TextInputEditText.kt

class TextInputEditText : TextInputEditText {
    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
 
     /**
     * Copied from TextInputLayout implementation
     */
    private fun getTextInputLayout(): TextInputLayout? {
        var parent = parent
        while (parent is View) {
            if (parent is TextInputLayout) {
                return parent
            }
            parent = parent.getParent()
        }
        return null
    }

    private val updateLayoutLabelStateFunction by lazy {
        TextInputLayout::class.java.getDeclaredMethod("updateLabelState", Boolean::class.java)
            .apply { isAccessible = true }
    }

    private var _myHint: CharSequence? = null
    var myHint: CharSequence?
        get() = _myHint
        set(value) {
            _myHint = value
            hint = value
            getTextInputLayout()?.let { updateLayoutLabelStateFunction.invoke(it, true) }
        }

    override fun getText(): Editable? {
        val text = super.getText()
        if (!text.isNullOrEmpty())
            return text
        /* We want this expression in TextInputLayout.java to be true if there's a hint set:
         *        final boolean hasText = editText != null && !TextUtils.isEmpty(editText.getText());
         * But for everyone else it should return the real value, so we check the caller.
         */
        if (!myHint.isNullOrEmpty() && Thread.currentThread().stackTrace[3].className == TextInputLayout::class.qualifiedName)
            return SpannableStringBuilder(myHint)
        return text
    }
}