Another refactoring step...

src/main/java/de/srsoftware/web4rail/BaseClass.java

@@ -8,6 +8,7 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
@@ -69,6 +70,7 @@ public abstract class BaseClass implements Constants{
 		private Contact contact;
 		private Direction direction;
 		private Integer waitTime;
+		List<EventListener> invalidationListeners = new LinkedList<>();
 		
 		public Context(BaseClass object) {
 			setMain(object);
@@ -147,12 +149,18 @@ public abstract class BaseClass implements Constants{
 		
 		public void invalidate() {
 			setMain(null);
+			invalidationListeners.forEach(EventListener::fire);
 		}
 		
 		public boolean invalidated() {
 			return isNull(main);
 		}
 		
+		public void onInvalidate(EventListener listener) {
+			invalidationListeners.add(listener);
+		}
+
+		
 		public Context setMain(BaseClass object) {
 			main = object;
 			LOG.debug("{}.setMain({})",this,object);

src/main/java/de/srsoftware/web4rail/EventListener.java

@@ -0,0 +1,5 @@
+package de.srsoftware.web4rail;
+
+public interface EventListener {
+	public void fire();
+}

src/main/java/de/srsoftware/web4rail/Route.java

@@ -38,6 +38,7 @@ import de.srsoftware.web4rail.tags.Input;
 import de.srsoftware.web4rail.tags.Table;
 import de.srsoftware.web4rail.tags.Window;
 import de.srsoftware.web4rail.threads.BrakeProcess;
+import de.srsoftware.web4rail.threads.RoutePrepper;
 import de.srsoftware.web4rail.tiles.Block;
 import de.srsoftware.web4rail.tiles.BlockContact;
 import de.srsoftware.web4rail.tiles.Contact;
@@ -95,6 +96,8 @@ public class Route extends BaseClass {
 	private HashSet<Contact>			   triggeredContacts = new HashSet<>();
 
 	private Route nextPreparedRoute;
+
+	private RoutePrepper nextRoutePrepper;
 	
 	public Route() {
 		conditions = new ConditionList();
@@ -394,8 +397,6 @@ public class Route extends BaseClass {
 	}
 	
 	private void free() {
-		context.invalidate(); // do not set to null: 
-		// this action may be called from route.contact → finishRoute, which calls train.updateTrace afterwards, which in turn requires context
 		Train train = context.train();
 		Vector<Tile> reversedPath = reverse(path());
 		for (Tile tile : reversedPath) {
@@ -684,6 +685,19 @@ public class Route extends BaseClass {
 		return true;
 	}
 	
+	public boolean prepareNext(Context context) {
+		if (isSet(nextRoutePrepper)) return false;
+		nextRoutePrepper = new RoutePrepper(context);
+		nextRoutePrepper.onRoutePrepared(() -> {
+			nextPreparedRoute = nextRoutePrepper.route();
+			nextRoutePrepper = null;
+		});
+		nextRoutePrepper.onFail(() -> {
+			nextRoutePrepper = null;
+		});
+		return nextRoutePrepper.prepareRoute();
+	}
+	
 	private Tag previewScript() {
 		Tag script = new Tag("script").attr("type", "text/javascript");
 		for (Tile tile : path) {
@@ -752,7 +766,7 @@ public class Route extends BaseClass {
 	
 	public boolean reserveFor(Context newContext) {
 		LOG.debug("{}.reserverFor({})",this,newContext);
-		if (isSet(context)) return false; // route already has context!
+//		if (isSet(context)) return false; // route already has context!
 		context = newContext;
 		for (Tile tile : path) {
 			if (newContext.invalidated() || !tile.reserveFor(newContext)) {
@@ -765,6 +779,7 @@ public class Route extends BaseClass {
 	
 	public boolean reset() {
 		LOG.debug("{}.reset()",this);
+		resetNext();
 		setSignals(Signal.RED);
 		Train train = context.train();
 		free();
@@ -773,6 +788,11 @@ public class Route extends BaseClass {
 		return true;
 	}
 	
