EditTextWithError.kt

class EditTextWithError(
    context: Context,
    attributeSet: AttributeSet
):FrameLayout(context,attributeSet) {

    private var errorText = ""
    private var linearLayout:LinearLayout
    private var editText:EditText
    private var linearLayoutWidth = WRAP_CONTENT
    private var linearLayoutHeight = WRAP_CONTENT
    private var linearLayoutMinWidth: Int?=null
    private var hint = ""

    init {

        linearLayoutWidth = attributeSet.getAttributeValue("http://schemas.android.com/apk/res/android", "layout_width").toIntOrNull() ?: 0
        linearLayoutHeight = attributeSet.getAttributeValue("http://schemas.android.com/apk/res/android", "layout_height").toIntOrNull() ?: 0
        linearLayoutMinWidth = attributeSet.getAttributeValue("http://schemas.android.com/apk/res/android", "minWidth").toIntOrNull()
        if (linearLayoutMinWidth!=null){
            linearLayoutWidth = linearLayoutMinWidth!!
        }
        hint = attributeSet.getAttributeValue("http://schemas.android.com/apk/res/android", "hint")

        linearLayout = LinearLayout(context)
        linearLayout.orientation = LinearLayout.VERTICAL

        val relativeLayout = RelativeLayout(context)
        relativeLayout.background = ContextCompat.getDrawable(context,R.drawable.rounded_gray_bg)
        relativeLayout.setPadding(dpToPx(16f), dpToPx(16f), dpToPx(16f),dpToPx(16f).toInt())

        editText = EditText(context)
        editText.background = null
        editText.hint = hint
        editText.setPadding(0,0,0,0)
        relativeLayout.addView(editText, linearLayoutWidth, linearLayoutHeight)
        linearLayout.addView(relativeLayout, linearLayoutWidth, linearLayoutHeight)

        context.obtainStyledAttributes(attributeSet,R.styleable.EditTextWithError).let {
            errorText = it.getString(R.styleable.EditTextWithError_error).orEmpty()

            showError(errorText)

            addView(linearLayout,linearLayoutWidth, linearLayoutHeight)

            it.recycle()
        }
    }

    fun showError(error:String){
        errorText = error

        if (errorText.isNotEmpty()){
            val errorTextView = AppCompatTextView(context)
            errorTextView.text = errorText
            errorTextView.setTextColor(ContextCompat.getColor(context,R.color.orange))
            errorTextView.textSize = 14f
            errorTextView.setPadding(dpToPx(4f), dpToPx(8f),0,0)
            if (linearLayout[linearLayout.childCount - 1] !is TextView){
                linearLayout.addView(errorTextView, WRAP_CONTENT, WRAP_CONTENT)
            }

        }
    }

    private fun dpToPx(dp:Float): Int {
        val displayMetrics: DisplayMetrics = context.resources.displayMetrics
        return (dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
    }

}