Cool things I learned, Part 3 - Extension functions - TextView

Extension functions are wonderful! Style the text view the same way again and again? Make it an extension function.

Here is the official Kotlin documentation on extensions: https://kotlinlang.org/docs/extensions.html

And here are my favorite extension functions that I've been using.

fun TextView.setTextOrGone(value: CharSequence?) {
  text = value.nullIfBlank.also { visibility = if (it != null) View.VISIBLE else View.GONE }
}

fun TextView.setCompoundDrawableWithTint(
  @DrawableRes drawable: Int,
  @ColorRes color: Int,
  direction: DrawableDirection
) {
  TextViewCompat.setCompoundDrawableTintList(
    this,
    ColorStateList.valueOf(resources.getColor(color))
  )
  val drawableResource = AppCompatResources.getDrawable(this.context, drawable)
  setCompoundDrawablesRelativeWithIntrinsicBounds(
    if (direction == DrawableDirection.START) drawableResource else null,
    if (direction == DrawableDirection.TOP) drawableResource else null,
    if (direction == DrawableDirection.END) drawableResource else null,
    if (direction == DrawableDirection.BOTTOM) drawableResource else null
  )
}

enum class DrawableDirection {
  TOP, BOTTOM, START, END
}

What are your favorite ways to use extensions in Kotlin?