Recycler view not updating properly

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I have asked this similar questions multiple times and its been more than 2 weeks that I am trying to figure out a solution for it. Yes, I am aware that there are multiple similar question but the reason why I am asking is because none of the solutions from stack over flow work.I am a beginner in Android development, hence I ask you to kindly help me with this problem. I have almost given up on my project.

How app works

App has two activities. Main activity is used for showing data in form of card views using recycler view which is loaded from SQ Lite DB. User can click on a card which on clicking will launch a new activity(REFERENCE ACTIVITY). Data of clicked card is loaded in second activity. Here user can perform UPDATE or DELETE function.

PROBLEM

The problem is that I have to restart my app just to see a change in a note. For example, if I create a note in second activity and return to main activity, that CREATED note is NOT visible until app is restarted. Same goes for when a note is updated or deleted. Change only occurs when app is restarted.

What I have tried so far...

  • called notifyDataSetChanged() in onRestart() of MAIN activity.

  • Recalled whole load that loads recycler view items in first place in onRestart()

  • Tried updating adapter with the new data

----- CODES -----

MAIN ACTIVITY

class MainActivity : AppCompatActivity() {

var dbHandler: PediaDatabase = PediaDatabase(this)
var adapter: PediaAdapter? = null
var newAdapter: PediaAdapter? = null
var layoutManager: RecyclerView.LayoutManager? = null
var list: ArrayList<UserNotes>? = ArrayList()
var listItems: ArrayList<UserNotes>? = ArrayList()
var updatedList: ArrayList<UserNotes> = ArrayList()
var tempList: ArrayList<UserNotes>? = null
var myPrefs: SharedPreferences? = null
var first_run: Boolean = true
var isCreated: Boolean = false
var isUpdated: Boolean = false
var isDeleted: Boolean = false
var isReturning: Boolean = false

var updatedTitle: String? = null
var updatedText: String? = null

val PREFS_NAME: String = "MYPREFS"
val REQUEST_CODE: Int = 1


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

     showOneTimeMessage()
     invalidateOptionsMenu()

    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
    {
        window.navigationBarColor = Color.BLACK
    }

}

override fun onRestart() {
    super.onRestart()

    if(isUpdated)
    {
        recyclerViewID.recycledViewPool.clear()
        var test = listItems!![adapPos]
        test.noteTitle = updatedTitle
        test.noteText = updatedText
        listItems!!.set(adapPos, test)
        adapter!!.notifyItemChanged(adapPos)

        isUpdated = false
    }
}


override fun onStart() {
    super.onStart()

    if(isReturning)
    {
        adapter!!.updateResults(this.listItems!!)
        adapter!!.notifyDataSetChanged()
    }

    adapter = PediaAdapter(this, listItems!!)
    layoutManager = LinearLayoutManager(this)

    recyclerViewID.adapter = adapter
    recyclerViewID.layoutManager = layoutManager


    list = dbHandler.readAllNotes()

    for(reader in list!!.iterator())
    {
        var note = UserNotes()

        note.noteTitle = reader.noteTitle
        note.noteText = reader.noteText
        note.noteID = reader.noteID
        note.noteDate = reader.noteDate

        listItems!!.add(note)
    }

    adapter!!.notifyDataSetChanged()


    if(dbHandler.totalNotes() == 0) {
        recyclerViewID.visibility = View.GONE
    }
    else{
        recyclerViewID.visibility = View.VISIBLE
        showWhenEmptyID.visibility = View.GONE
    }
    recyclerViewID.hasFixedSize()
}





override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)

    if(requestCode == REQUEST_CODE)
        if(resultCode == Activity.RESULT_OK)
        {
            //isCreated = data!!.extras!!.getBoolean("isCreated")

            updatedTitle = data!!.extras.getString("updatedTitle")
            updatedText = data!!.extras.getString("updatedText")

            isReturning = data.extras!!.getBoolean("returningBack")
           // isUpdated = data.extras!!.getBoolean("isUpdated")
        }
}


override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    menuInflater.inflate(R.menu.top_menu, menu)

    val item = menu!!.findItem(R.id.delete_note_menu)
    item.setVisible(false)
    return true
}

override fun onOptionsItemSelected(item: MenuItem?): Boolean {

    if(item!!.itemId == R.id.add_note_menu){

        isNewNote = true
        startActivity(Intent(this, ReferenceActivity::class.java))
    }

    if(item!!.itemId == R.id.delete_note_menu)
    {

        Toast.makeText(this,"DELETED", Toast.LENGTH_SHORT).show()
    }

    return super.onOptionsItemSelected(item)
}

private fun showOneTimeMessage()
{
    var data: SharedPreferences = getSharedPreferences(PREFS_NAME, 0)
    if(data.contains("isShown"))
    {
        first_run = data.getBoolean("isShown", true)
    }


