Draw Polyline from touched location to MyLocation

In this exercise, Google Maps Android API v2 is implemented with MyLocation enabled. When user LongClick on the Map, a marker will be drawn, and a Polyline from touched location to MyLocation will be drawn if MyLocation is available.

To get MyLocation programmatically, you have to enable my-location layer by calling setMyLocationEnabled(true). Then call getMyLocation(), it returns the currently displayed user location, or null if there is no location data available. Please noted that MyLocation may be need long time to available.

MainActivity.java

package com.example.androidmapex;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;

import android.location.Location;
import android.os.Bundle;
import android.widget.Toast;
import android.app.Activity;
import android.app.FragmentManager;

public class MainActivity extends Activity{
 
 private GoogleMap myMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        FragmentManager myFragmentManager = getFragmentManager();
        MapFragment myMapFragment1 = 
          (MapFragment)myFragmentManager.findFragmentById(R.id.map1);

        myMap = myMapFragment1.getMap();
        myMap.setMyLocationEnabled(true);
        myMap.setOnMapLongClickListener(myOnMapLongClickListener);

    }
 
 OnMapLongClickListener myOnMapLongClickListener =
   new OnMapLongClickListener(){

    @Override
    public void onMapLongClick(LatLng point) {
     myMap.addMarker(new MarkerOptions()
          .position(point)
          .title(point.toString()));
     
     Location myLocation = myMap.getMyLocation();
     if(myLocation == null){
      Toast.makeText(getApplicationContext(), 
        "My location not available", 
        Toast.LENGTH_LONG).show();
     }else{
      PolylineOptions polylineOptions = new PolylineOptions();
      polylineOptions.add(point);
      polylineOptions.add(
        new LatLng(myLocation.getLatitude(), myLocation.getLongitude()));
      myMap.addPolyline(polylineOptions);
     }
    }
  
 };
    
}

layout

<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:orientation="vertical"
    tools:context=".MainActivity" >

    <fragment
        android:id="@+id/map1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="5px"
        class="com.google.android.gms.maps.MapFragment"/>

</LinearLayout>

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The series:

A simple example using Google Maps Android API v2, step by step.