RecyclerView custom LayoutManager remove unwanted views - android-recyclerview

Question

I have a custom LayoutManager (inherited from LinearLayoutManager) that needs to calculate the item width of each child and remove all children from RecyclerView that has no space for them to appear.
Sample code (edited V2):
override fun onLayoutChildren(recycler: RecyclerView.Recycler, state: RecyclerView.State) {
super.onLayoutChildren(recycler, state)
// skip if orientation is vertical, for now we only horizontal custom menu
if (orientation == RecyclerView.VERTICAL) return
// skip if adapter has no items
if (itemCount == 0) return
var totalItemWidth = 0
var totalItemsCanFit = 0
// calculate menu item width and figure out how many items can fit in the screen
for (i in 0 until childCount) {
getChildAt(i)?.let { childView ->
totalItemWidth += getDecoratedMeasuredWidth(childView)
}
if (screenWidth > totalItemWidth) {
totalItemsCanFit++
}
}
// if all items can fit, do nothing and show the whole menu
if (childCount > totalItemsCanFit) {
// remove child views that have no space on screen
for (i in childCount - 1 downTo totalItemsCanFit) {
removeAndRecycleViewAt(i, recycler)
}
}
}
I have 2 questions:
Is the sample code above the correct way to approach this problem?
How can I add a 3-dot icon at the end after seeing that not all items could fit?
EDIT:
To clarify, what I am trying to achieve is a popup menu backed by a RecyclerView. The menu has no item limit, instead it should calculate each item width and remove all items that have no space. Also, add a 3-dot menu item as a more option at the end.

Answer 1

Regarding your first question:
See if addDisappearingView(View child) could help you,
according to the documentation:
To be called only during onLayoutChildren(Recycler, State) to add a
view to the layout that is known to be going away, either because it
has been removed or because it is actually not in the visible portion
of the container but is being laid out in order to inform RecyclerView
in how to animate the item out of view.
As for the second question - you simply need to implement a 'load more' feature to your recyclerView. How you'll implement this is up to your needs/design (if you want a button or auto-scroll...).
There are many tutorials for that, for example: https://androidride.com/android-recyclerview-load-more-on-scroll-example/ .