change datatype of timestep from int to float

# Conflicts:
#	app/src/main/java/de/hems/trafficsim/MainActivity.java
#	app/src/main/java/de/hems/trafficsim/Track.java

app/src/main/java/de/hems/trafficsim/Track.java

@@ -1,11 +1,13 @@
 package de.hems.trafficsim;
 
 import java.util.ArrayList;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Observable;
 
 public class Track extends Observable {
     protected List<Vehicle> vehicles;
+    protected List<List<VehicleTimeRecord>> vtr_list;
     protected float trackLength;
 
     public List<Vehicle> getVehicles() {
@@ -19,7 +21,7 @@ public class Track extends Observable {
     public Track(int numberVehicles, float trackLength) {
         this.trackLength = trackLength;
         this.vehicles = createVehiclesList(numberVehicles);
-
+        this.vtr_list = new LinkedList<>();
     }
 
     protected List<Vehicle> createVehiclesList(int numberVehicles){
@@ -46,9 +48,12 @@ public class Track extends Observable {
             }
             v.updateVelocity(distanceForerunner);
         }
-
+        List <VehicleTimeRecord> records = new ArrayList<>(vehicles.size());
+        this.vtr_list.add(records);
         for(Vehicle v: vehicles){
             v.timeElapse(50);
+            VehicleTimeRecord vtr = new VehicleTimeRecord(v.id, v.position, v.curVelocity, timeStep);
+            records.add(vtr);
         }
 
         this.setChanged();

app/src/main/java/de/hems/trafficsim/VehicleTimeRecord.java

@@ -13,12 +13,14 @@ public class VehicleTimeRecord {
         return timestep;
     }
 
+    protected int id;
     protected float position;
     protected float velocity;
     protected float timestep;
 
-    public VehicleTimeRecord(float position, float velocity, float timestep) {
-        this.position = position;
+    public VehicleTimeRecord(int id, float position, float velocity, float timestep) {
+        this.id = id;
+        this.position = position;   //needed???
         this.velocity = velocity;
         this.timestep = timestep;
     }