I have an activity with a bottom BottomNavigationView, FloatingActionButton and four fragments. I wanted to show the FloatingActionButton only when I am on the 'fragment1' and 'fragment2 and hide it when 'fragment3' or 'fragment4' is selected. On launching the app, the 'fragment1' is shown with the FloatingActionButton and I managed to hide it when I navigate to 'fragment3'. But the issue is when I navigate back to 'fragment1' from 'fragment3' or 'fragment4' the FloatingActionButton is still hidden.
Following is the xml of my 'HomeActivity'
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab_one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_hide_category"
app:layout_anchor="@id/bottom_appbar"/>
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="50dp"
app:defaultNavHost="true"
app:navGraph="@navigation/mobile_navigation"
app:layout_anchor="@id/bottom_appbar"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Following is the code I have in my 'HomeActivity' and I call it from the onCreateView of the fragments to hide it.
fun hideFabOne(){
binding.fabOne.hide()
}
Then I add the below code in the 'HomeActivity' and call it in from the fragments to show the FAB, the app crashes on launch.
fun showFabOne(){
binding.fabOne.show()
}
Edit:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
Caused by: android.view.InflateException: Binary XML file line #112 in com.abc.xyz:layout/activity_home: Error inflating class fragment
Caused by: kotlin.UninitializedPropertyAccessException: lateinit property binding has not been initialized
at com.abc.xyz.ui.activities.HomeActivity.showFabOne(HomeActivity.kt:110)
at com.abc.xyz.ui.fragments.HomeFragment.onCreateView(HomeFragment.kt:102)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2963)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1647)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3128)
at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3065)
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2988)
at androidx.fragment.app.FragmentStateManager.ensureInflatedView(FragmentStateManager.java:392)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:281)
at androidx.fragment.app.FragmentLayoutInflaterFactory.onCreateView(FragmentLayoutInflaterFactory.java:140)
at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:135)
at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:319)
at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:298)
at android.view.LayoutInflater.tryCreateView(LayoutInflater.java:1067)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:995)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:959)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1121)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1082)
at android.view.LayoutInflater.inflate(LayoutInflater.java:680)
at android.view.LayoutInflater.inflate(LayoutInflater.java:532)
at com.abc.xyz.databinding.ActivityHomeBinding.inflate(ActivityHomeBinding.java:59)
at com.abc.xyz.databinding.ActivityHomeBinding.inflate(ActivityHomeBinding.java:53)
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:38)
2021-11-10 11:23:40.557 13300-13300/com.abc.xyz E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3808)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Since you are using app:navGraph make use of addOnDestinationChangedListener to control the visibility of FloatingActionButton.
Inside HomeActivity do this
navController.addOnDestinationChangedListener { _, destination, _ ->
if(destination.id == /*FRAGMENT ID*/) {
// hide
} else {
// show
}
}