private void showDialog() {
        Window window = _alertDialog.getWindow();
        if (window != null) {
            TypedArray ta = _context.obtainStyledAttributes(R.styleable.FileChooser);
            window.setGravity(ta.getInt(R.styleable.FileChooser_fileChooserDialogGravity, Gravity.CENTER));
            ta.recycle();
        }
        _alertDialog.show();
    }
allows dialog title follows the current folder name

@param followDir dialog title will follow the changing of directory
@return this
android-file-chooser/src/main/java/com/obsez/android/lib/filechooser/ChooserDialog.java