Snackbar extensions on Kotlin, to create a useful small DSL.

ExtensionsSnackbar.kt

fun Context.colorInt(color: Int) = ContextCompat.getColor(this, color)

inline fun View.snack(@IntegerRes messageRes: Int, length: Int = Snackbar.LENGTH_LONG, f: Snackbar.() -> Unit) {
    snack(resources.getString(messageRes), length, f)
}

inline fun View.snack(message: String, length: Int = Snackbar.LENGTH_LONG, f: Snackbar.() -> Unit) {
    val snack = Snackbar.make(this, message, length)
    snack.f()
    snack.show()
}

inline fun View.snack(message: String, bgColor: Int? = null, length: Int = Snackbar.LENGTH_LONG, f: Snackbar.() -> Unit) {
    val snack = Snackbar.make(this, message, length)
    bgColor?.let{snack.view.setBackgroundColor(bgColor)}
    snack.f()
    snack.show()
}

fun Snackbar.action(@IntegerRes actionRes: Int, color: Int? = null, listener: (View) -> Unit) {
    action(view.resources.getString(actionRes), color, listener)
}

fun Snackbar.action(action: String, color: Int? = null, listener: (View) -> Unit) {
    setAction(action, listener)
    color?.let { setActionTextColor(color) }
}

MainActivity.kt

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_home)
        setSupportActionBar(toolbar)

        fab.setOnClickListener {
            it.snack("Snack message", bgColor = colorInt(R.color.red)) {
                action("Action", colorInt(R.color.white)) { toast("Action clicked") }
            }
        }
    }
}

Added a context extension to covert a resource color to a ColorInt.

Added a view extension to accept a background color for the snack bar.