[android] schedule work on the gl thread using GLSurfaceView#queueEvent

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java

@@ -28,6 +28,7 @@ import com.mapbox.mapboxsdk.annotations.MarkerViewManager;
 import com.mapbox.mapboxsdk.constants.MapboxConstants;
 import com.mapbox.mapboxsdk.constants.Style;
 import com.mapbox.mapboxsdk.egl.EGLConfigChooser;
+import com.mapbox.mapboxsdk.maps.renderer.GlSurfaceViewRenderThread;
 import com.mapbox.mapboxsdk.maps.widgets.CompassView;
 import com.mapbox.mapboxsdk.maps.widgets.MyLocationView;
 import com.mapbox.mapboxsdk.maps.widgets.MyLocationViewSettings;
@@ -312,6 +313,8 @@ public class MapView extends FrameLayout {
     });
     glSurfaceView.setRenderMode(RENDERMODE_WHEN_DIRTY);
     glSurfaceView.setVisibility(View.VISIBLE);
+
+    nativeMapView.setRenderThread(new GlSurfaceViewRenderThread(glSurfaceView));
   }
 
   /**
@@ -494,15 +497,6 @@ public class MapView extends FrameLayout {
   // Rendering
   //
 
-  // Called when the map needs to be rerendered
-  // Called via JNI from NativeMapView
-  protected void onInvalidate() {
-    if (glSurfaceView != null) {
-      glSurfaceView.requestRender();
-    }
-    // TODO: removable? postInvalidate();
-  }
-
   @Override
   protected void onSizeChanged(int width, int height, int oldw, int oldh) {
     if (destroyed) {

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java

@@ -20,6 +20,7 @@ import com.mapbox.mapboxsdk.camera.CameraPosition;
 import com.mapbox.mapboxsdk.geometry.LatLng;
 import com.mapbox.mapboxsdk.geometry.LatLngBounds;
 import com.mapbox.mapboxsdk.geometry.ProjectedMeters;
+import com.mapbox.mapboxsdk.maps.renderer.RenderThread;
 import com.mapbox.mapboxsdk.storage.FileSource;
 import com.mapbox.mapboxsdk.style.layers.CannotAddLayerException;
 import com.mapbox.mapboxsdk.style.layers.Filter;
@@ -52,6 +53,9 @@ final class NativeMapView implements GLSurfaceView.Renderer {
   // Used for callbacks
   private MapView mapView;
 
+  // Used to schedule work on the render thread
+  private RenderThread renderThread;
+
   //Hold a reference to prevent it from being GC'd as long as it's used on the native side
   private final FileSource fileSource;
 
@@ -69,7 +73,7 @@ final class NativeMapView implements GLSurfaceView.Renderer {
   // Constructors
   //
 
-  public NativeMapView(MapView mapView) {
+  public NativeMapView(final MapView mapView) {
     Context context = mapView.getContext();
     fileSource = FileSource.getInstance(context);
 
@@ -84,6 +88,10 @@ final class NativeMapView implements GLSurfaceView.Renderer {
   // Methods
   //
 
+  public void setRenderThread(RenderThread renderThread) {
+    this.renderThread = renderThread;
+  }
+
   private boolean isDestroyedOn(String callingMethod) {
     if (destroyed && !TextUtils.isEmpty(callingMethod)) {
       Timber.e(
@@ -104,7 +112,8 @@ final class NativeMapView implements GLSurfaceView.Renderer {
     if (isDestroyedOn("update")) {
       return;
     }
-    nativeUpdate();
+
+    requestRender();
   }
 
   public void render() {
@@ -864,9 +873,28 @@ final class NativeMapView implements GLSurfaceView.Renderer {
   // Callbacks
   //
 
-  protected void onInvalidate() {
-    if (mapView != null) {
-      mapView.onInvalidate();
+  /**
+   * Called from JNI whenever the native map
+   * needs rendering.
+   */
+  protected void requestRender() {
+    if (renderThread != null) {
+      renderThread.requestRender();
+    }
+  }
+
+  /**
+   * Called from JNI when work needs to be processed on
+   * the Renderer Thread.
+   */
+  protected void requestProcessing() {
+    if (renderThread != null) {
+      renderThread.queueEvent(new Runnable() {
+        @Override
+        public void run() {
+          nativeProcess();
+        }
+      });
     }
   }
 
@@ -905,6 +933,8 @@ final class NativeMapView implements GLSurfaceView.Renderer {
 
   private native void nativeDestroy();
 
+  private native void nativeProcess();
+
   private native void nativeInitializeDisplay();
 
   private native void nativeTerminateDisplay();
@@ -1130,9 +1160,7 @@ final class NativeMapView implements GLSurfaceView.Renderer {
   void addSnapshotCallback(@NonNull MapboxMap.SnapshotReadyCallback callback) {
     snapshotReadyCallback = callback;
     scheduleTakeSnapshot();
-    mapView.onInvalidate();
-    // TODO. this should do a request render
-    //render();
+    renderThread.requestRender();
   }
 
   //

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/GlSurfaceViewRenderThread.java

@@ -0,0 +1,25 @@
+package com.mapbox.mapboxsdk.maps.renderer;
+
+import android.opengl.GLSurfaceView;
+
+/**
+ * {@link RenderThread} implementation that schedules using the
+ * {@link GLSurfaceView} thread.
+ */
+public class GlSurfaceViewRenderThread implements RenderThread {
+  private final GLSurfaceView surfaceView;
+
+  public GlSurfaceViewRenderThread(GLSurfaceView surfaceView) {
+    this.surfaceView = surfaceView;
+  }
+
+  @Override
+  public void requestRender() {
+    surfaceView.requestRender();
+  }
+
+  @Override
+  public void queueEvent(Runnable runnable) {
+    surfaceView.queueEvent(runnable);
+  }
+}

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/RenderThread.java

@@ -0,0 +1,12 @@
+package com.mapbox.mapboxsdk.maps.renderer;
+
+/**
+ * Created by ivo on 11/09/2017.
+ */
+
+public interface RenderThread {
+
+  void requestRender();
+
+  void queueEvent(Runnable runnable);
+}