how to I call fragment from fragment with bottomnavigationview - Kotlin - android

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

Related

BottomNavigationView reloading fragments

I have implemented BottomNavigationView with NavController but fragments keep reloading on each click, even with the new navigation library update. I also tried setOnNavigationItemReselectedListener but it doesn't trigger anything. What am I doing wrong ?
I know this question have been asked more than once but I feel like I tried them all and none of them work. I was hoping I could avoid reverting my code with old libraries or using boilerplate solutions.
Here is my code :
build.gradle (:app)
implementation 'androidx.navigation:navigation-runtime-ktx:2.5.2'
implementation 'androidx.navigation:navigation-fragment-ktx:2.5.2'
implementation 'androidx.navigation:navigation-ui-ktx:2.5.2'
HomeActivity.kt
class HomeActivity : BaseActivity(), NavigationView.OnNavigationItemSelectedListener,
Serializable {
private lateinit var binding: ActivityHomeBinding
private lateinit var navController: NavController
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding= ActivityHomeBinding.inflate(layoutInflater)
setContentView(binding.root)
val navHostFragment = supportFragmentManager.findFragmentById(R.id.home_container) as NavHostFragment
navController = navHostFragment.navController
binding.bottomNavigation.setupWithNavController(navController)
}
}
activity_home.xml
<RelativeLayout 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"
android:fitsSystemWindows="true"
tools:openDrawer="start"
tools:context=".HomeActivity">
<androidx.fragment.app.FragmentContainerView
android:id="#+id/home_container"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
app:defaultNavHost="true"
app:layout_constraintBottom_toTopOf="#+id/bottom_navigation"
app:layout_constraintTop_toBottomOf="#+id/appbar_layout"
app:navGraph="#navigation/nav_main" />
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:menu="#menu/bottom_navigation_menu"
app:layout_constraintTop_toBottomOf="#+id/home_container"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="0.5"/>
</RelativeLayout>
nav_main.xml
<navigation 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/nav_main"
app:startDestination="#id/firstFragment">
<fragment
android:id="#+id/firstFragment"
android:name="com.projectName.ui.main.ContactsFragment"
tools:layout="#layout/fragment_contacts" />
<fragment
android:id="#+id/secondFragment"
android:name="com.projectName.SearchFragment"
android:label="#string/search"
tools:layout="#layout/search_fragment" />
<fragment
android:id="#+id/thirdFragment"
android:name="com.projectName.ui.main.NotificationsFragment"
tools:layout="#layout/notifications_fragment" />
<fragment
android:id="#+id/fourthFragment"
android:name="com.projectName.chat.ChatFragment"
tools:layout="#layout/fragment_main_page" />
</navigation>
bottom_navigation_menu.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="#+id/firstFragment"
android:enabled="true"
android:icon="#drawable/ic_baseline_contacts_24"
android:title=""
app:labelVisibilityMode="unlabeled"/>
<item
android:id="#+id/secondFragment"
android:enabled="true"
android:icon="#drawable/ic_search_white_24dp"
android:title=""
app:labelVisibilityMode="unlabeled"/>
<item
android:id="#+id/thirdFragment"
android:enabled="true"
android:icon="#drawable/ic_baseline_notifications_none_24"
android:title=""
app:labelVisibilityMode="unlabeled"/>
<item
android:id="#+id/fourthFragment"
android:enabled="true"
android:icon="#drawable/ic_message_white_24dp"
android:title=""
app:labelVisibilityMode="unlabeled"/>
</menu>
Fragments
class NotificationsFragment : Fragment() {
companion object {
fun newInstance() = NotificationsFragment()
}
private lateinit var viewModel: NotificationsViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
viewModel = ViewModelProvider(this).get(NotificationsViewModel::class.java)
return inflater.inflate(R.layout.notifications_fragment, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
}
I also gave every layout an ID like the document of savedInstateState suggests.
Thank you.
