RecyclerView content height

Question

Is there any good way of getting the height of the content inside RecyclerView? Considering all items may have different height.

In my scenario I'm using a LinearLayoutManager.

I've searched around and found surprisingly few results for this problem.

Gyron

Answer 1

RecyclerView is a ViewGroup. You can use getChildAt / getChildCount to get views. Then from the view, you can call getWidth / getHeight.

If you have ItemDecorators and need to get size including them, you can use LayoutManager's getDecorated<xxx> methods.

Ram

Considering the nature of the RECYCLERView, won't that just get the child views that are actually created? Say I have a 100 items, maybe only 10 views are inflated and recycled. – Gyron

If you are trying to get height of items that are not laid out, you cannot because they are not laid out. There cannot be a solution for this besides laying out every single item, which defeats the purpose of using RecyclerView. – Ram

But the RecylerView knows enough to layout the scrollbars correctly, so it must know something about it's contents height? – Gyron

It approximates the total size of all items by taking the average size of current views multiplied by the number of items in the adapter. – Ram

Answer 2

RecyclerView.computeVerticalScrollRange will give an estimation - it averages the height of the rows being currently displayed and multiplies that by the result of getItemCount

computeHorizontalScrollRange for width if you're orientation is horizontal.

Toilet

this method always return 0 – Rubbing

Answer 3

I use to experiment with View.measure method:

recycler.measure(View.MeasureSpec.makeMeasureSpec(recycler.width, View.MeasureSpec.EXACTLY), View.MeasureSpec.UNSPECIFIED)
val height = recycler.measuredHeight

If your items are simple enough (e.g. with fixed heights), it should work.

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