Need to disable expand on CollapsingToolbarLayout for certain fragments

Question

I have a AppCompatActivity that controls replacing many fragments. Here is my layout for it.

activity_main.xml

Answer 1

The following code achieves 3 objectives:

Disable CollapsingToolbarLayout expand or collapse by the user, but still allow AppBarLayout.setExpanded.

Prevent scrolling of RecyclerView or NestedScrollView from expanding or collapsing the CollapsingToolbarLayout.

// scrollView can be RecyclerView or NestedScrollView
ViewCompat.setNestedScrollingEnabled(scrollView, false)

Prevent the user from expanding or collapsing the CollapsingToolbarLayout by flicking the AppBar.

val params = appBar.layoutParams as CoordinatorLayout.LayoutParams
if (params.behavior == null)
    params.behavior = AppBarLayout.Behavior()
val behaviour = params.behavior as AppBarLayout.Behavior
behaviour.setDragCallback(object : AppBarLayout.Behavior.DragCallback() {
    override fun canDrag(appBarLayout: AppBarLayout): Boolean {
        return false
    }
})

https://code.luasoftware.com/tutorials/android/how-to-disable-or-lock-collapsingtoolbarlayout-collapse-or-expand/