completed implementation of the Guided scan follow mode.

Android/build.gradle

@@ -11,7 +11,7 @@ dependencies {
     compile 'com.android.support:cardview-v7:21.0.2'
     compile 'com.android.support:recyclerview-v7:21.0.2'
 
-    compile 'com.o3dr:3dr-services-lib:2.2.2'
+    compile 'com.o3dr:3dr-services-lib:2.2.6'
 
     compile files('libs/droneapi-java-0.3-SNAPSHOT.jar')
     compile files('libs/j2xx.jar')
@@ -28,7 +28,7 @@ android {
         applicationId 'org.droidplanner.android'
         minSdkVersion 14
         targetSdkVersion 21
-        versionCode 30013
+        versionCode 30014
         versionName getGitVersion()
     }
 

Android/res/layout/fragment_mode_follow.xml

@@ -14,7 +14,7 @@
         style="@style/ModeDetailText"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:text="@string/mode_guided"/>
+        android:text="@string/mode_follow"/>
 
     <Spinner
         android:id="@+id/follow_type_spinner"

Android/res/values/strings.xml

@@ -155,6 +155,7 @@
     <string name="mode_sport">Sport allows a pilot to control rate of rotation directly with the addition of self-leveling.</string>
     <string name="mode_stabilize">Stabilize levels the vehicle in flight.</string>
     <string name="mode_poshold">PosHold allows position hold (GPS) with direct response to pilot input.</string>
+    <string name="mode_follow">The vehicle follows the user based on the device GPS location.</string>
 
     <!-- Waypoint types -->
     <string name="waypointType_Waypoint">Waypoint</string>
@@ -526,5 +527,7 @@
     <string name="delete_selected_waypoints_confirm">Clear selected waypoints from the map?</string>
     <string name="delete_selected_waypoints_title">Clear selected waypoints</string>
     <string name="label_select_all">select all</string>
+    <string name="guided_scan_roi_set_message">Targeting selected location.</string>
+    <string name="mode_follow_guided_scan">Vehicle follows the user while remaining locked on a point of interest. Long click on the map to select the point of interest.</string>
 
 </resources>

Android/src/org/droidplanner/android/activities/FlightActivity.java

@@ -27,6 +27,7 @@
 import com.sothree.slidinguppanel.SlidingUpPanelLayout;
 
 import org.droidplanner.android.R;
+import org.droidplanner.android.fragments.DroneMap;
 import org.droidplanner.android.fragments.FlightActionsFragment;
 import org.droidplanner.android.fragments.FlightMapFragment;
 import org.droidplanner.android.fragments.TelemetryFragment;
@@ -415,6 +416,14 @@ public void setGuidedClickListener(FlightMapFragment.OnGuidedClickListener liste
         mapFragment.setGuidedClickListener(listener);
     }
 
+    public void addMapMarkerProvider(DroneMap.MapMarkerProvider provider){
+        mapFragment.addMapMarkerProvider(provider);
+    }
+
+    public void removeMapMarkerProvider(DroneMap.MapMarkerProvider provider){
+        mapFragment.removeMapMarkerProvider(provider);
+    }
+
     @Override
     public void onStart() {
         super.onStart();

Android/src/org/droidplanner/android/fragments/DroneMap.java

@@ -33,13 +33,18 @@
 import org.droidplanner.android.utils.prefs.AutoPanMode;
 import org.droidplanner.android.utils.prefs.DroidPlannerPrefs;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
 
 public abstract class DroneMap extends ApiListenerFragment {
 
 	private final static String TAG = DroneMap.class.getSimpleName();
 
+    public static final String ACTION_UPDATE_MAP = Utils.PACKAGE_NAME + ".action.UPDATE_MAP";
+
 	private static final IntentFilter eventFilter = new IntentFilter();
 	static {
 		eventFilter.addAction(MissionProxy.ACTION_MISSION_PROXY_UPDATE);
@@ -51,19 +56,24 @@ public abstract class DroneMap extends ApiListenerFragment {
 		eventFilter.addAction(AttributeEvent.STATE_DISCONNECTED);
 		eventFilter.addAction(AttributeEvent.CAMERA_FOOTPRINTS_UPDATED);
 		eventFilter.addAction(AttributeEvent.ATTITUDE_UPDATED);
+        eventFilter.addAction(ACTION_UPDATE_MAP);
 	}
 