EDIT
I could not find a solution for my problem so I used BottomNavigationView with ViewPager2 :
HomePagerAdapter.kt
private val TAB_TITLES = arrayOf(
Constants.CONTACTS,
Constants.SEARCH,
Constants.NOTIFICATIONS,
Constants.CHATS
)
class HomePagerAdapter(fa: FragmentActivity) : FragmentStateAdapter(fa) {
override fun getItemCount(): Int = TAB_TITLES.size
override fun createFragment(position: Int): Fragment {
return if (getPageTitle(position) == Constants.CONTACTS) {
ContactsFragment.newInstance()
} else if (getPageTitle(position) == Constants.SEARCH) {
SearchFragment.newInstance()
} else if (getPageTitle(position) == Constants.NOTIFICATIONS) {
NotificationsFragment.newInstance()
} else {
ChatsFragment.newInstance()
}
}
private fun getPageTitle(position: Int): String {
return TAB_TITLES[position]
}
}
HomeActivity.kt
class HomeActivity : BaseActivity(), NavigationView.OnNavigationItemSelectedListener,
Serializable, SearchFragment.OnPersonSelectedListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_home)
val homePagerAdapter = HomePagerAdapter(this)
val viewPager: ViewPager2 = findViewById(R.id.home_view_pager)
viewPager.adapter = homePagerAdapter
viewPager.isUserInputEnabled = false
viewPager.offscreenPageLimit = 1
viewPager.overScrollMode = ViewPager2.OVER_SCROLL_NEVER
findViewById<BottomNavigationView>(R.id.bottom_navigation)
.setOnItemSelectedListener {
when (it.itemId) {
R.id.firstFragment -> {
viewPager.setCurrentItem(0, false)
return#setOnItemSelectedListener true
}
R.id.secondFragment -> {
viewPager.setCurrentItem(1, false)
return#setOnItemSelectedListener true
}
R.id.thirdFragment -> {
viewPager.setCurrentItem(2, false)
return#setOnItemSelectedListener true
}
R.id.fourthFragment -> {
viewPager.setCurrentItem(3, false)
return#setOnItemSelectedListener true
}
else -> return#setOnItemSelectedListener false
}
}
}
}
activity_home.xml
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/home_view_pager"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/bottom_navigation"
app:layout_constraintTop_toBottomOf="#+id/appbar_layout"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottom_navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:menu="#menu/bottom_navigation_menu"
app:layout_constraintTop_toBottomOf="#+id/home_view_pager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="0.5"/>
If I understood your problem right, you want that whenever you change from one fragment to another by using the bottom navigation bar that the fragments will perserve their state. I think this might be helpful https://developer.android.com/guide/navigation/multi-back-stacks. Every tab on the bottom navigation will have its own graph and while switching from one tab to another the state will be saved. Let me know if this helps you out!

How to create custom navigation drawer with bottom navigation view in android?

this is MainActivity
class MainActivity : AppCompatActivity(), FragmentDrawerListener,
BottomNavigationView.OnNavigationItemSelectedListener {
private lateinit var drawerFragment: DrawerFragment
#Inject
lateinit var mainActivityViewModel: MainActivityViewModel
#Inject
lateinit var appPreference: AppPreference
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
AndroidInjection.inject(this)
setContentView(R.layout.activity_main)
setSupportActionBar(toolbar)
navigation.setOnNavigationItemSelectedListener(this)
displayView()
}
override fun onBackPressed() {
if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
drawer_layout.closeDrawer(GravityCompat.START)
} else {
super.onBackPressed()
}
}
override fun onDrawerItemSelected(view: View, position: Int) {
displayView(position)
}
private fun displayView() {
drawerFragment =
supportFragmentManager.findFragmentById(R.id.fragment_navigation_drawer) as DrawerFragment
drawerFragment.init(R.id.fragment_navigation_drawer, drawer_layout, toolbar)
displayView(0)
}
private fun displayView(position: Int) {
when (position) {
0 -> {
HomeFragment()
}
5 -> {
val intent = Intent(this, MerchantOnBoardingActivity::class.java)
startActivity(intent)
}
9 -> {
val intent = Intent(this, AppSecurityActivity::class.java)