+	public void resetNext() {
+		if (isSet(nextRoutePrepper)) nextRoutePrepper.stop();
+		if (isSet(nextPreparedRoute)) nextPreparedRoute.reset();
+	}
+	
 	public static void saveAll(String filename) throws IOException {
 		BufferedWriter file = new BufferedWriter(new FileWriter(filename));
 		file.write("{\""+ROUTES+"\":[\n");

src/main/java/de/srsoftware/web4rail/actions/PreserveRoute.java

@@ -30,6 +30,9 @@ public class PreserveRoute extends Action {
 			LOG.debug("Not preserving route, as train needs to stop for {} ms at {}!",waitTime,endBlock);
 			return false; // train is expected to wait in next block.
 		}
-		return isSet(route.getNextPreparedRoute()) || train.reserveRouteAfter(route);
+		if (isSet(route.getNextPreparedRoute())) return true;
+		Context nextContext = new Context(train).block(route.endBlock()).direction(route.endDirection);
+		context.onInvalidate(nextContext::invalidate);
+		return route.prepareNext(nextContext);
 	}
 }

src/main/java/de/srsoftware/web4rail/conditions/BlockFree.java

@@ -25,7 +25,7 @@ public class BlockFree extends Condition {
 
 	@Override
 	public boolean fulfilledBy(Context context) {
-		return block.isFreeFor(null) != inverted;
+		return block.isFreeFor(context) != inverted;
 	}
 	
 	@Override

src/main/java/de/srsoftware/web4rail/moving/Train.java

@@ -36,10 +36,9 @@ import de.srsoftware.web4rail.tags.Label;
 import de.srsoftware.web4rail.tags.Select;
 import de.srsoftware.web4rail.tags.Table;
 import de.srsoftware.web4rail.tags.Window;
-import de.srsoftware.web4rail.threads.RouteManager.Callback;
 import de.srsoftware.web4rail.threads.BrakeProcess;
 import de.srsoftware.web4rail.threads.DelayedExecution;
-import de.srsoftware.web4rail.threads.RouteManager;
+import de.srsoftware.web4rail.threads.RoutePrepper;
 import de.srsoftware.web4rail.tiles.Block;
 import de.srsoftware.web4rail.tiles.Contact;
 import de.srsoftware.web4rail.tiles.Tile;
@@ -92,7 +91,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 	public int speed = 0;
 	private static final String SHUNTING = "shunting";
 	private boolean shunting = false;
-	private RouteManager routeManager = null;
+	private RoutePrepper routePrepper = null;
 
 	private HashSet<Tile> stuckTrace = null;
 
@@ -422,7 +421,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 		if (isSet(brake)) brake.updateTime();
 		Integer waitTime = route.waitTime();
 		nextPreparedRoute = route.dropNextPreparedRoute();
-		if (isNull(nextPreparedRoute) || (isSet(waitTime) && waitTime > 0)) setSpeed(0);
+		if ((!autopilot)|| isNull(nextPreparedRoute) || (isSet(waitTime) && waitTime > 0)) setSpeed(0);
 		route = null;
 		direction = endDirection;		
 		endBlock.add(this, direction);		
@@ -490,7 +489,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 
 	public boolean isStoppable() {
 		if (speed > 0) return true;
-		if (isSet(routeManager) && routeManager.isActive()) return true;
+		if (isSet(routePrepper)) return true;
 		if (isSet(route)) return true;
 		return false;
 	}
@@ -721,7 +720,8 @@ public class Train extends BaseClass implements Comparable<Train> {
 	}
 
 	public String quitAutopilot() {
-		if (isSet(routeManager)) routeManager.quit();
+		if (isSet(routePrepper)) routePrepper.stop();
+//		if (isSet(route)) route.resetNext();
 		autopilot = false;
 		return t("Autopilot already was disabled!");
 	}
@@ -747,7 +747,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 		//if (child == nextRoute) nextRoute = null; // TODO
 		if (child == currentBlock) currentBlock = null;
 		if (child == destination) destination = null;
-		if (child == routeManager) routeManager = null;
+		if (child == routePrepper) routePrepper.stop();
 		cars.remove(child);
 		trace.remove(child);
 		super.removeChild(child);
@@ -758,21 +758,6 @@ public class Train extends BaseClass implements Comparable<Train> {
 		return tags().iterator();
 	}
 
