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I’m trying to get a popup to show up when I press a button. I wanted to make sure it even shows up before working on the details but the app just crashes when i press it. The commented block is what I originally intended the button to do (just adding an item to the recyclerview) but I decided I wanted to do something a bit different. It only had the problem of crashing when I started adding the popup window stuff. The app still runs fine even if I remove the popup window stuff and leave the commented block commented out. So I don’t know if the listadapter class is relevant but ill just include it.
MainActivity.kt
class MainActivity : AppCompatActivity() { private lateinit var listAdapter: ListAdapter override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) listAdapter = ListAdapter(mutableListOf()) recyclerView.adapter = listAdapter recyclerView.layoutManager = LinearLayoutManager(this) btn_add.setOnClickListener { /* //get text from textbox val itemText = et_reminder.text.toString() if (itemText.isNotEmpty()){ //create item with text val item = Item (itemText) //add to list listAdapter.addItem((item)) //clear textbox et_reminder.text.clear() }*/ val view : View = LayoutInflater.from(applicationContext).inflate (R.layout.popup_s,null) val popup: PopupWindow = PopupWindow(view, 250, 250,true) popup.showAtLocation(view, Gravity.NO_GRAVITY, 0,0) } } }
ListAdapter.kt
class ListAdapter( private val items: MutableList<Item> ): RecyclerView.Adapter<ListAdapter.ListViewHolder>() { class ListViewHolder(itemView: View):RecyclerView.ViewHolder(itemView) override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ListViewHolder { val itemView: View = LayoutInflater.from(parent.context).inflate (R.layout.list_item, parent, false) return ListViewHolder(itemView) } override fun onBindViewHolder(holder: ListViewHolder, position: Int) { val curr_item = items [position] holder.itemView.apply { tv_reminder.text = curr_item.text; cb_check.isChecked = curr_item.checked cb_check.setOnCheckedChangeListener { _, isChecked -> //changing status of checked curr_item.checked = isChecked for (i in items.indices.reversed()) { if (items[i].checked) { items.removeAt(i) notifyItemRemoved(i) } } } } } override fun getItemCount(): Int { return items.size } fun addItem (new_item: Item){ items.add (new_item) notifyItemInserted(items.size - 1) } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <androidx.recyclerview.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="match_parent" android:layout_height="0dp" android:background="@color/basically_black" app:layout_constraintBottom_toTopOf="@+id/et_reminder" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <EditText android:id="@+id/et_reminder" android:layout_width="0dp" android:layout_height="45dp" android:hint="Reminder" android:textSize="20sp" android:textColorHint="@color/white_purple" android:textColor="@color/white_purple" android:background="@color/basically_black" android:paddingStart="10dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/btn_add" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@id/recyclerView"/> <Button android:id="@+id/btn_add" android:layout_width="45dp" android:layout_height="wrap_content" android:text="+" android:textSize="20sp" android:background="@color/basically_black" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>
list_item.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="55dp" android:paddingStart="10dp"> <TextView android:id="@+id/tv_reminder" android:layout_width="0dp" android:layout_height="wrap_content" android:paddingTop="0dp" android:text="temp" android:textColor="@color/white_purple" android:textSize="20sp" android:maxLines="1" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toStartOf="@+id/cb_check" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <CheckBox android:id="@+id/cb_check" android:layout_width="wrap_content" android:layout_height="wrap_content" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>
popup_s.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true"> <EditText android:id="@+id/et_r" android:layout_width="wrap_content" android:layout_height="wrap_content" android:hint="Reminder" android:textColor="@color/white_purple" android:textColorHint="@color/gray" android:textSize="20sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="1.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="1.0"> </EditText> </androidx.constraintlayout.widget.ConstraintLayout>
Answer
I think that happen because you are trying to pass applicationContext it will give you Unable to add window — token null is not valid; is your activity running?
try to pass the current activity context instead cause PopupWindow can only be attached to an Activity
val view : View = LayoutInflater.from(this).inflate (R.layout.popup_s,null) val popup = PopupWindow(view, 250, 250,true) popup.showAtLocation(view, Gravity.NO_GRAVITY, 0,0)