Android Map start location chooser

CustomPreferenceActivity.java

package com.trumpstuff.mapdemo;

import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;

/**
 * Created on 04.10.2014.
 */
public class CustomPreferenceActivity extends PreferenceActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        CustomPreferenceFragment customPreferenceFragment = new CustomPreferenceFragment();
        getFragmentManager().beginTransaction().replace(android.R.id.content,customPreferenceFragment).commit();
        PreferenceManager.setDefaultValues(this,R.xml.preferences,false);
    }
}

CustomPreferenceFragment.java

package com.trumpstuff.mapdemo;

import android.app.Activity;
import android.content.SharedPreferences;
import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.Preference;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.util.Log;
import android.widget.Toast;

import java.io.IOException;
import java.util.List;

/**
 * Created on 04.10.2014.
 */
public class CustomPreferenceFragment extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener{
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
    }


    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String s) {
        Preference pref = findPreference(s);
        if(pref != null && pref.getKey().equals("start_location")){
            updateLocationSetting(pref);
        }
        //Other preference handling
    }
    private void updateLocationSetting(Preference preference){
        if(((EditTextPreference) preference).getText().equals("Global")){
            SharedPreferences sharedPreferences = PreferenceManager
                    .getDefaultSharedPreferences(
                            getActivity());
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putString("start_location_lat", "0");
            editor.putString("start_location_lng", "0");
            editor.apply();
            return;
        }
        if(Geocoder.isPresent()){
            Geocoder geocoder = new Geocoder(getActivity());
            try {
                List<Address> addresses = geocoder.getFromLocationName(((EditTextPreference) preference).getText(), 1);
                if (addresses != null && addresses.size() > 0){
                    Address address = addresses.get(0);
                    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
                    SharedPreferences.Editor editor = sharedPreferences.edit();
                    editor.putString("start_location_lat", String.valueOf(address.getLatitude()));
                    editor.putString("start_location_lng", String.valueOf(address.getLongitude()));
                    editor.apply();
                    Log.d("pref", sharedPreferences.getAll().toString());
                }
                else{
                    Toast.makeText(getActivity(), "Could not resolve Address: " + ((EditTextPreference) preference).getText(), Toast.LENGTH_LONG).show();
                }

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        else{
            Toast.makeText(getActivity(),"Geocoder not available on your system",Toast.LENGTH_LONG).show();
        }
    }

    @Override
    public void onResume() {
        super.onResume();
        getPreferenceManager().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
    }

    @Override
    public void onPause() {
        super.onPause();
        getPreferenceManager().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
    }
}

MainActivity.java

package com.trumpstuff.mapdemo;

import android.content.Intent;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends FragmentActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

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

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    /**
     * Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
     * installed) and the map has not already been instantiated.. This will ensure that we only ever
     * call {@link #setUpMap()} once when {@link #mMap} is not null.
     * <p>
     * If it isn't installed {@link SupportMapFragment} (and
     * {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
     * install/update the Google Play services APK on their device.
     * <p>
     * A user can return to this FragmentActivity after following the prompt and correctly
     * installing/updating/enabling the Google Play services. Since the FragmentActivity may not
     * have been completely destroyed during this process (it is likely that it would only be
     * stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
     * method in {@link #onResume()} to guarantee that it will be called.
     */
    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p>
     * This should only be called once and when we are sure that {@link #mMap} is not null.
     */
    private void setUpMap() {

        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
        Log.e("pref", sharedPreferences.getAll().toString());
        double lat = Double.parseDouble(sharedPreferences.getString("start_location_lat","0"));
        double lng = Double.parseDouble(sharedPreferences.getString("start_location_lng","0"));
        LatLng position = new LatLng(lat,lng);
        float zoom = 10;
        if(lat == 0 && lng == 0){
            zoom = mMap.getMinZoomLevel();
        }
        Log.d("zoom", String.valueOf(zoom));
        CameraUpdate centerStartPosition = CameraUpdateFactory.newLatLngZoom(position,zoom);
        mMap.animateCamera(centerStartPosition);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_MENU){
            startActivityForResult(new Intent(this,CustomPreferenceActivity.class),42);
            return true;
        }
        return super.onKeyUp(keyCode, event);
    }
}

preferences.xml

<?xml version="1.0" encoding="utf-8"?>

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <EditTextPreference
        android:key="start_location"
        android:defaultValue="Global"
        android:title="Start Location"
        android:summary="The start Location for the Map"/>
</PreferenceScreen>