Zero‑Adapter Multi‑Item RecyclerView Library for Android

Introduction

RecyclerView is a widely used list component in Android, but handling multiple item layouts often leads to large switch statements in the adapter, making the code hard to maintain. To solve this, the author created an open‑source library (GitHub: https://github.com/free46000/MultiItem) that provides a zero‑coding adapter by decoupling item types from the adapter through a ViewHolderManager mechanism, greatly improving extensibility.

Effect Screenshots

Usage

Multiple‑Type List Usage

Register different ViewHolderManager implementations for each data class and set the mixed data list to the adapter. No need to modify the adapter itself.

// Initialize adapter
BaseItemAdapter adapter = new BaseItemAdapter();
// Register TextBean manager
adapter.register(TextBean.class, new TextViewManager());
// Register ImageTextBean manager
adapter.register(ImageTextBean.class, new ImageAndTextManager());
// Register ImageBean manager
adapter.register(ImageBean.class, new ImageViewManager());
// Assemble data source list
List
list = new ArrayList<>();
list.add(new TextBean("AAA"));
list.add(new ImageBean(R.drawable.img1));
list.add(new ImageTextBean(R.drawable.img2, "BBB" + i));
// Set data and adapter
adapter.setDataItems(list);
recyclerView.setAdapter(adapter);

The TextViewManager (and similar managers) contain the full binding logic:

public class ImageViewManager extends BaseViewHolderManager
{
    @Override
    public void onBindViewHolder(BaseViewHolder holder, ImageBean data) {
        ImageView imageView = getView(holder, R.id.image);
        imageView.setImageResource(data.getImg());
    }
    @Override
    protected int getItemLayoutId() {
        return R.layout.item_image;
    }
}

Thus the library completely removes the need to extend RecyclerView.Adapter for multi‑type lists.

Same Data Source with Multiple ViewHolders

Useful for chat interfaces where a single message type can be displayed on the left or right. Register a ViewHolderManagerGroup that decides which manager to use based on the data:

BaseItemAdapter adapter = new BaseItemAdapter();
adapter.register(MessageBean.class, new ViewHolderManagerGroup<>(
        new SendMessageManager(),
        new ReceiveMessageManager()) {
    @Override
    public int getViewHolderManagerIndex(MessageBean itemData) {
        return itemData.getSender().equals(uid) ? 0 : 1;
    }
});
recyclerView.setAdapter(adapter);

Click Listeners

Set item click and long‑click callbacks directly on the adapter:

adapter.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(BaseViewHolder viewHolder) {
        toastUser(String.format("Clicked position %s data: %s",
                viewHolder.getItemPosition(), viewHolder.getItemData()));
    }
});
adapter.setOnItemLongClickListener(new OnItemLongClickListener() {
    @Override
    public void onItemLongClick(BaseViewHolder viewHolder) {
        toastUser(String.format("Long‑pressed position %s data: %s",
                viewHolder.getItemPosition(), viewHolder.getItemData()));
    }
});

Header and Footer

Two ways to add headers/footers: addHeadView / addFootView for raw views, or addHeadItem / addFootItem for data items.

// Register TextBean manager
adapter.register(TextBean.class, new TextViewManager());
// Add header view
TextView headView = new TextView(this);
headView.setText("Header added via addHeadView");
adapter.addHeadView(headView);
// Add header item
adapter.addHeadItem(new TextBean("Header added via addHeadItem"));
// Add footer view
TextView footView = new TextView(this);
footView.setText("Footer added via addFootView");
adapter.addFootView(footView);
// Add footer item
adapter.addFootItem(new TextBean("Footer added via addFootItem"));

Pull‑to‑Refresh and Load‑More

Enable load‑more (treated as a footer) before calling the method to start loading:

adapter.enableLoadMore(new LoadMoreHolderManager(this::loadData));
adapter.setLoadCompleted(isLoadAll);
adapter.setLoadFailed();

The LoadMoreHolderManager defines the layout and state handling:

public class LoadMoreHolderManager extends LoadMoreManager {
    public LoadMoreHolderManager(OnLoadMoreListener listener, boolean auto) {
        super(listener, auto);
    }
    @Override
    protected int getItemLayoutId() { return R.layout.item_load_more; }
    @Override
    protected void updateLoadInitView() { ((TextView)getView(loadMoreView,R.id.text)).setText(""); }
    @Override
    protected void updateLoadingMoreView() { ((TextView)getView(loadMoreView,R.id.text)).setText(R.string.loading_more); }
    @Override
    protected void updateLoadCompletedView(boolean all) {
        ((TextView)getView(loadMoreView,R.id.text)).setText(all ? R.string.load_all : R.string.load_has_more);
    }
    @Override
    protected void updateLoadFailedView() { ((TextView)getView(loadMoreView,R.id.text)).setText(R.string.load_failed); }
}

Enable Animation

Start item animations and optionally limit them to the first load:

adapter.enableAnimation(baseAnimation, false);
/**
 * Set animation duration (default 400ms)
 */
public void setAnimDuration(long duration) { ... }
/**
 * Set animation interpolator (default LinearInterpolator)
 */
public void setInterpolator(@NonNull Interpolator interpolator) { ... }

Summary

The library provides a clean, generic way to manage multiple RecyclerView item types without writing a custom adapter. By registering ViewHolderManager instances for each data class (or a group of managers for a single class), developers gain decoupled view creation, binding, header/footer support, click handling, pagination, and animation with minimal boilerplate.

Acknowledgements

Thanks to the following open‑source projects for inspiration: recyclerview‑animators MultiType