Changing Some UI Elements on Current Activity

Question

Application to implement:

User is prompted to input his source location, after that user is prompted to input his destination location. After completion, a route will appear between source and destination.

Implemented so far

Splash Screen with 500ms delay

After 500ms user is shifted to MainActivity

Here a user is prompted to enter his current location in a text box.

As user enters his source, a marker appears on google maps

About Textbox: The textbox I am using is a place autocomplete from Places API from google itself. This widget at any length of input shows specific place hints relative to the input. I am basically using the fragment implementation of this autocomplete textbox.

Problem: Now the problem I am facing is that I want my textbox that was inputting source should now input destination. What should i do change the input type?

Code:

.xml file

<fragment
    android:id="@+id/place_autocomplete_fragment"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:name="com.google.android.gms.location.places.ui.PlaceAutocompleteFragment" />

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.mazik.ahmed.androidappontheway.MapsActivity" />

.java file

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

    PlaceAutocompleteFragment autocompleteFragment = (PlaceAutocompleteFragment)
            getFragmentManager().findFragmentById(R.id.place_autocomplete_fragment);

    autocompleteFragment.setOnPlaceSelectedListener(new PlaceSelectionListener() {
        @Override
        public void onPlaceSelected(Place place) {
            LatLng latlng = new LatLng(place.getLatLng().latitude, place.getLatLng().longitude);
            mMap.addMarker(new MarkerOptions().position(latlng).title(place.getName().toString())
                    .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_VIOLET)));
        }

        @Override
        public void onError(Status status) { }
    });

What I want is that the autocomplete widget prompt for a re-input after assuring the source has been selected.