Thursday, April 21, 2016

Get my Last Known Location, by calling LocationServices.FusedLocationApi.getLastLocation()

The example show how to get my Last Known Location, by calling LocationServices.FusedLocationApi.getLastLocation() of Google play Service.


reference: Android Developers - Getting the Last Known Location


To use Google Play Service in your project, you have to Add Google Play Services to Android Studio project, refer last post.

MainActivity.java
package com.blogspot.android_er.androidgetlastlocation;

import android.location.Location;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;

public class MainActivity extends AppCompatActivity
        implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {

    Button btnGetLastLocation;
    TextView textLastLocation;

    GoogleApiClient mGoogleApiClient;
    Location mLastLocation;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnGetLastLocation = (Button) findViewById(R.id.getlastlocation);
        btnGetLastLocation.setOnClickListener(btnGetLastLocationOnClickListener);
        textLastLocation = (TextView) findViewById(R.id.lastlocation);

        // Create an instance of GoogleAPIClient.
        if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API)
                    .build();
        }
    }

    View.OnClickListener btnGetLastLocationOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if(mGoogleApiClient != null){
                if(mGoogleApiClient.isConnected()){
                    getMyLocation();
                }else{
                    Toast.makeText(MainActivity.this,
                            "!mGoogleApiClient.isConnected()", Toast.LENGTH_LONG).show();
                }
            }else{
                Toast.makeText(MainActivity.this,
                        "mGoogleApiClient == null", Toast.LENGTH_LONG).show();
            }
        }
    };

    private void getMyLocation(){
        try{
            /* code should explicitly check to see if permission is available
            (with 'checkPermission') or explicitly handle a potential 'SecurityException'
             */
            mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
            if (mLastLocation != null) {
                textLastLocation.setText(
                        String.valueOf(mLastLocation.getLatitude()) + "\n"
                                + String.valueOf(mLastLocation.getLongitude()));
                Toast.makeText(MainActivity.this,
                        String.valueOf(mLastLocation.getLatitude()) + "\n"
                                + String.valueOf(mLastLocation.getLongitude()),
                        Toast.LENGTH_LONG).show();
            }else{
                Toast.makeText(MainActivity.this,
                        "mLastLocation == null",
                        Toast.LENGTH_LONG).show();
            }
        } catch (SecurityException e){
            Toast.makeText(MainActivity.this,
                    "SecurityException:\n" + e.toString(),
                    Toast.LENGTH_LONG).show();
        }
    }

    @Override
    protected void onStart() {
        mGoogleApiClient.connect();
        super.onStart();
    }

    @Override
    protected void onStop() {
        mGoogleApiClient.disconnect();
        super.onStop();
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        getMyLocation();
    }

    @Override
    public void onConnectionSuspended(int i) {
        Toast.makeText(MainActivity.this,
                "onConnectionSuspended: " + String.valueOf(i),
                Toast.LENGTH_LONG).show();
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Toast.makeText(MainActivity.this,
                "onConnectionFailed: \n" + connectionResult.toString(),
                Toast.LENGTH_LONG).show();
    }
}


layout/activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:padding="16dp"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidgetlastlocation.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <Button
        android:id="@+id/getlastlocation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Get my last location"/>

    <TextView
        android:id="@+id/lastlocation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>


Permission:
Add uses-permission of ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION in your AndroidManifest.xml. In this example, I use ACCESS_FINE_LOCATION. (Read remark below about getLastLocation() return null)


remark: getLastLocation() return null!
- When run on real device, ASUS Zenfone 2 running Android 5.0:
According to Android Developers - Getting the Last Known Location, you can add permission of ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION. But in my trial, if add permission of ACCESS_COARSE_LOCATION, getLastLocation() return null mostly, around 2 success in more than 30 try. if add permission of ACCESS_FINE_LOCATION, it almost success every time.


Next:
- Requesting Permissions of Manifest.permission.ACCESS_FINE_LOCATION at Run Time

Related:
Request Location Updates with LocationListener.onLocationChanged()

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