public void setStyle(String regexp, int style) {
        Pattern p = Pattern.compile(regexp);
        Matcher m = p.matcher(block.getText());
        while (m.find()) {
            setStyle(m.start(), m.end(), style);
        }
    }
Set the font style of substring. If font doesn't contain style, default style is applied
@param regexp regular expression
@param style  the style to apply
jme3-core/src/main/java/com/jme3/font/BitmapText.java