startActivity(intent)
}
else -> {
val bundle = Bundle()
bundle.putInt("menuItemPosition", position - 1)
val intent = Intent(this, MenuActivity::class.java)
intent.putExtras(bundle)
startActivity(intent)
}
}
}
private fun showDefaultPage() {
val fragment = HomeFragment()
title = "Home"
val fragmentManager = supportFragmentManager
val fragmentTransaction = fragmentManager.beginTransaction()
fragmentTransaction.replace(R.id.main_content, fragment)
fragmentTransaction.commit()
supportActionBar?.title = title
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
var fragment: Fragment? = null
when (item.itemId) {
R.id.navigation_home -> fragment = HomeFragment()
R.id.navigation_monitor -> Toast.makeText(this, "Monitor", Toast.LENGTH_LONG).show()
R.id.navigation_profile -> Toast.makeText(this, "Profile", Toast.LENGTH_LONG).show()
}
return loadFragment(fragment)
}
private fun loadFragment(fragment: Fragment?): Boolean {
//switching fragment
if (fragment != null) {
supportFragmentManager
.beginTransaction()
.replace(R.id.fragment_container, fragment)
.commit()
return true
}
return false
}
}
This is my xml :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:local="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<androidx.drawerlayout.widget.DrawerLayout
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
local:popupTheme="#style/ThemeOverlay.AppCompat.Light"
local:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" />
<FrameLayout
android:id="#+id/main_content"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:itemIconTint="#color/design_default_color_primary"
app:itemTextColor="#color/design_default_color_primary"
app:labelVisibilityMode="labeled"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="#menu/navigation" />
</LinearLayout>
<fragment
android:id="#+id/fragment_navigation_drawer"
android:name="com.egpaid.employeeapp.home.homedashboard.DrawerFragment"
android:layout_width="260dp"
android:layout_height="match_parent"
android:layout_gravity="start"
app:layout="#layout/fragment_drawer"
tools:layout="#layout/fragment_drawer" />
</androidx.drawerlayout.widget.DrawerLayout>
</LinearLayout>
</RelativeLayout>
using this code i am able to display data but when i try to click on Home button on either from bottom navigation view or from drawber then i am getting
No view found for id 0x7f0900a3 (com.egpaid.employeeapp:id/fragment_container) for fragment HomeFragment{9d6bf5} (7b531975-d1d4-4ad4-b3c7-6f43ae436c6d) id=0x7f0900a3}
I don't know what i am missing i am trying to create custom navigation drawber with bottom navigation view please help me Thanks

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()
}
}
}
}

Android Jetpack Navigation Disable Scroll Position

I have a single activity with many fragments (Using jetpack navigation). On my first fragment, i have a recyclerview. If i scroll on the first fragment and then navigate to the other fragment, the fragment retains the scroll position and i don't want that. An example is as follows:
i.e. Suppose i have two fragments A and B, When my app starts it starts on A. Suppose i start scrolling on A and then navigate to B. My app retains the scroll position on B which is not what i want. I want fragment B to start on top. And then when it returns to fragment A, i want it to retain the scroll position it previously scrolled.
Fragment A.xml
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<data>
<import type="android.view.View" />
<variable
name="ViewModel"
type="....AccountViewModel" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/Layout_Fragment_Account"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--
Recyclerview
-->
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/RecyclerView_Account"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.accountListVisibility? View.VISIBLE : View.GONE}"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:visibility="gone" />
<!--
Empty Views and group
-->
<androidx.constraintlayout.widget.Group
android:id="#+id/Empty_View"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.accountEmptyViewVisibility?
