Destructuring declaration initializer of type ObjectAnimator

Question

I'm using kotlin destructuring declarations. I used it before with SpringAnimation and it worked perfectly. Now I want use it with ObjectAnimator and I get this error:

Destructuring declaration initializer of type ObjectAnimator! must have a 'component1()' function

Destructuring declaration initializer of type ObjectAnimator! must have a 'component2()' function

Here is my code:

val (xanimator, alphaanim) = findViewById<View>(R.id.imageView).let { img ->
            ObjectAnimator.ofFloat(img, "translationX", 100f).apply {
                duration = 2000
            }
            to
            ObjectAnimator.ofFloat(img, "alpha", 1.0f).apply {
                duration = 2000
            }
        }

What's wrong?

Answer 1

The issue here is that you can't start an infix call function call on a new line - the compiler essentially infers a semicolon/line ending after your first apply call. This is the same way with operators, see this issue for example.

So you need to reformat your code a bit for the to to connect, most simply like this:

val (xanimator: ObjectAnimator, alphaanim: ObjectAnimator) = findViewById<View>(R.id.imageView).let { img ->
    ObjectAnimator.ofFloat(img, "translationX", 100f).apply {
        duration = 2000
    } to
    ObjectAnimator.ofFloat(img, "alpha", 1.0f).apply {
        duration = 2000
    }
}

But for readability, maybe you could go with something like this:

val (xanimator: ObjectAnimator, alphaanim: ObjectAnimator) = findViewById<View>(R.id.imageView).let { img ->
    Pair(
            ObjectAnimator.ofFloat(img, "translationX", 100f).apply {
                duration = 2000
            },
            ObjectAnimator.ofFloat(img, "alpha", 1.0f).apply {
                duration = 2000
            }
    )
}

Or anything inbetween.