Delete an Item from the Recyclerview + Local database [Kotlin]

Question

I'm using "Swipe to delete" to delete an item from the Recyclerview & local database. If I touch and pull the item in the recyclerview to the right corner - a AlertDialog with the question "Should I delete your item?" will appear. As soon as I press "yes" the item should be deleted. So far...

Two weeks ago this function works perfectly. But if I press now "yes" the whole app crashes. (I already had the latest Andorid Studio version and I didn't change anything in the code. In addition to that my Logcat says that the problem is "adapter.removeAt(viewHolder.adapterPosition)" but I actually don't know how to find a better solution.

PS: Without the AlertDialog the delete function works perfectly. So maybe something is wrong with the AlertDialog? (But I need something like the AlertDialog)

It would be so awesome if somebody could help me.

My Code: MainActivity (Where my Recyclerview is displayed)

fun setupTaskRecyclerView(tasklist: ArrayList<TaskModel>){
    rv_task_view.layoutManager = LinearLayoutManager(this)
    rv_task_view.setHasFixedSize(true)
    tasklist.sortByDescending { it.id }
    
    val taskAdapter = TaskAdapter(this, tasklist )
    rv_task_view.adapter = taskAdapter


        //SwipeToDelete-----------
    val deleteSwipeHandler = object : SwipeToDeleteCallback(this){
        override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
            val adapter = rv_task_view.adapter as TaskAdapter
            var test = false
       
            AlertDialog.Builder(this@MainActivity)
                .setCancelable(false)
                .setTitle("Delete entry")
                .setMessage("Should I delete your item?")
                .setPositiveButton("YES"){
                        _, _ ->

                    adapter.removeAt(viewHolder.adapterPosition)

                    getTaskListFromLocalDatabase()
                }
                .setNegativeButton("NO"){
                        dialog, _ ->
                    dialog.dismiss()
                    getTaskListFromLocalDatabase() 
                    }.show()
            
            //adapter.removeAt(viewHolder.adapterPosition)
            getTaskListFromLocalDatabase() 
        }

    }
    val deleteItemTouchHelper = ItemTouchHelper(deleteSwipeHandler)
    deleteItemTouchHelper.attachToRecyclerView(rv_task_view)
    //-----------SwipeToDelete

}

In my local database

fun removeAt( position: Int){
    val dbHandler = DatabaseHandler(context)
    val isDeleted = dbHandler.deleteTask(list[position])
    if (isDeleted > 0){
        list.removeAt(position)
        notifyItemRemoved(position)
    }

}

Logcat says:

2021-04-12 22:15:33.976 18122-18122/com.example.to_do E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.to_do, PID: 18122
java.lang.ArrayIndexOutOfBoundsException: length=10; index=-1
    at java.util.ArrayList.get(ArrayList.java:439)
    at TaskAdapter.removeAt(TaskAdapter.kt:182) //--> is this val isDeleted = dbHandler.deleteTask(list[position])
    at com.example.to_do.Activity.MainActivity$setupTaskRecyclerView$deleteSwipeHandler$1$onSwiped$1.onClick(MainActivity.kt:250) // --> is adapter.removeAt(viewHolder.adapterPosition)
    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:177)
    at android.os.Handler.dispatchMessage(Handler.java:107)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

2021-04-12 22:15:40.314 18122-18135/com.example.to_do W/System: A resource failed to call close.

Answer 1

As alert dialog shows, you window will get a pause and it may lead to some unexpected behavior like this, try to store position before opening the dialog like

        val targetPosition = viewHolder.adapterPosition
        
        AlertDialog.Builder(this@MainActivity)
            .setCancelable(false)
            .setTitle("Delete entry")
            .setMessage("Should I delete your item?")
            .setPositiveButton("YES"){
                    _, _ ->

                adapter.removeAt(targetPosition) //use it here

                getTaskListFromLocalDatabase()
            }