-	public boolean reserveRouteAfter(Route route) {
-		LOG.debug("reserveRouteAfter({})",route);
-		if (isNull(routeManager)) routeManager = new RouteManager();
-		Context newContext = new Context(this).block(route.endBlock()).direction(route.endDirection);
-		if (routeManager.isSearching()) return false;
-		routeManager.setContext(newContext);
-		routeManager.setCallback(new Callback() {			
-			@Override
-			public void routePrepared(Route nextRoute) {
-				route.setNextPreparedRoute(nextRoute);
-			}
-		});
-		return routeManager.prepareRoute();
-	}
-
 	/**
 	 * This turns the train as if it went through a loop. Example:
 	 * before: CabCar→ MiddleCar→ Loco→
@@ -921,24 +906,20 @@ public class Train extends BaseClass implements Comparable<Train> {
 			nextPreparedRoute = null;
 			return null;
 		}
-		if (isNull(routeManager)) routeManager = new RouteManager();
+		if (isSet(routePrepper)) return t("Already searching route for {}",this);
+		routePrepper = new RoutePrepper(new Context(this).block(currentBlock).direction(direction));
 		
-		Callback callback = new Callback() {
-			@Override
-			public void routePrepared(Route route) {
-				route.start();
-				plan.stream(t("Started {}",Train.this));
-			}		
-		};		 
+		routePrepper.onRoutePrepared(() -> {
+			routePrepper.route().start();
+			routePrepper = null;
+			plan.stream(t("Started {}",Train.this));
+		});
 		
-		if (routeManager.isActive()) { // es wird bereits eine Anschlussroute gesucht
-			// in diesem Fall muss bloß dass Callback des Route-Managers aktualisiert werden
-			routeManager.setCallback(callback);
-		} else { // routeManager nicht aktiv →> neuen Context setzen und starten			
-			routeManager.setContext(new Context(this).block(currentBlock).direction(direction));
-			routeManager.start(callback);
-		}
+		routePrepper.onFail(() -> {
+			routePrepper = null;
+		});
 		
+		routePrepper.start();		
 		
 		return null;
 	}
@@ -950,7 +931,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 	
 	public void startBrake() {
 		LOG.debug("{}.startBrake()",this);
-		if (isSet(nextPreparedRoute)) return;
+		if (autopilot && isSet(nextPreparedRoute)) return;
 		brake = new BrakeProcess(this);
 	}
 

src/main/java/de/srsoftware/web4rail/threads/RoutePrepper.java

@@ -1,45 +1,42 @@
 package de.srsoftware.web4rail.threads;
 
 import java.util.HashSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map.Entry;
 import java.util.TreeMap;
 import java.util.Vector;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import de.srsoftware.web4rail.Application;
 import de.srsoftware.web4rail.BaseClass;
+import de.srsoftware.web4rail.EventListener;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.Route;
 import de.srsoftware.web4rail.moving.Train;
 import de.srsoftware.web4rail.tiles.Block;
 import de.srsoftware.web4rail.tiles.Tile;
 
-public class RouteManager extends BaseClass {
+public class RoutePrepper extends BaseClass implements Runnable{
+	private Context context;
+	private Route route;
+	private List<EventListener> failListeners = new LinkedList<>(); 
+	private List<EventListener> foundListeners = new LinkedList<>();
+	private List<EventListener> lockedListeners = new LinkedList<>();
+	private List<EventListener> preparedListeners= new LinkedList<>();
 	
-	private enum State{
-		IDLE,SEARCHING,PREPARING
-	}
-
-	public static abstract class Callback {
-		public abstract void routePrepared(Route route);
+	public RoutePrepper(Context c) {
+		List<String> errors = new LinkedList<>();
+		if (isNull(c.train())) errors.add(t("No train in context for {}",getClass().getSimpleName()));
+		if (isNull(c.block())) errors.add(t("No block in context for {}",getClass().getSimpleName()));
+		if (isNull(c.direction())) errors.add(t("No direction in context for {}",getClass().getSimpleName()));
+		if (!errors.isEmpty()) throw new NullPointerException(String.join(", ", errors));
+		context = c;
 	}
-
-	private static final Logger LOG = LoggerFactory.getLogger(RouteManager.class);
-	private Context ctx;
-	private State state;
-	private Callback callback;
 	