    Log.d("FIRST_RUN", first_run.toString())

    if(first_run)
    {
        val oneTimeMsg = SweetAlertDialog(this)
        oneTimeMsg.setTitleText("Hey there!")
        oneTimeMsg.setContentText("Thank you for downloading! Please don`t forget to rate our app :)").show()

        oneTimeMsg.setConfirmClickListener(object : SweetAlertDialog.OnSweetClickListener
        {

            override fun onClick(sweetAlertDialog: SweetAlertDialog?)
            {
                oneTimeMsg.dismissWithAnimation()
            }
        }).show()


        myPrefs = getSharedPreferences(PREFS_NAME, 0)
        var editor: SharedPreferences.Editor = (myPrefs as SharedPreferences).edit()
        editor.putBoolean("isShown", false)
        editor.commit()

    }
}

REFERENCE ACTIVITY

class ReferenceActivity : AppCompatActivity() {

var dbHandler: PediaDatabase? = null
var note = UserNotes()

var noteExisted: Boolean = false
var cardAdapterPos: Int? = null

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

    getSupportActionBar()!!.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM)
     getSupportActionBar()!!.setCustomView(R.layout.custom_toolbar)
      val dateTxtView = findViewById<View>(resources.getIdentifier("action_bar_title", "id", packageName)) as TextView


    overridePendingTransition(R.anim.slide_in, R.anim.slide_out)

    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
        window.navigationBarColor = Color.BLACK


    dbHandler = PediaDatabase(this)
    val data = intent
        if(isNewNote != true/*isNewNote.extras.getBoolean("isNewNote") != true*/)
        {
            getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN)

            if(data != null)
            {
                noteExisted = true

                this.cardAdapterPos = data.extras.getInt("cardPosition")
                cardID = data.extras.getInt("cardID")


                existingNote = dbHandler!!.readNote(cardID)

                refTitleID.setText(existingNote.noteTitle, TextView.BufferType.EDITABLE)
                refTextID.setText(existingNote.noteText, TextView.BufferType.EDITABLE)
                dateTxtView.text = existingNote.noteDate.toString()
            }
        }else{
            dateTxtView.text = "New note"
        }
}

override fun onStop() {
    super.onStop()


    var title: String = refTitleID.text.toString().trim()
    var text: String = refTextID.text.toString().trim()

    if(existingNote.noteText == text && existingNote.noteTitle == title)
        finish()

    if(noteExisted)
    {
        if(TextUtils.isEmpty(title))
            title = "No title"


        existingNote.noteTitle = title
        existingNote.noteText = text
        existingNote.noteDate = System.currentTimeMillis().toString() //TODO TRY THIS


        dbHandler!!.updateNote(existingNote)

        var dataCreate = this.intent
        dataCreate.putExtra("isUpdated", true)
        dataCreate.putExtra("updatedTitle", title)
        dataCreate.putExtra("updatedText",text)
        dataCreate.putExtra("returningBack", true)
        setResult(Activity.RESULT_OK, dataCreate)


        finish()
    }
    else
    {
        if(TextUtils.isEmpty(title) && TextUtils.isEmpty(text))
        {
            finish()
        }
        else
        {
            if(TextUtils.isEmpty(title))
                title = "No title"

            note.noteTitle = title
            note.noteText = text
            note.noteDate = System.currentTimeMillis().toString()
           // note.noteID =

            dbHandler!!.createNote(note)

            var dataCreate = this.intent
            dataCreate.putExtra("isCreated", true)
            dataCreate.putExtra("returningBack", true)
            setResult(Activity.RESULT_OK, dataCreate)

            finish()
        }
    }
}


override fun onCreateOptionsMenu(menu: Menu?): Boolean {

    menuInflater.inflate(R.menu.top_menu, menu)
    val addItem: MenuItem = menu!!.findItem(R.id.add_note_menu)
    val delItem:MenuItem = menu.findItem(R.id.delete_note_menu)