View.VISIBLE : View.GONE}"
app:constraint_referenced_ids="Empty_View_Illustration,Empty_View_Title,Empty_View_Subtitle" />
<ImageView
android:id="#+id/Empty_View_Illustration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:scaleType="centerCrop"
app:layout_constraintBottom_toTopOf="#+id/Empty_View_Title"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed"
app:srcCompat="#drawable/il_account" />
<TextView
android:id="#+id/Empty_View_Title"
style="#style/Locky.Text.Title6"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginEnd="32dp"
android:text="#string/text_title_emptyView_accounts"
android:textAlignment="center"
app:layout_constraintBottom_toTopOf="#id/Empty_View_Subtitle"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Empty_View_Illustration"
app:layout_constraintVertical_chainStyle="packed"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent=".8" />
<TextView
android:id="#+id/Empty_View_Subtitle"
style="#style/Locky.Text.Subtitle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginStart="32dp"
android:layout_marginEnd="32dp"
android:layout_marginBottom="?attr/actionBarSize"
android:text="#string/text_subtitle_emptyView_accounts"
android:textAlignment="center"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.6"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Empty_View_Title"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent=".8" />
<!--
Progress Bar
-->
<include
android:id="#+id/Progress_Bar"
layout="#layout/custom_view_list_loading"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.loadingStatus? View.VISIBLE : View.GONE}"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
Fragment A.kt:
class AccountFragment : Fragment() {
private var _binding: FragmentAccountBinding? = null
private var _viewModel: AccountViewModel? = null
private var _lastClickTime: Long = 0
private val binding get() = _binding!!
private val viewModel get() = _viewModel!!
companion object {
const val TAG = "ACCOUNT_FRAGMENT_DEBUG"
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
_binding = FragmentAccountBinding.inflate(inflater, container, false)
// Fetch view model
_viewModel = ViewModelProvider(this).get(AccountViewModel::class.java)
//Bind view model to layout
binding.viewModel = _viewModel
// Bind lifecycle owner
binding.lifecycleOwner = this
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
/* Hides the soft keyboard */
hideSoftKeyboard(binding.root)
/* Observe snack bar events */
observeSnackBarEvent()
/* Observe the account list changes */
observeAccounts()
/* Observe back stack entry result after navigating from sort sheet */
observeBackStackEntryForSortSheet()
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.menu_toolbar_filter, menu)
super.onCreateOptionsMenu(menu, inflater)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return when (item.itemId) {
R.id.Toolbar_Filter -> {
navigateToSort()
true
}
else -> false
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
/*
* My Functions
*/
private fun observeBackStackEntryForSortSheet() {
val navController = findNavController()
// After a configuration change or process death, the currentBackStackEntry
// points to the dialog destination, so you must use getBackStackEntry()
// with the specific ID of your destination to ensure we always
// get the right NavBackStackEntry
val navBackStackEntry = navController.getBackStackEntry(R.id.Fragment_Account)
// Create our observer and add it to the NavBackStackEntry's lifecycle
val observer = LifecycleEventObserver { _, event ->
if (event == Lifecycle.Event.ON_RESUME
&& navBackStackEntry.savedStateHandle.contains(KEY_ACCOUNTS_SORT)
) {
viewModel.sortChange(
navBackStackEntry.savedStateHandle.get<AccountSort>(
KEY_ACCOUNTS_SORT
)!!
)
navBackStackEntry.savedStateHandle.remove<AccountSort>(KEY_ACCOUNTS_SORT)
}
}
navBackStackEntry.lifecycle.addObserver(observer)
// As addObserver() does not automatically remove the observer, we
// call removeObserver() manually when the view lifecycle is destroyed
viewLifecycleOwner.lifecycle.addObserver(LifecycleEventObserver { _, event ->
if (event == Lifecycle.Event.ON_DESTROY) {
navBackStackEntry.lifecycle.removeObserver(observer)
}
})
}
private fun observeSnackBarEvent() {
viewModel.showSnackBarEvent.observe(viewLifecycleOwner, Observer {
if (it != null) {
snackBarAction(it)
}
})
}
private fun observeAccounts() {
with(viewModel) {
accounts.observe(viewLifecycleOwner, Observer {
if (it != null) {
//set loading flag to hide loading animation
doneLoading()
//Alternate visibility for account list and empty view
alternateAccountListVisibility(it.size)
//Submit the cards
initiateAccounts().submitList(it)
}
})
}
}
private fun initiateAccounts(): AccountAdapter {
val adapter = AccountAdapter(
AccountClickListener {
