diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
old mode 100644
new mode 100755
index 26b8ddfc..21abdc87
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -13,6 +13,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+        
         <provider
             android:name="androidx.core.content.FileProvider"
             android:authorities="de.t_dankworth.fileprovider"
@@ -22,120 +23,110 @@
                 android:name="android.support.FILE_PROVIDER_PATHS"
                 android:resource="@xml/share_image_file_paths" />
         </provider>
-        <activity
-            android:name=".activities.AboutActivity"
-            android:label="@string/about_dialog">
-        </activity>
+        
         <activity
             android:name=".activities.MainActivity"
             android:label="@string/app_name">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
-
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+        
+        <activity
+            android:name=".activities.AboutActivity"
+            android:label="@string/about_dialog"
+            android:parentActivityName=".activities.MainActivity" />
+        
         <activity
             android:name=".activities.ScannerActivity"
             android:label="@string/app_name"
             android:parentActivityName=".activities.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
-
                 <category android:name="android.intent.category.DEFAULT" />
-
                 <data android:mimeType="image/*" />
             </intent-filter>
         </activity>
-        <activity
-            android:name=".activities.generator.WifiGeneratorActivity"
-            android:label="@string/title_activity_wifi_generator"
-            android:parentActivityName=".activities.generator.GenerateActivity" />
-        <activity android:name=".activities.ThirdPartyScannerActivity">
+        
+        <activity 
+            android:name=".activities.ThirdPartyScannerActivity">
             <intent-filter>
                 <action android:name="com.google.zxing.client.android.SCAN" />
-
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>
-        <activity android:name=".activities.generator.GeneratorResultActivity" />
+        
+        <activity 
+            android:name=".activities.generator.GeneratorResultActivity" />
+        
         <activity
             android:name=".activities.generator.GenerateActivity"
             android:label="@string/activity_generate"
             android:parentActivityName=".activities.MainActivity" />
+        
         <activity
             android:name=".activities.HistoryActivity"
-            android:label="@string/activity_history" />
+            android:label="@string/activity_history"
+            android:parentActivityName=".activities.MainActivity" />
+        
         <activity
             android:name=".activities.HistoryDetailsActivity"
-            android:label="@string/activity_history_details" />
+            android:label="@string/activity_history_details"
+            android:parentActivityName=".activities.HistoryActivity" />
+        
         <activity
             android:name=".activities.SettingsActivity"
             android:label="@string/title_activity_settings"
-            android:parentActivityName=".activities.MainActivity">
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value=".activities.MainActivity" />
-        </activity>
-        <activity
-            android:name=".activities.generator.GeoGeneratorActivity"
-            android:label="@string/title_activity_geo_generator"
-            android:parentActivityName=".activities.generator.GenerateActivity">
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value=".activities.generator.GenerateActivity" />
-        </activity>
+            android:parentActivityName=".activities.MainActivity" />
+        
         <activity
             android:name=".activities.generator.TextGeneratorActivity"
             android:label="@string/activity_generate"
             android:parentActivityName=".activities.generator.GenerateActivity">
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
-
                 <category android:name="android.intent.category.DEFAULT" />
-
                 <data android:mimeType="text/plain" />
             </intent-filter>
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
-
                 <category android:name="android.intent.category.DEFAULT" />
-
                 <data android:mimeType="text/x-vcard" />
             </intent-filter>
-
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value=".activities.generator.GenerateActivity" />
         </activity>
+        
         <activity
             android:name=".activities.generator.BarcodeGenerateActivity"
             android:label="@string/activity_barcode_generator"
             android:parentActivityName=".activities.generator.GenerateActivity">
             <intent-filter>
                 <action android:name="android.intent.action.SEND" />
-
                 <category android:name="android.intent.category.DEFAULT" />
-
                 <data android:mimeType="text/plain" />
             </intent-filter>
-
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value=".activities.generator.GenerateActivity" />
         </activity>
+        
+        <activity
+            android:name=".activities.generator.GeoGeneratorActivity"
+            android:label="@string/title_activity_geo_generator"
+            android:parentActivityName=".activities.generator.GenerateActivity" />
+        
         <activity
             android:name=".activities.generator.VCardGeneratorActivity"
             android:label="@string/title_activity_vcard_generator"
-            android:parentActivityName=".activities.generator.GenerateActivity">
-            <meta-data
-                android:name="android.support.PARENT_ACTIVITY"
-                android:value=".activities.generator.GenerateActivity" />
-        </activity>
+            android:parentActivityName=".activities.generator.GenerateActivity" />
+        
+        <activity
+            android:name=".activities.generator.WifiGeneratorActivity"
+            android:label="@string/title_activity_wifi_generator"
+            android:parentActivityName=".activities.generator.GenerateActivity" />
+        
         <activity
             android:name="com.journeyapps.barcodescanner.CaptureActivity"
             android:screenOrientation="fullSensor"
             tools:replace="screenOrientation" />
+        
     </application>
 
