[Android] Custom text style or insert emoji to string content

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    SpannableString styledString
            = new SpannableString("Large\n\n"     // index 0 - 5
            + "Bold\n\n"          // index 7 - 11
            + "Underlined\n\n"    // index 13 - 23
            + "Italic\n\n"        // index 25 - 31
            + "Strikethrough\n\n" // index 33 - 46
            + "Colored\n\n"       // index 48 - 55
            + "Highlighted\n\n"   // index 57 - 68
            + "K Superscript\n\n" // "Superscript" index 72 - 83 
            + "K Subscript\n\n"   // "Subscript" index 87 - 96
            + "Url\n\n"           //  index 98 - 101
            + "Clickable\n\n");   // index 103 - 112

    // make the text twice as large
    styledString.setSpan(new RelativeSizeSpan(2f), 0, 5, 0);

    // make text bold
    styledString.setSpan(new StyleSpan(Typeface.BOLD), 7, 11, 0);

    // underline text
    styledString.setSpan(new UnderlineSpan(), 13, 23, 0);

    // make text italic
    styledString.setSpan(new StyleSpan(Typeface.ITALIC), 25, 31, 0);

    styledString.setSpan(new StrikethroughSpan(), 33, 46, 0);

    // change text color
    styledString.setSpan(new ForegroundColorSpan(Color.GREEN), 48, 55, 0);

    // highlight text
    styledString.setSpan(new BackgroundColorSpan(Color.CYAN), 57, 68, 0);

    // superscript
    styledString.setSpan(new SuperscriptSpan(), 72, 83, 0);
    // make the superscript text smaller
    styledString.setSpan(new RelativeSizeSpan(0.5f), 72, 83, 0);

    // subscript
    styledString.setSpan(new SubscriptSpan(), 87, 96, 0);
    // make the subscript text smaller
    styledString.setSpan(new RelativeSizeSpan(0.5f), 87, 96, 0);

    // url
    styledString.setSpan(new URLSpan("http://www.google.com"), 98, 101, 0);

    // clickable text
    ClickableSpan clickableSpan = new ClickableSpan() {

        @Override
        public void onClick(View widget) {
            // We display a Toast. You could do anything you want here.
            Toast.makeText(SpanExample.this, "Clicked", Toast.LENGTH_SHORT).show();

        }
    };

    styledString.setSpan(clickableSpan, 103, 112, 0);


    // Give the styled string to a TextView
    TextView textView = new TextView(this);

    // this step is mandated for the url and clickable styles.
    textView.setMovementMethod(LinkMovementMethod.getInstance());

    // make it neat
    textView.setGravity(Gravity.CENTER);
    textView.setBackgroundColor(Color.WHITE);

    textView.setText(styledString);

    setContentView(textView);

}