-	public RouteManager() {
-		state =State.IDLE;
-	}
-
 	private static TreeMap<Integer, List<Route>> availableRoutes(Context context, HashSet<Route> visitedRoutes) {
 		String inset = "";
 		for (int i = 0; i < visitedRoutes.size(); i++) inset += "    ";
-		LOG.debug("{}{}.availableRoutes({})", inset, RouteManager.class.getSimpleName(), context);
+		LOG.debug("{}{}.availableRoutes({})", inset, RoutePrepper.class.getSimpleName(), context);
 
 		Block block = context.block();
 		Train train = context.train();
@@ -135,9 +132,9 @@ public class RouteManager extends BaseClass {
 		}
 		return availableRoutes;
 	}
-
-	public static Route chooseRoute(Context context) {
-		LOG.debug("{}.chooseRoute({})", RouteManager.class.getSimpleName(), context);
+	
+	private static Route chooseRoute(Context context) {
+		LOG.debug("{}.chooseRoute({})", RoutePrepper.class.getSimpleName(), context);
 		TreeMap<Integer, List<Route>> availableRoutes = availableRoutes(context, new HashSet<Route>());
 		while (!availableRoutes.isEmpty()) {
 			if (context.invalidated()) break;
@@ -158,63 +155,71 @@ public class RouteManager extends BaseClass {
 		return null;
 	}
 	
-	public boolean isActive() {
-		return state != State.IDLE;
+	
+	private void notify(List<EventListener> listeners) {
+		for (EventListener listener: listeners) {
+			listener.fire();
+		}		
+	}
+	
+	public void onFail(EventListener l) {
+		failListeners.add(l);
 	}
-
-	public boolean isSearching() {
-		return state == State.SEARCHING;
+	
+	public void onRouteFound(EventListener l) {
+		foundListeners.add(l);
+	}
+	
+	public void onRouteLocked(EventListener l) {
+		lockedListeners.add(l);
 	}
+	
+	public void onRoutePrepared(EventListener l) {
+		preparedListeners.add(l);
+	}
+	
 
+	
 	public boolean prepareRoute() {
 		try {
-			if (isNull(ctx) || ctx.invalidated()) return false;
-			state = State.SEARCHING;	
-			Route route = chooseRoute(ctx);		
-			if (isNull(route)) return false;
-			ctx.route(route);
-			if (!route.reserveFor(ctx)) {
+			if (isNull(context) || context.invalidated()) return false;
+			route = chooseRoute(context);		
+			if (isNull(route)) return false;			
+			context.route(route);
+			notify(foundListeners);
+			if (!route.reserveFor(context)) {
 				route.reset();
+				route = null;
 				return false;
 			}
-			state = State.PREPARING;
+			notify(lockedListeners);
 			if (!route.prepareAndLock()) {
 				route.reset();
+				route = null;
 				return false;
 			}		
-			if (isNull(route) || isNull(callback)) return false;
-			callback.routePrepared(route);
+			notify(preparedListeners);
 			return true;
 		} finally {
-			state = State.IDLE;
+			if (isNull(route)) notify(failListeners);
 		}
 	}
 
-	public void quit() {
-		LOG.debug("{}.quit", this);
-		callback = null;
-		if (isSet(ctx)) ctx.invalidate();
-	}
 
-	public void setContext(Context context) {
-		ctx = context;
+	public Route route() {
+		return route;
 	}
 
-	public void setCallback(Callback callback) {
-		if (!ctx.invalidated()) this.callback = callback; 
+	@Override
+	public void run() {
+		prepareRoute();
 	}
 
-	public void start(Callback callback) {
-		setCallback(callback);
-		new Thread(Application.threadName(this)) {
-			public void run() {
-				prepareRoute();
-			};
-		}.start();
+	public void start() {
+		new Thread(this,Application.threadName(this)).start();
 	}
-	
-	@Override
-	public String toString() {
-		return getClass().getSimpleName() + "(" + ctx.train() + ")";
+
+	public void stop() {
+		context.invalidate();
 	}
 }