Android Custom Attr is not in my AttributeSet

Question

I have a custom attribute defined as such in my res/values/attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <attr name="hint" format="string" />

    <declare-styleable name="McEditText">
        <attr name="hint"  />
    </declare-styleable>
</resources>

I refer to it in McEditText.kt

class McEditText @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet
) : ConstraintLayout( context, attrs) {

    private var _layout :ConstraintLayout
    private var _editText: EditText
    var hint :String = ""

    init {
        context.theme.obtainStyledAttributes(attrs, R.styleable.McEditText, 0, 0).apply {
            try {
                hint = getString(R.styleable.McEditText_hint).toString()
            } finally {
                recycle()
            }

            _layout = inflate( context, R.layout.layout_mcedittext, this@McEditText ) as ConstraintLayout
            _editText = _layout.findViewById(R.id.mc_edit_text)
            _editText.hint = hint

            for (i in 0 until attrs!!.attributeCount) {
                Log.e("ATTRS", i.toString() + ": " + 
                    attrs.getAttributeName(i) + " " + attrs.getAttributeValue(i) ) }
        }
    }
}

Then in my XML I have

<?xml version="1.0" encoding="utf-8"?>
<!-- Merge into a ConstraintLayout -->
<merge
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/mc_edit_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        custom:hint="poofy"/>
</merge>

Running the code you would expect to see a text area with a hint of "poofy". But no, the hint is "null"! (So much for kotlin's null safety). The log shows this:

E/ATTRS: 0: id @2131296465
E/ATTRS: 1: layout_width -1
E/ATTRS: 2: layout_height -2
E/ATTRS: 3: layout_constraintStart_toStartOf 0
E/ATTRS: 4: layout_constraintTop_toTopOf 0

As you can see the custom hint attr is missing. Why?

(And yes, I tried it with the format="string" inside the local attr rather than referred to from the outer scope. Same deal)

Answer 1

See the comment above. Embarassing mistake.