how do i update items that change in recyclerview use diffutil? - android-recyclerview

Question

DiffUtil do not update items recyclerview with the same id and not same the content,
The model has [id : Int and title : String]. I want to the diffUtilCallBack check items with the same id and not same title and update to recyclerview
Please help me fix it
my DiffUtil CallBAck
class DiffCB(
val oldl : ArrayList<Test>,
val newl : ArrayList<Test>
) : DiffUtil.Callback() {
override fun getOldListSize(): Int {
return oldl.size
}
override fun getNewListSize(): Int {
return newl.size
}
override fun areItemsTheSame(oldItemPos: Int, newItemPos: Int): Boolean {
return oldl[oldItemPos].id == newl[newItemPos].id
}
override fun areContentsTheSame(oldItemPos: Int, newItemPos: Int): Boolean {
return oldl[oldItemPos].title.equals(newl[newItemPos].title)
}
}
my Adapter.kt
class TestAdapter(val click: TestClick) :
RecyclerView.Adapter<TestAdapter.TestVH>() {
var list: ArrayList<Test> = ArrayList()
inner class TestVH(val bin: ItemTestBinding) : RecyclerView.ViewHolder(bin.root) {
fun bind(test: Test) {
bin.tvTestId.text = "[id: ${test.id}]"
bin.tvTestTitle.text = test.title
bin.cbTest.isChecked = test.select
bin.cbTest.setOnClickListener {
click.click(test)
}
}
}
fun sumbitData(newl: ArrayList<Test>) {
val diff = DiffCB(this.list, newl)
val diffResult = DiffUtil.calculateDiff(diff)
list.clear()
this.list.addAll(newl)
diffResult.dispatchUpdatesTo(this)
}
override fun getItemCount(): Int {
return list.size
}
override fun onBindViewHolder(holder: TestVH, position: Int) {
holder.bind(list[position])
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TestVH {
return TestVH(ItemTestBinding.inflate(LayoutInflater.from(parent.context),
parent, false))
}
}
my Activity.kt
class TestActivity : AppCompatActivity(), TestClick {
private var list : ArrayList<Test> = ArrayList()
private lateinit var bin : ActivityTestBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
bin = ActivityTestBinding.inflate(layoutInflater)
setContentView(bin.root)
val viewModel = ViewModelProviders.of(this).get(TestViewModel::class.java)
val manager = LinearLayoutManager(this)
bin.rvTest.layoutManager = manager
val adapter = TestAdapter(this)
bin.rvTest.adapter = adapter
//init first data
viewModel.setTests(initData())
viewModel.getTests().observe(this, Observer {
adapter.sumbitData(it as ArrayList<Test>)
})
bin.btnTest.setOnClickListener{
viewModel.setTests(updateData())
}
}
fun updateData() : ArrayList<Test> {
for (i in 2..6) {
var test = Test()
test.id = i
test.title = "title test $i update"
list.add(test)
}
return list
}
fun initData() : ArrayList<Test> {
for (i in 1..3) {
var test = Test()
test.id = i
test.title = "title test $i"
list.add(test)
}
return list
}
override fun click(test: Test) {
Toast.makeText(this, "${test.id} ${test.title}", Toast.LENGTH_SHORT).show()
}
}
it is first data
after update data, items with the same id have not been updated (id 2, 3)