Fixed NavigationView module selection

app/src/main/java/de/sebse/fuplanner/MainActivity.java

@@ -6,6 +6,7 @@ import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentTransaction;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.util.Pair;
 import android.view.View;
 import android.support.design.widget.NavigationView;
 import android.support.v4.view.GravityCompat;
@@ -238,12 +239,11 @@ public class MainActivity extends AppCompatActivity
             log.d("Modules.get", success.size());
             //SubMenu moduleMenu = navigationView.getMenu().findItem(R.id.nav_modules).getSubMenu();
             int i = 0;
-            for (Iterator<Modules.Module> it = success.latestSemesterIterator(); it.hasNext(); ) {
-                Modules.Module module = it.next();
-                MenuItem menuItem = mNavigationView.getMenu().add(Menu.NONE, Menu.NONE, 101 + i, module.title);
-                final int finalI = i;
+            for (Iterator<Pair<Modules.Module, Integer>> it = success.latestSemesterIterator(); it.hasNext(); ) {
+                Pair<Modules.Module, Integer> module = it.next();
+                MenuItem menuItem = mNavigationView.getMenu().add(Menu.NONE, Menu.NONE, 101 + i, module.first.title);
                 menuItem.setOnMenuItemClickListener(item -> {
-                    onModulesFragmentInteraction(finalI);
+                    onModulesFragmentInteraction(module.second);
                     return false;
                 });
                 i++;

app/src/main/java/de/sebse/fuplanner/services/KVV/types/Modules.java

@@ -2,6 +2,7 @@ package de.sebse.fuplanner.services.KVV.types;
 
 import android.content.Context;
 import android.support.annotation.NonNull;
+import android.util.Pair;
 
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -27,8 +28,8 @@ import de.sebse.fuplanner.tools.logging.Logger;
 public class Modules implements Iterable<Modules.Module>, Serializable {
     private final SortedModuleList list;
     private String latestSemester = null;
-    private String username = null;
-    private transient Logger log = new Logger(this);
+    private String username;
+    //private transient Logger log = new Logger(this);
     private static final String FILE_NAME = "ModuleListSaving";
 
     public Modules(String username) {
@@ -107,8 +108,8 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
         };
     }
 
-    public Iterator<Module> latestSemesterIterator() {
-        return new Iterator<Module>() {
+    public Iterator<Pair<Module, Integer>> latestSemesterIterator() {
+        return new Iterator<Pair<Module, Integer>>() {
             private int index = -1;
             private int next = -1;
             @Override
@@ -119,13 +120,13 @@ public class Modules implements Iterable<Modules.Module>, Serializable {
             }
 
             @Override
-            public Module next() {
+            public Pair<Module, Integer> next() {
                 if (index == next)
                     predict();
                 if (next == -1)
                     return null;
                 index = next;
-                return list.get(index);
+                return new Pair<>(list.get(index), index);
             }
 
             @Override