Added camera access permission

app/src/main/AndroidManifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <uses-feature android:name="android.hardware.camera"/>
+    <uses-permission android:name="android.permission.CAMERA"/>
+
     <application
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"

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

 package com.example.ueberwachungssystem;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 
+import android.Manifest;
+import android.app.AlertDialog;
+import android.content.DialogInterface;
+import android.content.pm.PackageManager;
 import android.os.Bundle;
+import android.view.View;
+import android.widget.Button;
+import android.widget.Toast;
 
 public class MainActivity extends AppCompatActivity {
 
+    private static final int CAMERA_PERMISSION_REQUEST_CODE = 101;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+
+        Button B1 = findViewById(R.id.B1);
+        B1.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                    getCameraAccess();
+            }
+        });
+    }
+
+
+    private boolean isCameraAccessAllowed() {
+        return ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED;
+    }
+
+    private void getCameraAccess() {
+        if (!isCameraAccessAllowed())
+            ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.CAMERA}, CAMERA_PERMISSION_REQUEST_CODE);
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+
+        if (requestCode == CAMERA_PERMISSION_REQUEST_CODE && grantResults.length > 0) {
+            boolean cameraRights = grantResults[0] == PackageManager.PERMISSION_GRANTED;
+            if (cameraRights) {
+                Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
+            } else {
+                Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
+            }
+        }
+    }
+
+    private void showDialogue(String message) {
+        new AlertDialog.Builder(this)
+                .setMessage(message)
+                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        requestPermissions(new String[] {Manifest.permission.CAMERA}, CAMERA_PERMISSION_REQUEST_CODE);
+                    }
+                })
+                .setNegativeButton("Cancel", null)
+                .create()
+                .show();
     }
 }

app/src/main/java/com/example/ueberwachungssystem/VideoDetection.java

+package com.example.ueberwachungssystem;
+
+
+
+public class VideoDetection {
+
+
+}

app/src/main/res/layout/activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
-<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout 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:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:layout_gravity="center"
+    android:gravity="center"
+    android:orientation="vertical"
     tools:context=".MainActivity">
 
     <TextView
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
-</androidx.constraintlayout.widget.ConstraintLayout>
+    <Button
+        android:id="@+id/B1"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Button"
+        tools:layout_editor_absoluteX="156dp"
+        tools:layout_editor_absoluteY="189dp" />
+
+</LinearLayout>