Sectioned RecyclerView

Sectioned RecyclerView allows you to easily split a RecyclerView into sections with headers.

---

Gradle Dependency

Repository

repositories {
    maven { url "https://jitpack.io" }
}

Dependency

dependencies {

    // ... other dependencies here

    compile('com.github.afollestad.sectioned-recyclerview:0.1.0') {
        transitive = true
    }
}

Adapter

Here's a basic example:

public class MainAdapter extends SectionedRecyclerViewAdapter<MainAdapter.MainVH> {

    @Override
    public int getSectionCount() {
        return 20; // number of sections.
    }

    @Override
    public int getItemCount(int section) {
        return 8; // number of items in section (section index is parameter).
    }

    @Override
    public void onBindHeaderViewHolder(MainVH holder, int section) {
        // Setup header view.
    }

    @Override
    public void onBindViewHolder(MainVH holder, int section, int relativePosition, int absolutePosition) {
        // Setup non-header view.
        // 'section' is section index.
        // 'relativePosition' is index in this section.
        // 'absolutePosition' is index out of all non-header items.
        // See sample projec for a visual of how these indices work.
    }

    @Override
    public MainVH onCreateViewHolder(ViewGroup parent, boolean header) {
        // Change inflated layout based on 'header'. 
        View v = LayoutInflater.from(parent.getContext())
                .inflate(header ? R.layout.header: R.layout.normal, parent, false);
        return new MainVH(v);
    }

    public static class MainVH extends RecyclerView.ViewHolder {

        public MainVH(View itemView) {
            super(itemView);
            // Setup view holder.
            // You'd want some views to be optional, e.g. for header vs. normal.
        }
    }
}

Layout Manager

If you're using a LinearLayoutManager, you're all set. If you're using a GridLayoutManager, you need to tell the adapter:

GridLayoutManager manager = // ...
adapter.setLayoutManager(manager);

This is vital to getting headers to span all columns.