How to center progress indicator in ProgressDialog easily (when no title/text passed along)

I did some testing and I feel that the best way to achieve this is doing a custom Dialog.

Here is an example of what I did. This will answer question number 2 but will give you an idea of how to fix question number 1.

public class MyProgressDialog extends Dialog {

    public static MyProgressDialog show(Context context, CharSequence title,
            CharSequence message) {
        return show(context, title, message, false);
    }

    public static MyProgressDialog show(Context context, CharSequence title,
            CharSequence message, boolean indeterminate) {
        return show(context, title, message, indeterminate, false, null);
    }

    public static MyProgressDialog show(Context context, CharSequence title,
            CharSequence message, boolean indeterminate, boolean cancelable) {
        return show(context, title, message, indeterminate, cancelable, null);
    }

    public static MyProgressDialog show(Context context, CharSequence title,
            CharSequence message, boolean indeterminate,
            boolean cancelable, OnCancelListener cancelListener) {
        MyProgressDialog dialog = new MyProgressDialog(context);
        dialog.setTitle(title);
        dialog.setCancelable(cancelable);
        dialog.setOnCancelListener(cancelListener);
        /* The next line will add the ProgressBar to the dialog. */
        dialog.addContentView(new ProgressBar(context), new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
        dialog.show();

        return dialog;
    }

    public MyProgressDialog(Context context) {
        super(context, R.style.NewDialog);
    }
}

All the static methods comes from this link, nothing strange, but the magic occurs in the constructor.
Check that I pass as parameter an style. That style is the following:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="NewDialog" parent="@android:Theme.Dialog">
        <item name="android:windowFrame">@null</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowTitleStyle">@null</item>
        <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
        <item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
        <item name="android:backgroundDimEnabled">false</item>
        <item name="android:background">@android:color/transparent</item>
    </style>
</resources>

The result of this is a ProgressBar rotating in the center of the screen. Without backgroundDim and without the Dialog box.