added "new map" button

fixed minor model/logic issues

mapview/2D/tools/ToolSelector.h

@@ -181,8 +181,10 @@ private:
 			// set the currently focused object (if any)
 			focused = el;
 
-			// focus the new one (if any)
-			if (focused) {focused->getMV2D()->focus();}
+			// focus the new one (if any, and focus supported)
+			if (focused && focused->getMV2D()) {
+				focused->getMV2D()->focus();
+			}
 
 			// update the help-text
 			showHelp();

mapview/3D/MapView3D.cpp

@@ -185,12 +185,21 @@ void MapView3D::showFloorplan() {
 }
 
 void MapView3D::showGrid() {
+
+	// delete the previous grid (if any)
 	if (gridModel) {delete gridModel; gridModel = nullptr;}
+
+	// build a new model
 	GridModel* gm = new GridModel();
 	Floorplan::IndoorMap* im = getModel()->getMap();
 	gm->rebuild(im);
+
+	// remember
 	this->gridModel = gm;
+
+	// update UI
 	update();
+
 }
 
 void MapView3D::draw() {

mapview/3DGrid/GridModel.h

@@ -21,7 +21,8 @@ class GridModel {
 
 private:
 
-	int gridSize_cm = 20;
+	int gridSize_cm = 30;	// TODO
+
 	Grid<MyNode> grid;
 	Floorplan::IndoorMap* im;
 

mapview/model/MapModel.h

@@ -53,10 +53,17 @@ public:
 
 	/** create a new, empty root node */
 	void startEmpty() {
+
+		emit aboutToReset();
+		cleanup();
+
 		im = new Floorplan::IndoorMap();
 		root = new MMRoot(nullptr, im);
 		root->addListener(this);
 		//root->addSublayer(new MMFloors(root, im));
+
+		emit reset();
+
 	}
 
 	void cleanup() {