Set span for items in GridLayoutManager using SpanSizeLookup

Question

I want to implement grid-like layout with section headers. Think of https://github.com/TonicArtos/StickyGridHeaders

What I do now:

mRecyclerView = (RecyclerView) view.findViewById(R.id.grid);
mLayoutManager = new GridLayoutManager(getActivity(), 2);
mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int position) {
                switch(mAdapter.getItemViewType(position)){
                    case MyAdapter.TYPE_HEADER:
                        return 1;
                    case MyAdapter.TYPE_ITEM:
                        return 2;
                    default:
                        return -1;
                }
            }
        });

mRecyclerView.setLayoutManager(mLayoutManager);

Now both regular items and headers have span size of 1. How do I solve this?

Solution 1

The problem was that header should have span size of 2, and regular item should have span size of 1. So correct implementations is:

mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
            @Override
            public int getSpanSize(int position) {
                switch(mAdapter.getItemViewType(position)){
                    case MyAdapter.TYPE_HEADER:
                        return 2;
                    case MyAdapter.TYPE_ITEM:
                        return 1;
                    default:
                        return -1;
                }
            }
        });

Solution 2

Header should have a span equal to the span count of the entire list.

mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
    @Override
    public int getSpanSize(int position) {
           switch(mAdapter.getItemViewType(position)){
                    case MyAdapter.TYPE_HEADER:
                        return mLayoutManager.getSpanCount();
                    case MyAdapter.TYPE_ITEM:
                        return 1;
                    default:
                        return -1;
                }
    }
});

Solution 3

Answer to my own question: Override the getSpanSizeLookup() from the Activity after setting the adapter.

Comments

[yigit]

this implementation looks correct to me. Did you debug if your mAdapter.getItemViewType(position) is returning the correct value ?

[BladeCoder]

"1" seems like a safer default value than "-1".

[Vijay Ram]

I am a newbie. For me, this link helped me 3 RecyclerView Infinite Scroll Examples

[Karthik Rk]

get span size method determines the amount span width your cell is going to take not the number of col row should have !!

[Ronny Shibley]

when spanning the first item, it's messing up the height of the next ones. It works on any other item. Any idea ?

[Umair]

@RonnyShibley any solution for the issue you stated above ... I am also facing the same issue, first item after the header doesn't shows , others are all shown up as required

[Mahdi]

This is not woking.

[Bruno Bieri]

How comes no one links to the actual documentation: developer.android.com/reference/kotlin/androidx/recyclerview‌​/… Hence, this answer seems more accurate to me then the currently accepted one. Maybe create a const variable with the span count and use it for the GridLayoutManager constructor and in the getSpanSize method to avoid the getSpanCount call for every header.