custom view generate data binding error when use it

Question

I have created a custom view as following

class SquareCheckBox @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyle: Int = 0) : ConstraintLayout (context, attrs, defStyle){

    private var layout: ConstraintLayout
    private var checkImageView : ImageView
    private var iconImageView : ImageView
    private var titleTextView : TextView

    var isChecked : Boolean = false
    var iconImage : Int = -1
    var title : String = ""

    init {

        val inflater = context.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
        val view = inflater.inflate(R.layout.item_square_checkbox, this, true)

        layout = view.layout
        checkImageView = view.checkImageView
        iconImageView = view.iconImageView
        titleTextView = view.titleTextView

        initAttributes(attrs)
        applyUIChanges()
        addAction()

    }

    fun initAttributes(attrs: AttributeSet?){

        attrs?.let {
            val typedArray = context.obtainStyledAttributes(it, R.styleable.square_checkbox_attributes, 0, 0)
            isChecked = typedArray.getBoolean(R.styleable.square_checkbox_attributes_isChecked, false)
            iconImage = typedArray.getResourceId(R.styleable.square_checkbox_attributes_iconImage, -1)
            title = typedArray.getString(R.styleable.square_checkbox_attributes_title)

            typedArray.recycle()
        }
    }

    fun applyUIChanges () {

        if (isChecked) {
            checkImageView.visibility = View.VISIBLE
            titleTextView.setTextColor(resources.getColor(android.R.color.black))
            layout.setBackgroundResource(R.drawable.xml_square_checkbox_selected)
        } else {
            checkImageView.visibility = View.INVISIBLE
            titleTextView.setTextColor(resources.getColor(R.color.lightGray))
            layout.setBackgroundResource(R.drawable.xml_square_checkbox_unselected)
        }

        if (iconImage != -1) {
            iconImageView.setImageResource(iconImage)
        }

        titleTextView.setText(title)
    }

    fun addAction () {

        layout.setOnClickListener(object : View.OnClickListener {
            override fun onClick(v: View?) {
                isChecked = !isChecked
                applyUIChanges()
            }
        })
    }
}

and this is the xml

<merge xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:app="http://schemas.android.com/apk/res-auto"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content">

    <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/layout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/xml_square_checkbox_unselected">

        <ImageView
                android:id="@+id/checkImageView"
                android:layout_width="20dp"
                android:layout_height="20dp"
                android:src="@drawable/ic_ckeck"
                android:tint="@color/colorPrimary"
                android:visibility="visible"
                app:layout_constraintEnd_toEndOf="parent"
                android:layout_marginTop="4dp"
                app:layout_constraintTop_toTopOf="parent"
                android:layout_marginEnd="4dp"
                android:layout_marginRight="4dp"/>

        <ImageView
                android:id="@+id/iconImageView"
                android:layout_width="35dp"
                android:layout_height="35dp"
                android:layout_centerHorizontal="true"
                android:src="@drawable/ic_placeholder_squre" app:layout_constraintTop_toBottomOf="@+id/checkImageView"
                app:layout_constraintBottom_toTopOf="@+id/titleTextView"
                app:layout_constraintEnd_toEndOf="parent" android:layout_marginEnd="8dp"
                android:layout_marginRight="8dp" app:layout_constraintStart_toStartOf="parent"
                android:layout_marginLeft="8dp" android:layout_marginStart="8dp"/>

        <TextView
                android:id="@+id/titleTextView"
                android:layout_width="90dp"
                android:layout_height="wrap_content"
                android:layout_below="@id/iconImageView"
                android:ellipsize="end"
                android:gravity="center"
                android:lines="2"
                android:text="@string/text"
                android:maxLines="2"
                android:textColor="@android:color/black"
                android:textSize="12sp"
                android:layout_marginBottom="4dp"
                android:layout_marginStart="4dp"
                android:layout_marginEnd="4dp"
                android:layout_marginRight="4dp"
                android:layout_marginTop="8dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/iconImageView"
                app:layout_constraintEnd_toEndOf="parent"
                />

    </androidx.constraintlayout.widget.ConstraintLayout>
</merge>

and now when i try to use my custom view in my MVVM like this

<com.playground.components.SquareCheckBox
                android:id="@+id/inAppMessageCheckBox"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:isChecked="@{viewModel.inAppEnabled}"
                app:iconImage="@drawable/ic_allow_inapp"
                app:title="@string/post_listing_settings_in_app_message"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintEnd_toStartOf="@+id/voipCheckBox" android:layout_marginStart="8dp"
                android:layout_marginEnd="8dp">

it gives me the following error

****/ data binding error ****msg:Cannot find the setter for attribute 'app:isChecked' with parameter type boolean on com.playground.components.SquareCheckBox. file:/Volumes/Data/Work/Amira_Playground/Playground/app/src/main/res/layout/recycler_view_basic_information_settings_item.xml loc:20:33 - 20:54 ****\ data binding error ****

can anyone please advice ?

Answer 1

Seems like it should work, but maybe there's a problem with setter's name/parameter resolving. The docs state that:

For an attribute named example, the library automatically tries to find the method setExample(arg) that accepts compatible types as the argument. The namespace of the attribute isn't considered, only the attribute name and type are used when searching for a method.

You can work this issue around easily with a custom binding adapter. See: https://developer.android.com/topic/libraries/data-binding/binding-adapters

Like this:

@BindingAdapter("isChecked")
fun setIsChecked(view: SquareCheckBox, checked: Boolean) {
    view.setChecked(checked)
}