Как синхронизировать прокрутку первых позиций из 2 RecyclerViews?

Ответ 1

Объединяя два RecyclerView s, есть четыре случая движения:

а. Прокрутка горизонтального ресайклера влево

б. Прокрутка вправо

с. Прокрутка вертикального ресайклера вверху

д. Прокрутка к нижней части

Случаи a и c не нужно заботиться, так как они работают из коробки. Для случаев b и d вам нужно сделать две вещи:

• Знайте, в каком ресайклере вы находитесь (вертикальный или горизонтальный), а в каком направлении прокрутка (вверх или вниз или влево или вправо) и
• вычислить смещение (элементов списка) из числа видимых элементов в otherRecyclerView (если экран больше, смещение также должно быть больше).

Полагая, что это было немного странно, но результат довольно прямолинейный.

    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
            if (masterView == otherRecyclerView) {
                thisRecyclerView.stopScroll();
                otherRecyclerView.stopScroll();
                syncScroll(1, 1);
            }
            masterView = thisRecyclerView;
        } else if (newState == RecyclerView.SCROLL_STATE_IDLE && masterView == thisRecyclerView) {
            masterView = null;
        }
    }

    @Override
    public void onScrolled(RecyclerView recyclerview, int dx, int dy) {
        super.onScrolled(recyclerview, dx, dy);
        if ((dx == 0 && dy == 0) || (masterView != null && masterView != thisRecyclerView)) {
            return;
        }
        syncScroll(dx, dy);
    }

    void syncScroll(int dx, int dy) {
        LinearLayoutManager otherLayoutManager = (LinearLayoutManager) otherRecyclerView.getLayoutManager();
        LinearLayoutManager thisLayoutManager = (LinearLayoutManager) thisRecyclerView.getLayoutManager();
        int offset = 0;
        if ((thisLayoutManager.getOrientation() == HORIZONTAL && dx > 0) || (thisLayoutManager.getOrientation() == VERTICAL && dy > 0)) {
            // scrolling horizontal recycler to left or vertical recycler to bottom
            offset = otherLayoutManager.findLastCompletelyVisibleItemPosition() - otherLayoutManager.findFirstCompletelyVisibleItemPosition();
        }
        int currentItem = thisLayoutManager.findFirstCompletelyVisibleItemPosition();
        otherLayoutManager.scrollToPositionWithOffset(currentItem, offset);
    }

Конечно, вы могли бы объединить два предложения if, поскольку тела одинаковы. Ради удобочитаемости я подумал, что хорошо держать их в стороне.

if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
    if (masterView == otherRecyclerView) {
        thisRecyclerView.stopScroll();
        otherRecyclerView.stopScroll();
        syncScroll(1, 1);
    }
    masterView = thisRecyclerView;
}

newState равно SCROLL_STATE_DRAGGING, когда ресайклеров коснулся и немного потянул. Поэтому, если это касание (& drag) после касания соответствующего "другого" ресайклера, второе условие (masterView == otherRecyclerview) истинно. Оба ресайклера останавливаются тогда, а "другой" повторитель синхронизируется с "this" одним.

Ответ 2

1-) Менеджер макетов

Текущая smoothScrollToPosition не возвращает элемент вверх. Поэтому напишите новый менеджер макетов. И пусть переопределить этот менеджер макетов smoothScrollToPosition.

public class TopLinearLayoutManager extends LinearLayoutManager
{
    public TopLinearLayoutManager(Context context, int orientation)
    {
        //orientation : vertical or horizontal
        super(context, orientation, false);
    }

    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position)
    {
        RecyclerView.SmoothScroller smoothScroller = new TopSmoothScroller(recyclerView.getContext());
        smoothScroller.setTargetPosition(position);
        startSmoothScroll(smoothScroller);
    }

    private class TopSmoothScroller extends LinearSmoothScroller
    {
        TopSmoothScroller(Context context)
        {
            super(context);
        }

        @Override
        public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference)
        {
            return (boxStart - viewStart);
        }
    }
}

2-) Настройка

    //horizontal one
    RecyclerView rvMario = (RecyclerView) findViewById(R.id.rvMario);

