Implement cancel draggable during onAnnotationDrag

app/src/main/java/com/mapbox/mapboxsdk/plugins/testapp/activity/annotation/CircleActivity.java

@@ -103,12 +103,13 @@ public void onAnnotationDragStarted(Circle annotation) {
         }
 
         @Override
-        public void onAnnotationDrag(Circle annotation) {
+        public boolean onAnnotationDrag(Circle annotation) {
           draggableInfoTv.setText(String.format(
             Locale.US,
             "ID: %s\nLatLng:%f, %f",
             annotation.getId(),
             annotation.getLatLng().getLatitude(), annotation.getLatLng().getLongitude()));
+          return true;
         }
 
         @Override

app/src/main/java/com/mapbox/mapboxsdk/plugins/testapp/activity/annotation/SymbolActivity.java

@@ -142,12 +142,13 @@ public void onAnnotationDragStarted(Symbol annotation) {
         }
 
         @Override
-        public void onAnnotationDrag(Symbol annotation) {
+        public boolean onAnnotationDrag(Symbol annotation) {
           draggableInfoTv.setText(String.format(
             Locale.US,
             "ID: %s\nLatLng:%f, %f",
             annotation.getId(),
             annotation.getLatLng().getLatitude(), annotation.getLatLng().getLongitude()));
+          return true;
         }
 
         @Override

plugin-annotation/src/main/java/com/mapbox/mapboxsdk/plugins/annotation/DraggableAnnotationController.java

@@ -101,13 +101,18 @@ boolean onMove(MoveGestureDetector detector) {
       );
 
       if (shiftedGeometry != null) {
+        Geometry oldGeometry = draggedAnnotation.geometry;
         draggedAnnotation.setGeometry(
           shiftedGeometry
         );
         annotationManager.internalUpdateSource();
         if (!annotationManager.getDragListeners().isEmpty()) {
           for (D d : annotationManager.getDragListeners()) {
-            d.onAnnotationDrag(draggedAnnotation);
+            if (!d.onAnnotationDrag(draggedAnnotation)) {
+              draggedAnnotation.setGeometry(oldGeometry);
+              stopDragging(draggedAnnotation);
+              return true;
+            }
           }
         }
         return true;

plugin-annotation/src/main/java/com/mapbox/mapboxsdk/plugins/annotation/OnAnnotationDragListener.java

@@ -18,8 +18,9 @@ public interface OnAnnotationDragListener<T extends Annotation> {
    * Called when an annotation dragging is in progress.
    *
    * @param annotation the annotation
+   * @return False if this drag should be canceled, true otherwise.
    */
-  void onAnnotationDrag(T annotation);
+  boolean onAnnotationDrag(T annotation);
 
   /**
    * Called when an annotation dragging has finished.