-	private final BroadcastReceiver eventReceiver = new BroadcastReceiver() {
+    private static final List<MarkerInfo> NO_EXTERNAL_MARKERS = Collections.emptyList();
+
+    private final BroadcastReceiver eventReceiver = new BroadcastReceiver() {
 		@Override
 		public void onReceive(Context context, Intent intent) {
 			if (!isResumed())
 				return;
 
 			final String action = intent.getAction();
             switch (action) {
+                case ACTION_UPDATE_MAP:
                 case MissionProxy.ACTION_MISSION_PROXY_UPDATE:
                     postUpdate();
                     break;
+
                 case AttributeEvent.GPS_POSITION: {
                     mMapFragment.updateMarker(graphicDrone);
                     mMapFragment.updateDroneLeashPath(guided);
@@ -124,8 +134,10 @@ public void run() {
 				return;
 
 			final List<MarkerInfo> missionMarkerInfos = missionProxy.getMarkersInfos();
+            final List<MarkerInfo> externalMarkers = collectMarkersFromProviders();
 
 			final boolean isThereMissionMarkers = !missionMarkerInfos.isEmpty();
+            final boolean isThereExternalMarkers = !externalMarkers.isEmpty();
 			final boolean isHomeValid = home.isValid();
 			final boolean isGuidedVisible = guided.isVisible();
 
@@ -145,6 +157,9 @@ public void run() {
 					markersOnTheMap.removeAll(missionMarkerInfos);
 				}
 
+                if(isThereExternalMarkers)
+                    markersOnTheMap.removeAll(externalMarkers);
+
 				mMapFragment.removeMarkers(markersOnTheMap);
 			}
 
@@ -160,6 +175,9 @@ public void run() {
 				mMapFragment.updateMarkers(missionMarkerInfos, isMissionDraggable());
 			}
 
+            if(isThereExternalMarkers)
+                mMapFragment.updateMarkers(externalMarkers, false);
+
 			mMapFragment.updateMissionPath(missionProxy);
 
 			mMapFragment.updatePolygonsPaths(missionProxy.getPolygonsPath());
@@ -168,6 +186,8 @@ public void run() {
 		}
 	};
 
+    private final ConcurrentLinkedQueue<MapMarkerProvider> markerProviders = new ConcurrentLinkedQueue<>();
+
 	protected DPMap mMapFragment;
 
 	protected DroidPlannerPrefs mAppPrefs;
@@ -342,4 +362,38 @@ public void updateMapBearing(float bearing) {
 	public void skipMarkerClickEvents(boolean skip) {
 		mMapFragment.skipMarkerClickEvents(skip);
 	}
+
+    public void addMapMarkerProvider(MapMarkerProvider provider){
+        if(provider != null) {
+            markerProviders.add(provider);
+            postUpdate();
+        }
+    }
+
+    public void removeMapMarkerProvider(MapMarkerProvider provider){
+        if(provider != null) {
+            markerProviders.remove(provider);
+            postUpdate();
+        }
+    }
+
+    public interface MapMarkerProvider {
+        MarkerInfo[] getMapMarkers();
+    }
+
+    private List<MarkerInfo> collectMarkersFromProviders(){
+        if(markerProviders.isEmpty())
+            return NO_EXTERNAL_MARKERS;
+
+        List<MarkerInfo> markers = new ArrayList<>();
+        for(MapMarkerProvider provider : markerProviders){
+            MarkerInfo[] externalMarkers = provider.getMapMarkers();
+            Collections.addAll(markers, externalMarkers);
+        }
+
+        if(markers.isEmpty())
+            return NO_EXTERNAL_MARKERS;
+
+        return markers;
+    }
 }

Android/src/org/droidplanner/android/fragments/mode/FlightModePanel.java

@@ -61,7 +61,6 @@ public void onApiDisconnected() {
 
 	private void onModeUpdate(Drone drone) {
 		// Update the info panel fragment
-		drone = getDrone();
         final State droneState = drone.getAttribute(AttributeType.STATE);
 		Fragment infoPanel;
 		if (droneState == null || !droneState.isConnected()) {