-</manifest>
\ No newline at end of file
+</manifest>
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/AboutActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/AboutActivity.java
index 2ae6e6bf..b2f088e4 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/AboutActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/AboutActivity.java
@@ -1,7 +1,5 @@
 package de.t_dankworth.secscanqr.activities;
 
-import androidx.appcompat.app.AppCompatActivity;
-
 import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
@@ -14,7 +12,9 @@
 import mehdi.sakout.aboutpage.AboutPage;
 import mehdi.sakout.aboutpage.Element;
 
-public class AboutActivity extends AppCompatActivity {
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
+public class AboutActivity extends MyAppCompatActivity {
 
     private boolean drakMode = false;
 
@@ -66,4 +66,4 @@ private void loadTheme(){
             drakMode = false;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryActivity.java
index d47934e4..100f0d32 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryActivity.java
@@ -6,7 +6,6 @@
 
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
@@ -29,6 +28,8 @@
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 import de.t_dankworth.secscanqr.util.HistoryViewModel;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 import static de.t_dankworth.secscanqr.util.ButtonHandler.shareTo;
 
 
@@ -41,7 +42,7 @@
  */
 
 
-public class HistoryActivity extends AppCompatActivity {
+public class HistoryActivity extends MyAppCompatActivity {
 
     private static final String TAG = "History";
     private GeneralHandler generalHandler;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryDetailsActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryDetailsActivity.java
index 17f614e7..14955464 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryDetailsActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/HistoryDetailsActivity.java
@@ -14,8 +14,6 @@
 import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 import com.journeyapps.barcodescanner.BarcodeEncoder;
 
-import androidx.appcompat.app.AppCompatActivity;
-
 import android.graphics.Bitmap;
 import android.os.Bundle;
 import android.view.MenuItem;
@@ -32,6 +30,8 @@
 import de.t_dankworth.secscanqr.util.DatabaseHelper;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 import static de.t_dankworth.secscanqr.util.ButtonHandler.copyToClipboard;
 import static de.t_dankworth.secscanqr.util.ButtonHandler.createContact;
 import static de.t_dankworth.secscanqr.util.ButtonHandler.openInWeb;
@@ -45,7 +45,7 @@
 * This class is the HistoryDetailsActivity shows details and further functionality for the chosen item
 */
 
-public class HistoryDetailsActivity extends AppCompatActivity {
+public class HistoryDetailsActivity extends MyAppCompatActivity {
 
     private GeneralHandler generalHandler;
 
@@ -153,8 +153,10 @@ private void showQrImage() {
             BarcodeEncoder barcodeEncoder = new BarcodeEncoder();
             bitmap = barcodeEncoder.createBitmap(bitMatrix);
             codeImage.setImageBitmap(bitmap);
+            codeImage.setEnabled(true);
         } catch (Exception e){
-            codeImage.setVisibility(View.GONE);
+            codeImage.setImageResource(R.drawable.ic_baseline_error_24);
+            codeImage.setEnabled(false);
         }
     }
 }
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/ScannerActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/ScannerActivity.java
index bf871a63..70e3c032 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/ScannerActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/ScannerActivity.java
@@ -11,7 +11,6 @@
 import androidx.annotation.NonNull;
 import com.google.android.material.bottomnavigation.BottomNavigationItemView;
 import com.google.android.material.bottomnavigation.BottomNavigationView;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.lifecycle.ViewModelProvider;
 
