began refactoring to avoid code duplicates

ClimateGoApp/app/src/main/java/de/cdaut/climategoapp/activities/ActivityUtils.java

@@ -0,0 +1,44 @@
+package de.cdaut.climategoapp.activities;
+
+import android.content.Intent;
+import android.view.MenuItem;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.drawerlayout.widget.DrawerLayout;
+
+import de.cdaut.climategoapp.R;
+
+public final class ActivityUtils {
+    private ActivityUtils() {
+        throw new IllegalAccessError("Utility Class");
+    }
+
+    public static boolean handleNavBarItemClicks(@NonNull MenuItem item,
+                                                 AppCompatActivity rootClass,
+                                                 DrawerLayout drawer) {
+
+        Class<? extends AppCompatActivity> targetActivityClass;
+
+        switch (item.getItemId()) {
+            case R.id.nav_main:
+                targetActivityClass = HomeActivity.class;
+                break;
+            case R.id.nav_debug:
+                targetActivityClass = DebugActivity.class;
+                break;
+            default:
+                throw new IllegalAccessError("Illegal activity met in nav drawer");
+        }
+
+        if (targetActivityClass.equals(rootClass.getClass())) {
+            drawer.closeDrawers();
+            return false;
+        }
+
+        Intent targetIntent = new Intent(rootClass, targetActivityClass);
+        rootClass.startActivity(targetIntent);
+
+        return false;
+    }
+}

ClimateGoApp/app/src/main/java/de/cdaut/climategoapp/activities/DebugActivity.java

@@ -1,8 +1,10 @@
 package de.cdaut.climategoapp.activities;
 
+import android.content.Intent;
 import android.os.Bundle;
 
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.ActionBarDrawerToggle;
 import androidx.appcompat.app.AppCompatActivity;
 
@@ -18,7 +20,9 @@ import de.cdaut.climategoapp.databinding.ActivityDebugBinding;
 import android.view.Menu;
 import android.view.MenuItem;
 
-public class DebugActivity extends AppCompatActivity {
+import com.google.android.material.navigation.NavigationView;
+
+public class DebugActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
 
     private AppBarConfiguration appBarConfiguration;
     private ActivityDebugBinding binding;
@@ -37,7 +41,7 @@ public class DebugActivity extends AppCompatActivity {
 
         // drawer layout instance to toggle the menu icon to open
         // drawer and back button to close drawer
-        drawerLayout = findViewById(R.id.my_drawer_layout);
+        drawerLayout = findViewById(R.id.debug_drawer_layout);
         actionBarDrawerToggle = new ActionBarDrawerToggle(this,
                 drawerLayout,
                 R.string.nav_open,
@@ -50,6 +54,8 @@ public class DebugActivity extends AppCompatActivity {
 
         // to make the Navigation drawer icon always appear on the action bar
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+        setNavigationViewListener();
     }
 
     @Override
@@ -84,4 +90,14 @@ public class DebugActivity extends AppCompatActivity {
         return NavigationUI.navigateUp(navController, appBarConfiguration)
                 || super.onSupportNavigateUp();
     }
+
+    @Override
+    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
+        return ActivityUtils.handleNavBarItemClicks(item, this, drawerLayout);
+    }
+
+    private void setNavigationViewListener() {
+        NavigationView navigationView = findViewById(R.id.nav_drawer);
+        navigationView.setNavigationItemSelectedListener(this);
+    }
 }

ClimateGoApp/app/src/main/java/de/cdaut/climategoapp/activities/HomeActivity.java

@@ -52,7 +52,7 @@ public class HomeActivity extends AppCompatActivity implements NavigationView.On
         actionBarDrawerToggle.syncState();
 
         // to make the Navigation drawer icon always appear on the action bar
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+        getSupportActionBar(). setDisplayHomeAsUpEnabled(true);
 
         setNavigationViewListener();
     }
@@ -93,29 +93,7 @@ public class HomeActivity extends AppCompatActivity implements NavigationView.On
 
     @Override
     public boolean onNavigationItemSelected(@NonNull MenuItem item) {
-
+        return ActivityUtils.handleNavBarItemClicks(item, this, drawerLayout);
-        Class<? extends AppCompatActivity> targetActivityClass;
-
-        switch (item.getItemId()) {
-            case R.id.nav_main:
-                targetActivityClass = HomeActivity.class;
-                break;
-            case R.id.nav_debug:
-                targetActivityClass = DebugActivity.class;
-                break;
-            default:
-                throw new IllegalAccessError("Illegal activity met in nav drawer");
-        }
-
-        if(targetActivityClass.equals(this.getClass())) {
-            drawerLayout.closeDrawers();
-            return false;
-        }
-
-        Intent targetIntent = new Intent(this, targetActivityClass);
-        startActivity(targetIntent);
-
-        return false;
     }
 
     private void setNavigationViewListener() {

ClimateGoApp/app/src/main/res/layout/activity_debug.xml

@@ -2,7 +2,7 @@
 <androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/my_drawer_layout"
+    android:id="@+id/debug_drawer_layout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".activities.HomeActivity"
@@ -28,6 +28,7 @@
     and shows the navigation drawer-->
     <!--include the menu created in the menu folder-->
     <com.google.android.material.navigation.NavigationView
+        android:id="@+id/nav_drawer"
         android:layout_width="wrap_content"
         android:layout_height="match_parent"
         android:layout_gravity="start"