Correctly derail trains on switches

basics_input.txt

@@ -20,4 +20,7 @@ add train 2 T1-Beta
 put train 1 at (0,5) in direction 0,1
 put train 2 at (0,0) in direction 1,0
 step 1
+put train 1 at (0,0) in direction 0,-1
+set switch 3 position (0,0)
+put train 1 at (0,0) in direction 0,-1
 exit

basics_output.txt

@@ -24,3 +24,6 @@ electrical engine T1-Beta added to train 2
 OK
 OK
 Crash of train 1,2
+OK
+OK
+OK

src/edu/kit/informatik/model/ModelRailwaySimulation.java

@@ -91,8 +91,12 @@ public class ModelRailwaySimulation {
      * @return whether the switch could be set
      */
     public boolean setSwitch(final int id, final Vector2D position) {
-        // TODO Falls Gleiseweichen auf denen ein Zug bereitssteht, geschaltet werden, entgleist der daraufstehende Zug
-        return railNetwork.setSwitch(id, position);
+        boolean success = railNetwork.setSwitch(id, position);
+        if (success) {
+            // derail trains on switch TODO: await forum answer on printing derailed trains
+            trains.values().stream().filter(train -> train.isOnRail(id)).forEach(Train::removeFromRails);
+        }
+        return success;
     }
 
     /**

src/edu/kit/informatik/model/Train.java

@@ -27,7 +27,7 @@ public final class Train {
     /**
      * List of positions this train touches.
      */
-    private List<Vector2D> position;
+    private LinkedList<Vector2D> position;
     /**
      * Direction of the train head.
      */
@@ -149,7 +149,7 @@ public final class Train {
         }
 
         LinkedList<Vector2D> positions = new LinkedList<>();
-        positions.add(position);
+        positions.addLast(position);
         Vector2D positioningDirection = direction.negated();
         Vector2D rollingStockPosition = position;
         if (length > 10000) {
@@ -163,7 +163,7 @@ public final class Train {
                     || (positions.contains(rollingStockPosition) && !positions.get(0).equals(rollingStockPosition))) {
                 return false;
             }
-            positions.add(rollingStockPosition);
+            positions.addLast(rollingStockPosition);
         }
         Set<Rail> occupiedRails = new HashSet<>();
         for (int i = 0; i < positions.size(); i++) {
@@ -217,7 +217,7 @@ public final class Train {
     public Vector2D getFrontPosition() {
         if (position != null) {
             // make sure caller can not modify internal data
-            return new Vector2D(position.get(0));
+            return new Vector2D(position.getFirst());
         } else {
             return null;
         }
@@ -229,7 +229,7 @@ public final class Train {
     public Vector2D getRearPosition() {
         if (position != null) {
             // make sure caller can not modify internal data
-            return new Vector2D(position.get(position.size() - 1));
+            return new Vector2D(position.getLast());
         } else {
             return null;
         }
@@ -250,7 +250,7 @@ public final class Train {
         if (position.size() == 1) {
             return direction.negated();
         } else {
-            return position.get(position.size() - 1).subtract(position.get(position.size() - 2));
+            return position.getLast().subtract(position.get(position.size() - 2)); // TODO
         }
     }
 
@@ -269,9 +269,9 @@ public final class Train {
      */
     public void moveTo(final RailwayNetwork railNetwork, final Vector2D nextPosition) {
         // make sure caller can not modiy internal state
-        position.add(0, new Vector2D(nextPosition));
-        Vector2D last = position.remove(position.size() - 1);
-        updateOccupiedRails(railNetwork, position.get(0), last, position.get(position.size() - 1));
+        position.addFirst(new Vector2D(nextPosition));
+        Vector2D last = position.removeLast();
+        updateOccupiedRails(railNetwork, position.getFirst(), last, position.getLast());
     }
 
     /**
@@ -280,9 +280,9 @@ public final class Train {
      * @param rearPosition position to move rear of the train to
      */
     public void moveBackTo(final RailwayNetwork railNetwork, final Vector2D rearPosition) {
-        Vector2D last = position.remove(0);
-        position.add(new Vector2D(rearPosition));
-        updateOccupiedRails(railNetwork, position.get(position.size() - 1), last, position.get(0));
+        Vector2D last = position.removeFirst();
+        position.addLast(new Vector2D(rearPosition));
+        updateOccupiedRails(railNetwork, position.getLast(), last, position.getFirst());
     }
 
     /**

src/edu/kit/informatik/model/Vector2D.java

@@ -1,7 +1,5 @@
 package edu.kit.informatik.model;
 
-import java.util.Objects;
-
 /**
  * A two-dimensional vector, usually a position or movement direction vector.
  *
@@ -141,9 +139,4 @@ public class Vector2D {
 
         return false;
     }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(x, y);
-    }
 }