👀 Views: 27 💬 Answers: 1 📅 Created: 2025-06-25

android layout material-design Java

I'm refactoring my project and I'm having trouble getting my Floating Action Button (FAB) to behave correctly when placed inside a CoordinatorLayout that also contains a NestedScrollView. The FAB is supposed to hide and show depending on the scroll events of the NestedScrollView, but it seems to be stuck in a position on the screen instead of adhering to the expected behavior. My layout XML looks like this: ```xml <androidx.coordinatorlayout.widget.CoordinatorLayout 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"> <ScrollView android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="androidx.core.widget.NestedScrollView"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <!-- Your content here --> </LinearLayout> </ScrollView> <com.google.android.material.floatingactionbutton.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:layout_margin="16dp" app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior" /> </androidx.coordinatorlayout.widget.CoordinatorLayout> ``` When I scroll down, the FAB does not hide as expected, nor does it show when scrolling up. I'm using Android SDK version 31 and Material Components version 1.4.0. I've tried setting the `layout_behavior` on the ScrollView to `androidx.core.widget.NestedScrollView`, but it doesn't seem to help. I've also checked that my NestedScrollView is indeed nested; I can see scroll events being triggered. However, the FAB is always visible. I suspect it might be an issue with how the layout behaviors are interacting. Can anyone suggest how to fix this behavior or what I might be missing? My development environment is Debian.