Switch to ViewPager2 was successful; it was essentially a drop-in replacement. There's a bug in the connected TabLayout where, if the app starts and scrolls programmatically to Wednesday or later, the tab won't be focussed until the user starts scrolling again

app/src/main/java/com/denizk0461/studip/adapter/StudIPEventPageAdapter.kt

@@ -7,7 +7,7 @@ import androidx.recyclerview.widget.RecyclerView
 import com.denizk0461.studip.model.StudIPEvent
 import com.denizk0461.studip.databinding.ItemEventPageBinding
 
-class StudIPEventPageAdapter(private val events: List<StudIPEvent>) : RecyclerView.Adapter<StudIPEventPageAdapter.EventPageViewHolder>() {
+class StudIPEventPageAdapter(private var events: List<StudIPEvent>) : RecyclerView.Adapter<StudIPEventPageAdapter.EventPageViewHolder>() {
 
     class EventPageViewHolder(val binding: ItemEventPageBinding) : RecyclerView.ViewHolder(binding.root)
 
@@ -29,4 +29,9 @@ class StudIPEventPageAdapter(private val events: List<StudIPEvent>) : RecyclerVi
             scheduleLayoutAnimation()
         }
     }
+
+    fun setNewItems(items: List<StudIPEvent>) {
+        events = items
+        notifyDataSetChanged()
+    }
 }

app/src/main/java/com/denizk0461/studip/data/Misc.kt

@@ -2,7 +2,7 @@ package com.denizk0461.studip.data
 
 import com.denizk0461.studip.model.StudIPEvent
 
-object DummyData {
+object Misc {
 
     val events: Array<StudIPEvent> = arrayOf(
         StudIPEvent(1, "Literatures", "Nittel", "MZH 1380/1400", 0, 3, 1),
@@ -58,4 +58,6 @@ object DummyData {
         val length = (timeslotEndMap[splitTime[1]] ?: 0)
         return Pair(start, length)
     }
+
+    val mysteryLink = "https://www.youtube.com/watch?v=nhIQMCXJzLI"
 }

app/src/main/java/com/denizk0461/studip/data/StudIPParser.kt

@@ -24,7 +24,7 @@ class StudIPParser {
                 val parsedLecturers = entryHeader.substring(delimiter + 1 until entryHeader.length - 1)
 
                 val entryInfos = entry.getElementsByTag("dd")[0].text().split(", ", limit = 2)
-                val timeSlot = DummyData.parseTimeslot(entryInfos[0])
+                val timeSlot = Misc.parseTimeslot(entryInfos[0])
 
                 val event = StudIPEvent(
                 id = id,

app/src/main/java/com/denizk0461/studip/fragment/EventFragment.kt

@@ -1,23 +1,17 @@
 package com.denizk0461.studip.fragment
 
 import android.os.Bundle
-import android.util.Log
 import androidx.fragment.app.Fragment
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.viewModels
 import androidx.navigation.fragment.NavHostFragment.Companion.findNavController
-import androidx.recyclerview.widget.LinearLayoutManager
-import androidx.recyclerview.widget.PagerSnapHelper
-import androidx.recyclerview.widget.RecyclerView
-import androidx.recyclerview.widget.RecyclerView.OnScrollListener
 import com.denizk0461.studip.R
 import com.denizk0461.studip.adapter.StudIPEventPageAdapter
 import com.denizk0461.studip.databinding.FragmentEventBinding
 import com.denizk0461.studip.viewmodel.EventViewModel
-import com.google.android.material.tabs.TabLayout
+import com.google.android.material.tabs.TabLayoutMediator
-import com.google.android.material.tabs.TabLayout.OnTabSelectedListener
 import java.util.*
 
 /**
@@ -30,11 +24,16 @@ class EventFragment : Fragment() {
     // This property is only valid between onCreateView and
     // onDestroyView.
     private val binding get() = _binding!!
-    private lateinit var recyclerViewAdapter: StudIPEventPageAdapter
+
-    private lateinit var layoutManager: LinearLayoutManager
+    private lateinit var viewPagerAdapter: StudIPEventPageAdapter
     private var dayOfWeek: Int = 0
-    private val pagerSnapHelper = PagerSnapHelper()
+    private val dayStrings = listOf(
-    private var isUserScrolling = false
+        R.string.monday,
+        R.string.tuesday,
+        R.string.wednesday,
+        R.string.thursday,
+        R.string.friday,
+    )
 
     private val viewModel: EventViewModel by viewModels()
 
@@ -54,15 +53,15 @@ class EventFragment : Fragment() {
             else -> 0
         }
 
