings().setCompassEnabled(true);
mMap.getUiSettings().setZoomControlsEnabled(true);
// Getting LocationManager object from System Service
// LOCATION_SERVICE
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
// Creating a criteria object to retrieve provider
Criteria criteria = new Criteria();
// Getting the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
// Getting Current Location From GPS
Location location = locationManager.getLastKnownLocation(provider);
// mLatitude = location.getLatitude();
// mLongitude = location.getLongitude();
// myLocation = new LatLng(mLatitude, mLongitude);
//
// mMap.addMarker(new MarkerOptions()
// .position(myLocation)
// .title("I'm Here!")
// .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)));
// mMap.moveCamera(CameraUpdateFactory.newLatLng(myLocation));
// onLocationChanged(location);
if (location != null) {
onLocationChanged(location);
}
StringBuilder sb = new StringBuilder(
"https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("location=" + mLatitude + "," + mLongitude);
sb.append("&radius=1000");
sb.append("&key=API_KEY");
// Creating a new non-ui thread task to download Google place json
// data
PlacesTask placesTask = new PlacesTask();
// Invokes the "doInBackground()" method of the class PlaceTask
placesTask.execute(sb.toString());
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab_more);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Finding you some more places!", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
StringBuilder sb = new StringBuilder(
"https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("pagetoken=xxxxx" );
sb.append("&key=API_KEY");
// Creating a new non-ui thread task to download Google place json
// data
PlacesTask placesTask = new PlacesTask();
// Invokes the "doInBackground()" method of the class PlaceTask
placesTask.execute(sb.toString());
}
});
}
/**
* A method to download json data from url
*/
private String downloadUrl(String strUrl) throws IOException {
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(strUrl);
// Creating an http connection to communicate with url
urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(
iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line);
}
data = sb.toString();
Log.d("data", "json response: " + data);
br.close();
} catch (Exception e) {
Log.d("Exception while downloading url", e.toString());
} finally {
iStream.close();
urlConnection.disconnect();
}
return data;
}
/**
* A class, to download Google Places
*/
private class PlacesTask extends AsyncTask<String, Integer, String> {
String data = null;
// Invoked by execute() method of this object
@Override
protected String doInBackground(String... url) {
try {
data = downloadUrl(url[0]);
} catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
// Executed after the complete execution of doInBackground() method
@Override
protected void onPostExecute(String result) {
ParserTask parserTask = new ParserTask();
// Start parsing the Google places in JSON format
// Invokes the "doInBackground()" method of the class ParseTask
parserTask.execute(result);
}
}
/**
* A class to parse the Google Places in JSON format
*/
private class ParserTask extends
AsyncTask<String, Integer, List<HashMap<String, String>>> {
JSONObject jObject;
// Invoked by execute() method of this object
@Override
protected List<HashMap<String, String>> doInBackground(
String... jsonData) {
List<HashMap<String, String>> places = null;
PlaceJSONParser placeJsonParser = new PlaceJSONParser();
try {
jObject = new JSONObject(jsonData[0]);
/** Getting the parsed data as a List construct */
places = placeJsonParser.parse(jObject);
} catch (Exception e) {
Log.d("Exception", e.toString());
}
return places;
}
// Executed after the complete execution of doInBackground() method
@Override
protected void onPostExecute(List<HashMap<String, String>> list) {
// Clears all the existing markers
mMap.clear();
for (int i = 0; i < list.size(); i++) {
// Creating a marker
MarkerOptions markerOptions = new MarkerOptions();
// Getting a place from the places list
HashMap<String, String> hmPlace = list.get(i);
// Getting latitude of the place
double lat = Double.parseDouble(hmPlace.get("lat"));
// Getting longitude of the place
double lng = Double.parseDouble(hmPlace.get("lng"));
// Getting name
String name = hmPlace.get("place_name");
String vicinity = hmPlace.get("vicinity");
LatLng latLng = new LatLng(lat, lng);
// Setting the position for the marker
markerOptions.position(latLng);
markerOptions.title(name);
markerOptions.snippet(vicinity);
// Placing a marker on the touched position
Marker m = mMap.addMarker(markerOptions);
// Linking Marker id and place reference
mMarkerPlaceLink.put(m.getId(), hmPlace.get("reference"));
}
}
}
@Override
public void onLocationChanged(Location location) {
mLatitude = location.getLatitude();
mLongitude = location.getLongitude();
LatLng latLng = new LatLng(mLatitude, mLongitude);
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(15));
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
And this class is called to get the JSON data:
package com.example.test.outandabout;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class PlaceJSONParser {
/** Receives a JSONObject and returns a list */
public List<HashMap<String,String>> parse(JSONObject jObject){
JSONArray jPlaces = null;
try {
/** Retrieves all the elements in the 'places' array */
jPlaces = jObject.getJSONArray("results");
} catch (JSONException e) {
e.printStackTrace();
}
/** Invoking getPlaces with the array of json object
* where each json object represent a place
*/
return getPlaces(jPlaces);
}
private List<HashMap<String, String>> getPlaces(JSONArray jPlaces){
int placesCount = jPlaces.length();
List<HashMap<String, String>> placesList = new ArrayList<HashMap<String,String>>();
HashMap<String, String> place = null;
/** Taking each place, parses and adds to list object */
for(int i=0; i<placesCount;i++){
try {
/** Call getPlace with place JSON object to parse the place */
place = getPlace((JSONObject)jPlaces.get(i));
placesList.add(place);
} catch (JSONException e) {
e.printStackTrace();
}
}
return placesList;
}
/** Parsing the Place JSON object */
private HashMap<String, String> getPlace(JSONObject jPlace){
HashMap<String, String> place = new HashMap<String, String>();
String placeName = "-NA-";
String vicinity = "-NA-";
String latitude="";
String longitude="";
String reference="";
try {
// Extracting Place name, if available
if(!jPlace.isNull("name")){
placeName = jPlace.getString("name");
}
// Extracting Place Vicinity, if available
if(!jPlace.isNull("vicinity")){
vicinity = jPlace.getString("vicinity");
}
latitude = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lat");
longitude = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lng");
reference = jPlace.getString("reference");
place.put("place_name", placeName);
place.put("vicinity", vicinity);
place.put("lat", latitude);
place.put("lng", longitude);
place.put("reference", reference);
} catch (JSONException e) {
e.printStackTrace();
}
return place;
}
}
Any help will be appreciated!