How to disable user interaction while ProgressBar is visible in android?

Your question: How to disable the user interaction while ProgressBar is visible in android?

To disable the user interaction you just need to add the following code

getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);

To get user interaction back you just need to add the following code

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

Here is an example:
Note:I am giving you just an example to show how to disable or retain user interaction

Add a progress bar in your xml.Something like this

<ProgressBar
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/progressBar"
    android:visibility="gone"/>

In MainActivity when a button pressed you show the progressbar and disable the user interaction.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mImageView = (ImageView) findViewById(R.id.imageView);
    mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
    mImageView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mProgressBar.setVisibility(View.VISIBLE);
            getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
        }
    });
}

And when user backPressed you remove the progressbar again retain the user interaction.Something like this

  @Override
public void onBackPressed() {
    super.onBackPressed();
    mProgressBar.setVisibility(View.GONE);
    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
}

If you want to add a feature of disable and greyed out display, you need to add in your xml layout file a linear layout that fills the parent. Set its background to #B0000000 and its visibilty to GONE. Then programmatically set its visibility to VISIBLE.

Hope this help!