Canvas ND: Do del() on reinit

This also makes sure the /canvas/by-index/canvas[3/4]/ nodes are removed
and then recrated, as well as making sure the MapStructure del() path is
followed and working. Unfortunately the NDs are still blank after reinit.

Nasal/canvas/MapStructure.nas

@@ -1,3 +1,5 @@
+var _MP_dbg_lvl = "info";
+
 var dump_obj = func(m) {
 	var h = {};
 	foreach (var k; keys(m))
@@ -235,11 +237,9 @@ var DotSym = {
 			),
 		};
 		if (m.controller != nil) {
-			#print("Creating controller");
 			temp = m.controller.new(m.model,m);
 			if (temp != nil)
 				m.controller = temp;
-			#print("Initializing controller");
 			m.controller.init(model);
 		}
 		else die("default controller not found");
@@ -248,7 +248,7 @@ var DotSym = {
 		return m;
 	},
 	del: func() {
-		#print("DotSym.del()");
+		printlog(_MP_dbg_lvl, "DotSym.del()");
 		me.deinit();
 		if (me.controller != nil)
 			me.controller.del(me.model);
@@ -333,7 +333,7 @@ var SymbolLayer = {
 			e.update();
 	},
 	del: func() {
-		#print("SymbolLayer.del()");
+		printlog(_MP_dbg_lvl, "SymbolLayer.del()");
 		me.controller.del();
 		foreach (var e; me.list)
 			e.del();

Nasal/canvas/api.nas

@@ -422,26 +422,16 @@ var Map = {
   df_controller: nil,
   new: func(ghost)
   {
-    return { parents: [Map, Group.new(ghost)] };
+    return { parents: [Map, Group.new(ghost)] }.setController();
   },
   del: func()
   {
     #print("canvas.Map.del()");
-    call(func {
+    if (me.controller != nil)
       me.controller.del(me);
-    }, var err=[]);
+    foreach (var k; keys(me.layers)) {
-    if (size(err)) {
+      me.layers[k].del();
-      debug.printerror(err);
+      delete(me.layers, k);
-      setsize(err, 0);
-    }
-    call(func {
-      foreach (var l; me.layers)
-        call(l[0].del, nil, l[0]);
-      setsize(me.layers, 0);
-    }, err);
-    if (size(err)) {
-      debug.printerror(err);
-      setsize(err, 0);
     }
     # call inherited 'del'
     me.parents = subvec(me.parents,1);

Nasal/canvas/map/VOR.lcontroller

@@ -30,7 +30,7 @@ var new = func(layer) {
 	return m;
 };
 var del = func() {
-	#print("VOR.lcontroller.del()");
+	printlog(_MP_dbg_lvl, "VOR.lcontroller.del()");
 	foreach (var l; me.listeners)
 		removelistener(l);
 };
@@ -49,7 +49,7 @@ var changed_freq = func(update=1) {
 	if (update) me.layer.update();
 };
 var searchCmd = func {
-	#print("Running query:", me.query_type);
+	printlog(_MP_dbg_lvl, "Running query:", me.query_type);
 	return positioned.findWithinRange(100, me.query_type); # the range should also be exposed, it will typically be controlled via a GUI widget or NavDisplay switch
 };
 

Nasal/canvas/map/navdisplay.mfd

@@ -383,11 +383,17 @@ var NavDisplay = {
 
 	# reset handler
 	handle_reinit: func {
-		print("Cleaning up NavDisplay listeners");
+		print("Cleaning up NavDisplay");
 		# shut down all timers and other loops here
 		me.update_timer.stop();
 		foreach(var l; me.listeners)
 			removelistener(l);
+		# clean up MapStructure
+		me.map.del();
+		# destroy the canvas
+		if (me.canvas_handle != nil)
+			me.canvas_handle.del();
+		me.inited = 0;
 	},
 
 	listen: func(p,c) {
@@ -434,6 +440,8 @@ var NavDisplay = {
 	new : func(prop1, switches=default_switches, style='Boeing') {
 		var m = { parents : [NavDisplay]};
 
+		m.inited = 0;
+
 		m.listeners=[]; # for cleanup handling
 		m.aircraft_source = NDSourceDriver.new(); # uses the main aircraft as the driver/source (speeds, position, heading)
 
@@ -484,11 +492,14 @@ var NavDisplay = {
 
 		return m;
 	},
-	newMFD: func(canvas_group)
+	newMFD: func(canvas_group, parent=nil)
 	{
-		me.listen("/sim/signals/reinit", func me.handle_reinit() );
+		if (me.inited) die("MFD already was added to scene");
+		me.inited = 1;
+		me.listen("/sim/signals/reinit", func(n) me.handle_reinit() );
 		me.update_timer = maketimer(0.05, func me.update() ); # TODO: make interval configurable via ctor
 		me.nd = canvas_group;
+		me.canvas_handle = parent;
 
 		# load the specified SVG file into the me.nd group and populate all sub groups
 
@@ -587,7 +598,7 @@ var NavDisplay = {
 			if(!layer['isMapStructure'])
 				the_layer = me.layers[layer.name] = canvas.MAP_LAYERS[layer.name].new( render_target, layer.name, controller );
 			else {
-				#print("Setting up MapStructure-based layer for ND, name:", layer.name);
+				printlog(_MP_dbg_lvl, "Setting up MapStructure-based layer for ND, name:", layer.name);
 				render_target.addLayer(factory: canvas.SymbolLayer, type_arg: layer.name);
 				the_layer = me.layers[layer.name] = render_target.getLayer(layer.name);
 			}
@@ -990,7 +1001,7 @@ var NavDisplay = {
 		me.symbols.planArcs.setVisible(me.in_mode('toggle_display_mode', ['PLAN']));
 
 		if (abs(userVSpd) > 5) {
-			var altDiff = getprop("autopilot/settings/target-altitude-ft")-getprop("instrumentation/altimeter/indicated-altitude-ft");
+			var altDiff = (getprop("autopilot/settings/target-altitude-ft") or 0)-(getprop("instrumentation/altimeter/indicated-altitude-ft") or 0);
 			if (abs(altDiff) > 50 and altDiff/userVSpd > 0) {
 				var altRangeNm = altDiff/userVSpd*userSpd*KT2MPS*M2NM;
 				if(altRangeNm > 1) {