Add styleable snapshotter.

MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/snapshotter/MapSnapshotter.java

@@ -31,6 +31,7 @@
 import com.mapbox.mapboxsdk.maps.Style;
 import com.mapbox.mapboxsdk.maps.TelemetryDefinition;
 import com.mapbox.mapboxsdk.storage.FileSource;
+import com.mapbox.mapboxsdk.style.layers.Layer;
 import com.mapbox.mapboxsdk.utils.FontUtils;
 import com.mapbox.mapboxsdk.utils.ThreadUtils;
 
@@ -412,6 +413,15 @@ public void start(@NonNull SnapshotReadyCallback callback, ErrorHandler errorHan
   @Keep
   public native void setStyleJson(String styleJson);
 
+  /**
+   * Add a new layer to snapshotter before snapshotter starts.
+   *
+   * @param layer the layer to add.
+   */
+  public void addLayer(Layer layer){
+    nativeAddLayer(layer.getNativePtr());
+  }
+
   /**
    * Must be called in on the thread
    * the object was created on.
@@ -631,6 +641,9 @@ protected native void nativeInitialize(MapSnapshotter mapSnapshotter,
   @Keep
   protected native void nativeCancel();
 
+  @Keep
+  protected native void nativeAddLayer(long id);
+
   @Override
   @Keep
   protected native void finalize() throws Throwable;

MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/snapshot/MapSnapshotterActivity.java

@@ -1,5 +1,6 @@
 package com.mapbox.mapboxsdk.testapp.activity.snapshot;
 
+import android.graphics.Color;
 import android.os.Bundle;
 import androidx.appcompat.app.AppCompatActivity;
 import android.view.ViewTreeObserver;
@@ -12,6 +13,7 @@
 import com.mapbox.mapboxsdk.geometry.LatLng;
 import com.mapbox.mapboxsdk.geometry.LatLngBounds;
 import com.mapbox.mapboxsdk.snapshotter.MapSnapshotter;
+import com.mapbox.mapboxsdk.style.layers.FillLayer;
 import com.mapbox.mapboxsdk.testapp.R;
 
 import java.util.ArrayList;
@@ -20,6 +22,9 @@
 
 import timber.log.Timber;
 
+import static com.mapbox.mapboxsdk.style.expressions.Expression.color;
+import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.fillColor;
+
 /**
  * Test activity showing how to use a the {@link com.mapbox.mapboxsdk.snapshotter.MapSnapshotter}
  */
@@ -96,6 +101,10 @@ private void startSnapShot(final int row, final int column) {
 
     MapSnapshotter snapshotter = new MapSnapshotter(MapSnapshotterActivity.this, options);
 
+    FillLayer water = new FillLayer("water","mapbox");
+    water.setProperties(fillColor(color(Color.GREEN)));
+
+    snapshotter.addLayer(water);
     snapshotter.start(snapshot -> {
       Timber.i("Got the snapshot");
       ImageView imageView = new ImageView(MapSnapshotterActivity.this);