Änderungen im Manifest und in der MainActivity.java: Ergänzung zweier Internet-Permissions inklusive Abfrage dieser, wenn der Button "connectionButton" betätigt wird.

Allerdings: Internet Permission wird automatisch erteilt, Abfrage ist eigentlich sinnlos.

app/src/main/AndroidManifest.xml

 
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.CAMERA"/>
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
+
 
     <uses-feature android:name="android.hardware.camera"/>
 

app/src/main/java/com/example/greenwatch/MainActivity.java

 package com.example.greenwatch;
 
+import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
+import android.content.DialogInterface;
 import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.os.Build;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.Toast;
+import android.Manifest;
 
 import com.example.greenwatch.adapters.AlarmHistoryListAdapter;
 import com.example.greenwatch.adapters.DeviceListAdapter;
     private Button connectionButton;
     private MainActivityViewModel mMainActivityViewModel;
 
+    private static final int REQUEST_PERMISSION_INTERNET = 123;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         connectionButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                openConnectionActivity();
+                if(ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.INTERNET) != PackageManager.PERMISSION_GRANTED
+                        || ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_WIFI_STATE) != PackageManager.PERMISSION_GRANTED
+                        || ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CHANGE_WIFI_MULTICAST_STATE) != PackageManager.PERMISSION_GRANTED) {
+
+                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.INTERNET, Manifest.permission.ACCESS_WIFI_STATE, Manifest.permission.CHANGE_WIFI_MULTICAST_STATE}, REQUEST_PERMISSION_INTERNET);
+                } else {
+                    openConnectionActivity();
+                }
             }
         });
     }
         mMainActivityViewModel.updateDevice(mMainActivityViewModel.getLocalDeviceUUID(), "10:51",  true, "Audio", 10);
     }
 
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        if (requestCode == REQUEST_PERMISSION_INTERNET) {
+            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                // Berechtigungen wurden gewährt
+                Toast.makeText(this, "Berechtigungen gewährt", Toast.LENGTH_SHORT).show();
+                openConnectionActivity();
+            } else {
+                // Berechtigungen wurden nicht gewährt
+                Toast.makeText(this, "Berechtigungen nicht gewährt", Toast.LENGTH_SHORT).show();
+            }
+        }
+    }
+
+
 }