navigateToSelectedAccount(it)
},
AccountOptionsClickListener { view, card ->
view.apply {
isEnabled = false
}
createPopupMenu(view, card)
})
binding.RecyclerViewAccount.apply {
this.adapter = adapter
setHasFixedSize(true)
}
return adapter
}
private fun createPopupMenu(view: View, account: Account) {
requireContext().createPopUpMenu(
view,
R.menu.menu_moreoptions_account,
PopupMenu.OnMenuItemClickListener {
when (it.itemId) {
R.id.Menu_CopyUsername -> copyToClipboardAndToast(account.username)
R.id.Menu_CopyPass -> copyToClipboardAndToast(account.password)
R.id.Menu_ShowPass -> triggerSnackBarEvent(account.password)
else -> false
}
}, PopupMenu.OnDismissListener {
view.apply {
isEnabled = true
}
})
}
private fun navigateToSort() {
if (SystemClock.elapsedRealtime() - _lastClickTime >= 800) {
_lastClickTime = SystemClock.elapsedRealtime()
navigateTo(AccountFragmentDirections.actionFragmentAccountToBottomSheetFragmentAccountFilter())
}
}
private fun navigateToSelectedAccount(account: Account) {
navigateTo(
AccountFragmentDirections.actionFragmentAccountToFragmentViewAccount(
account
)
)
}
private fun snackBarAction(message: String) {
binding.LayoutFragmentAccount.snackbar(message) {
action(getString(R.string.button_snack_action_close)) { dismiss() }
}
viewModel.doneShowingSnackBar()
}
private fun triggerSnackBarEvent(message: String): Boolean {
viewModel.setSnackBarMessage(message)
return true
}
private fun copyToClipboardAndToast(message: String): Boolean {
copyToClipboard(message)
toast(getString(R.string.message_copy_successful))
return true
}
Fragment B.xml
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<data>
<variable
name="Account"
type="....Account" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/Layout_Credential_View"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/Account_Logo"
imageUrl="#{Account.logoUrl}"
loadingResource="#{#drawable/ic_image_loading}"
errorResource="#{#drawable/ic_account_placeholder}"
android:layout_width="100dp"
android:layout_height="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:src="#drawable/ic_account_placeholder" />
<TextView
android:id="#+id/Account_Name"
style="#style/Locky.Text.Title5.Name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="32dp"
android:textAlignment="center"
android:text="#{Account.accountName}"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Account_Logo"
tools:text="This can be a very very very long title toooooo" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/RecyclerView_Credentials_Field"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="24dp"
android:layout_marginEnd="8dp"
android:nestedScrollingEnabled="true"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Account_Name" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
Fragment B.kt
class ViewAccountFragment : Fragment() {
private var _binding: FragmentViewAccountBinding? = null
private var _viewModel: ViewAccountViewModel? = null
private lateinit var _account: Account
private val binding get() = _binding!!
private val viewModel get() = _viewModel!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
//Fetch the layout and do the binding
_binding = FragmentViewAccountBinding.inflate(inflater, container, false)
//Instantiate view model
_viewModel = ViewModelProvider(this).get(ViewAccountViewModel::class.java)
binding.lifecycleOwner = this
//Fetch the account clicked on the previous screen
_account = ViewAccountFragmentArgs.fromBundle(requireArguments()).parcelcredaccount
with(_account) {
//Bind the account to the layout for displaying
binding.account = this
//Submit the account details to the recyclerview
initiateCredentialsFieldList().submitList(viewModel.fieldList(this))
}
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
/* Hides the soft keyboard */
hideSoftKeyboard(binding.root)
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.menu_credentials_actions, menu)
super.onCreateOptionsMenu(menu, inflater)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return when (item.itemId) {
R.id.Action_Duplicate -> {
/*
* We set the account id to empty here
* When the add screen receives it, it wil perceive it as a new account that needs to be
* added to the database
*/
navigateToEditScreen(_account.copy(accountID = generateUniqueID()))
true
}
R.id.Action_Edit -> {
navigateToEditScreen(_account)
true
}
R.id.Action_Delete -> {
deleteConfirmationDialog(_account.accountName)
true
}
else -> false
}
}
private fun initiateCredentialsFieldList(): CredentialsViewAdapter {
val credentialsAdapter =
CredentialsViewAdapter(
CopyClickListener { data ->
copyToClipboardAndToast(data)
},
ViewClickListener { data ->
snackBarAction(data)
})
binding.RecyclerViewCredentialsField.apply {
adapter = credentialsAdapter
