Disappearing/Blank Ads -> Rendering API -> Banner API

[omertanveer]

Describe the bug
I am trying to do a basic implementation using the Rendering ApI -> Banner API as mentioned in the following link:
https://docs.prebid.org/prebid-mobile/modules/rendering/android-sdk-integration-pb.html

I am rendering the banner view in a recycler view, and the very first time it shows fine as expected.
But as soon as I send the app to the background and come back, the banner view for some reason just doesn't display anymore. The same problem also happens if I just scroll the recycler view, and then scroll back to the banner view.
It just doesn't show at all.

The only prebid logs that I can see happening in case when I send the app to the background and come back are as follow:
PrebidJsExecutor D evaluateJavaScript: mraid.onViewableChange(false);
PrebidWebViewCleanupRu D Unable to execute destroy on WebView. WebView is null.

The attached video shows the issue:
https://github.com/prebid/prebid-mobile-android/assets/3583890/ace0c27e-05f3-41b4-aa7f-79f8492d7776

I am using:
org.prebid:prebid-mobile-sdk-admob-adapters:2.2.0
com.google.android.gms:play-services-ads:23.0.0
Samsung SM-M315F Android version 12

Would be great if someone can shed some light on this.

[omertanveer]

Would be great if someone can shed some light here.
Also in the demos I am unable to find any example that is related to use of BannerView inside a Recycler View

[YuriyVelichkoPI]

Hi @omertanveer, sorry for the long silence. The described behaviour looks like a bug. Could you attach the simple project that reproduces the bug? You don't need to share any ad unit IDs or other parameters, we'll use our own one, but the app skeleton will be helpful.

[ValentinPostindustria]

Hello.
It seems like the Prebid SDK automatically removes the WebView with an ad when the view is detached from the window. It really looks like the implementation problem, and it should not behave like this. The banner must be reusable.

We will conduct further research to resolve this issue. But currently, you can try the approach with RecyclerView.Adapter.onViewAttachedToWindow listener.

    private fun setupRecycler() {
        val recyclerView = binding.recyclerView

        adapter = FeedAdapter(
            activity = this,
            items = buildList {
                repeat(3) { add(FeedItem.Placeholder) }
                add(FeedItem.Banner)
                repeat(6) { add(FeedItem.Placeholder) }
            }
        )

        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.adapter = adapter
        recyclerView.setHasFixedSize(false)
    }


private class FeedAdapter(
    private val items: List<FeedItem>,
    private val activity: Activity,
) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    private var bannerView: BannerView? = null

    private companion object {
        const val TYPE_PLACEHOLDER = 1
        const val TYPE_BANNER = 2
    }

    override fun getItemViewType(position: Int): Int = when (items[position]) {
        is FeedItem.Placeholder -> TYPE_PLACEHOLDER
        is FeedItem.Banner -> TYPE_BANNER
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        return when (viewType) {
            TYPE_PLACEHOLDER -> {
                val v = View(parent.context).apply {
                    layoutParams = RecyclerView.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT,
                        dp(parent, 500)
                    )
                    setBackgroundColor("#e0e0e0".toColorInt())
                }
                PlaceholderVH(v)
            }

            TYPE_BANNER -> {
                val container = FrameLayout(parent.context).apply {
                    layoutParams = RecyclerView.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT,
                        dp(parent, 50)
                    )
                    setBackgroundColor(Color.WHITE)
                }
                BannerVH(container)
            }

            else -> error("Unknown viewType=$viewType")
        }
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        when (items[position]) {
            is FeedItem.Placeholder -> Unit
            is FeedItem.Banner -> (holder as BannerVH).bind()
        }
    }

    override fun onViewAttachedToWindow(holder: RecyclerView.ViewHolder) {
        val bannerHolder = holder as? BannerVH ?: return
        bannerHolder.attachToWindow()
    }

    override fun onViewDetachedFromWindow(holder: RecyclerView.ViewHolder) {
        val bannerHolder = holder as? BannerVH ?: return
        bannerHolder.detachFromWindow()
    }

    override fun getItemCount(): Int = items.size

    override fun onViewRecycled(holder: RecyclerView.ViewHolder) {
        if (holder is BannerVH) {
            holder.unbind()
        }
        super.onViewRecycled(holder)
    }

    fun release() {
        Log.d("TESTV", "Release!!!")
        bannerView?.destroy()
        bannerView = null
    }

    private inner class PlaceholderVH(view: View) : RecyclerView.ViewHolder(view)

    private inner class BannerVH(private val container: FrameLayout) : RecyclerView.ViewHolder(container) {

        private var wasDetached = false

        fun bind() {
            if (bannerView == null) {
                bannerView = createBannerView()
            }
            val view = bannerView!!
            view.loadAd()
            if (view.parent !== container) {
                Log.d("TESTV", "New parent container")
                (view.parent as? ViewGroup)?.removeView(view)
                container.removeAllViews()
                container.addView(
                    view,
                    ViewGroup.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT,
                        ViewGroup.LayoutParams.WRAP_CONTENT
                    )
                )
            }
        }

        fun unbind() {
            Log.d("TESTV", "Unbind")
            container.removeAllViews()
        }

        fun attachToWindow() {
            Log.d("TESTV", "Attach to window")
            if (wasDetached) {
                Log.d("TESTV", "Reloading")
                wasDetached = false
                bannerView?.loadAd()
            }
        }

        fun detachFromWindow() {
            Log.d("TESTV", "Detach from window")
            wasDetached = true
        }

        private fun createBannerView(): BannerView {
            Log.d("TESTV", "Creating new banner view")
            val bannerView = BannerView(activity, "prebid-demo-banner-320-50", AdSize(320, 50))
            bannerView.setAutoRefreshDelay(30)
            return bannerView
        }
    }


}

private sealed interface FeedItem {
    data object Placeholder : FeedItem
    data object Banner : FeedItem
}