: It is the backbone of the CoordinatorLayout ecosystem. When you want a CollapsingToolbarLayout to expand or collapse as the user scrolls, a NestedScrollView (or a RecyclerView ) must be the direct child to send those scroll signals up to the AppBar.
RecyclerView with NestedScrollView best practices and how to avoid it nestedscrollview
In the modern Android ecosystem, user interfaces are rarely simple. They often consist of complex hybrids: a collapsing toolbar, a tab layout, a view pager, and within each tab, a RecyclerView or ListView . When you put scrolling containers inside other scrolling containers, you encounter the infamous . : It is the backbone of the CoordinatorLayout ecosystem
implementation 'androidx.core:core:1.x.x' // or usually included automatically in newer projects implementation 'androidx.appcompat:appcompat:1.x.x' a tab layout