setHasFixedSize(true)
}
return credentialsAdapter
}
private fun deleteAndNavigateBackToAccountList() {
with(_account) {
viewModel.delete(accountID)
toast(getString(R.string.message_credentials_deleted, accountName))
findNavController().popBackStack()
}
}
navigation.xml
<fragment
android:id="#+id/Fragment_Account"
android:name="....AccountFragment"
android:label="Accounts"
tools:layout="#layout/fragment_account">
<action
android:id="#+id/action_Fragment_Account_to_Fragment_View_Account"
app:destination="#id/Fragment_View_Account" />
<action
android:id="#+id/action_Fragment_Account_to_BottomSheet_Fragment_Account_Filter"
app:destination="#id/BottomSheet_Fragment_Account_Filter" />
</fragment>
MainActivity.xml
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<androidx.drawerlayout.widget.DrawerLayout
android:id="#+id/Drawer_Main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.main.MainActivity">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/Layout_Coordinator_Main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/Toolbar_Main"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/colorOnSurface"
android:outlineAmbientShadowColor="#color/colorShadowColor"
android:outlineSpotShadowColor="#color/colorShadowColor">
<TextView
android:id="#+id/Toolbar_Main_Title"
style="#style/Locky.Text.Title6.Toolbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="#string/app_name" />
</com.google.android.material.appbar.MaterialToolbar>
<androidx.core.widget.NestedScrollView
android:id="#+id/Nested_Scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:fillViewport="true">
<fragment
android:id="#+id/Navigation_Host"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/navigation_drawer_main" />
</androidx.core.widget.NestedScrollView>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/FAB_Search"
style="#style/Locky.FloatingActionButton.Mini"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="0dp"
android:layout_marginBottom="85dp"
app:layout_anchor="#id/FAB_Add"
app:layout_anchorGravity="top|center_horizontal"
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
app:srcCompat="#drawable/ic_search" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/FAB_Add"
style="#style/Locky.FloatingActionButton.Normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
app:srcCompat="#drawable/ic_add" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.navigation.NavigationView
android:id="#+id/Navigation_View"
style="#style/Locky.Widget.Custom.NavigationView"
android:layout_width="280dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:clipToPadding="false"
android:paddingStart="0dp"
android:paddingEnd="16dp"
app:headerLayout="#layout/drawer_header"
app:itemTextAppearance="#style/Locky.Text.Body.Drawer"
app:menu="#menu/menu_drawer_main" />
</androidx.drawerlayout.widget.DrawerLayout>
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var _binding: ActivityMainBinding
private lateinit var _viewModel: MainActivityViewModel
private lateinit var _appBarConfiguration: AppBarConfiguration
//Fragments that can navigate with the drawer
private val _navigationFragments = setOf(
R.id.Fragment_Card,
R.id.Fragment_Account,
R.id.Fragment_Device
)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
_binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
_viewModel = ViewModelProvider(this).get(MainActivityViewModel::class.java)
_binding.lifecycleOwner = this
//Set the support action bar to the toolbar
setSupportActionBar(_binding.ToolbarMain)
//Remove the default actionbar title
supportActionBar?.setDisplayShowTitleEnabled(false)
/* Updates the app settings*/
updateAppSettings()
//Setup the navigation components
navigationUISetup()
//Load FABs
listenerForAddFab()
listenerForSearchFab()
//Scroll changes to adjust toolbar elevation accordingly
setUpNestedScrollChangeListener()
}
override fun onOptionsItemSelected(item: MenuItem) =
item.onNavDestinationSelected(findNavController(R.id.Navigation_Host)) || super.onOptionsItemSelected(
item
)
override fun onSupportNavigateUp() =
findNavController(R.id.Navigation_Host).navigateUp(_appBarConfiguration)
override fun finish() {
super.finish()
ActivityNavigator.applyPopAnimationsToPendingTransition(this)
}
private fun navigationUISetup() {
//Fetch the Nav Controller
val navController = findNavController(R.id.Navigation_Host)
//Setup the App Bar Configuration
_appBarConfiguration = AppBarConfiguration(_navigationFragments, _binding.DrawerMain)
//Use Navigation UI to setup the app bar config and navigation view
NavigationUI.setupActionBarWithNavController(this, navController, _appBarConfiguration)
NavigationUI.setupWithNavController(_binding.NavigationView, navController)
//Set the mini FABs with navigation to navigate to fragments accordingly.