    addItem.setVisible(false)
    delItem.setVisible(false)

    if(noteExisted)
        delItem.setVisible(true)

    return true
}

override fun onOptionsItemSelected(item: MenuItem?): Boolean {

    if(item!!.itemId == R.id.delete_note_menu)
    {
        val dialogMsg = SweetAlertDialog(this, SweetAlertDialog.WARNING_TYPE)
        dialogMsg.setTitleText("Are you sure?")
        dialogMsg.setContentText("You won`t be able to recover this note!")
        dialogMsg.setConfirmText("Yes, delete it!")

        dialogMsg.setConfirmClickListener(object: SweetAlertDialog.OnSweetClickListener {

            override fun onClick(sweetAlertDialog: SweetAlertDialog?) {
                dialogMsg.dismissWithAnimation()


                dbHandler!!.deleteNote(cardID)


                val successMsg = SweetAlertDialog(sweetAlertDialog!!.context, SweetAlertDialog.SUCCESS_TYPE)
                successMsg.setTitleText("Note deleted!")
                successMsg.setContentText("So long,note").show()
                successMsg.setCancelable(false)

                //TODO Disable 'OK' button on successMsg dialogbox

                Handler().postDelayed({
                    successMsg.dismissWithAnimation()
                    finish()
                }, 1200)

            }
        }).show()

    }
    return super.onOptionsItemSelected(item)
}

ADAPTER

class PediaAdapter(private val context: Context,
               private var noteslist: ArrayList<UserNotes>): RecyclerView.Adapter<PediaAdapter.ViewHolder>() {

override fun onCreateViewHolder(p0: ViewGroup, p1: Int): ViewHolder
{
    val view = LayoutInflater.from(context).inflate(R.layout.list_row,p0,false)

    return ViewHolder(view, noteslist)
}

override fun getItemCount(): Int
{
    return noteslist.size
}

override fun onBindViewHolder(p0: ViewHolder, p1: Int)
{
    p0.bindItems(noteslist[p1])
}

inner class ViewHolder(itemView: View, list: ArrayList<UserNotes>): RecyclerView.ViewHolder(itemView), View.OnClickListener
{
    private var noteTitle = itemView.findViewById(R.id.listTitleID) as TextView
    private var noteText = itemView.findViewById(R.id.listTextID) as TextView

    var mList = list


    init
    {
        itemView.setOnClickListener(this)
    }

    fun bindItems(note: UserNotes)
    {
        //var id = note.noteID
        noteTitle.text = note.noteTitle
        noteText.text = note.noteText
    }

    override fun onClick(v: View?)
    {

        var mPosition: Int =  adapterPosition //For forwarding position to ref activity
        var note = mList[mPosition]
        adapPos = adapterPosition


        var cardID = Intent(itemView.context, ReferenceActivity::class.java)
        cardID.putExtra("cardPosition", mPosition)
        cardID.putExtra("cardID", note.noteID) //TODO THIS IS FETCHING NOTE_ID VALUES FROM DB

        Toast.makeText(itemView.context, "card id = " + note.noteID, Toast.LENGTH_SHORT).show()

        itemView.context.startActivity(cardID)
    }

}

fun updateResults(items: ArrayList<UserNotes>)
{
    this.noteslist = items
}

Yes, I know its hard to go through someones code. I have tried to fix it many times sitting all day trying to figure it out and still no luck. I am requesting you to please help me with this. I don't care if you do in Java, I just need a way to fix it.

1 Answers

Declare your MainActivity in AndroidManifest.xml file like this.

android:launchMode="singleTask"

Before Finishing 'ReferenceActivity' (i.e calling finish()), make an Intent call to your 'MainActivity'. Also, override 'onNewIntent()' method inside your 'MainActivity'.

@Override
protected void onNewIntent(Intent intent)

Inside 'onNewIntent()' method, load you data again as you're already doing in 'onStart()' and 'onRestart()'.

Explanation, What we're doing is adding a single reference of our 'MainActivity' in Activity Stack, so whenever an intent call is made to 'MainActivity' instead of creating multiple reference it just create one reference and call newIntentMethod every time.

Hopefully, that will fix your issue.

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