Develop Reference

ViewPager2 misses the tablayout indicator

The following problem occurred with me after migration from viewPager to viewPager2 - when I open my app, the tablyout indicator is missing by default. But if you make some swiping, the indicator will appears! Looks weird, because I made everything correct. There are my simplified Kotlin-code:
class ScheduleWeekFragment : ScheduleBaseFragment<ScheduleWeekViewModel>(ScheduleWeekViewModel::class) {
private val viewBinding by viewBinding(FragmentWeekBinding::bind)
private var titles: Array<String>? = null
// listeners
private val viewPagerListener = object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
viewModel.updateDayTitle(position)
}
}
// observers
private val selectedDayObserver = Observer<Int> {
viewBinding.viewPager2.currentItem = it
}
// lifecycle
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
titles = context?.resources?.getStringArray(R.array.schedule_fragment_day_abbreviations)
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? =
inflater.inflate(R.layout.fragment_week, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewBinding.viewPager2.adapter = ScheduleViewPagerAdapter(this)
viewBinding.viewPager2.setPageTransformer(ZoomOutPageTransformer)
TabLayoutMediator(viewBinding.tabLayout, viewBinding.viewPager2) { tab, position ->
tab.text = titles?.getOrNull(position)
}.attach()
// observers
viewModel.viewPagerPosition.observe(viewLifecycleOwner, selectedDayObserver)
// listeners
viewBinding.viewPager2.registerOnPageChangeCallback(viewPagerListener)
}
override fun onDestroyView() {
viewBinding.viewPager2.unregisterOnPageChangeCallback(viewPagerListener)
super.onDestroyView()
}
}
And there is my simplified xml-code:
<?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:id="#+id/fragmentWeek"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
style="#style/TabLayout1"
android:layout_width="match_parent"
android:layout_height="40dp"
android:verticalScrollbarPosition="left"
app:layout_constraintEnd_toEndOf="#+id/viewPager2"
app:layout_constraintStart_toStartOf="#+id/viewPager2"
app:layout_constraintTop_toBottomOf="#+id/scheduleToolbar"
app:tabGravity="start"
app:tabMode="scrollable"
android:background="#color/white"
tools:ignore="SpeakableTextPresentCheck" />
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPager2"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:background="#color/white"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/tabLayout"
tools:ignore="SpeakableTextPresentCheck" />
</androidx.constraintlayout.widget.ConstraintLayout>

The problem was inside my observer:
private val selectedDayObserver = Observer<Int> {
// viewBinding.viewPager2.currentItem = it // wrong!
viewBinding.viewPager2.setCurrentItem(it, false) // correct!
}
I didn't find why in the official docs, but difference exists: the first variant works good with viewpager1, but for viewpager2, be careful and use the second complex variant.

