Unconditional layout inflation from view adapter. kotlin - android-layout

Question

I am getting following warning in Android Studio:
"Unconditional layout inflation from view adapter: Should use View Holder pattern (use recycled view passed into this method as the second parameter) for smoother scrolling." on inflater.inflate(R.layout.animal_ticket, null) line.
How do I fix the warning? I am not able to find solution for that problem.
Thanks!
override fun getView(p0: Int, p1: View?, p2: ViewGroup?): View {
val animal = listOfAnimals[p0]
val inflater = LayoutInflater.from(context)
var holder = ViewHolder()
val myView = inflater.inflate(R.layout.animal_ticket, null)
myView.tvName.text = animal.name!!
myView.tvDes.text = animal.description!!
myView.jvAnimalImage.setImageResource(animal.image!!)
return myView
}

Answer 1

If there was previously another View of the same view type (getItemViewType(position: Int) returned the same value) that scrolled off screen, the list view may pass in that instance as the second parameter to getView(). It will be faster to reuse that view than to inflate a new one.
You should also use the ViewHolder to cache things about the view, such as the relatively expensive findViewById(). You can attach it to and retrieve it from the view by tag.
override fun getView(position: Int, convertView: View?, parent: ViewGroup?) {
val animal = listOfAnimals[position]
val myView = convertView ?:
LayoutInflater.from(context).inflate(R.layout.animal_ticket, parent, false)
val holder = myView.tag as? ViewHolder ?: ViewHolder(myView)
myView.tag = holder
holder.tvName.text = animal.name!! // etc
}
class ViewHolder(view: View) {
val tvName: TextView = view.name // etc
}

Answer 2

For any RecyclerView, you need your own ViewHolder class that has all of the views listed inside animal_ticket.
Basically, it works like this:
1) Create ViewHolder that 'holds' all of the views of the item you want to display;
2) Bind the ViewHolder to the RecyclerView and assign values to the views inside;
Here is a example adapter I wrote :
class MyActivity : Activity() {
//users is the list we're going to use to get information for the views
val users = ArrayList<User>()
//...getting user information
//.. your activity stuff here
//Creating our adapter
/*
Note that to extend the RecyclerView.Adapter, you need to specify a
ViewHolder. The code becomes much easier to manage if you just put the
ViewHolder inside your adapter.
*/
inner class MyAdapter : RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
//This is the view holder
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
//Here you declare your views and get them from the itemView
//The itemView is one that is passed each time to the RecyclerView
//(the items inside your XML layout file)
internal val userImageView = itemView.findViewById(R.id.userImage)
internal val userFullName = itemView.findViewById(R.id.userName)
}
//This is where you return your own ViewHolder with your layout
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
//user_list_item.xml is below
val itemView = layoutInflater.inflate(R.layout.user_list_item, parent, false))
return MyViewHolder(itemView)
}
//In here is where you want to set your values for the views
override fun onBindViewHolder(holder: SentRequestViewHolder, position: Int) {
val currentUser = users[position]
holder.userImage.drawable = currentUser.drawable
holder.userFullName.text = currentUser.name
}
//You must override this method as well for the adapter to work properly
override fun getItemCount() = users.size
}
You have to override these methods when using a RecyclerView.Adapter
Here is the user_list_item.xml
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="100dp">
<ImageView
android:id="#+id/userImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<TextView
android:id="#+id/userName"
android:layout_below="#id/userImage"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</RelativeLayout>