public class LinkedLayout extends LinearLayout {
  private Context mContext;
  private BaseScrollableContainer mTabContainer;
  private BaseScrollableContainer mContentContainer;
  private SectionIndexer mSectionIndexer; // 代理
  ...
}

public abstract class BaseScrollableContainer<VG extends ViewGroup> {
  protected Context mContext;
  public VG mViewGroup;
  protected RealOnScrollListener mRealOnScrollListener;
  private EventDispatcher mEventDispatcher;
  ...
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <com.fashare.linkedscrolldemo.ui.LinkedLayout
    android:id="@+id/linked_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"/>
</RelativeLayout>

public class LinkedLayout extends LinearLayout {
  ...
  private static final int MEASURE_BY_WEIGHT = 0;
  private static final float WEIGHT_TAB = 1;
  private static final float WEIGHT_CONTENT = 3;

  public void setContainers(BaseScrollableContainer tabContainer, BaseScrollableContainer contentContainer) {
    mTabContainer = tabContainer;
    mContentContainer = contentContainer;
    mTabContainer.setEventDispatcher(this);
    mContentContainer.setEventDispatcher(this);

    // 设置 LayoutParams
    mTabContainer.mViewGroup.setLayoutParams(new LinearLayout.LayoutParams(
        MEASURE_BY_WEIGHT,
        ViewGroup.LayoutParams.WRAP_CONTENT,
        WEIGHT_TAB
    ));

    mContentContainer.mViewGroup.setLayoutParams(new LinearLayout.LayoutParams(
        MEASURE_BY_WEIGHT,
        ViewGroup.LayoutParams.MATCH_PARENT,
        WEIGHT_CONTENT
    ));

    this.addView(mTabContainer.mViewGroup);
    this.addView(mContentContainer.mViewGroup);
    this.setOrientation(HORIZONTAL);
  }
}

mTabContainer = new ListViewTabContainer(this, mListView); 
mContentContainer = new RecyclerViewContentContainer(this, mRecyclerView);

// RecyclerView
public class RecyclerViewContentContainer extends BaseScrollableContainer<RecyclerView> {
  ...
  @Override
  protected void setOnScrollListener() {
    mViewGroup.addOnScrollListener(new ProxyOnScrollListener());
  }

  private class ProxyOnScrollListener extends RecyclerView.OnScrollListener {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
      if(newState == RecyclerView.SCROLL_STATE_IDLE) {      // 停止滑动
        1.停止时的逻辑...
      }else if(newState == RecyclerView.SCROLL_STATE_DRAGGING){  // 按下拖动
        2.刚刚拖动时的逻辑...
      }
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) { // 滑动
      3.滑动时的逻辑...
    }
  }
}

// ListView
public class ListViewTabContainer extends BaseScrollableContainer<ListView> {
  ...
  @Override
  protected void setOnScrollListener() {
    mViewGroup.setOnScrollListener(new ProxyOnScrollListener());
    ...
  }

  public class ProxyOnScrollListener implements AbsListView.OnScrollListener{
    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
      if(scrollState == SCROLL_STATE_IDLE) {       // 停止滑动
        1.停止时的逻辑...
      }else if(scrollState == SCROLL_STATE_TOUCH_SCROLL) // 按下拖动
        2.刚刚拖动时的逻辑...
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
      3.滑动时的逻辑...        // 滑动
    }
  }
}

public interface OnScrollListener {
  // tab 点击事件
  void onClick(int position);

  // 1.滑动开始
  void onScrollStart();

  // 2.滑动结束
  void onScrollStop();

  // 3.触发 onScrolled()
  void onScrolled();

  // 用户手动滑, 触发的 onScrolled()
  void onScrolledByUser();

  // 程序调用 scrollTo(), 触发的 onScrolled()
  void onScrolledByInvoked();
}

public class RealOnScrollListener implements OnScrollListener {
  public boolean isTouching = false; // 处于触摸状态
  private int mCurPosition = 0;    // 当前选中项
  private BaseViewGroupUtil<VG> mViewUtil; // ViewGroup 工具类
  ...
}

/*
 * 事件分发者
 */
public interface EventDispatcher {
  /**
   * 分发事件: fromView 中的 pos 被选中
   * @param pos
   * @param fromView
   */
  void dispatchItemSelectedEvent(int pos, View fromView);
}
/*
 * 事件接受者
 */
public interface EventReceiver {
  /**
   * 收到事件: 立即选中 newPos
   * @param newPos
   */
  void selectItem(int newPos);
}

public abstract class BaseScrollableContainer<VG extends ViewGroup>
    implements EventReceiver {
  protected RealOnScrollListener mRealOnScrollListener;
  private EventDispatcher mEventDispatcher; // 持有分发者
  ...
  public void setEventDispatcher(EventDispatcher eventDispatcher) {
    mEventDispatcher = eventDispatcher;
  }
  // 掉用 mEventDispatcher，也就是 LinkedLayout
  protected void dispatchItemSelectedEvent(int curPosition){
    if(mEventDispatcher != null)
      mEventDispatcher.dispatchItemSelectedEvent(curPosition, mViewGroup);
  }
  @Override
  public void selectItem(int newPos) {
    mRealOnScrollListener.selectItem(newPos);
  }
  // OnScrollListener: 代理模式
  public class RealOnScrollListener implements OnScrollListener {
    ...
    public void selectItem(int position){
      mCurPosition = position;
      Log.d("setitem", position + "");
      // 来自另一边的联动事件
      mViewUtil.smoothScrollTo(position);
//      if(mViewUtil.isVisiblePos(position))  // curSection 可见时, 不滚动
        mViewUtil.setViewSelected(position);
    }
    @Override
    public void onClick(int position) {
      isTouching = true;
      mViewUtil.setViewSelected(mCurPosition = position);
      dispatchItemSelectedEvent(position); // 点击tab，分发事件
      isTouching = false;
    }
    ...
    @Override
    public void onScrolled() {
      mCurPosition = mViewUtil.updatePosOnScrolled(mCurPosition);
      if(isTouching)     // 来自用户, 通知 对方 联动
        onScrolledByUser();
      else          // 来自对方, 被动滑动不响应
        onScrolledByInvoked();
    }
    @Override
    public void onScrolledByUser() {
      dispatchItemSelectedEvent(mCurPosition);  // 来自用户, 通知 对方 联动
    }
  }
}

public class LinkedLayout extends LinearLayout implements EventDispatcher {
  private BaseScrollableContainer mTabContainer;
  private BaseScrollableContainer mContentContainer;
  private SectionIndexer mSectionIndexer; // 分组接口
  ...
  @Override
  public void dispatchItemSelectedEvent(int pos, View fromView) {
    if (fromView == mContentContainer.mViewGroup) { // 来自 content, 转发给 tab
      int convertPos = mSectionIndexer.getSectionForPosition(pos);
      mTabContainer.selectItem(convertPos);
    } else {          // 来自 tab, 转发给 content
      int convertPos = mSectionIndexer.getPositionForSection(pos);
      mContentContainer.selectItem(convertPos);
    }
  }
}