Is there any way to use multiple LayoutManagers with MergeAdapter in a RecyclerView?

user_10870164 0
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I'm working with MergeAdapter (A.K.A ConcatAdapter)

https://medium.com/androiddevelopers/merge-adapters-sequentially-with-mergeadapter-294d2942127a

But what I need to do is that the first Adapter should show a gridlayout and the second one a linearlayout, so , if I do it like this

 val headerAdapter = HeaderAdapter(requireContext(), Header("TestHeader"))
        val dividerViewAdapter = DividerViewAdapter(requireContext())
        val animalAdapter = DividerViewAdapter(requireContext(),DataSource.animalList) // -> this should be shown as a GridLayout
        val mergeAdapter = MergeAdapter(headerAdapter,dividerViewAdapter,animalAdapter)
        test_rv.layoutManager = LinearLayoutManager(requireContext())
        test_rv.adapter = mergeAdapter

Now this code works fine, but since it has a linearlayoutmanager all the content will be shown as a LinearLayout in which my animalAdapter will not display as I want.

Is there anyway to setup different layoutmanagers for the different adapters to show the data in the way I want ?

android-fragments android-recyclerview android-adapter kotlin android
3 Answers

Actually there is here's how i solved it :

    class HorizontalContainerAdapter(private val lifecycleOwner: LifecycleOwner, val adapter : ListAdapter<*, *>) :
ListAdapter<String, HorizontalContainerAdapter.Holder>(diffCallback) {

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Holder {
    val inflater = LayoutInflater.from(parent.context)
    return Holder(DataBindingUtil.inflate(inflater, R.layout.item_horizontal_container, parent, false), adapter)
}

override fun onBindViewHolder(holder: Holder, position: Int) {
    holder.binding.lifecycleOwner = lifecycleOwner
}

override fun getItemViewType(position: Int): Int {
    return R.layout.item_horizontal_container
}

override fun getItemCount(): Int {
     return 1
}

class Holder(val binding: ItemHorizontalContainerBinding, adapter: ListAdapter<*, *>) : RecyclerView.ViewHolder(binding.root) {

    init {
        binding.recyclerView.layoutManager = LinearLayoutManager(binding.recyclerView.context, LinearLayoutManager.HORIZONTAL, false)
        binding.recyclerView.adapter = adapter
    }
}

companion object {
    val diffCallback by lazy {
        object :
            DiffUtil.ItemCallback<String>() {

            override fun areItemsTheSame(oldItem: String, newItem: String): Boolean {
                return oldItem == newItem
            }

            override fun areContentsTheSame(oldItem: String, newItem: String): Boolean {
                return oldItem == newItem
            }
        }
    }
}

Mergeadapter / ConcatAdapter with Horizontal and Vertical Layouts

Best Of luck

user_106830490

No, there's not a way to have multiple LayoutManagers associated with one RecyclerView. The LayoutManager is for the entire RecyclerView, and is not associated with the Adapter. To put it another way: the adapter doesn't have a layout manager; instead the RecyclerView has a layout manager, and it also has an adapter.

If this were not the case, the behavior would get very strange if, say, it switched from a GridLayoutManager to a LinearLayoutManager in the middle of a row.

For your particular scenario, a row (for a vertical list) or column (for a horizontal list) in a linear layout is the same as an item in a grid with a span count equal to the number of spans, so you can simply use a GridLayoutManager for the entire RecyclerView if you set the span counts correctly.

user_2082730

GridLayoutManager.setSpanSizeLookup is very useful for similar situations. Instead of using the multipe layout managers, you can use GridLayoutManager.

For example, when I add 1 vertical, 3 horizontal and then 4 vertical objects one after the other, the code will be as follows:

ConcatAdapter concatAdapter = new ConcatAdapter(
        verticalItemAdapter, // contains  1 vertical item
        horizontalItemAdapter, // contains 3 horizontal items
        verticalItemAdapter, // contains 4 vertical items
);
int verticalSpanCount = 1;
int horizontalSpanCount = 3;

GridLayoutManager layoutManager = new GridLayoutManager(context, horizontalSpanCount);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
    @Override
    public int getSpanSize(int position) {
        return concatAdapter.getWrappedAdapterAndPosition(position).first instanceof HorizontalItemAdapter
                ? verticalSpanCount 
                : horizontalSpanCount;
    }
});
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(concatAdapter);
user_119531960
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