Custom Progress Dialog not able to access components

Question

I am trying to create a customized version of the ProgressDialog as it does not meet my current layout requirements.

I would like to render a vertically stacked ProgressDialog with the title centered on top of a centered spinner and the centered spinner on top of a message that typically receives updates on percentage of completion in a string format.

While trying to update the ProgressDialog's title and message, I am returned NullPointerException for the components.

How do I attempt to update the title and message of the progress dialog periodically ?

My code for the ProgressDialog.java class:

public class ProgressDialog extends AppCompatDialogFragment {
    public volatile TextView progressDialogMessage = null;
    public volatile TextView progressDialogTitle = null;
    private View view = null;
    private volatile AlertDialog aldialogInst = null;
    private String title = "";
    private String message = "";

    public ProgressDialog() {
    }

    public ProgressDialog(String title, String message) {
        this.title = title;
        this.message = message;
    }

    @Override
    public AlertDialog onCreateDialog(@Nullable Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(), R.style.CustomAlertDialog);
        LayoutInflater inflater = getActivity().getLayoutInflater();
        view = inflater.inflate(R.layout.activity_progress_dialog, null);
        progressDialogMessage = view.findViewById(R.id.progressDialogMessage);
        progressDialogTitle = view.findViewById(R.id.progressDialogTitle);

        System.out.println("[INF] ProgressDialog :: onCreate :: started ...");

        if (progressDialogTitle == null) {
            System.out.println("DIALOG TITLE IS NULL !!!");
        }

        builder.setView(view).setTitle(null);

        progressDialogTitle.setText(this.title);
        progressDialogMessage.setText(this.message);

        aldialogInst = builder.create();

        return aldialogInst;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        System.out.println("[INF] ProgressDialog :: onAttach :: started ...");
    }

    public void updateDialog(String title, @Nullable String message) {
        progressDialogTitle.setText(title);
        progressDialogMessage.setText(message);
        progressDialogTitle.invalidate();
        progressDialogMessage.invalidate();
    }

    public boolean isReady() {
        if (aldialogInst != null) {
            return true;
        }

        return false;
    }

    public AlertDialog getAlertDialog() {
        return aldialogInst;
    }
}

The XML for layout activity_progress_dialog.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <TextView
        android:id="@+id/progressDialogTitle"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="16dp"
        android:fontFamily="@font/lexend_deca_bold"
        android:textAlignment="center"
        android:textColor="@color/ventac_black"
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/progressDialogMessage"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="16dp"
        android:fontFamily="@font/lexend_deca_light"
        android:textAlignment="center"
        android:textColor="@color/ventac_gray_1"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/progressDialogSpinner" />

    <ProgressBar
        android:id="@+id/progressDialogSpinner"
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:indeterminateDrawable="@drawable/spinner"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/progressDialogTitle" />

    <Space
        android:layout_width="0dp"
        android:layout_height="32dp"
        android:layout_marginStart="157dp"
        android:layout_marginEnd="218dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/progressDialogMessage" />

</androidx.constraintlayout.widget.ConstraintLayout>

The MainActivity.java class:

package com.xxx.yyy.ui;

import androidx.activity.OnBackPressedCallback;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.lifecycle.LiveData;
import androidx.work.Operation;
import androidx.work.PeriodicWorkRequest;
import androidx.work.WorkInfo;
import androidx.work.WorkManager;

import android.app.ActivityManager;
import android.app.ApplicationExitInfo;
import android.content.Context;
import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.hardware.usb.UsbDevice;
import android.os.Build;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;

import java.io.IOException;
import java.io.InputStream;
import java.security.Security;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

public class MainActivity extends AppCompatActivity {

    private static Context myContext = null;

    @RequiresApi(api = Build.VERSION_CODES.TIRAMISU)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);    
        myContext = this;
        System.out.println("===== SHOWING CUSTOM NOTIFICATION DIALOG START =====");

        ProgressDialog dialog = new ProgressDialog("Downloading Provenance", "0%");
        dialog.show(((AppCompatActivity) myContext).getSupportFragmentManager(), "progdialog");
        dialog.updateDialog("HELLO", "100%");
        System.out.println("===== SHOWING CUSTOM NOTIFICATION DIALOG END =====");
    }

    @Override
    protected void onResume() {
        super.onResume();
    }

    @Override
    protected void onStop() {
        super.onStop();
    }

    @Override
    protected void onStart() {
        super.onStart();
    }
}

The error message:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.watchlink.keepertag.ui.ProgressDialog.updateDialog(ProgressDialog.java:69)
at com.watchlink.keepertag.ui.MainActivity.onCreate(MainActivity.java:45)
at android.app.Activity.performCreate(Activity.java:8591)
at android.app.Activity.performCreate(Activity.java:8570)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1384)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4150)