How to set app:icon dynamically with data binding?

Question

I have this XML:

<Button
     android:id="@+id/btn_default"
     app:icon="@{model.actionBarData.myDynamicIcon}" />

And I have this method and LiveData in my model's actionBarData to set the icon programmatically:

private var _myDynamicIcon = MutableLiveData<Int>()
val myDynamicIcon: LiveData<Int>
    get() = _myDynamicIcon


// Called by some logic in my app

fun setMyDynamicIcon() {
    _myDynamicIcon.value = when (status) {
        status.STATUS1 -> R.drawable.icon1
        status.STATUS2 -> R.drawable.icon2
        status.STATUS3 -> R.drawable.icon3
    }
}

I want the icon to change when setMyDynamicIcon is called. However I get error:

Cannot find a setter for <android.widget.Button app:icon> that accepts parameter type 'androidx.lifecycle.LiveData<java.lang.Integer>'

I also tried storing a Drawable object in myDynamicIcon, this did not work either (same error but with Drawable type).

How can I set the app:icon via data binding?

Answer 1

Thx @generatedAcc.x09218. Final code using Binding Adapters:

XML:

 <Button
       android:id="@+id/btn_default"
       app:dynamicIcon="@{model.actionBarData.status}" />

Adapter:

@BindingAdapter("dynamicIcon")
fun View.setDynamicIcon(status: Status?) {
    status?.let {
        val iconResource = when(status) {
            Status.STATUS1 -> R.drawable.ic_1
            Status.STATUS2 -> R.drawable.ic_2
            Status.STATUS3 -> R.drawable.ic_3
        }

        (this as MaterialButton).setIconResource(iconResource)
    }
}

LiveData:

    private var _status = MutableLiveData<Status>()
    val status: LiveData<Status>
        get() = _status

    fun setStatus(status: Status) {
        _status.value = status
    }

The icon changes on setStatus call.