Implementing Viewpager2 in a fragment with Recycler view

I'm trying to implement viewpager2 in a fragment which shows a list of notes with Recycler View. I tried different solutions but I'm unable to figure it out.
Here is my fragment_notes_list.xml :
<androidx.recyclerview.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/notes_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
list_item_notes.xml used to display recycler view viewholder:
<androidx.cardview.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="#+id/card_pertanyaan"
android:layout_width="match_parent"
android:layout_height="96dp"
android:layout_marginLeft="16dp"
android:layout_marginTop="12dp"
android:layout_marginRight="16dp"
android:clickable="true"
android:foreground="?selectableItemBackground"
card_view:cardBackgroundColor="#595959"
card_view:cardCornerRadius="8dp"
card_view:contentPadding="10dp">
<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:id="#+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/notes_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="8dp"
android:text="Title"
android:textColor="#color/white"
app:layout_constraintBottom_toTopOf="#+id/notes_body"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<TextView
android:id="#+id/notes_body"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:textColor="#color/white"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/notes_title" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>
Relevant snippets from fragment class NotesListFragment.kt :
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.fragment_notes_list, container, false)
notesRecyclerView =
view.findViewById(R.id.notes_recycler_view) as RecyclerView
registerForContextMenu(notesRecyclerView)
notesRecyclerView.layoutManager = LinearLayoutManager(context)
notesRecyclerView.adapter = adapter
return view
}
private inner class ScreenSlidePagerAdapter(fa: Fragment) : FragmentStateAdapter(fa) {
override fun getItemCount(): Int = NUM_PAGES
override fun createFragment(position: Int): Fragment {
return if (position == 0) {
NotesListFragment()
} else {
CalenderFragment()
}
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
notesListViewModel.notesListLiveData.observe(
viewLifecycleOwner,
Observer { notes ->
notes?.let {
Log.i(TAG, "got notes")
updateUI(notes)
}
})
}
private inner class NotesAdapter(var notes: List<Notes>) : RecyclerView.Adapter<NotesHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): NotesHolder {
val view = layoutInflater.inflate(R.layout.list_item_notes, parent, false)
/* viewPager = view.findViewById(R.id.pager)
val pagerAdapter = ScreenSlidePagerAdapter(this#NotesListFragment)
viewPager.adapter = pagerAdapter */
return NotesHolder(view)
}
override fun getItemCount() = notes.size
override fun onBindViewHolder(holder: NotesHolder, position: Int) {
val note = notes[position]
holder.bind(note)
}
}
I'm confused should I add ViewPager2 with FrameLayout in list_item_notes.xml?
But then how can I implement ScreenSliderPagerAdapter for it?

I assume you would like to have 2 fragments: list and calendar and thats why you need to implement ViewPager2. Your NotesListFragment looks good. You have recyclerview with notes there, but what you want now is to provide list of NotesListFragment and CalendarFragment which will be scrollable in left/right direction. First, extract ScreenSlidePagerAdapter outside of your fragment code. Next you have to add ViewPager2 to your parent activity/fragment
<androidx.viewpager2.widget.ViewPager2
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
And then in your parent activity/fragment pair it with adapter like this way:
val viewPager = findViewById(R.id.pager)
val pagerAdapter = ScreenSlidePagerAdapter(this)
viewPager.adapter = pagerAdapter
You can read more about this in official docs: https://developer.android.com/training/animation/screen-slide-2

I had tried implementing ViewPager in Main Activity earlier also. But this way i cannot close viewpager fragments since they are always visible. How do I get around this?
here is my main activity after the changes you suggested:
class MainActivity : AppCompatActivity(),
NotesListFragment.Callbacks {
private lateinit var viewPager: ViewPager2
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
viewPager = findViewById(R.id.pager)
val pagerAdapter = ScreenSlidePagerAdapter(this)
viewPager.adapter = pagerAdapter
}
override fun onNotesSelected(notesId: UUID) {
val fragment = NotesFragment.newInstance(notesId)
supportFragmentManager
.beginTransaction()
.replace(R.id.fragment_container, fragment)
.addToBackStack(null)
.commit()
}
fun onNotesDeleted(notes: Notes) {
val fragment = NotesListFragment()
supportFragmentManager
.beginTransaction()
.replace(R.id.fragment_container, fragment)
.commit()
Toast.makeText(this, "Note Deleted", Toast.LENGTH_SHORT).show()
}
mainactivity.xml:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.viewpager2.widget.ViewPager2
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/pager"/>
</FrameLayout>
here are some screenshots,
https://drive.google.com/drive/folders/13ITZqcaeDeydCe0tW2Iu7VoSGSZnrlkg?usp=sharing

Solved the problem.
Since, I was unable to add Viewpager with recycler view of NotesListFragment, I made another Parent Fragment with viewpager and put NotesListFragment inside it.