 import android.view.MenuItem;
@@ -57,6 +56,8 @@
 import de.t_dankworth.secscanqr.util.HistoryEntity;
 import de.t_dankworth.secscanqr.util.HistoryViewModel;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 import static de.t_dankworth.secscanqr.util.ButtonHandler.copyToClipboard;
 import static de.t_dankworth.secscanqr.util.ButtonHandler.createContact;
 import static de.t_dankworth.secscanqr.util.ButtonHandler.openInWeb;
@@ -71,7 +72,7 @@
  * This class is the MainActivity and is the starting point of the App
  * From here the User can start a QR-Code scan and can go to the Generate Activity
  */
-public class ScannerActivity extends AppCompatActivity {
+public class ScannerActivity extends MyAppCompatActivity {
 
     private TextView mTvInformation, mTvFormat, mLabelInformation, mLabelFormat;
     private BottomNavigationView action_navigation;
@@ -409,4 +410,4 @@ private void handleSendPicture(){
             Toast.makeText(activity, getResources().getText(R.string.error_code_not_found), Toast.LENGTH_LONG).show();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/SettingsActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/SettingsActivity.java
index 8c1d28ea..6673cc37 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/SettingsActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/SettingsActivity.java
@@ -10,7 +10,6 @@
 import android.preference.ListPreference;
 import android.preference.Preference;
 import android.preference.PreferenceActivity;
-import androidx.appcompat.app.ActionBar;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceManager;
 import android.view.MenuItem;
@@ -94,19 +93,6 @@ private static void bindPreferenceSummaryToValue(Preference preference) {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setupActionBar();
-    }
-
-    /**
-     * Set up the {@link android.app.ActionBar}, if the API is available.
-     */
-    private void setupActionBar() {
-        ActionBar actionBar = getSupportActionBar();
-        if (actionBar != null) {
-            // Show the Up button in the action bar.
-            //Because of a NUG deactivated
-            //actionBar.setDisplayHomeAsUpEnabled(true);
-        }
     }
 
     /**
@@ -221,16 +207,5 @@ public boolean onOptionsItemSelected(MenuItem item) {
             return super.onOptionsItemSelected(item);
         }
     }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            // Respond to the action bar's Up/Home button
-            case android.R.id.home:
-                super.onBackPressed();
-                return true;
-        }
-        return super.onOptionsItemSelected(item);
-
-    }
+    
 }
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/ThirdPartyScannerActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/ThirdPartyScannerActivity.java
index 9f3fc19e..a60b9a23 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/ThirdPartyScannerActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/ThirdPartyScannerActivity.java
@@ -4,7 +4,6 @@
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
-import androidx.appcompat.app.AppCompatActivity;
 import android.os.Bundle;
 
 import com.google.zxing.client.android.Intents;
@@ -13,6 +12,8 @@
 
 import de.t_dankworth.secscanqr.R;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 25.10.2020
@@ -22,7 +23,7 @@
  * If your desired app does not support SecScanQR for scanning QR-Codes please ask them to implement it.
  */
 
-public class ThirdPartyScannerActivity extends AppCompatActivity {
+public class ThirdPartyScannerActivity extends MyAppCompatActivity {
 
     final Activity activity = this;
     private String qrcode = "";
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/BarcodeGenerateActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/BarcodeGenerateActivity.java
index fa74ce7d..71964319 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/BarcodeGenerateActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/BarcodeGenerateActivity.java
@@ -3,7 +3,6 @@
 
 import android.content.Intent;
 import android.os.Bundle;
-import androidx.appcompat.app.AppCompatActivity;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
@@ -17,6 +16,7 @@
 import de.t_dankworth.secscanqr.activities.MainActivity;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
 
 /**
  * Created by Thore Dankworth
@@ -26,7 +26,7 @@
  * This class is all about the value to BARCODE Generate Activity.
  */
 
-public class BarcodeGenerateActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
+public class BarcodeGenerateActivity extends MyAppCompatActivity implements AdapterView.OnItemSelectedListener {
 
     EditText text;
     int format;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GenerateActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GenerateActivity.java
index 0ee80656..7b58fd90 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GenerateActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GenerateActivity.java
@@ -5,7 +5,6 @@
 
 import android.os.Bundle;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.cardview.widget.CardView;
 import android.view.View;
 
@@ -13,6 +12,7 @@
 import de.t_dankworth.secscanqr.R;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
 
