Easy Spannable on Kotlin

Example.kt

val spanned = spannable{ bold("some") + italic(" formatted") + color(Color.RED, " text") }

val nested = spannable{ bold(italic("nested ")) + url("www.google.com", "text") }

val noWrapping = bold("no ") + sub("wrapping ) + sup("also ") + "works"

text_view.text = spanned + nested + noWrapping

Spannable.kt

import android.text.Spannable
import android.text.SpannableString
import android.text.TextUtils
import android.text.style.*
fun spannable(func: () -> SpannableString) = func()
private fun span(s: CharSequence, o: Any) = (if (s is String) SpannableString(s) else s as? SpannableString
        ?: SpannableString("")).apply { setSpan(o, 0, length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE) }

operator fun SpannableString.plus(s: SpannableString) = SpannableString(TextUtils.concat(this, s))
operator fun SpannableString.plus(s: String) = SpannableString(TextUtils.concat(this, s))

fun bold(s: CharSequence) = span(s, StyleSpan(android.graphics.Typeface.BOLD))
fun italic(s: CharSequence) = span(s, StyleSpan(android.graphics.Typeface.ITALIC))
fun underline(s: CharSequence) = span(s, UnderlineSpan())
fun strike(s: CharSequence) = span(s, StrikethroughSpan())
fun sup(s: CharSequence) = span(s, SuperscriptSpan())
fun sub(s: CharSequence) = span(s, SubscriptSpan())
fun size(size: Float, s: CharSequence) = span(s, RelativeSizeSpan(size))
fun color(color: Int, s: CharSequence) = span(s, ForegroundColorSpan(color))
fun background(color: Int, s: CharSequence) = span(s, BackgroundColorSpan(color))
fun url(url: String, s: CharSequence) = span(s, URLSpan(url))

I'm new to Android/Kotlin development, certainly I'm doing something wrong, :) but I cannot make color and background work.
The other modifiers work as expected. color makes text invisible (text color == background color); background doesn't change anything.
While Html.fromHtml() works fine...

EDITED: Finally I found out, what's wrong: color is not RGB, but ARGB, there must be an ALPHA value in it.

hey great job you did there but you fall short to notice that if we want to apply multiple spans to the same text its not possible and the solution was to create couple extra function to receive SpannableString

import android.text.Spannable
import android.text.SpannableString
import android.text.SpannableStringBuilder
import android.text.TextUtils
import android.text.style.*

fun spannable(func: () -> SpannableString) = func()
private fun span(s: CharSequence, o: Any) =
    (if (s is String) SpannableString(s) else s as? SpannableString
        ?: SpannableString("")).apply { setSpan(o, 0, length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE) }

operator fun SpannableString.plus(s: SpannableString) = SpannableString(TextUtils.concat(this, s))
operator fun SpannableString.plus(s: String) = SpannableString(TextUtils.concat(this, s))

fun bold(s: CharSequence) = span(s, StyleSpan(android.graphics.Typeface.BOLD))
fun bold(s: SpannableString) = span(s, StyleSpan(android.graphics.Typeface.BOLD))
fun italic(s: CharSequence) = span(s, StyleSpan(android.graphics.Typeface.ITALIC))
fun italic(s: SpannableString) = span(s, StyleSpan(android.graphics.Typeface.ITALIC))
fun underline(s: CharSequence) = span(s, UnderlineSpan())
fun underline(s: SpannableString) = span(s, UnderlineSpan())
fun strike(s: CharSequence) = span(s, StrikethroughSpan())
fun strike(s: SpannableString) = span(s, StrikethroughSpan())
fun sup(s: CharSequence) = span(s, SuperscriptSpan())
fun sup(s: SpannableString) = span(s, SuperscriptSpan())
fun sub(s: CharSequence) = span(s, SubscriptSpan())
fun sub(s: SpannableString) = span(s, SubscriptSpan())
fun size(size: Float, s: CharSequence) = span(s, RelativeSizeSpan(size))
fun size(size: Float, s: SpannableString) = span(s, RelativeSizeSpan(size))
fun color(color: Int, s: CharSequence) = span(s, ForegroundColorSpan(color))
fun color(color: Int, s: SpannableString) = span(s, ForegroundColorSpan(color))
fun background(color: Int, s: CharSequence) = span(s, BackgroundColorSpan(color))
fun background(color: Int, s: SpannableString) = span(s, BackgroundColorSpan(color))
fun url(url: String, s: CharSequence) = span(s, URLSpan(url))
fun url(url: String, s: SpannableString) = span(s, URLSpan(url))
fun normal(s: CharSequence) = span(s, SpannableString(s))
fun normal(s: SpannableString) = span(s, SpannableString(s))

