How to Draw Polyline in Google Maps in Android?

Drawing a polyline on Google Maps in an Android app involves using the Google Maps Android API. Here's a step-by-step guide on how to do it:

Setup Google Maps SDK for Android:
- Make sure you have the Google Maps SDK for Android added to your project. If not, add the following dependency to your app's build.gradle:
```
implementation 'com.google.android.gms:play-services-maps:17.0.1'
```
- Ensure you have the necessary permissions in your AndroidManifest.xml:
```
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
```
- Obtain an API key from the Google Cloud Console and add it to your AndroidManifest.xml:
```
<meta-data
    android:name="com.google.android.geo.API_KEY"
    android:value="YOUR_API_KEY"/>
```

Initialize the Google Map:

Set up a SupportMapFragment or MapView in your layout XML:

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:name="com.google.android.gms.maps.SupportMapFragment"/>

Draw the Polyline:

In your activity or fragment:

public class MapsActivity extends AppCompatActivity implements OnMapReadyCallback {

    @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);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        List<LatLng> points = new ArrayList<>();
        points.add(new LatLng(37.783, -122.403));
        points.add(new LatLng(37.794, -122.407));
        // ... add as many points as you need

        PolylineOptions polylineOptions = new PolylineOptions()
                .addAll(points)
                .width(10) // width of the polyline
                .color(Color.RED) // color of the polyline
                .geodesic(true); // makes the line follow the Earth's curvature

        googleMap.addPolyline(polylineOptions);
    }
}

This code sets up a simple Android activity with a Google Map, then draws a red polyline based on a list of LatLng points.

Remember, when working with Google Maps SDK for Android, it's important to keep track of your usage. If your application has a large number of users, you may incur costs. Always check the Google Maps Platform pricing to ensure you're aware of any costs associated with usage.

Draw polyline on Google Maps in Android:

Use PolylineOptions to draw a polyline on Google Maps.

PolylineOptions polylineOptions = new PolylineOptions()
        .add(new LatLng(lat1, lng1), new LatLng(lat2, lng2), /*...*/)
        .width(5)
        .color(Color.RED);

googleMap.addPolyline(polylineOptions);

Implementing polyline drawing in Android with Google Maps:
- Continuously add new points to the PolylineOptions to implement polyline drawing on Google Maps.
```
// Inside a loop or touch event listener
polylineOptions.add(new LatLng(newLat, newLng));
polyline.setPoints(polylineOptions.getPoints());
```

Draw polyline on Google Map using PolylineOptions:

Continuously add points to PolylineOptions to draw a polyline on Google Maps.

PolylineOptions polylineOptions = new PolylineOptions()
        .width(5)
        .color(Color.RED);

// Inside a loop or touch event listener
polylineOptions.add(new LatLng(newLat, newLng));
polyline.setPoints(polylineOptions.getPoints());

Android Google Maps polyline between two points:

Use PolylineOptions to create a polyline between two points on Google Maps.

PolylineOptions polylineOptions = new PolylineOptions()
        .add(new LatLng(lat1, lng1), new LatLng(lat2, lng2))
        .width(5)
        .color(Color.RED);

googleMap.addPolyline(polylineOptions);

Displaying a path with polyline on Google Map in Android:

Continuously update the PolylineOptions with the path points to display it on Google Maps.

PolylineOptions polylineOptions = new PolylineOptions()
        .width(5)
        .color(Color.RED);

// Inside a loop or touch event listener
polylineOptions.add(new LatLng(newLat, newLng));
googleMap.addPolyline(polylineOptions);

Code example for drawing a polyline on Google Maps in Android:

Combine the above snippets based on your specific use case.

GoogleMap googleMap = // Get the GoogleMap instance

PolylineOptions polylineOptions = new PolylineOptions()
        .width(5)
        .color(Color.RED);

// Inside a loop or touch event listener
polylineOptions.add(new LatLng(newLat, newLng));
googleMap.addPolyline(polylineOptions);