-        viewModel.allEvents.observe(viewLifecycleOwner) { events ->
+        viewPagerAdapter = StudIPEventPageAdapter(listOf())//DummyData.events.toList())
-            recyclerViewAdapter = StudIPEventPageAdapter(events)//DummyData.events.toList())
+        binding.viewPager.adapter = viewPagerAdapter
-            binding.recyclerView.adapter = recyclerViewAdapter
-            layoutManager = LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
-            binding.recyclerView.layoutManager = layoutManager
-            binding.recyclerView.onFlingListener = null
-            pagerSnapHelper.attachToRecyclerView(binding.recyclerView)
-//            binding.recyclerView.scheduleLayoutAnimation()
 
+        TabLayoutMediator(binding.dayTabLayout, binding.viewPager) { tab, position ->
+            tab.text = getString(dayStrings[position])
+        }.attach()
+
+        viewModel.allEvents.observe(viewLifecycleOwner) { events ->
+            viewPagerAdapter.setNewItems(events)
             switchToCurrentDayView()
         }
 
@@ -70,42 +69,15 @@ class EventFragment : Fragment() {
             launchWebview()
         }
 
-        binding.recyclerView.addOnScrollListener(object : OnScrollListener() {
-
-            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
-                super.onScrollStateChanged(recyclerView, newState)
-                if (newState == RecyclerView.SCROLL_STATE_IDLE) {
-                    binding.dayTabs.getTabAt(layoutManager.findFirstVisibleItemPosition())?.select()
-                }
-            }
-        })
-
-        binding.dayTabs.addOnTabSelectedListener(object : OnTabSelectedListener {
-            override fun onTabSelected(tab: TabLayout.Tab) {
-                isUserScrolling = false
-                binding.recyclerView.smoothScrollToPosition(tab.position)
-                Log.d("HELLO4", binding.recyclerView.scrollY.toString())
-                 // TODO where to set isUserScrolling back to true?
-            }
-            override fun onTabUnselected(tab: TabLayout.Tab?) {}
-            override fun onTabReselected(tab: TabLayout.Tab?) {}
-        })
-
-//        binding.daytabmonday.setOnClickListener { binding.recyclerView.scrollToPosition(0) }
-//        binding.daytabtuesday.setOnClickListener { binding.recyclerView.scrollToPosition(1) }
-//        binding.daytabwednesday.setOnClickListener { binding.recyclerView.scrollToPosition(2) }
-//        binding.daytabthursday.setOnClickListener { binding.recyclerView.scrollToPosition(3) }
-//        binding.daytabfriday.setOnClickListener { binding.recyclerView.scrollToPosition(4) }
-
 //        binding.buttonFirst.setOnClickListener {
 //            findNavController().navigate(R.id.action_FirstFragment_to_SecondFragment)
 //        }
     }
 
-    override fun onResume() {
+//    override fun onResume() {
-        super.onResume()
+//        super.onResume()
-        switchToCurrentDayView()
+//        switchToCurrentDayView()
-    }
+//    }
 
     override fun onDestroyView() {
         super.onDestroyView()
@@ -113,8 +85,8 @@ class EventFragment : Fragment() {
     }
 
     private fun switchToCurrentDayView() {
-        binding.recyclerView.scrollToPosition(dayOfWeek)
+//        binding.viewpager.currentItem = dayOfWeek
-        binding.dayTabs.getTabAt(dayOfWeek)?.select()
+        binding.dayTabLayout.getTabAt(dayOfWeek)?.select()
     }
 
     private fun launchWebview() {

app/src/main/res/layout/fragment_event.xml

@@ -7,52 +7,24 @@
     tools:context=".fragment.EventFragment">
 
     <com.google.android.material.tabs.TabLayout
-        android:id="@+id/day_tabs"
+        android:id="@+id/day_tab_layout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         app:tabMode="scrollable"
         android:background="@android:color/transparent"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintEnd_toEndOf="parent">
+        app:layout_constraintEnd_toEndOf="parent"/>
 
-        <com.google.android.material.tabs.TabItem
+    <androidx.viewpager2.widget.ViewPager2
-            android:layout_width="wrap_content"
+        android:id="@+id/view_pager"
-            android:layout_height="wrap_content"
-            android:text="@string/monday"/>
-
-        <com.google.android.material.tabs.TabItem
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="@string/tuesday"/>
-
-        <com.google.android.material.tabs.TabItem
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="@string/wednesday"/>
-
-        <com.google.android.material.tabs.TabItem
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="@string/thursday"/>
-
-        <com.google.android.material.tabs.TabItem
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="@string/friday"/>
-
-    </com.google.android.material.tabs.TabLayout>
-
-    <androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/recycler_view"
         android:layout_width="0dp"
         android:layout_height="0dp"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/day_tabs"
+        app:layout_constraintTop_toBottomOf="@+id/day_tab_layout"
-        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintBottom_toBottomOf="parent"/>
-        android:scrollbars="horizontal"
+<!--    app:layout_behavior="@string/appbar_scrolling_view_behavior"-->
-        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/fab"