this way it possible to nest spanns

spannable {
            italic(underline(bold(size(2f, color(Color.RED, "Red Bold Color")))))
        }

thanks.

nice i love it!

This is amazing ♥️

This is amazing ❤️

Glad you like it ❤️

Thank you so much for your great idea.
My solution with using Kotlin extensions.

private const val EMPTY_STRING = ""
private const val FIRST_SYMBOL = 0

fun spannable(func: () -> SpannableString) = func()

private fun span(s: CharSequence, o: Any) = getNewSpannableString(s).apply {
    setSpan(o, FIRST_SYMBOL, length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
}

private fun getNewSpannableString(charSequence: CharSequence): SpannableString{
    return if (charSequence is String){
        SpannableString(charSequence)
    }else{
        charSequence as? SpannableString ?: SpannableString(EMPTY_STRING)
    }
}

operator fun SpannableString.plus(s: CharSequence) = SpannableString(TextUtils.concat(this, "", s))

fun CharSequence.makeSpannableString() = span(this, Spanned.SPAN_COMPOSING)
fun CharSequence.makeBold() = span(this, StyleSpan(BOLD))
fun CharSequence.makeItalic() = span(this, StyleSpan(ITALIC))
fun CharSequence.makeUnderline() = span(this, UnderlineSpan())
fun CharSequence.makeStrike() = span(this, StrikethroughSpan())
fun CharSequence.makeSuperscript() = span(this, SuperscriptSpan())
fun CharSequence.makeSubscript() = span(this, SubscriptSpan())
fun CharSequence.makeAnotherSize(size : Float) = span(this, RelativeSizeSpan(size))
fun CharSequence.makeAnotherColor(color : Int) = span(this, ForegroundColorSpan(color))
fun CharSequence.makeAnotherBackground(color : Int) = span(this, BackgroundColorSpan(color))
fun CharSequence.makeUrl(url : String) = span(this, URLSpan(url))

Using example:

textView.text = spannable{ 
    "Example".makeSpannableString()
             .makeBold()
             .makeItalic()
             .makeUnderline()
}

nice job

Thanks for all you guys! I'm using @Scorpio93 implementation, very nice job!

I also added a two more extensions for ClickableSpan:

/** You will need set movementMethod = LinkMovementMethod.getInstance() in the TextView to allow clicking on the span */
fun CharSequence.clickable(listener: View.OnClickListener) : SpannableString {
    val clickSpan = object : ClickableSpan() {
        override fun onClick(widget: View) {
            listener.onClick(widget)
        }
    }
    return span(this, clickSpan)
}
/** You will need set movementMethod = LinkMovementMethod.getInstance() in the TextView to allow clicking on the span */
fun CharSequence.clickableWithoutUnderline(listener: View.OnClickListener) : SpannableString {
    val clickSpan = object : ClickableSpan() {
        override fun onClick(widget: View) {
            listener.onClick(widget)
        }
        override fun updateDrawState(ds: TextPaint) {
            super.updateDrawState(ds)
            ds.isUnderlineText = false
        }
    }
    return span(this, clickSpan)
}

Nice job~Thanks for all you guys!