Find hypertext link in textview and get Callback when user clicks on it.

ViewExtensions.kt

/**
 * Enables click support for a TextView from a [fullText] String, which one containing one or multiple URLs.
 * The [callback] will be called when a click is triggered.
 */
fun MaterialTextView.setTextWithLinkSupport(
    fullText: Spannable,
    callback: (String) -> Unit
) {
    val spannable = SpannableString(fullText)
    val matcher = Patterns.WEB_URL.matcher(spannable)
    while (matcher.find()) {
        val url = spannable.toString().substring(matcher.start(), matcher.end())
        val urlSpan = object : URLSpan(fullText.toString()) {
            override fun onClick(widget: View) {
                callback(url)
            }
        }
        spannable.setSpan(urlSpan, matcher.start(), matcher.end(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
    }
    text = spannable
    movementMethod = LinkMovementMethod.getInstance() // Make link clickable
}

/*
  finds and colors all urls contained in a string 
  @param linkColor color for the url default is blue
  @param linkClickAction action to perform when user click that link
 */
fun String.linkify(linkColor:Int = Color.BLUE,linkClickAction:((link:String) -> Unit)? = null): SpannableStringBuilder {
    val builder = SpannableStringBuilder(this)
    val matcher = Patterns.WEB_URL.matcher(this)
    while(matcher.find()){
        val start = matcher.start()
        val end = matcher.end()
        builder.setSpan(ForegroundColorSpan(Color.BLUE),start,end,0)
        val onClick = object : ClickableSpan(){
            override fun onClick(p0: View) {
                    linkClickAction?.invoke(matcher.group())
            }
        }
        //builder.setSpan(onClick,start,end,0)
    }
    return builder
}