adding onclicklistener to recycler view with viewbinding, kotlin - kotlin

Question

Trying to add an onclicklistener to the items in my recycler view, that will use an intent to open another activity. I've tried finding examples, but I can only find examples using Java or Kotlin examples that aren't using viewbinding.
package com.truuce.anotherrvtest
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.recyclerview.widget.GridLayoutManager
import com.truuce.anotherrvtest.databinding.ActivityHeroBinding
class HeroActivity : AppCompatActivity() {
var binding: ActivityHeroBinding? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityHeroBinding.inflate(layoutInflater)
setContentView(binding?.root)
val adapter = CardAdapter(HeroList.heroList)
binding?.heroRV?.adapter = adapter
binding?.heroRV?.layoutManager = GridLayoutManager(applicationContext, 3)
}
override fun onDestroy() {
super.onDestroy()
binding = null
}
}
package com.truuce.anotherrvtest
import android.content.Context
import android.content.Intent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.truuce.anotherrvtest.databinding.HeroCardBinding
class CardAdapter(val heroList: List<Hero>) : RecyclerView.Adapter<CardAdapter.MainViewHolder>() {
inner class MainViewHolder(val heroBinding: HeroCardBinding) :
RecyclerView.ViewHolder(heroBinding.root) {
fun bindHero(hero: Hero){
heroBinding.heroNameTV.text = hero.heroName
heroBinding.heroIV.setImageResource(hero.image)
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MainViewHolder {
return MainViewHolder(HeroCardBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}
override fun onBindViewHolder(holder: MainViewHolder, position: Int) {
val hero = heroList[position]
holder.bindHero(hero)
}
override fun getItemCount() = heroList.size
}
tried adding View.OnClickListener to MainViewHolder, then implemented a member. OnClick(p0: View){}, but no idea how to get it working.

Answer 1

You should add a functional property for a click listener in your adapter.
The Activity can set the item click listener behavior.
class CardAdapter(
val heroList: List<Hero>,
val itemClickListener: (Hero)->Unit
) : RecyclerView.Adapter<CardAdapter.MainViewHolder>() {
inner class MainViewHolder(val heroBinding: HeroCardBinding) :
RecyclerView.ViewHolder(heroBinding.root) {
fun bindHero(hero: Hero) = with(heroBinding) {
heroNameTV.text = hero.heroName
heroIV.setImageResource(hero.image)
root.setOnClickListener { itemClickListener(hero) }
}
}
//...
}
// In Activity:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityHeroBinding.inflate(layoutInflater)
setContentView(binding?.root)
val adapter = CardAdapter(HeroList.heroList) { hero ->
// do something with hero item when it's clicked
}
binding?.heroRV?.adapter = adapter
binding?.heroRV?.layoutManager = GridLayoutManager(applicationContext, 3)
}