 /**
  * Created by Thore Dankworth
@@ -22,7 +22,7 @@
  * This class is just a forwarding to the specific generators
  */
 
-public class GenerateActivity extends AppCompatActivity implements View.OnClickListener {
+public class GenerateActivity extends MyAppCompatActivity implements View.OnClickListener {
 
     final Activity activity = this;
     private GeneralHandler generalHandler;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeneratorResultActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeneratorResultActivity.java
index c7b169b4..eea48dc2 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeneratorResultActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeneratorResultActivity.java
@@ -8,12 +8,10 @@
 import android.os.Environment;
 import androidx.annotation.NonNull;
 import androidx.core.app.ActivityCompat;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.content.FileProvider;
 
 import android.os.Bundle;
 import android.util.Log;
-import android.view.MenuItem;
 import android.view.View;
 import android.widget.Button;
 import android.widget.ImageView;
@@ -39,6 +37,8 @@
 import de.t_dankworth.secscanqr.R;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 14.03.2021
@@ -47,7 +47,7 @@
  * This class is all about showing the QR Code/Barcode and give the opportunity to save them
  */
 
-public class GeneratorResultActivity extends AppCompatActivity {
+public class GeneratorResultActivity extends MyAppCompatActivity {
 
     ImageView codeImage;
     Button btnSave, btnShare;
@@ -236,9 +236,5 @@ private void requestPermission(){
             ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQ_EXTERNAL_STORAGE_PERMISSION);
         }
     }
-
-    public boolean onOptionsItemSelected(MenuItem item){
-        finish();
-        return true;
-    }
+    
 }
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeoGeneratorActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeoGeneratorActivity.java
index 95cb54cf..07f11302 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeoGeneratorActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/GeoGeneratorActivity.java
@@ -5,7 +5,6 @@
 
 import android.content.Intent;
 import android.os.Bundle;
-import androidx.appcompat.app.AppCompatActivity;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
@@ -21,6 +20,8 @@
 import de.t_dankworth.secscanqr.activities.MainActivity;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 13.12.2019
@@ -28,7 +29,7 @@
  *
  * This class is all about the geo location to QR-Code Generate Activity.
  */
-public class GeoGeneratorActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{
+public class GeoGeneratorActivity extends MyAppCompatActivity implements AdapterView.OnItemSelectedListener{
 
     EditText tfLatitude, tfLongtitude;
     CheckBox cbLatitude, cbLongtitude;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/TextGeneratorActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/TextGeneratorActivity.java
index a1d99110..dac7a6b6 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/TextGeneratorActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/TextGeneratorActivity.java
@@ -6,7 +6,6 @@
 import android.net.Uri;
 import android.os.Bundle;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 
 import android.view.View;
@@ -26,6 +25,8 @@
 import de.t_dankworth.secscanqr.activities.MainActivity;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 13.12.2019
@@ -34,7 +35,7 @@
  * This class is all about the Text to QR-Code Generate Activity.
  */
 
-public class TextGeneratorActivity extends AppCompatActivity  implements AdapterView.OnItemSelectedListener {
+public class TextGeneratorActivity extends MyAppCompatActivity  implements AdapterView.OnItemSelectedListener {
 
     EditText text;
     int format;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/VCardGeneratorActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/VCardGeneratorActivity.java
index 2d006af4..13e73d80 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/VCardGeneratorActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/VCardGeneratorActivity.java
@@ -3,7 +3,6 @@
 import android.content.Intent;
 import android.os.Bundle;
 
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 import android.view.View;
 import android.widget.AdapterView;
@@ -18,6 +17,8 @@
 import de.t_dankworth.secscanqr.activities.MainActivity;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 01.05.2020
@@ -26,7 +27,7 @@
  * This class is all about the VCard to QR-Code Generate Activity.
  */
 
-public class VCardGeneratorActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{
+public class VCardGeneratorActivity extends MyAppCompatActivity implements AdapterView.OnItemSelectedListener{
 
