Demo issue of RecyclerBinderUpdateCallback belong to fblitho (http://fblitho.com)

PlaygroundComponentSpec.java

import android.graphics.Color;
import android.support.v7.util.DiffUtil;
import android.support.v7.widget.OrientationHelper;
import com.facebook.litho.Column;
import com.facebook.litho.ComponentContext;
import com.facebook.litho.ComponentInfo;
import com.facebook.litho.ComponentLayout;
import com.facebook.litho.annotations.LayoutSpec;
import com.facebook.litho.annotations.OnCreateLayout;
import com.facebook.litho.widget.LinearLayoutInfo;
import com.facebook.litho.widget.Recycler;
import com.facebook.litho.widget.RecyclerBinder;
import com.facebook.litho.widget.RecyclerBinderUpdateCallback;
import com.facebook.litho.widget.Text;
import java.util.Arrays;
import java.util.List;

@LayoutSpec
public class PlaygroundComponentSpec {

  @OnCreateLayout
  static ComponentLayout onCreateLayout(
      ComponentContext c) {

    final RecyclerBinder recyclerBinder = new RecyclerBinder(
        c,
        4.0f,
        new LinearLayoutInfo(c, OrientationHelper.VERTICAL, false));

    addDataToBinder(recyclerBinder, c);

    return Column.create(c)
        .backgroundColor(Color.WHITE)
        .child(
            Recycler.create(c)
                .binder(recyclerBinder)
                .withLayout()
                .flex(1)
                .build())
        .build();
  }

  private static void addDataToBinder(RecyclerBinder recyclerBinder, final ComponentContext c) {

    final List<String> items = Arrays.asList(
        "Item 1",
        "Item 2",
        "Item 3");

    final DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(new DiffUtil.Callback() {
      @Override public int getOldListSize() {
        return 0;
      }

      @Override public int getNewListSize() {
        return items.size();
      }

      @Override public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
        return false;
      }

      @Override public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
        return false;
      }
    });

    final RecyclerBinderUpdateCallback<String> updateCallback = RecyclerBinderUpdateCallback.acquire(
        0,
        items,
        new RecyclerBinderUpdateCallback.ComponentRenderer<String>() {
          @Override public ComponentInfo render(String item, int idx) {
            return ComponentInfo.create()
                .component(
                    Text.create(c)
                        .textSizeSp(20)
                        .text(item)
                        .build())
                .build();
          }
        },
        recyclerBinder);

    diffResult.dispatchUpdatesTo(updateCallback);
  }
}