How to replace fragment inside ViewPager and change toolbar

I found an interesting feature in one of the applications, I want to repeat it. The application has ViewPager and TabLayout and a bunch of fragments inside.
On the first fragment there is a button img1
, by pressing it, the fragment is replaced by another img2
while ads_banner is removed and the toolbar is replaced,
and when swiping to the right and back, it shows fragment1, please tell me how this can be done. Here is what I already wrote:
MainActivity
class MainActivity : AppCompatActivity() {
private var mAdView: AdView? = null
#SuppressLint("ResourceType")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val adRequest = AdRequest.Builder().build()
mAdView = findViewById(R.id.adView)
mAdView!!.loadAd(adRequest)
initTab()
}
fun initTab() {
tab_layout.addTab(tab_layout.newTab().setIcon(R.drawable.image1)
tab_layout.addTab(tab_layout.newTab().setIcon(R.drawable.image2)
tab_layout.addTab(tab_layout.newTab().setIcon(R.drawable.image3)
tab_layout.tabGravity = TabLayout.GRAVITY_FILL
val adapter = MyPagerAdapter(supportFragmentManager, tab_layout.tabCount)
pager.adapter = adapter
pager.offscreenPageLimit = 2
pager.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(tab_layout))
tab_layout.addOnTabSelectedListener(object : TabLayout.OnTabSelectedListener {
override fun onTabSelected(tab: TabLayout.Tab) {
pager.currentItem = tab.position
if (tab.position == 0) {
tab_layout.getTabAt(0)!!.setIcon(R.drawable.image1_focus)
}
if (tab.position == 1) {
tab_layout.getTabAt(1)!!.setIcon(R.drawable.image2_focus)
}
if (tab.position == 2) {
tab_layout.getTabAt(2)!!.setIcon(R.drawable.image3_focus)
}
}
override fun onTabUnselected(tab: TabLayout.Tab) {
if (tab.position == 0) tab_layout.getTabAt(0)!!.setIcon(R.drawable.image1)
if (tab.position == 1) tab_layout.getTabAt(1)!!.setIcon(R.drawable.image2)
if (tab.position == 2) tab_layout.getTabAt(2)!!.setIcon(R.drawable.image3)
}
override fun onTabReselected(tab: TabLayout.Tab) {
}
})
}
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:id="#+id/mainlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:fitsSystemWindows="true"
android:orientation="vertical"
tools:context=".MainActivity">
<com.google.android.gms.ads.AdView
android:id="#+id/adView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:background="#color/transparent"
app:adSize="SMART_BANNER"
app:adUnitId="#string/banner_key"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
style="#style/MyToolbar"
android:layout_width="match_parent"
android:layout_height="35dp"
android:layout_marginTop="2dp"
android:gravity="center"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/adView"
app:popupTheme="#style/AppTheme.PopupOverlay">
<TextView
android:id="#+id/toolbar_txt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:fontFamily="#font/sf_pro_display_regular"
android:textColor="#color/black"
android:textSize="24sp"
tools:layout_editor_absoluteX="206dp"
tools:layout_editor_absoluteY="7dp" />
</androidx.appcompat.widget.Toolbar>
<androidx.viewpager.widget.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/tab_layout"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/toolbar" />
<com.google.android.material.tabs.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="#fff"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:tabBackground="#drawable/tab_color_selector"
app:tabIndicatorColor="#2196F3"
app:tabIndicatorGravity="top"
app:tabIndicatorHeight="4dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
MyPagerAdapter
class MyPagerAdapter(fm: FragmentManager, internal var mNumOfTabs: Int) : FragmentStatePagerAdapter(fm) {
override fun getItem(position: Int): Fragment {
when (position) {
0 -> {
return RootFragment()
// return Fragment1()
}
1 -> {
return Fragment2()
}
2 -> {
return Fragment3()
}
}
}
override fun getCount(): Int {
return mNumOfTabs
}
}
Fragment1
class Fragment1: Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.fragment_1, container, false)
return view
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
btnfr1.setOnClickListener {
val trans = fragmentManager!!.beginTransaction()
trans.replace(R.id.root_frame, Fragment4())
trans.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
trans.addToBackStack(null)
trans.commit()
}
}
RootFragment
class RootFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.root_fragment, container, false)
val transaction = fragmentManager!!.beginTransaction()
transaction.replace(R.id.root_frame, Fragment1())
transaction.commit()
return view
}
}
root_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/root_frame" >
</FrameLayout>
In Fragment1, only the button for calling Fragment4. Tried to do as here https://www.codexpedia.com/android/android-viewpager-fragment-swap/
it turned out to replace Fragment1 with Fragment4, but I don’t know how to reset Fragment4 when swiping and don’t understand how to replace Toolbar and remove ads.