Navigation.setViewNavController(_binding.FABAdd, navController)
Navigation.setViewNavController(_binding.FABSearch, navController)
//Add on change destination listener to navigation controller to handle fab visibility
navigationDestinationChangeListener_FAB(navController)
//Add on change destination listener to navigation controller to handle screen title visibility
navigationDestinationChangeListener_ToolbarTitle(navController)
}
private fun setUpNestedScrollChangeListener() =
_binding.NestedScroll.setOnScrollChangeListener { _, _, scrollY, _, _ ->
if (scrollY > 0) {
_binding.ToolbarMain.elevation = 12F
} else {
_binding.ToolbarMain.elevation = 0F
}
}
private fun navigationDestinationChangeListener_ToolbarTitle(navController: NavController) {
navController.addOnDestinationChangedListener { _, nd, _ ->
when (nd.id) {
R.id.Fragment_Account -> updateToolbar(getString(R.string.text_title_screen_accounts))
R.id.Fragment_Card -> updateToolbar(getString(R.string.text_title_screen_cards))
R.id.Fragment_Device -> updateToolbar(getString(R.string.text_title_screen_devices))
R.id.Fragment_Settings -> updateToolbar(getString(R.string.text_title_screen_settings))
R.id.Fragment_Profile -> updateToolbar(getString(R.string.text_title_screen_profile))
R.id.Fragment_About -> updateToolbar(getString(R.string.text_title_screen_about))
R.id.Fragment_Donate -> updateToolbar(getString(R.string.text_title_screen_donate))
else -> {
//Show the toolbar
updateToolbar(null)
}
}
}
}
private fun navigationDestinationChangeListener_FAB(navController: NavController) {
navController.addOnDestinationChangedListener { nc, nd, _ ->
when (nd.id) {
nc.graph.startDestination,
R.id.Fragment_Card,
R.id.Fragment_Device -> {
_binding.DrawerMain.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
//Show all the FABs
showFABs()
}
else -> {
_binding.DrawerMain.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
//Hide all the FABs
hideFABs()
}
}
}
}
private fun getFadeNavOptions(): NavOptions? {
return NavOptions.Builder()
.setEnterAnim(R.anim.anim_fade_in)
.setExitAnim(R.anim.anim_fade_out)
.build()
}
private fun hideFABs() {
_binding.FABSearch.hide()
_binding.FABAdd.hide()
}
private fun showFABs() {
_binding.FABSearch.show()
_binding.FABAdd.show()
showFABFromSlidingBehavior(_binding.FABSearch, _binding.FABSearch.isVisible)
showFABFromSlidingBehavior(_binding.FABAdd, _binding.FABAdd.isVisible)
}
private fun showFABFromSlidingBehavior(fab: FloatingActionButton, isVisible: Boolean) {
val layoutParams: ViewGroup.LayoutParams = fab.layoutParams
if (layoutParams is CoordinatorLayout.LayoutParams) {
val behavior = layoutParams.behavior
if (behavior is HideBottomViewOnScrollBehavior) {
if (isVisible) {
behavior.slideUp(fab)
} else {
behavior.slideDown(fab)
}
}
}
}
I have attached a gif to demontstrate the issue here:
In the GIF i navigate from 3 fragments (Fragment A > Fragment B > Fragment C)
Is there anything i am doing wrong here ?
you have the same layoutmanager for both fragments, when you populate your different fragments; the same layoutmanager is called. Which then tries to restore the same position thinking its the same recyclerview, which is kind of a feature when you think about it.
from the docs:
Called when the RecyclerView is ready to restore the state based on a
previous RecyclerView. Notice that this might happen after an actual
layout, based on how Adapter prefers to restore State. See
RecyclerView.Adapter.getStateRestorationPolicy()
which means what we need is not to restore the state which can be done by passing
PREVENT to RecyclerView.Adapter.StateRestorationPolicy
solution1: in your fragment B adapter just call adapter.stateRestorationPolicy = PREVENT
solution2: create a different layoutmanager for fragment B in case you want to restore position for something else.
