Android – AutoCompleteTextView with Google Places Autocomplete API

In this article, we will develop and Android application which populates an AutoCompleteTextView with Google Places Autocomplete api.

This application is developed in Eclipse (4.2.1) with ADT plugin (21.1.0) and Android SDK ( 21.1.0 ).

1. Create a new Android application project namely “LocationPlacesAutocomplete”

Figure 1 : Create new Android application project

2. Configure the project

Figure 2 : Configure application project

3. Design application launcher icon

Figure 3 : Design application launcher icon

4. Create a blank activity

Figure 4 : Create a blank activity

5. Enter MainActivity details

Figure 5 : Enter MainActivity details

6. Get the API key for Google Places API

We can create API key for Google Place API by clicking “Create new Browser key”  available at the “API Access” pane of the Google console URL : http://code.google.com/apis/console.

Also ensure that, “Places API” is enabled in the “Services” pane of the Google console.

7. Update the file res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">LocationPlacesAutocomplete</string>
    <string name="hello_world">Hello world!</string>
    <string name="menu_settings">Settings</string>
    <string name="str_atv_places">Enter Place Here</string>
</resources>

8. Create a new class namely “CustomAutoCompleteTextView” in the file src/in/wptrafficanalyzer/locationplacesautocomplete/CustomAutoCompleteTextView.java

package in.wptrafficanalyzer.locationplacesautocomplete;

import java.util.HashMap;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.AutoCompleteTextView;

/** Customizing AutoCompleteTextView to return Place Description
 * corresponding to the selected item
 */
public class CustomAutoCompleteTextView extends AutoCompleteTextView {

    public CustomAutoCompleteTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /** Returns the place description corresponding to the selected item */
    @Override
    protected CharSequence convertSelectionToString(Object selectedItem) {
        /** Each item in the autocompetetextview suggestion list is a hashmap object */
        HashMap<String, String> hm = (HashMap<String, String>) selectedItem;
        return hm.get("description");
    }
}

9. Update the layout file res/layout/activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <in.wptrafficanalyzer.locationplacesautocomplete.CustomAutoCompleteTextView
        android:id="@+id/atv_places"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:hint="@string/str_atv_places" />
</RelativeLayout>

10. Create a new class namely “PlaceJSONParser” in the file src/in/wptrafficanalyzer/locationplacesautocomplete/PlaceJSONParser.java

package in.wptrafficanalyzer.locationplacesautocomplete;

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("predictions");
        } 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 id="";
        String reference="";
        String description="";

        try {

            description = jPlace.getString("description");
            id = jPlace.getString("id");
            reference = jPlace.getString("reference");

            place.put("description", description);
            place.put("_id",id);
            place.put("reference",reference);

        } catch (JSONException e) {
            e.printStackTrace();
        }
        return place;
    }
}

11. Update the class “MainActivity” in the file src/in/wptrafficanalyzer/locationplacesautocomplete/MainActivity.java

package in.wptrafficanalyzer.locationplacesautocomplete;

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.net.URLEncoder;
import java.util.HashMap;
import java.util.List;

import org.json.JSONObject;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.widget.AutoCompleteTextView;
import android.widget.SimpleAdapter;

public class MainActivity extends Activity {

    AutoCompleteTextView atvPlaces;
    PlacesTask placesTask;
    ParserTask parserTask;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        atvPlaces = (AutoCompleteTextView) findViewById(R.id.atv_places);
        atvPlaces.setThreshold(1);

        atvPlaces.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                placesTask = new PlacesTask();
                placesTask.execute(s.toString());
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
                // TODO Auto-generated method stub
            }

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub
            }
        });
    }

    /** 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();

            br.close();

        }catch(Exception e){
            Log.d("Exception while downloading url", e.toString());
        }finally{
            iStream.close();
            urlConnection.disconnect();
        }
        return data;
    }

    // Fetches all places from GooglePlaces AutoComplete Web Service
    private class PlacesTask extends AsyncTask<String, Void, String>{

        @Override
        protected String doInBackground(String... place) {
            // For storing data from web service
            String data = "";

            // Obtain browser key from https://code.google.com/apis/console
            String key = "key=YOUR_API_KEY";

            String input="";

            try {
                input = "input=" + URLEncoder.encode(place[0], "utf-8");
            } catch (UnsupportedEncodingException e1) {
                e1.printStackTrace();
            }

            // place type to be searched
            String types = "types=geocode";

            // Sensor enabled
            String sensor = "sensor=false";

            // Building the parameters to the web service
            String parameters = input+"&"+types+"&"+sensor+"&"+key;

            // Output format
            String output = "json";

            // Building the url to the web service
            String url = "https://maps.googleapis.com/maps/api/place/autocomplete/"+output+"?"+parameters;

            try{
                // Fetching the data from we service
                data = downloadUrl(url);
            }catch(Exception e){
                Log.d("Background Task",e.toString());
            }
            return data;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);

            // Creating ParserTask
            parserTask = new ParserTask();

            // Starting Parsing the JSON string returned by Web Service
            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;

        @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;
        }

        @Override
        protected void onPostExecute(List<HashMap<String, String>> result) {

            String[] from = new String[] { "description"};
            int[] to = new int[] { android.R.id.text1 };

            // Creating a SimpleAdapter for the AutoCompleteTextView
            SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), result, android.R.layout.simple_list_item_1, from, to);

            // Setting the adapter
            atvPlaces.setAdapter(adapter);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

Note : Replace “YOUR_API_KEY” at 108 with the api key obtained in the Step 6

12. Update the file AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="in.wptrafficanalyzer.locationplacesautocomplete"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="16" />

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="in.wptrafficanalyzer.locationplacesautocomplete.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

13. Screenshots of the application

Figure 6 : User inputs name of place in AutoCompleteTextView

Figure 7 : User selected a place from the AutoCompleteTextView dropdown list

14. Download Source Code

Android - AutoCompleteTextView with Google Places Autocomplete API - R1 356.04 KB

Download Full Source Code

How to hire me?

I am George Mathew, working as software architect and Android app developer at wptrafficanalyzer.in

You can hire me on hourly basis or on project basis for Android applications development.

For hiring me, please mail your requirements to info@wptrafficanalyzer.in.

My other blogs
store4js.blogspot.com

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Tags: asynchronous, ASyncTask, AutoCompleteTextView, google places api