How to make a simple onClickListener in my recyclerView?

Question

I'm a beginner here and I'm struggling to find a good explanation on how to make an onClickListener, I don't want to copy, I want to understand everything, as I'm already working hard on understanding the process of creating recyclerView

I am currently trying to create a Quiz application with levels. My recyclerView has a number of "cardViews" that represent each level. Basically, I want people to click on the first level, for example, to access a new activity (the game activity). And each of my levels will be directed to a game activity when they click on it. But I really don't understand how to do this simple thing... Thanks!

Here is my HomeActivity, my AdapterLvl and Data Class:

class HomeActivity : AppCompatActivity() {
lateinit var listLvl: RecyclerView

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_home)


    listLvl = findViewById<RecyclerView>(R.id.listLvl)

    val items = listOf(
        Lvl("First LVL", R.drawable.background_color),
        Lvl("Second LVL", R.drawable.background_color2),
        Lvl("Third LVL", R.drawable.background_color),
        Lvl("Fourth LVL", R.drawable.background_color2),
        Lvl("Fifth LVL", R.drawable.background_color),
        Lvl("Sixth LVL", R.drawable.background_color2),
        Lvl("Seventh LVL", R.drawable.background_color),
        Lvl("Eighth LVL", R.drawable.background_color2),
        Lvl("Ninth LVL", R.drawable.background_color),
        Lvl("Tenth LVL", R.drawable.background_color2),
    )
        listLvl.apply {
            layoutManager = LinearLayoutManager(this@HomeActivity)
            adapter = LvlAdapter(items)

        }

}

}

class LvlAdapter(var items: List<Lvl>) : RecyclerView.Adapter<LvlAdapter.LvlViewHolder>() {

val limit = 10;

inner class LvlViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    var titleLvl: TextView
    var buttonLvl: ImageView

    init {
        titleLvl = itemView.findViewById(R.id.titleLvl)
        buttonLvl = itemView.findViewById(R.id.buttonLvl)
    }

    fun bind(lvl: Lvl) {
        titleLvl.text = lvl.title
        buttonLvl.setImageResource(lvl.button)
    }

}
// return the viewHolder with the item view, but inflate from xml to view first
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): LvlViewHolder {
    val itemView = LayoutInflater.from(parent.context).inflate(R.layout.lvl_card, parent, false)
    return LvlViewHolder(itemView)

}
// what we bind in the viewHolder (ce qu'on injecte)
override fun onBindViewHolder(holder: LvlViewHolder, position: Int) {
    var lvl = items[position]
    holder.bind(lvl)

}
// return a size of the items
override fun getItemCount(): Int {
    if(items.size > limit){
        return limit
    } else {
    return items.size
}

} }

data class Lvl(
var title : String,
var button : Int

)

Same question https://stackoverflow.com/questions/53696176/kotlin-android-studio-handle-button-click-inside-recyclerview-adapter/53696352#53696352 — Alexander, May 25 '22 at 14:38
what @Alexander has linked here should be enough for you, you have multiple ways of getting context if you want to start the next activity, you can pass it in as a parameter or take it from one of the views you have here, this is most likely going to be the most simple solution you can find, till you learn a bit more and want to decouple your logic out of the adapter — a_local_nobody, May 25 '22 at 14:44
This is good solution for your learning -https://stackoverflow.com/questions/24471109/recyclerview-onclick — Sandesh Khutal, May 25 '22 at 15:58

score 0 · Answer 1 · answered May 26 '22 at 00:21

In your fragment, make a method that starts your activity

private fun openGameActivity() { 
    startActivity(Intent(context, GameActivity::class.java)) 
}

Now pass it to your adapter

class LvlAdapter(var items: List<Lvl>, private val openGameActivity: () -> Unit)

adapter = LvlAdapter(items, ::openGameActivity)

and to your ViewHolder

class LvlViewHolder(itemView: View, private val openGameActivity: () -> Unit)

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): LvlViewHolder {
    val itemView = LayoutInflater.from(parent.context).inflate(R.layout.lvl_card, parent, false)
    return LvlViewHolder(itemView, openGameActivity)
}

Finally, call the method when user clicks on whatever view you want

fun bind(lvl: Lvl) {
    titleLvl.text = lvl.title
    buttonLvl.setImageResource(lvl.button)
    buttonLvl.setOnClickListener {
        openGameActivity()
    }
}

@Célia Apologies, I should have said in your view class, whether that be an activity or a fragment. The same pattern can be applied in either case. — Cole Tustin, May 30 '22 at 22:00

How to make a simple onClickListener in my recyclerView?

1 Answers1