    //vertical one
    RecyclerView rvLuigi = (RecyclerView) findViewById(R.id.rvLuigi);

    final LinearLayoutManager managerMario = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
    rvMario.setLayoutManager(managerMario);
    ItemMarioAdapter adapterMario = new ItemMarioAdapter(itemList);
    rvMario.setAdapter(adapterMario);

     //Snap to start by using Ruben Sousa RecyclerViewSnap
    SnapHelper snapHelper = new GravitySnapHelper(Gravity.START);
    snapHelper.attachToRecyclerView(rvMario);

    final TopLinearLayoutManager managerLuigi = new TopLinearLayoutManager(MainActivity.this, LinearLayoutManager.VERTICAL);
    rvLuigi.setLayoutManager(managerLuigi);
    ItemLuigiAdapter adapterLuigi = new ItemLuigiAdapter(itemList);
    rvLuigi.setAdapter(adapterLuigi);

3-) Прокручивающий прослушиватель

rvMario.addOnScrollListener(new RecyclerView.OnScrollListener()
{
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy)
    {
     super.onScrolled(recyclerView, dx, dy);

     //get firstCompleteleyVisibleItemPosition
     int firstCompleteleyVisibleItemPosition = managerMario.findFirstCompletelyVisibleItemPosition();

     if (firstCompleteleyVisibleItemPosition >= 0)
     {  
      //vertical one, smooth scroll to position
      rvLuigi.smoothScrollToPosition(firstCompleteleyVisibleItemPosition);
     }
    }

    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState)
    {
     super.onScrollStateChanged(recyclerView, newState);
    }
});

4-) Выход

Ответ 3

Если у вас есть просмотр главного ресайклера (который будет получать действия прокрутки пользователя), вы можете использовать нижеприведенный код для реализации необходимой функциональности

masterRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                int firstCompletelyVisiblePosition = layoutManager.findFirstVisibleItemPosition();
                slaveRecyclerView.smoothScrollToPosition(pos);
            }
        });

Ответ 4

Основываясь на Бураке TopLinearLayoutManager, но исправляя логику OnScrollListener, мы, наконец, получаем гладкое и правильное привязку (горизонтальное RecyclerView).

public class MainActivity extends AppCompatActivity {
    View masterView = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity);
        final LayoutInflater inflater = LayoutInflater.from(this);
        final RecyclerView topRecyclerView = findViewById(R.id.topReccyclerView);
        RecyclerView.Adapter adapterTop = new RecyclerView.Adapter<RecyclerView.ViewHolder>() {
            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return new ViewHolder(inflater.inflate(R.layout.horizontal_cell, parent, false));
            }

            @Override
            public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
                ((TextView) holder.itemView).setText(String.valueOf(position));
                holder.itemView.setBackgroundColor(position % 2 == 0 ? Integer.valueOf(0xffff0000) : Integer.valueOf(0xff00ff00));
            }

            @Override
            public int getItemCount() {
                return 100;
            }

            class ViewHolder extends RecyclerView.ViewHolder {
                final TextView textView;

                ViewHolder(View itemView) {
                    super(itemView);
                    textView = itemView.findViewById(R.id.textView);
                }
            }
        };
        topRecyclerView.setAdapter(adapterTop);

        final RecyclerView bottomRecyclerView = findViewById(R.id.bottomRecyclerView);
        RecyclerView.Adapter adapterBottom = new RecyclerView.Adapter() {
            int baseHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 50f, getResources().getDisplayMetrics());

            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return new ViewHolder(inflater.inflate(R.layout.vertical_cell, parent, false));
            }

            @Override
            public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
                ((TextView) holder.itemView).setText(String.valueOf(position));
                holder.itemView.setBackgroundColor((position % 2 == 0) ? Integer.valueOf(0xffff0000) : Integer.valueOf(0xff00ff00));
                holder.itemView.getLayoutParams().height = baseHeight + (position % 3 == 0 ? 0 : baseHeight / (position % 3));
            }

            @Override
            public int getItemCount() {
                return 100;
            }

            class ViewHolder extends RecyclerView.ViewHolder {
                final TextView textView;

                ViewHolder(View itemView) {
                    super(itemView);
                    textView = itemView.findViewById(R.id.textView);
                }
            }
        };
        bottomRecyclerView.setAdapter(adapterBottom);

