Adding AddMarkerOverlay, which allows the user to put markers on the map when double tapping

app/src/main/java/uca/baptistearthur/geocaching/ui/overlay/AddMarkerOverlay.kt

@@ -0,0 +1,31 @@
+package uca.baptistearthur.geocaching.ui.overlay
+
+import android.graphics.Rect
+import android.util.Log
+import android.view.MotionEvent
+import org.osmdroid.util.GeoPoint
+import org.osmdroid.views.MapView
+import org.osmdroid.views.overlay.Overlay
+
+class AddMarkerOverlay : Overlay() {
+
+    private var locations: MutableSet<GeoPoint> = mutableSetOf()
+
+    override fun onDoubleTap(e: MotionEvent?, mapView: MapView?): Boolean {
+        Log.d("GeoMap", "Longpress")
+        val proj = mapView?.projection;
+        if(proj!=null){
+            val loc = proj.fromPixels(e?.x?.toInt()!!, e?.y?.toInt() !! ) as GeoPoint
+            locations.add(loc)
+            val marker = PlaceMarker(mapView, locations)
+            marker.position = loc
+            marker.title = "Step " + locations.size
+            mapView.overlays.add(marker)
+            mapView.invalidate()
+        }
+        return true;
+    }
+
+
+
+}