How to create Settings for Switching ON and OFF of 'keep_screen_ON'

I have been struggling to create a CheckBox Switch for FLAG_KEEP_SCREEN_ON that can switch ON/OFF the screen display. I have managed to create it but it only works for one activity. I want to place the button maybe in the MainActivity where it will be easier for a user to quickly decide to either keep the screen ON/OFF. I want it to be one and only control switch for the entire activities in the app.
Please any help will be much appreciated.

This is what i did that doesn't work as a control settings in all activities.

This is the XML

<RelativeLayout
       android:id="@+id/mainlayout"
        android:background="@drawable/layout_bg2"
        android:layout_width="match_parent"
        android:layout_height="30sp">



    <Switch
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginTop="2dp"

       android:layout_marginLeft="50dp"
        android:id="@+id/ScreenController"/>

    <TextView
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="Keeps Screen OFF"
        android:layout_centerHorizontal="true"
        android:background="@drawable/layout_bg2"
        android:layout_marginTop="2dp"
        android:layout_toRightOf="@id/ScreenController"
        android:layout_marginLeft="30dp"
        android:textSize="16sp"
        android:textStyle="bold"
        android:textColor="#000000"
        android:fontFamily="serif"
        android:id="@+id/StatusText"/>

    </RelativeLayout>

This is the Java code

MySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView,
                                         boolean isChecked) {

                if(isChecked){

                    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
                    String currentText = MySwitch.getText().toString();
                    MyText.setText(currentText.equals("Screen Light Stays ON") ? "Screen Light Stays OFF" : "Screen Light Stays ON");
                    MyText.setTextColor(Color.parseColor("#FFEB3B"));

                }else{

                    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

                    String currentText = MySwitch.getText().toString();
                    MyText.setText(currentText.equals("Screen Light Stays OFF") ? "Screen Light Stays ON" : "Screen Light Stays OFF");
                    MyText.setTextColor(Color.parseColor("#000000"));


                }
            }
        });

save your variable in shared preference then have an activity that checks the variable and sets the flag.
you will then just extend this activity in all your activities.

 public class Main2Activity extends AppCompatActivity {
String shared_prefs_name="MY_prefs_name";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(screen_on()){
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}else{
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
}
public void set_screen_on( boolean screen_on) {
SharedPreferences.Editor saver = getSharedPreferences(shared_prefs_name, MODE_PRIVATE).edit();
saver.putBoolean("screen_on", screen_on);
saver.commit();
if(screen_on)
{
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}else{
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
}
public boolean screen_on() {
SharedPreferences prefs = getSharedPreferences(shared_prefs_name, MODE_PRIVATE);
return prefs.getBoolean("screen_on", false);
}
}

So you can use it in you activity like so .

public class Main3Activity extends Main2Activity {
Switch MySwitch;
TextView MyText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main3);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
MySwitch=(Switch)findViewById(R.id.ScreenController);
MyText=(TextView) findViewById(R.id.StatusText);
MySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
set_screen_on(isChecked);
if(isChecked){
String currentText = MySwitch.getText().toString();
MyText.setText(currentText.equals("Screen Light Stays ON") ? "Screen Light Stays OFF" : "Screen Light Stays ON");
MyText.setTextColor(Color.parseColor("#FFEB3B"));
}else{
String currentText = MySwitch.getText().toString();
MyText.setText(currentText.equals("Screen Light Stays OFF") ? "Screen Light Stays ON" : "Screen Light Stays OFF");
MyText.setTextColor(Color.parseColor("#000000"));
}
}
});
if(screen_on())
{
String currentText = MySwitch.getText().toString();
MyText.setText(currentText.equals("Screen Light Stays ON") ? "Screen Light Stays OFF" : "Screen Light Stays ON");
MyText.setTextColor(Color.parseColor("#FFEB3B"));
}else{
String currentText = MySwitch.getText().toString();
MyText.setText(currentText.equals("Screen Light Stays OFF") ? "Screen Light Stays ON" : "Screen Light Stays OFF");
MyText.setTextColor(Color.parseColor("#000000"));
}
}
}

Main thing is to extend Main2Activity to get accees to the boolean screen_on() and to set with set_screen_on(boolean);