        TopLinearLayoutManager topLayoutManager = new TopLinearLayoutManager(this, LinearLayoutManager.HORIZONTAL);
        topRecyclerView.setLayoutManager(topLayoutManager);
        TopLinearLayoutManager bottomLayoutManager = new TopLinearLayoutManager(this, LinearLayoutManager.VERTICAL);
        bottomRecyclerView.setLayoutManager(bottomLayoutManager);

        final OnScrollListener topOnScrollListener = new OnScrollListener(topRecyclerView, bottomRecyclerView);
        final OnScrollListener bottomOnScrollListener = new OnScrollListener(bottomRecyclerView, topRecyclerView);
        topRecyclerView.addOnScrollListener(topOnScrollListener);
        bottomRecyclerView.addOnScrollListener(bottomOnScrollListener);

        GravitySnapHelper snapHelperTop = new GravitySnapHelper(Gravity.START);
        snapHelperTop.attachToRecyclerView(topRecyclerView);
    }

    class OnScrollListener extends RecyclerView.OnScrollListener {
        private RecyclerView thisRecyclerView;
        private RecyclerView otherRecyclerView;
        int lastItemPos = Integer.MIN_VALUE;

        OnScrollListener(RecyclerView thisRecyclerView, RecyclerView otherRecyclerView) {
            this.thisRecyclerView = thisRecyclerView;
            this.otherRecyclerView = otherRecyclerView;
        }

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
            if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
                masterView = thisRecyclerView;
            } else if (newState == RecyclerView.SCROLL_STATE_IDLE && masterView == thisRecyclerView) {
                masterView = null;
                lastItemPos = Integer.MIN_VALUE;
            }
        }

        @Override
        public void onScrolled(RecyclerView recyclerview, int dx, int dy) {
            super.onScrolled(recyclerview, dx, dy);
            if ((dx == 0 && dy == 0) || (masterView != thisRecyclerView)) {
                return;
            }
            int currentItem = ((TopLinearLayoutManager) thisRecyclerView.getLayoutManager()).findFirstCompletelyVisibleItemPosition();
            if (lastItemPos == currentItem) {
                return;
            }
            lastItemPos = currentItem;
            otherRecyclerView.getLayoutManager().smoothScrollToPosition(otherRecyclerView, null, currentItem);
        }
    }
}

Ответ 5

Еще одно простое решение, прекрасно работающее на моем устройстве

Переменная

RecyclerView horizontalRecyclerView, verticalRecyclerView;
LinearLayoutManager horizontalLayoutManager, verticalLayoutManager;

ArrayList<String> arrayList = new ArrayList<>();
ArrayList<String> arrayList2 = new ArrayList<>();

RecyclerView код

horizontalRecyclerView = findViewById(R.id.horizontalRc);
verticalRecyclerView = findViewById(R.id.verticalRc);

horizontalRecyclerView.setHasFixedSize(true);
verticalRecyclerView.setHasFixedSize(true);

horizontalLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
verticalLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);

horizontalRecyclerView.setLayoutManager(horizontalLayoutManager);
verticalRecyclerView.setLayoutManager(verticalLayoutManager);

for (int i = 0; i < 50; i++) {
     arrayList.add("" + i);
     arrayList2.add("" + i);
 }

 MyDataAdapter horizontalAdapter = new MyDataAdapter(this, arrayList);
 MyDataAdapter verticalAdapter = new MyDataAdapter(this, arrayList2);

 horizontalRecyclerView.setAdapter(horizontalAdapter);
 verticalRecyclerView.setAdapter(verticalAdapter);

логика внутри RecyclerView.addOnScrollListener

 horizontalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = horizontalLayoutManager.findFirstCompletelyVisibleItemPosition();
                verticalLayoutManager.scrollToPositionWithOffset(pos, 20);

            }

        });


        verticalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = verticalLayoutManager.findFirstCompletelyVisibleItemPosition();
                horizontalLayoutManager.scrollToPositionWithOffset(pos, 20);


            }
        });

