RecyclerMultipleAdapter.kt

package com.lydia.custom.recycler

import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import java.lang.reflect.ParameterizedType

/**
 * WARNING !
 *
 * Please annotate all the view holder used on children of this class with [androidx.annotation.Keep]
 * See [com.lydia.adapter.RecipientListAdapter.ContactViewHolder]
 *
 *
 */
abstract class RecyclerMultipleAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
    val onClickListeners: HashMap<Class<*>, OnItemClickListener<*>> = HashMap()
    val onLongClickListeners: HashMap<Class<*>, OnLongItemClickListener<*>> = HashMap()

    @Suppress("UNCHECKED_CAST")
    abstract class ViewTypeBinder<Entity, VH : RecyclerView.ViewHolder>(val layoutId: Int) {
        abstract fun onBindViewType(entity: Entity, holder: VH)

        internal fun bindViewType(entity: Any, holder: RecyclerView.ViewHolder) {
            onBindViewType(entity as Entity, holder as VH)
        }

        internal val entityClazz = (this.javaClass.genericSuperclass as ParameterizedType).actualTypeArguments[0] as Class<Entity>
        internal val holderClazz = (this.javaClass.genericSuperclass as ParameterizedType).actualTypeArguments[1] as Class<VH>
    }

    protected val items = ArrayList<Any>()

    abstract val typeBinders: List<ViewTypeBinder<*, *>>

    protected inline fun <Entity, VH : RecyclerView.ViewHolder> binder(layoutId: Int, crossinline onBindType: (Entity, VH) -> Unit): ViewTypeBinder<Entity, VH> {
        return object : ViewTypeBinder<Entity, VH>(layoutId) {
            override fun onBindViewType(entity: Entity, holder: VH) {
                onBindType.invoke(entity, holder)
            }
        }
    }

    @Suppress("UNCHECKED_CAST")
    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val entity = items[position]
        val typeBinderIndex = getItemViewType(position)

        check(typeBinderIndex != -1) { "A type binder was not found at position $position" }

        val typeBinder = typeBinders[typeBinderIndex]

        typeBinder.bindViewType(entity, holder)

        onClickListeners[typeBinder.entityClazz]?.let {
            holder.itemView.setOnClickListener {
                (onClickListeners[typeBinder.entityClazz] as OnItemClickListener<Any>?)?.onItemClick(entity)
            }
        }

        onLongClickListeners[typeBinder.entityClazz]?.let {
            holder.itemView.setOnLongClickListener {
                (onLongClickListeners[typeBinder.entityClazz] as OnLongItemClickListener<Any>?)?.onLongItemClick(entity)
                true
            }
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val binder = typeBinders[viewType]
        if (binder.holderClazz == RecyclerView.ViewHolder::class.java) {
            return object : RecyclerView.ViewHolder(LayoutInflater.from(parent.context).inflate(binder.layoutId, parent, false)) {}
        }
        return binder.holderClazz.declaredConstructors[0].newInstance(LayoutInflater.from(parent.context).inflate(binder.layoutId, parent, false)) as RecyclerView.ViewHolder
    }

    override fun getItemCount() = items.size

    open fun setItems(items: List<Any>) {
        this.items.clear()
        this.items.addAll(items)
        notifyDataSetChanged()
    }

    fun addItems(items: List<Any>) {
        this.items.addAll(items)
        notifyDataSetChanged()
    }

    override fun getItemViewType(position: Int): Int {
        return typeBinders.indexOfFirst { it.entityClazz == items[position].javaClass }
    }

    inline fun <reified Entity> addOnClickListener(crossinline listener: (Entity) -> Unit) {
        onClickListeners[Entity::class.java] = object : OnItemClickListener<Entity> {
            override fun onItemClick(entity: Entity) {
                listener.invoke(entity)
            }
        }
    }

    inline fun <reified Entity> addOnLongClickListener(crossinline listener: (Entity) -> Boolean) {
        onLongClickListeners[Entity::class.java] = object : OnLongItemClickListener<Entity> {
            override fun onLongItemClick(entity: Entity): Boolean {
                return listener.invoke(entity)
            }
        }
    }

    interface OnItemClickListener<Entity> {
        fun onItemClick(entity: Entity)
    }

    interface OnLongItemClickListener<Entity> {
        fun onLongItemClick(entity: Entity): Boolean
    }
}