The trick is that as RootFragment is the fragment on the 0th index, what you need to do is show the original fragment as a child fragment of RootFragment using fragment transactions via childFragmentManager.
This way, you can replace the children of RootFragment, without actually having to replace RootFragment itself inside the ViewPager.

You need to implement createFragment and getItemCount methods in MyPagerAdapter to supply instances of fragments as pages to ViewPager.
Modify MyPagerAdapter class as shown below and test:
class MyPagerAdapter(fm: FragmentManager, internal var mNumOfTabs: Int) : FragmentStatePagerAdapter(fm) {
override fun getItemCount(): Int = mNumOfTabs
override fun createFragment(position: Int): Fragment {
when (position) {
0 -> {
return RootFragment()
}
1 -> {
return Fragment2()
}
2 -> {
return Fragment3()
}
}
}
}

how to I call fragment from fragment with bottomnavigationview - Kotlin

I have got problems.
There are 5 fragment in MainActivity. It is D1, D2, D3, D4, D5 Fragment. And there is BottomNavigationView in MainActivity. I want to call DxFragment from D1fragment. The button will be clicked and only the frame will change. But the button navigation bar will not change.
I've been looking for a while. I couldn't find the solution. Can anyone please help?
MAINACTIVITY
class MainActivity : AppCompatActivity() {
private lateinit var bottomNavigationView : BottomNavigationView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
bottomNavigationView = findViewById(R.id.nav_view)
navigateFragment(false)
}
public fun loadFragment (fragment: Fragment){
supportFragmentManager.beginTransaction().also { fragmentTransaction ->
fragmentTransaction.replace(R.id.bottom_nav_host_fragment, fragment)
fragmentTransaction.commit()
}
}
public fun navigateFragment ( stateFragment : Boolean) {
bottomNavigationView = findViewById(R.id.nav_view)
bottomNavigationView.setOnNavigationItemSelectedListener { menuItem : MenuItem ->
when{
menuItem.itemId== R.id.navigation_home -> {
loadFragment(D1Fragment())
return#setOnNavigationItemSelectedListener true
}
menuItem.itemId == R.id.navigation_map -> {
loadFragment(D2Fragment())
return#setOnNavigationItemSelectedListener true
}
menuItem.itemId == R.id.navigation_userpage -> {
loadFragment(D3Fragment())
return#setOnNavigationItemSelectedListener true
}
menuItem.itemId == R.id.navigation_fav -> {
loadFragment(D4Fragment())
return#setOnNavigationItemSelectedListener true
}
menuItem.itemId == R.id.navigation_list -> {
loadFragment(D5Fragment())
return#setOnNavigationItemSelectedListener true
}
stateFragment == true -> {
loadFragment(BlankFragment())
return#setOnNavigationItemSelectedListener true
}
else -> {
return#setOnNavigationItemSelectedListener true
}
}
}
}
override fun onSupportNavigateUp(): Boolean {
return Navigation.findNavController(this, R.id.bottom_nav_host_fragment).navigateUp() ||
super.onSupportNavigateUp()
}
}
ACTIVITY_MAIN.XML
some part
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/nav_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="0dp"
android:layout_marginEnd="0dp"
android:background="?android:attr/windowBackground"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="#menu/bottom_menu" />
<FrameLayout
android:id="#+id/bottom_nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#id/nav_view"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
FRAGMENT_D1.XML
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".D1Fragment">
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CLICK AND GO BLANKFRAGMENT" />
</FrameLayout>
D1FRAGMENT
class D1Fragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_d1, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
button.setOnClickListener {
Toast.makeText(context , "CLICKED" , Toast.LENGTH_SHORT ).show()
Navigation.findNavController(view).navigate(R.id.action_d1Fragment_to_blankFragment)
}
super.onViewCreated(view, savedInstanceState)
}
}
BUTTON CLICK AND ERROR
java.lang.IllegalStateException: View android.widget.FrameLayout{16424ce5 V.E..... ........ 0,0-1080,1365} does not have a NavController set
at androidx.navigation.Navigation.findNavController(Navigation.java:84)
at com.axisting.bottomelledeneme.D1Fragment$onViewCreated$1.onClick(D1Fragment.kt:35)