Надеюсь, что это поможет кому-то

ЦЕЛЬ

public class Main4Activity extends AppCompatActivity {

    RecyclerView horizontalRecyclerView, verticalRecyclerView;
    LinearLayoutManager horizontalLayoutManager, verticalLayoutManager;

    ArrayList<String> arrayList = new ArrayList<>();
    ArrayList<String> arrayList2 = new ArrayList<>();

    boolean isVertical = true, isHorizontal = true;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main4);


        horizontalRecyclerView = findViewById(R.id.horizontalRc);
        verticalRecyclerView = findViewById(R.id.verticalRc);

        horizontalRecyclerView.setHasFixedSize(true);
        verticalRecyclerView.setHasFixedSize(true);

        horizontalLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        verticalLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);

        horizontalRecyclerView.setLayoutManager(horizontalLayoutManager);
        verticalRecyclerView.setLayoutManager(verticalLayoutManager);

        for (int i = 0; i < 50; i++) {
            arrayList.add("" + i);
            arrayList2.add("" + i);
        }

        MyDataAdapter horizontalAdapter = new MyDataAdapter(this, arrayList);
        MyDataAdapter verticalAdapter = new MyDataAdapter(this, arrayList2);

        horizontalRecyclerView.setAdapter(horizontalAdapter);
        verticalRecyclerView.setAdapter(verticalAdapter);

        horizontalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = horizontalLayoutManager.findFirstCompletelyVisibleItemPosition();
                verticalLayoutManager.scrollToPositionWithOffset(pos, 20);


            }

        });


        verticalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = verticalLayoutManager.findFirstCompletelyVisibleItemPosition();
                horizontalLayoutManager.scrollToPositionWithOffset(pos, 20);


            }
        });



       /* horizontalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = horizontalLayoutManager.findFirstCompletelyVisibleItemPosition();
                verticalLayoutManager.scrollToPositionWithOffset(pos, 20);

                *//*if (isHorizontal) {
                    int pos = horizontalLayoutManager.findFirstCompletelyVisibleItemPosition();
                    verticalLayoutManager.scrollToPositionWithOffset(pos, 20);
                    Log.e("isHorizontal", "TRUE");
                    isVertical = false;
                } else {
                    isHorizontal = true;
                }*//*

            }

           *//* @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                isVertical = true;
            }*//*
        });


        verticalRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

            *//* @Override
             public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                 super.onScrollStateChanged(recyclerView, newState);
                 isHorizontal = true;
             }
 *//*
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                int pos = verticalLayoutManager.findFirstCompletelyVisibleItemPosition();
                horizontalLayoutManager.scrollToPositionWithOffset(pos, 20);

               *//* if (isVertical) {
                    int pos = verticalLayoutManager.findFirstCompletelyVisibleItemPosition();
                    horizontalLayoutManager.scrollToPositionWithOffset(pos, 20);
                    Log.e("isVertical", "TRUE");
                    isHorizontal = false;
                } else {
                    isVertical = true;
                }*//*


            }
        });*/


    }
}

Код адаптера

public class MyDataAdapter extends RecyclerView.Adapter<MyDataAdapter.ViewHolder> {

    Context context;
    ArrayList<String> arrayList;


    public MyDataAdapter(Context context, ArrayList<String> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
    }

    @Override
    public MyDataAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.temp, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(MyDataAdapter.ViewHolder holder, int position) {

        if (position % 2 == 0) {
            holder.tvNumber.setBackgroundResource(R.color.colorGreen);
        } else {
            holder.tvNumber.setBackgroundResource(R.color.colorRed);
        }
        holder.tvNumber.setText(arrayList.get(position));
    }

    @Override
    public int getItemCount() {
        return arrayList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        TextView tvNumber;

        public ViewHolder(View itemView) {
            super(itemView);
            tvNumber = itemView.findViewById(R.id.tvNumber);
        }
    }
}

Макет действий

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


    <android.support.v7.widget.RecyclerView
        android:id="@+id/horizontalRc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:visibility="gone" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/verticalRc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="20dp"
        android:visibility="gone" />



</LinearLayout>    

temp Layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="40dp">

    <TextView
        android:id="@+id/tvNumber"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="50dp" />


</LinearLayout>

COLOR

<color name="colorGreen">#307832</color>
<color name="colorRed">#ff4c4c</color>