Custom Grid Layout Setup

package com.blogspot.kidsmaths.ui.dashboard


import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.navigation.findNavController
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.ListAdapter
import androidx.recyclerview.widget.RecyclerView
import com.blogspot.kidsmaths.GameType
import com.blogspot.kidsmaths.databinding.DashboardListItemBinding
import com.blogspot.kidsmaths.databinding.ListItemDashboardHeaderBinding
import com.blogspot.kidsmaths.models.GameHeader
import com.blogspot.kidsmaths.models.GameItem
import com.blogspot.kidsmaths.models.GameItemType

class DashboardListAdapter :
    ListAdapter<GameItemType, RecyclerView.ViewHolder>(DashboardListDiff()) {
    companion object {
        private const val HEADER = 0
        private const val ITEM = 1

    }

    class DashboardListDiff : DiffUtil.ItemCallback<GameItemType>() {
        override fun areItemsTheSame(oldItem: GameItemType, newItem: GameItemType): Boolean {
            return oldItem.id == newItem.id
        }

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

    }

    override fun getItemViewType(position: Int): Int {
        return when (getItem(position)) {
            is GameItemType.ITEM -> ITEM
            is GameItemType.HEADER -> HEADER
        }
    }

    class ItemViewHolder(private val binding: DashboardListItemBinding) :
        RecyclerView.ViewHolder(binding.root) {
        fun bind(item: GameItem) {
            binding.imgDataItem.setImageResource(item.image)
            binding.tvDataName.text = item.type.name
            binding.root.setOnClickListener {
                val directions = if (item.type == GameType.EXAM) {
                    DashboardFragmentDirections.actionDashboardFragmentToCompetitiveExamsFragment2()
                } else {
                    DashboardFragmentDirections.actionDashboardFragmentToGameFragment(item.type)
                }
                binding.root.findNavController().navigate(directions)
            }
        }

        companion object {
            fun from(parent: ViewGroup): ItemViewHolder {
                val view = DashboardListItemBinding.inflate(
                    LayoutInflater.from(parent.context),
                    parent,
                    false
                )
                return ItemViewHolder(view)
            }
        }
    }

    class HeaderViewHolder(private val binding: ListItemDashboardHeaderBinding) :
        RecyclerView.ViewHolder(binding.root) {
        fun bind(data: GameHeader) {
            binding.data = data
        }

        companion object {
            fun from(parent: ViewGroup): HeaderViewHolder {
                val view = ListItemDashboardHeaderBinding.inflate(
                    LayoutInflater.from(parent.context),
                    parent,
                    false
                )
                return HeaderViewHolder(view)
            }
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView
    .ViewHolder {
        return when (viewType) {
            HEADER -> HeaderViewHolder.from(parent)
            ITEM -> ItemViewHolder.from(parent)
            else -> throw ClassCastException("Unable to cast to videotape : $viewType")
        }
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        when (holder) {
            is ItemViewHolder -> holder.bind((getItem(position) as GameItemType.ITEM).data)
            is HeaderViewHolder -> holder.bind((getItem(position) as GameItemType.HEADER).data)
        }
    }
}

class DashboardSpanSizeLookup(private val list: List<GameItemType>) :
    GridLayoutManager.SpanSizeLookup() {
    override fun getSpanSize(position: Int): Int {
        return when (list[position]) {
            is GameItemType.HEADER -> 2
            is GameItemType.ITEM -> 1
            else -> 1
        }
    }
}