Create OverlayTracker as a prent of MarkerTracker to allow tracking of other objects.

src/main/org/insa/graphics/drawing/BasicDrawing.java

@@ -38,10 +38,7 @@ public class BasicDrawing extends JPanel implements Drawing {
      */
     private static final long serialVersionUID = 96779785877771827L;
 
-    public class BasicMarkerTracker implements MarkerTracker {
-
-        // Point of the marker.
-        private Point point;
+    public class BasicOverlayTracker implements OverlayTracker {
 
         // Image of the marker
         protected BufferedImage image;
@@ -49,23 +46,11 @@ public class BasicDrawing extends JPanel implements Drawing {
         // Visible?
         protected boolean visible;
 
-        public BasicMarkerTracker(Point point, BufferedImage image) {
-            this.point = point;
+        public BasicOverlayTracker(BufferedImage image) {
             this.image = image;
             this.visible = true;
         }
 
-        @Override
-        public Point getPoint() {
-            return point;
-        }
-
-        @Override
-        public void moveTo(Point point) {
-            this.point = point;
-            BasicDrawing.this.repaint();
-        }
-
         @Override
         public void setVisible(boolean visible) {
             this.visible = visible;
@@ -80,6 +65,29 @@ public class BasicDrawing extends JPanel implements Drawing {
 
     };
 
+    public class BasicMarkerTracker extends BasicOverlayTracker implements MarkerTracker {
+
+        // Point of the marker.
+        private Point point;
+
+        public BasicMarkerTracker(Point point, BufferedImage image) {
+            super(image);
+            this.point = point;
+        }
+
+        @Override
+        public Point getPoint() {
+            return point;
+        }
+
+        @Override
+        public void moveTo(Point point) {
+            this.point = point;
+            BasicDrawing.this.repaint();
+        }
+
+    };
+
     // Default path color.
     public static final Color DEFAULT_PATH_COLOR = new Color(255, 0, 255);
 

src/main/org/insa/graphics/drawing/MapViewDrawing.java

@@ -27,6 +27,7 @@ import org.mapsforge.map.awt.graphics.AwtGraphicFactory;
 import org.mapsforge.map.awt.util.AwtUtil;
 import org.mapsforge.map.awt.view.MapView;
 import org.mapsforge.map.datastore.MapDataStore;
+import org.mapsforge.map.layer.Layer;
 import org.mapsforge.map.layer.Layers;
 import org.mapsforge.map.layer.cache.TileCache;
 import org.mapsforge.map.layer.hills.HillsRenderConfig;
@@ -46,37 +47,47 @@ public class MapViewDrawing extends MapView implements Drawing {
      */
     private static final long serialVersionUID = 8606967833704938092L;
 
-    public class MapViewMarkerTracker implements MarkerTracker {
+    public class MapViewOverlayTracker implements OverlayTracker {
 
         // Marker associated.
-        private Marker marker;
+        protected Layer layer;
+
+        public MapViewOverlayTracker(Layer marker) {
+            this.layer = marker;
+        }
+
+        @Override
+        public void setVisible(boolean visible) {
+            this.layer.setVisible(visible);
+        }
+
+        @Override
+        public void delete() {
+            MapViewDrawing.this.getLayerManager().getLayers().remove(layer);
+        }
+
+    };
+
+    public class MapViewMarkerTracker extends MapViewOverlayTracker implements MarkerTracker {
 
         public MapViewMarkerTracker(Marker marker) {
-            this.marker = marker;
+            super(marker);
         }
 
         @Override
         public Point getPoint() {
+            Marker marker = (Marker) super.layer;
             return new Point(marker.getLatLong().getLongitude(), marker.getLatLong().getLatitude());
         }
 
         @Override
         public void moveTo(Point point) {
+            Marker marker = (Marker) this.layer;
             this.delete();
-            Marker marker = new Marker(convertPoint(point), this.marker.getBitmap(), this.marker.getHorizontalOffset(),
-                    this.marker.getVerticalOffset());
-            this.marker = marker;
-            MapViewDrawing.this.getLayerManager().getLayers().add(this.marker);
-        }
-
-        @Override
-        public void setVisible(boolean visible) {
-            this.marker.setVisible(visible);
-        }
-
-        @Override
-        public void delete() {
-            MapViewDrawing.this.getLayerManager().getLayers().remove(marker);
+            marker = new Marker(convertPoint(point), marker.getBitmap(), marker.getHorizontalOffset(),
+                    marker.getVerticalOffset());
+            this.layer = marker;
+            MapViewDrawing.this.getLayerManager().getLayers().add(this.layer);
         }
 
     };

src/main/org/insa/graphics/drawing/MarkerTracker.java

@@ -2,7 +2,7 @@ package org.insa.graphics.drawing;
 
 import org.insa.graph.Point;
 
-public interface MarkerTracker {
+public interface MarkerTracker extends OverlayTracker {
 
     /**
      * @return The point associated with this marker.
@@ -14,16 +14,4 @@ public interface MarkerTracker {
      */
     public void moveTo(Point point);
 
-    /**
-     * Show or hide this marker - A marker should be visible when created.
-     * 
-     * @param visible true to show the marker, false to hide.
-     */
-    public void setVisible(boolean visible);
-
-    /**
-     * Delete this marker.
-     */
-    public void delete();
-
 }

src/main/org/insa/graphics/drawing/OverlayTracker.java

@@ -0,0 +1,17 @@
+package org.insa.graphics.drawing;
+
+public interface OverlayTracker {
+
+    /**
+     * Show or hide this marker - A marker should be visible when created.
+     * 
+     * @param visible true to show the marker, false to hide.
+     */
+    public void setVisible(boolean visible);
+
+    /**
+     * Delete this marker.
+     */
+    public void delete();
+
+}