[android] - expose source layer identifier (#8709)

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/CircleLayer.java

@@ -59,6 +59,15 @@ public class CircleLayer extends Layer {
     return this;
   }
 
+  /**
+   * Get the source layer.
+   *
+   * @return sourceLayer the source layer to get
+   */
+  public String getSourceLayer() {
+    return nativeGetSourceLayer();
+  }
+
   /**
    * Set a single filter.
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/FillLayer.java

@@ -59,6 +59,15 @@ public class FillLayer extends Layer {
     return this;
   }
 
+  /**
+   * Get the source layer.
+   *
+   * @return sourceLayer the source layer to get
+   */
+  public String getSourceLayer() {
+    return nativeGetSourceLayer();
+  }
+
   /**
    * Set a single filter.
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Layer.java

@@ -73,6 +73,8 @@ public abstract class Layer {
 
   protected native void nativeSetSourceLayer(String sourceLayer);
 
+  protected native String nativeGetSourceLayer();
+
   protected native float nativeGetMinZoom();
 
   protected native float nativeGetMaxZoom();

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/LineLayer.java

@@ -59,6 +59,15 @@ public class LineLayer extends Layer {
     return this;
   }
 
+  /**
+   * Get the source layer.
+   *
+   * @return sourceLayer the source layer to get
+   */
+  public String getSourceLayer() {
+    return nativeGetSourceLayer();
+  }
+
   /**
    * Set a single filter.
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/SymbolLayer.java

@@ -59,6 +59,15 @@ public class SymbolLayer extends Layer {
     return this;
   }
 
+  /**
+   * Get the source layer.
+   *
+   * @return sourceLayer the source layer to get
+   */
+  public String getSourceLayer() {
+    return nativeGetSourceLayer();
+  }
+
   /**
    * Set a single filter.
    *

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/layer.java.ejs

@@ -79,6 +79,15 @@ public class <%- camelize(type) %>Layer extends Layer {
 
 <% } -%>
 <% if (type !== 'background' && type !== 'raster') { -%>
+  /**
+   * Get the source layer.
+   *
+   * @return sourceLayer the source layer to get
+   */
+  public String getSourceLayer() {
+    return nativeGetSourceLayer();
+  }
+
   /**
    * Set a single filter.
    *