     EditText tfFirstName, tfName, tfOrg, tfTeleWork, tfTelePrivate, tfMobil, tfEmail, tfWeb, tfStreet, tfPLZ, tfCity, tfState, tfCountry, tfPhoto, tfBday, tfNote;
     int format;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/WifiGeneratorActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/WifiGeneratorActivity.java
index 3ea6050c..1303d283 100644
--- a/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/WifiGeneratorActivity.java
+++ b/app/src/main/java/de/t_dankworth/secscanqr/activities/generator/WifiGeneratorActivity.java
@@ -2,7 +2,6 @@
 
 import android.app.Activity;
 import android.content.Intent;
-import androidx.appcompat.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.AdapterView;
@@ -18,6 +17,8 @@
 import de.t_dankworth.secscanqr.R;
 import de.t_dankworth.secscanqr.util.GeneralHandler;
 
+import de.t_dankworth.secscanqr.util.MyAppCompatActivity;
+
 /**
  * Created by Thore Dankworth
  * Last Update: 24.10.2020
@@ -26,7 +27,7 @@
  * This class is all about the wifi information to QR-Code Generate Activity.
  */
 
-public class WifiGeneratorActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{
+public class WifiGeneratorActivity extends MyAppCompatActivity implements AdapterView.OnItemSelectedListener{
 
     EditText tfSSID, tfPassword;
     CheckBox cbHidden;
diff --git a/app/src/main/java/de/t_dankworth/secscanqr/util/MyAppCompatActivity.java b/app/src/main/java/de/t_dankworth/secscanqr/util/MyAppCompatActivity.java
new file mode 100755
index 00000000..3cdc83d7
--- /dev/null
+++ b/app/src/main/java/de/t_dankworth/secscanqr/util/MyAppCompatActivity.java
@@ -0,0 +1,17 @@
+package de.t_dankworth.secscanqr.util;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+/**
+ * A {@link androidx.appcompat.app.AppCompatActivity} which overrides
+ * the home navigation button to call onBackPressed.
+ */
+public abstract class MyAppCompatActivity extends AppCompatActivity {
+
+    @Override
+    public boolean onSupportNavigateUp() {
+        onBackPressed();
+        return false;
+    }
+    
+}
diff --git a/app/src/main/res/layout/activity_history_details.xml b/app/src/main/res/layout/activity_history_details.xml
old mode 100644
new mode 100755
index 89d8b6e0..05f12ec4
--- a/app/src/main/res/layout/activity_history_details.xml
+++ b/app/src/main/res/layout/activity_history_details.xml
@@ -20,8 +20,9 @@
             <ImageView
                 android:id="@+id/resultImageHistory"
                 android:clickable="true"
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
+                android:background="@drawable/border_image"
+                android:layout_width="250px"
+                android:layout_height="250px"
                 android:layout_margin="10sp"
                 android:maxWidth="250sp"
                 android:maxHeight="250sp"
@@ -65,7 +66,7 @@
                 android:visibility="visible"
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintStart_toStartOf="parent"
-                app:layout_constraintTop_toBottomOf="@+id/tvFormatHistory" />
+                app:layout_constraintTop_toBottomOf="@+id/resultImageHistory" />
 
             <TextView
                 android:id="@+id/tvTxtqrcodeHistory"
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
old mode 100644
new mode 100755
index 0ab0f280..119d3629
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -23,7 +23,7 @@
 
             <androidx.cardview.widget.CardView
                 android:id="@+id/scan_card"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:clickable="true"
                 android:layout_columnWeight="1"
@@ -59,7 +59,7 @@
 
             <androidx.cardview.widget.CardView
                 android:id="@+id/generate_card"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:clickable="true"
                 android:layout_columnWeight="1"
@@ -94,7 +94,7 @@
 
             <androidx.cardview.widget.CardView
                 android:id="@+id/history_card"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:clickable="true"
                 android:layout_columnWeight="1"
@@ -130,7 +130,7 @@
 
             <androidx.cardview.widget.CardView
                 android:id="@+id/settings_card"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:clickable="true"
                 android:layout_columnWeight="1"
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
old mode 100644
new mode 100755
index 742d1baf..e5300dd6
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -26,17 +26,4 @@
         <item name="android:textColorHint">#8c8c8c</item>
     </style>
 
-
-
-
-
-    <style name="AppTheme.NoActionBar">
-        <item name="windowActionBar">false</item>
-        <item name="windowNoTitle">true</item>
-    </style>
-
-    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Light" />
-
-    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
-
 </resources>