You only needs to have a principal class,
Example main's activity, it contains the BottomNavigationView and fragment. the fragments have the other element
Example
<?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">
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/bottom_nav_menu" />
</androidx.con straintlayout.widget.ConstraintLayout>
You only need to attach the fragment

Viewpager inside BottomsheetdialogFragment not showing Fragment

I have implemented BottomSheetDialogFragment into OptionsFragment.In which I have added viewpager so I can do swipe animation for SignInSignUpOptionsFragment which I want to add in viewpager and button to Swipe SignInSignUpOptionsFragment with different option. SignInSignUpOptionsFragment has options of Login(+ social accounts).
AccountFragment
login_btn.onClickListener( v -> {
OptionsFragment optionsFragment = new OptionsFragment(true);
optionsFragment.show(getChildFragmentManager(), "Login");
});
OptionsFragment
class OptionsFragment(private val isLogin: Boolean) : BottomSheetDialogFragment() {
private var fragmentView: View? = null
lateinit var viewPager: ViewPager
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
fragmentView = inflater.inflate(R.layout.signup_popover, container, false)
val pagerAdapter = MyPagerAdapter(childFragmentManager)
viewPager = fragmentView!!.findViewById(R.id.vpPager)
viewPager.adapter = pagerAdapter
viewPager.currentItem = 0
return fragmentView
}
}
class MyPagerAdapter(fragmentManager: FragmentManager?) : FragmentStatePagerAdapter(fragmentManager!!, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
// Returns total number of pages
override fun getCount(): Int {
return NUM_ITEMS
}
// Returns the fragment to display for that page
override fun getItem(position: Int): Fragment {
return when(position) {
0 -> SignInSignUpOptionsFragment.newInstance(true)
1 -> SignInSignUpOptionsFragment.newInstance(false)
else -> null!!
}
}
// Returns the page title for the top indicator
override fun getPageTitle(position: Int): CharSequence? {
return "Page $position"
}
companion object {
private const val NUM_ITEMS = 2
}
here's my layout file
<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="match_parent"
android:layout_height="match_parent"
android:background="#color/utilityGrey2">
<androidx.viewpager.widget.ViewPager
android:id="#+id/vpPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="parent" />
<LinearLayout
android:id="#+id/login_no_account_group"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="24dp"
android:layout_marginLeft="21dp"
android:layout_marginRight="21dp"
android:layout_marginTop="52dp"
android:orientation="vertical"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/vpPager">
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/switch_sign_up_description"
style="#style/HelpText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="#string/no_account" />
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/switch_sign_up"
style="#style/HelpText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="#string/sign_up_caps" />
</LinearLayout>
but I am not able to see any fragment inside ViewPager. Only bottom "login_no_account_group" is displaying as Bottomsheet. I don't want to use TabLayout, instead I want to change page on switch_sign_up click
viewPager.currentItem = 1
Is it possible ? any other alternative welcome as well