How to grey out a button?

You could Also make it appear as disabled by setting the alpha (making it semi-transparent). This is especially useful if your button background is an image, and you don’t want to create states for it.

button.setAlpha(.5f);
button.setClickable(false);

update: I wrote the above solution pre Kotlin and when I was a rookie. It’s more of a “quick’n’dirty” solution, but I don’t recommend it in a professional environment.

Today, if I wanted a generic solution that works on any button/view without having to create a state list, I would create a Kotlin extension.

fun View.disable() {
    getBackground().setColorFilter(Color.GRAY, PorterDuff.Mode.MULTIPLY)
    setClickable(false)
}

In Java you can do something is similar with a static util function and you would just have to pass in the view as variable. It’s not as clean but it works.