Setup margin/padding between different adapters in ConcatAdapter Android

Question

Is it possible to set up spaces (margin/padding) between different adapters in ConcatAdapter? I have just a simple sample of code, like below, but according to the design I have to add margin exactly between different adapters (not holder items in one adapter). What is the best way to achieve that?

val firstAdapter: FirstAdapter = …
val secondAdapter: SecondAdapter = …
val thirdAdapter: ThirdAdapter = …
val concatAdapter = ConcatAdapter(firstAdapter, secondAdapter, thirdAdapter)

recyclerView.adapter = concatAdapter

Probably, it is one of the possible solutions, but definitely not the best. — Michael Abyzov, Jul 12 '21 at 09:40
I've solved this similarly as @pop suggested (I think, it should be a solution for the question): just add emptySpaceAdapter (or holder if you have just one adapter) there. — Michael Abyzov, Jul 29 '21 at 10:31

score 2 · Accepted Answer · answered Jul 29 '21 at 13:54

I managed to do something like this:

class EmptySpaceAdapter(private val context: Context, private val height: Int) : RecyclerView.Adapter<BaseViewHolder<*>>() {

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<*> {
    val view = View(context)
    view.layoutParams = ViewGroup.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, height)
    return EmptySpaceViewHolder(view)
}

override fun getItemCount() = 1

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)

override fun onBindViewHolder(holder: BaseViewHolder<*>, position: Int) {
    when (holder) {
        is EmptySpaceViewHolder -> holder.bind(true, position)
        else -> throw IllegalArgumentException("No view holder to show this data, did you forgot to add it to the onBindViewHolder?")
    }
}

inner class EmptySpaceViewHolder(itemView: View) : BaseViewHolder<Boolean>(itemView) {
    override fun bind(item: Boolean, position: Int) {
        Timber.d("onBind empty space")
    }
  }
}

ViewHolder:

abstract class BaseViewHolder<T>(itemView: View) : RecyclerView.ViewHolder(itemView) {
    abstract fun bind(item: T, position: Int)
}

Setup margin/padding between different adapters in ConcatAdapter Android

1 Answers1