Issue #2284 BaseLoaderCallback requires use of Activity fixed.

android/service/doc/BaseLoaderCallback.rst

@@ -9,3 +9,52 @@ Base Loader Callback Interface implementation
 
 .. image:: img/AndroidAppUsageModel.png
 
+Using in Java Activity
+----------------------
+
+There is a very base code snippet implementing the async initialization with BaseLoaderCallback. See the "15-puzzle" OpenCV sample for details.
+
+.. code-block:: java
+    :linenos:
+
+    public class MyActivity extends Activity implements HelperCallbackInterface
+    {
+    private BaseLoaderCallback mOpenCVCallBack = new BaseLoaderCallback(this) {
+       @Override
+       public void onManagerConnected(int status) {
+         switch (status) {
+           case LoaderCallbackInterface.SUCCESS:
+           {
+              Log.i(TAG, "OpenCV loaded successfully");
+              // Create and set View
+              mView = new puzzle15View(mAppContext);
+              setContentView(mView);
+           } break;
+           default:
+           {
+              super.onManagerConnected(status);
+           } break;
+         }
+       }
+    };
+
+    /** Call on every application resume **/
+    @Override
+    protected void onResume()
+    {
+        Log.i(TAG, "called onResume");
+        super.onResume();
+
+        Log.i(TAG, "Trying to load OpenCV library");
+        if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+        {
+            Log.e(TAG, "Cannot connect to OpenCV Manager");
+        }
+    }
+
+Using in Service
+----------------
+
+Default BaseLoaderCallback implementation treat application context as Activity and calls Activity.finish() method to exit in case of initialization failure. 
+To override this behavior you need to override finish() method of BaseLoaderCallback class and implement your own finalization method. 
+