RecyclerView LayoutManager different span counts on different rows

Question

I want a RecyclerView.LayoutManager that allows me to specify different span counts for different rows as a repeating pattern. For example 2,3 with 10 items would look like this:

  -------------   |     |     |   |     |     |   -------------   |   |   |   |   |   |   |   |   -------------   |     |     |   |     |     |   -------------   |   |   |   |   |   |   |   |   ------------- 

I can think of a way to hack this with GridLayoutManager and SpanSizeLookup but has anybody come up with a cleaner way to do this?

Answer 1

To do what you want, you probably have to write your own LayoutManager.

I think this is easier:

    // Create a grid layout with 6 columns     // (least common multiple of 2 and 3)     GridLayoutManager layoutManager = new GridLayoutManager(this, 6);      layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {         @Override         public int getSpanSize(int position) {             // 5 is the sum of items in one repeated section             switch (position % 5) {             // first two items span 3 columns each             case 0:             case 1:                 return 3;             // next 3 items span 2 columns each             case 2:             case 3:             case 4:                 return 2;             }             throw new IllegalStateException("internal error");         }     }); 

---

If your grid item needs to know its span size, you can find it like this within ViewHolder:

        // this line can return null when the view hasn't been added to the RecyclerView yet         RecyclerView recyclerView = (RecyclerView) itemView.getParent();         GridLayoutManager gridLayoutManager = (GridLayoutManager) recyclerView.getLayoutManager();         int spanSize = gridLayoutManager.getSpanSizeLookup().getSpanSize(getLayoutPosition());