Bugfix for Concurrent Exception

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

@@ -45,20 +45,14 @@ public class MainActivity extends AppCompatActivity implements Observer {
                 if (viewStackRef.getChildCount() > 0)
                     viewStackRef.removeViewAt(0);
                 viewStackRef.addView(newTrView);
-                //viewStackRef.addView(newTrView, 0);
-                //int childCount = viewStackRef.getChildCount();
-                //if (childCount > 30) {
-                //    viewStackRef.removeViewAt(childCount-1);
-                //}
             }
         });
 
+
     }
 
     public void onStepButtonClick(View view) {
-        //for (int j = 0; j < 3000; j++) {
-            this.track.timeElapse();
-        //}
+        this.track.timeElapse();
     }
 
     public void onPlayButtonClick(View view) {

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

@@ -7,6 +7,7 @@ import android.graphics.Paint;
 import android.view.View;
 import android.view.ViewGroup;
 
+import java.util.ConcurrentModificationException;
 import java.util.List;
 
 public class TimeRecordView extends View {
@@ -58,16 +59,21 @@ public class TimeRecordView extends View {
         int y = 0;
         List<List<VehicleTimeRecord>> stepList = this.track.getVtrList();
         for (int curStepIdx = stepList.size()-1; curStepIdx >= stepList.size()-1-50 && curStepIdx >= 0; curStepIdx--) {
-            List<VehicleTimeRecord> step = stepList.get(curStepIdx);
-            int i = 0;
-            for (VehicleTimeRecord r : step) {
-                int left = (int) (this.pixelPerVehicle * r.getPosition());
-                this.paint.setColor(getColor(r.getVelocity(), r.getMaxVelocity()));
-                canvas.drawRect(left, y, left + this.pixelPerVehicle - 1,
-                        y+10, this.paint);
-                i++;
+            try {
+                List<VehicleTimeRecord> step = stepList.get(curStepIdx);
+                int i = 0;
+                for (VehicleTimeRecord r : step) {
+                    int left = (int) (this.pixelPerVehicle * r.getPosition());
+                    this.paint.setColor(getColor(r.getVelocity(), r.getMaxVelocity()));
+                    canvas.drawRect(left, y, left + this.pixelPerVehicle - 1,
+                            y + 10, this.paint);
+                    i++;
+                }
+                y += 10;
+            } catch (ConcurrentModificationException ex) {
+                System.out.println("Concurrent Exception occured, skipping record");
+                continue;
             }
-            y += 10;
         }
     }
 }

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

@@ -73,11 +73,11 @@ public class Track extends Observable {
         this.setChanged();
         this.notifyObservers();
         this.clearChanged();
-        try  {
-            Thread.sleep(125);
-        } catch (InterruptedException ex) {
-
-        }
+//        try  {
+//            Thread.sleep(125);
+//        } catch (InterruptedException ex) {
+//
+//        }
     }
 
     public float avg_step(int step){