Added TabLayout/Viewpager to About-Fragment

Removed Padding (should be in every single Fragment)

app/src/main/java/net/xcreen/restsms/AboutFragment.java

@@ -1,13 +1,25 @@
 package net.xcreen.restsms;
 
+import androidx.appcompat.widget.LinearLayoutCompat;
 import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentStatePagerAdapter;
+import androidx.viewpager.widget.ViewPager;
+
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.tabs.TabLayout;
+
 public class AboutFragment extends Fragment {
 
+    private TabLayout tabLayout;
+    private ViewPager viewPager;
+    private AppBarLayout mainAppBarLayout;
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -15,7 +27,74 @@ public class AboutFragment extends Fragment {
 
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        // Inflate the layout for this fragment
-        return inflater.inflate(R.layout.fragment_about, container, false);
+        View rootView = inflater.inflate(R.layout.fragment_about, container, false);
+
+        //Set Tabs
+        tabLayout = new TabLayout(getActivity());
+        tabLayout.addTab(tabLayout.newTab().setText(getResources().getText(R.string.about_about_me)));
+        tabLayout.addTab(tabLayout.newTab().setText(getResources().getText(R.string.about_app_information)));
+        tabLayout.addTab(tabLayout.newTab().setText(getResources().getText(R.string.about_third_party_librarys)));
+        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
+        tabLayout.setBackgroundColor(getResources().getColor(R.color.colorDarkBlack, null));
+        tabLayout.setTabTextColors(getResources().getColor(R.color.colorWhite, null), getResources().getColor(R.color.colorLightBlue, null));
+        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
+            @Override
+            public void onTabSelected(TabLayout.Tab tab) {
+                viewPager.setCurrentItem(tab.getPosition());
+            }
+
+            @Override
+            public void onTabUnselected(TabLayout.Tab tab) { }
+
+            @Override
+            public void onTabReselected(TabLayout.Tab tab) { }
+        });
+
+        //Add TabLayout to the AppBarLayout
+        mainAppBarLayout = getActivity().findViewById(R.id.appbar_layout);
+        mainAppBarLayout.addView(tabLayout, new LinearLayoutCompat.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
+
+        //Set Page-Adapter to ViewPager
+        FragmentPageAdapter pagerAdapter = new FragmentPageAdapter(getFragmentManager(), tabLayout.getTabCount());
+        viewPager = rootView.findViewById(R.id.about_view_pager);
+        viewPager.setAdapter(pagerAdapter);
+        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
+
+        return rootView;
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        //Remove Tab-Layout
+        mainAppBarLayout.removeView(tabLayout);
+    }
+}
+
+class FragmentPageAdapter extends FragmentStatePagerAdapter {
+    private int numberOfTabs;
+
+    public FragmentPageAdapter(FragmentManager fm, int numberOfTabs) {
+        super(fm);
+        this.numberOfTabs = numberOfTabs;
+    }
+
+    @Override
+    public Fragment getItem(int position) {
+        switch (position) {
+            case 0:
+                return new AboutMeFragment();
+            case 1:
+                return new AboutMeFragment();
+            case 2:
+                return new AboutMeFragment();
+            default:
+                return null;
+        }
+    }
+
+    @Override
+    public int getCount() {
+        return numberOfTabs;
     }
 }

app/src/main/java/net/xcreen/restsms/AboutMeFragment.java

@@ -0,0 +1,25 @@
+package net.xcreen.restsms;
+
+import android.os.Bundle;
+
+import androidx.fragment.app.Fragment;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+
+public class AboutMeFragment extends Fragment {
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+    }
+
+    @Override
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        // Inflate the layout for this fragment
+        return inflater.inflate(R.layout.fragment_about_me, container, false);
+    }
+}

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

@@ -22,6 +22,7 @@
             android:orientation="vertical">
 
             <com.google.android.material.appbar.AppBarLayout
+                android:id="@+id/appbar_layout"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:theme="@style/AppTheme.AppBarOverlay">
@@ -39,8 +40,7 @@
                 android:id="@+id/main_framelayout"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
-                android:background="@color/colorLightBlack"
-                android:padding="@dimen/fragment_padding"/>
+                android:background="@color/colorLightBlack" />
 
         </LinearLayout>
 

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

@@ -5,9 +5,9 @@
     android:layout_height="match_parent"
     tools:context=".AboutFragment">
 
-    <TextView
+    <androidx.viewpager.widget.ViewPager
+        android:id="@+id/about_view_pager"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:text="ABOUT" />
+        android:layout_height="match_parent" />
 
 </FrameLayout>

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

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:padding="@dimen/fragment_padding"
+    tools:context=".AboutMeFragment">
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="TextView" />
+</FrameLayout>

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

@@ -4,6 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:padding="@dimen/fragment_padding"
     tools:context=".HomeFragment">
 
     <ScrollView

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

@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:padding="@dimen/fragment_padding"
     tools:context=".SettingsFragment">
 
     <TextView

app/src/main/res/values/strings.xml

@@ -13,4 +13,8 @@
     <string name="server_failed_to_start">Server failed to start!</string>
     <string name="invalid_sim">Sim-Card is missing or not ready to send sms!</string>
     <string name="no_sms_permission">SMS-Permission is required to run the server!</string>
+
+    <string name="about_about_me">About Me</string>
+    <string name="about_app_information">App-Information</string>
+    <string name="about_third_party_librarys">Third-Party Librarys</string>
 </resources>