Custom Dialog extends Dialog not rendering layout by onCreate is executed

Question

I am trying to create a custom Dialog using the following implementation.

The problem is Android is not rendering the layout even though I do set the layout with setContentView().

Example of when .show() is called:

I searched for a possible solution. It appears most use AlertDialog.Builder although I opted for another easier and reusable route i.e. ProgressDialog. Also, this solution suggest to place the layout resource on the constructor - which I am skeptical of, but naturally did not work.

Code files below:

The source file ProgressDialog.java

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.widget.ProgressBar;
import android.widget.TextView;
import androidx.annotation.NonNull;

import com.example.android.R;

public class ProgressDialog extends Dialog {

    private ProgressBar progressBar;
    private TextView textView;

    public ProgressDialog(@NonNull Context context) {
        super(context);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.progress_dialog);
        progressBar = findViewById(R.id.progressBarDialog);
        progressBar.setProgress(0);
        textView = findViewById(R.id.progressBarText);
    }

    public void setProgress(int progress){
        if (progressBar != null) {
            progressBar.setProgress(progress);
        }
    }

    public void setText(String text){
        if (textView != null) {
            textView.setText(text);
        }
    }
}

and with the progress_dialog.xml layout as follows:

<?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:id="@+id/linearLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/progressBarText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ProgressBar
        android:id="@+id/progressBarDialog"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginBottom="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/progressBarText" />
</androidx.constraintlayout.widget.ConstraintLayout>

What is causing this problem, why does Android not render the dialog content?

Update from @md-asaduzzaman's comment

How to use:

ProgressDialog dialog = new ProgressDialog (SomeActivityHere.this);
dialog.show();

// optional
dialog.setProgress(0);
dialog.setText(getString(R.string.someString));

Alternatively one can pass in a bundle of arguments

Answer 1

It's a problem of your layout. Change layout_width of your view from 0dp to wrap_content or match_parent or any fixed size according your requiremnet.

android:layout_width="wrap_content"

Beside this your Dialog is not work as expected as setProgress and setText execute before the dialog created. So, Change your dialog implementation like below:

public class ProgressDialog extends Dialog {

    private ProgressBar progressBar;
    private TextView textView;

    private String mText;
    private int mProgress;


    public ProgressDialog(@NonNull Context context) {
        super(context);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.progress_dialog);
        progressBar = findViewById(R.id.progressBarDialog);
        progressBar.setProgress(mProgress);

        textView = findViewById(R.id.progressBarText);
        textView.setText(mText);
    }

    public void setProgress(int progress){
        mProgress = progress;

        if (progressBar != null) {
            progressBar.setProgress(mProgress);
        }
    }

    public void setText(String text){
        mText = text;

        if (textView != null) {
            textView.setText(mText);
        }
    }
}

Output: