MultiType

An Android library to create multiple item types list views easily and flexibly.

English Version | 《Android 复杂的列表视图新写法 · 详解篇》

Previously, when we need to develop a complex RecyclerView / ListView, it is a difficult and troublesome work. We should override the getItemViewType() of RecyclerView.Adapter , add some types, and create some ViewHolders relating to those types. The process is cumbersome.

Once we need to add a new item type, we have to go to the original adapter and modify some old codes, and adapter classes will be bulkier.

Today, I created a new intuitive and flexible way to easily create complex RecyclerViews, with the MultiType library, we could insert a new item type without changing the old adapter codes and make them more readable.

Getting started

In your build.gradle:

dependencies {
    implementation 'me.drakeet.multitype:multitype:3.4.2'
}

Note: MultiType does not support RecyclerView below version 23.0.0.

Usage

Step 1. Create a class, It would be your data model/Java bean, for example:

public class TextItem {

    public final @NonNull String text;

    public TextItem(@NonNull String text) {
        this.text = text;
    }
}

Step 2. Create a class extends ItemViewBinder<T, VH extends ViewHolder>, for example:

public class TextItemViewBinder extends ItemViewBinder<TextItem, TextItemViewBinder.TextHolder> {

    static class TextHolder extends RecyclerView.ViewHolder {
    
        private @NonNull final TextView text;

        TextHolder(@NonNull View itemView) {
            super(itemView);
            this.text = (TextView) itemView.findViewById(R.id.text);
        }
    }

    @NonNull @Override
    protected TextHolder onCreateViewHolder(@NonNull LayoutInflater inflater, @NonNull ViewGroup parent) {
        View root = inflater.inflate(R.layout.item_text, parent, false);
        return new TextHolder(root);
    }

    @Override
    protected void onBindViewHolder(@NonNull TextHolder holder, @NonNull TextItem textItem) {
        holder.text.setText("hello: " + textItem.text);
        Log.d("demo", "position: " + getPosition(holder));
        Log.d("demo", "adapter: " + getAdapter());
    }
}

Step 3. Just register your types and setup your RecyclerView and List<Object> in your Activity, for example:

public class SampleActivity extends AppCompatActivity {

    private MultiTypeAdapter adapter;
    private Items items;

    @Override 
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.list);

        adapter = new MultiTypeAdapter();
        adapter.register(TextItem.class, new TextItemViewBinder());
        adapter.register(ImageItem.class, new ImageItemViewBinder());
        adapter.register(RichItem.class, new RichItemViewBinder());
        recyclerView.setAdapter(adapter);

        /* Mock the data */
        TextItem textItem = new TextItem("world");
        ImageItem imageItem = new ImageItem(R.mipmap.ic_launcher);
        RichItem richItem = new RichItem("小艾大人赛高", R.mipmap.avatar);

        items = new Items();
        for (int i = 0; i < 20; i++) {
            items.add(textItem);
            items.add(imageItem);
            items.add(richItem);
        }
        adapter.setItems(items);
        adapter.notifyDataSetChanged();
    }
}

That's all, you're good to go!

Advanced usage

One to many:

adapter.register(Data.class).to(
    new DataType1ViewBinder(),
    new DataType2ViewBinder()
).withLinker((position, data) ->
    data.type == Data.TYPE_2 ? 1 : 0
);

adapter.register(Data.class).to(
    new DataType1ViewBinder(),
    new DataType2ViewBinder()
).withClassLinker((position, data) -> {
    if (data.type == Data.TYPE_2) {
        return DataType2ViewBinder.class;
    } else {
        return DataType1ViewBinder.class;
    }
});

More methods that you can override by ItemViewBinder:

protected long getItemId(@NonNull T item)
protected void onViewRecycled(@NonNull VH holder)
protected boolean onFailedToRecycleView(@NonNull VH holder)
protected void onViewAttachedToWindow(@NonNull VH holder)
protected void onViewDetachedFromWindow(@NonNull VH holder)

Wiki

Change Log

https://github.com/drakeet/MultiType/releases

Android Studio Plugin

• drakeet/MultiTypeTemplates

An intellij idea plugin for Android to generate MultiType Item and ItemViewBinder easily.

Sample screenshots

You could check the sample module for more details and after running it will look like:

And it has been used in drakeet/TimeMachine:

License

Copyright 2017 drakeet.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.