bulletspan_api21_second_solution.kt

 override fun handleTag(opening: Boolean, tag: String, output: Editable, xmlReader: XMLReader) {
    if (tag == "li" && opening) {
        output.setSpan(Bullet(), output.length, output.length, Spannable.SPAN_INCLUSIVE_EXCLUSIVE)
    }
    if (tag == "li" && !opening) {
        output.append("\n\n")
        val lastMark = output.getSpans(0, output.length, Bullet::class.java).lastOrNull()
        lastMark?.let {
            val start = output.getSpanStart(it)
            output.removeSpan(it)
            if (start != output.length) {
                output.setSpan(BulletSpan(), start, output.length, Spanned.SPAN_INCLUSIVE_EXCLUSIVE)
            }
        }
    }
}