Auto-resizing EditText font with callback

AutoResizingEditTextExt.kt

//  to change text size in related fields (like "+" in front of phone numbers or quasi-hint text in the field below):
//    binding.textEdit.autocorrectSize { size ->
//        binding.phoneCountryPrefixTextField.setTextSize(TypedValue.COMPLEX_UNIT_PX, size)
//        binding.hintBelowInputTextField.setTextSize(TypedValue.COMPLEX_UNIT_PX, size)
//    }
// or just myEditText.autocorrectSize() somewhere in onViewCreated()

fun EditText.autocorrectSize(callback: ((Float) -> Unit)? = null) {

    val originalTextSize = this.textSize

    val bounds = Rect()
    val paintForSearch = Paint()
    paintForSearch.typeface = paint.typeface
    paintForSearch.strokeWidth = paint.strokeWidth
    paintForSearch.isAntiAlias = true
    paintForSearch.textSize = paint.textSize

    doAfterTextChanged {

        val actualText = it.toString()

        if (width > 0) {

            val minCorrection = width - originalTextSize / 2

            paintForSearch.getTextBounds(actualText, 0, actualText.length, bounds)

            if (bounds.width() > minCorrection) {
                do {
                    paintForSearch.getTextBounds(actualText, 0, actualText.length, bounds)
                    if (bounds.width() > minCorrection) {
                        paintForSearch.textSize = max(paintForSearch.textSize - 1f, 10f)
                    }
                } while (bounds.width() > minCorrection)
            } else if (originalTextSize > paintForSearch.textSize) {
                do {
                    paintForSearch.getTextBounds(actualText, 0, actualText.length, bounds)
                    if (bounds.width() < minCorrection) {
                        paintForSearch.textSize = min(paintForSearch.textSize + 1f, originalTextSize)
                    }
                } while (bounds.width() < minCorrection && paintForSearch.textSize < originalTextSize)
            }
        }

        setTextSize(TypedValue.COMPLEX_UNIT_PX, paintForSearch.textSize)

        callback?.invoke(paintForSearch.textSize)
    }
}