Anko: inner scope of apply, confusing property resolution

Question

I'm writing an Android layout using Anko DSL. When defining a TextView, I wanted to make it center-aligned, so I wrote this:

verticalLayout {
    textView(R.string.txt_greeting).apply {
        gravity = Gravity.CENTER_HORIZONTAL // <- this should have changed the alignment
        textSize = 20.0f
    }
    //...
}

But the alignment didn't change. In debugger I saw that gravity is set for the LinearLayout which is the TextView's parent.

Changing the statement to either

textView(R.string.txt_greeting).let { it.gravity = Gravity.CENTER_HORIZONTAL }

and

textView(R.string.txt_greeting).apply { [email protected] = Gravity.CENTER_HORIZONTAL }

and even

textView(R.string.txt_greeting).apply { this.gravity = Gravity.CENTER_HORIZONTAL }

solves the problem, thus in the original code implicit this is definitely resolved to this@verticalLayout.

Why does this happen?

Do I misunderstand something in Kotlin lambdas or is it a bug in Kotlin or Anko?

Answer 1

It was actually a bug in scoping.

The corresponding issue has been marked as fixed, so the fix is likely to appear in the next release.