Null protection & Readability changes (Creators-of-Create#6325)

* Error Null cannot be Null

- Add more TrackEdge null protection
- Replace 2 for loops with enhanced for loops to improve readability
- Remove some unneeded unboxing
- Cleanup some interfaces
- Remove private from enum constructor, it's already private
- set enum value as final
- remove static from inner interfaces & enums

* Revert new Random()

* unused import

Author: IThundxr

src/main/java/com/simibubi/create/content/trains/entity/Train.java

@@ -619,7 +619,7 @@ private void collideWithOtherTrains(Level level, Carriage carriage) {
 	public Pair<Train, Vec3> findCollidingTrain(Level level, Vec3 start, Vec3 end, ResourceKey<Level> dimension) {
 		Vec3 diff = end.subtract(start);
 		double maxDistanceSqr = Math.pow(AllConfigs.server().trains.maxAssemblyLength.get(), 2.0);
-		
+
 		Trains: for (Train train : Create.RAILWAYS.sided(level).trains.values()) {
 			if (train == this)
 				continue;
@@ -962,6 +962,9 @@ public void collectInitiallyOccupiedSignalBlocks() {
 		TrackNode node1 = trailingPoint.node1;
 		TrackNode node2 = trailingPoint.node2;
 		TrackEdge edge = trailingPoint.edge;
+
+		if (edge == null) return;
+
 		double position = trailingPoint.position;
 		EdgeData signalData = edge.getEdgeData();
 
@@ -1219,20 +1222,19 @@ public int countPlayerPassengers() {
 	public void determineHonk(Level level) {
 		if (lowHonk != null)
 			return;
-		for (int index = 0; index < carriages.size(); index++) {
-			Carriage carriage = carriages.get(index);
-			DimensionalCarriageEntity dimensional = carriage.getDimensionalIfPresent(level.dimension());
-			if (dimensional == null)
-				return;
-			CarriageContraptionEntity entity = dimensional.entity.get();
-			if (entity == null || !(entity.getContraption()instanceof CarriageContraption otherCC))
-				break;
-			Pair<Boolean, Integer> first = otherCC.soundQueue.getFirstWhistle(entity);
-			if (first != null) {
-				lowHonk = first.getFirst();
-				honkPitch = first.getSecond();
-			}
-		}
+        for (Carriage carriage : carriages) {
+            DimensionalCarriageEntity dimensional = carriage.getDimensionalIfPresent(level.dimension());
+            if (dimensional == null)
+                return;
+            CarriageContraptionEntity entity = dimensional.entity.get();
+            if (entity == null || !(entity.getContraption() instanceof CarriageContraption otherCC))
+                break;
+            Pair<Boolean, Integer> first = otherCC.soundQueue.getFirstWhistle(entity);
+            if (first != null) {
+                lowHonk = first.getFirst();
+                honkPitch = first.getSecond();
+            }
+        }
 	}
 
 	public float distanceToLocationSqr(Level level, Vec3 location) {

src/main/java/com/simibubi/create/content/trains/entity/TravellingPoint.java

@@ -40,28 +40,24 @@ public class TravellingPoint {
 	public boolean blocked;
 	public boolean upsideDown;
 
-	public static enum SteerDirection {
+	public enum SteerDirection {
 		NONE(0), LEFT(-1), RIGHT(1);
 
-		float targetDot;
+		final float targetDot;
 
-		private SteerDirection(float targetDot) {
+		SteerDirection(float targetDot) {
 			this.targetDot = targetDot;
 		}
 	}
 
-	public static interface ITrackSelector
-		extends BiFunction<TrackGraph, Pair<Boolean, List<Entry<TrackNode, TrackEdge>>>, Entry<TrackNode, TrackEdge>> {
-	};
+	public interface ITrackSelector
+		extends BiFunction<TrackGraph, Pair<Boolean, List<Entry<TrackNode, TrackEdge>>>, Entry<TrackNode, TrackEdge>> { };
 
-	public static interface IEdgePointListener extends BiPredicate<Double, Pair<TrackEdgePoint, Couple<TrackNode>>> {
-	};
+	public interface IEdgePointListener extends BiPredicate<Double, Pair<TrackEdgePoint, Couple<TrackNode>>> { };
 
-	public static interface ITurnListener extends BiConsumer<Double, TrackEdge> {
-	};
+	public interface ITurnListener extends BiConsumer<Double, TrackEdge> { };
 
-	public static interface IPortalListener extends Predicate<Couple<TrackNodeLocation>> {
-	};
+	public interface IPortalListener extends Predicate<Couple<TrackNodeLocation>> { };
 
 	public TravellingPoint() {}
 
@@ -78,8 +74,7 @@ public IEdgePointListener ignoreEdgePoints() {
 	}
 
 	public ITurnListener ignoreTurns() {
-		return (d, c) -> {
-		};
+		return (d, c) -> { };
 	}
 
 	public IPortalListener ignorePortals() {
@@ -113,15 +108,14 @@ public ITrackSelector follow(TravellingPoint other, @Nullable Consumer<Boolean>
 			Vector<List<Entry<TrackNode, TrackEdge>>> frontiers = new Vector<>(validTargets.size());
 			Vector<Set<TrackEdge>> visiteds = new Vector<>(validTargets.size());
 
-			for (int j = 0; j < validTargets.size(); j++) {
-				ArrayList<Entry<TrackNode, TrackEdge>> e = new ArrayList<>();
-				Entry<TrackNode, TrackEdge> entry = validTargets.get(j);
-				e.add(entry);
-				frontiers.add(e);
-				HashSet<TrackEdge> e2 = new HashSet<>();
-				e2.add(entry.getValue());
-				visiteds.add(e2);
-			}
+            for (Entry<TrackNode, TrackEdge> validTarget : validTargets) {
+                ArrayList<Entry<TrackNode, TrackEdge>> e = new ArrayList<>();
+                e.add(validTarget);
+                frontiers.add(e);
+                HashSet<TrackEdge> e2 = new HashSet<>();
+                e2.add(validTarget.getValue());
+                visiteds.add(e2);
+            }
 
 			for (int i = 0; i < 20; i++) {
 				for (int j = 0; j < validTargets.size(); j++) {
@@ -233,7 +227,7 @@ public double travel(TrackGraph graph, double distance, ITrackSelector trackSele
 		Double blockedLocation =
 			edgeTraversedFrom(graph, forward, signalListener, turnListener, prevPos, collectedDistance);
 		if (blockedLocation != null) {
-			position = blockedLocation.doubleValue();
+			position = blockedLocation;
 			traveled = position - prevPos;
 			return traveled;
 		}
@@ -289,7 +283,7 @@ public double travel(TrackGraph graph, double distance, ITrackSelector trackSele
 
 				if (blockedLocation != null) {
 					traveled -= position;
-					position = blockedLocation.doubleValue();
+					position = blockedLocation;
 					traveled += position;
 					break;
 				}
@@ -349,7 +343,7 @@ public double travel(TrackGraph graph, double distance, ITrackSelector trackSele
 
 				if (blockedLocation != null) {
 					traveled -= position;
-					position = blockedLocation.doubleValue();
+					position = blockedLocation;
 					traveled += position;
 					break;
 				}