EDIT :: QA :: how can i set the view to be on top (Near Status Bar) :
Well, since you are populating your fragments inside a NestedScrollView you should call NestedScrollView.scrollTo(0, 0); when you navigate to the required fragment probably by waiting on a callback from addOnDestinationChangedListener inside your MainActivity.kt

How can I combine a bottom navigation view, a Tablayout and a Viewpager in Android Kotlin?

I've been trying to combine a bottom navigation view, a tablayout and a viewpager. I already have the tableyout working with the viewpager, but when selecting another item (different from the one containing the tableyout) from the bottom navigation view nothing happens and it seems that they were disabled. I do not know what I'm doing wrong. I am a novice on Android.
I want something like this:
MainActivity.kt
class MainActivity : AppCompatActivity() {
private val onNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
when (item.itemId) {
R.id.navigation_data_sheet -> {
replaceFragment(DataSheetFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_search -> {
replaceFragment(SearchFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_notifications -> {
replaceFragment(NotificationsFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_profile -> {
val intent = Intent(this#MainActivity, NoLoginActivity::class.java)
startActivity(intent)
finish()
return#OnNavigationItemSelectedListener true
}
}
false
}
private fun replaceFragment(fragment: Fragment) {
val fragmentTransition = supportFragmentManager.beginTransaction()
fragmentTransition.replace(R.id.fragmentContainer, fragment)
fragmentTransition.commit()
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
replaceFragment(DataSheetFragment())
val navView: BottomNavigationView = findViewById(R.id.bottom_navigation)
navView.setOnNavigationItemSelectedListener(onNavigationItemSelectedListener)
}}
PagerAdapter.kt
class PagerAdapter(fm: FragmentManager) : FragmentPagerAdapter(fm) {
override fun getItem(position: Int): Fragment {
return when (position) {
0 -> {
SpecimensFragment()
}
else -> {
return FungiFragment()
}
}
}
override fun getCount(): Int {
return 2
}
override fun getPageTitle(position: Int): CharSequence {
return when (position) {
0 -> "Especímenes"
else -> {
return "Hongos"
}
}
}}
DataSheetFragment.kt: Fragment que contiene el tablayout
class DataSheetFragment : Fragment() {
private lateinit var viewPager: ViewPager
private lateinit var tabs: TabLayout
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view: View = inflater.inflate(R.layout.fragment_data_sheet, container, false)
viewPager = view.findViewById(R.id.viewPager)
tabs = view.findViewById(R.id.data_sheet_tabs)
val fragmentAdapter = PagerAdapter(childFragmentManager)
viewPager.adapter = fragmentAdapter
tabs.setupWithViewPager(viewPager)
return view
}}
fragment_data_sheet.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".Fragments.DataSheetFragment"
>
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:title="#string/data_sheet"
app:titleTextColor="#color/white"
android:background="#color/colorPrimary"
>
</androidx.appcompat.widget.Toolbar>
<com.google.android.material.tabs.TabLayout
android:id="#+id/data_sheet_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/toolbar"
android:background="#color/background_color"
app:tabTextAppearance="#style/TabLayoutTextAppearance"
>
<com.google.android.material.tabs.TabItem
android:id="#+id/specimens_tab"
android:text="#string/specimens"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<com.google.android.material.tabs.TabItem
android:id="#+id/fungi_tab"
android:text="#string/fungi"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</com.google.android.material.tabs.TabLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/data_sheet_tabs"
/>
</androidx.constraintlayout.widget.ConstraintLayout>

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