可以无限滚动，支持自动滚动，设置滚动一屏幕时间的LayoutManger

可以无限滚动，支持自动滚动，设置滚动一屏幕时间的LayoutManger

package com.trs.v7.home.toutiao_v2.provider.layout_manager;


import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;

import androidx.recyclerview.widget.PagerSnapHelper;
import androidx.recyclerview.widget.RecyclerView;

import com.trs.news.R;


public class LooperLayoutManager extends RecyclerView.LayoutManager {
    private static final String TAG = "LooperLayoutManager";
    private boolean looperEnable = true;
    private RecyclerView recyclerView;
    //    private Handler mCyclicRollHandler;
    private int pixNumberPer10ms = 3;//每10毫秒移动的像素值
    private boolean autoScroll = true;
    private PagerSnapHelper snapHelper;

    public LooperLayoutManager(RecyclerView recyclerView) {
        this(recyclerView, true, true, 8000);
    }

    public LooperLayoutManager(RecyclerView recyclerView, boolean looperEnable, boolean autoScroll, int scrollOneScreenUseTimeInMilliSeconds) {
        this.looperEnable = looperEnable;
        this.autoScroll = true;
        this.recyclerView = recyclerView;
        clearLooperInfo(recyclerView);
        LooperInfo looperInfo=new LooperInfo();
        looperInfo.onScrollListener=onScrollListener;
        recyclerView.addOnScrollListener(onScrollListener);
        looperInfo.onAttachStateChangeListener=attachStateChangeListener;
        this.recyclerView.addOnAttachStateChangeListener(attachStateChangeListener);
        int widthPixels = recyclerView.getResources().getDisplayMetrics().widthPixels;
        //毫秒
        pixNumberPer10ms = (int) (widthPixels * 1.0f / scrollOneScreenUseTimeInMilliSeconds * 10);
        pixNumberPer10ms = Math.max(1, pixNumberPer10ms);//最低一个像素
        if (!autoScroll) {
            //添加snap实现自动停在item中间的功能
            recyclerView.setOnFlingListener(null);
            snapHelper = new PagerSnapHelper();
            snapHelper.attachToRecyclerView(recyclerView);
            looperInfo.pagerSnapHelper=snapHelper;
        }
        looperInfo.runnable=cycleRollRunnable;
        bindLooperInfo(recyclerView,looperInfo);
    }

    private void clearLooperInfo(RecyclerView recyclerView) {
        Object tag = recyclerView.getTag(R.id.looper_info);
        if(tag instanceof LooperInfo){
            LooperInfo looperInfo= (LooperInfo) tag;
            recyclerView.removeOnScrollListener(looperInfo.onScrollListener);
            recyclerView.removeOnAttachStateChangeListener(looperInfo.onAttachStateChangeListener);
            if(looperInfo.pagerSnapHelper!=null) {
                looperInfo.pagerSnapHelper.attachToRecyclerView(null);
            }
            recyclerView.removeCallbacks(looperInfo.runnable);
            recyclerView.setTag(R.id.looper_info,null);
        }

    }

    private void bindLooperInfo(RecyclerView recyclerView,LooperInfo looperInfo){
        recyclerView.setTag(R.id.looper_info,looperInfo);
    }

    private static class LooperInfo{
        PagerSnapHelper pagerSnapHelper;
        RecyclerView.OnScrollListener onScrollListener;
        View.OnAttachStateChangeListener onAttachStateChangeListener;
        Runnable runnable;
    }

    //当recycleView出现在屏幕上的时候自动滚动，脱离屏幕取消消息，避免内存泄漏
    private View.OnAttachStateChangeListener attachStateChangeListener = new View.OnAttachStateChangeListener() {
        @Override
        public void onViewAttachedToWindow(View v) {
            recyclerView.removeCallbacks(cycleRollRunnable);
            recyclerView.setTag(R.id.tv_title,cycleRollRunnable);
            recyclerView.postDelayed(cycleRollRunnable, 1000);

        }

        @Override
        public void onViewDetachedFromWindow(View v) {
            recyclerView.removeCallbacks(cycleRollRunnable);
        }
    };


    @Override
    public boolean isAutoMeasureEnabled() {
        return true;
    }

    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public boolean canScrollHorizontally() {
        return true;
    }

    @Override
    public boolean canScrollVertically() {
        return false;
    }

    Runnable cycleRollRunnable = new Runnable() {
        @Override
        public void run() {
            if (autoScroll) {
                recyclerView.scrollBy(pixNumberPer10ms, 0);
                Object tag = recyclerView.getTag(R.id.tv_title);
                if(tag==this) {
                    recyclerView.postDelayed(this, 10);
                }
            }
        }
    };



    RecyclerView.OnScrollListener onScrollListener = new RecyclerView.OnScrollListener() {
        private boolean dragging;

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
            if (newState == RecyclerView.SCROLL_STATE_DRAGGING) {
                //Dragging
                recyclerView.removeCallbacks(cycleRollRunnable);
                dragging = true;
            } else if (newState == RecyclerView.SCROLL_STATE_IDLE) {
                if (dragging) {
                    dragging = false;
                    recyclerView.removeCallbacks(cycleRollRunnable);
                    recyclerView.setTag(R.id.tv_title,cycleRollRunnable);
                    recyclerView.postDelayed(cycleRollRunnable, 1000);
                }
            }
        }

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


    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() <= 0) {
            return;
        }
        //preLayout主要支持动画，直接跳过
        if (state.isPreLayout()) {
            return;
        }
        //将视图分离放入scrap缓存中，以准备重新对view进行排版
        detachAndScrapAttachedViews(recycler);

        int autualWidth = 0;

        for (int i = 0; i < getItemCount(); i++) {
            //初始化，将在屏幕内的view填充
            View itemView = recycler.getViewForPosition(i);
            addView(itemView);
            //测量itemView的宽高
            measureChildWithMargins(itemView, 0, 0);
            RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) itemView.getLayoutParams();
            int width = getDecoratedMeasuredWidth(itemView) ;
            int height = getDecoratedMeasuredHeight(itemView);
            int left=autualWidth;
            int right=autualWidth+width+lp.rightMargin+lp.leftMargin;
            int top=0;
            int bottom=height+lp.topMargin+lp.bottomMargin;

            layoutDecoratedWithMargins(itemView, left, top, right, bottom);

            autualWidth = right;
            //如果当前布局过的itemView的宽度总和大于RecyclerView的宽，则不再进行布局
           /* if (autualWidth > getWidth()) {
                break;
            }*/
        }
    }

    @Override
    public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
        //1.左右滑动的时候，填充子view
        int travl = fill(dx, recycler, state);
        if (travl == 0) {
            return 0;
        }

        //2.滚动
        offsetChildrenHorizontal(travl * -1);

        //3.回收已经离开界面的
        recyclerHideView(dx, recycler, state);
        return travl;
    }



    /**
     * 左右滑动的时候，填充
     */
    private int fill(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (dx > 0) {
            //标注1.向左滚动
            View lastView = getChildAt(getChildCount() - 1);
            if (lastView == null) {
                return 0;
            }
            int lastPos = getPosition(lastView);
            //标注2.可见的最后一个itemView完全滑进来了，需要补充新的
            if (lastView.getRight() < getWidth()) {
                View scrap = null;
                //标注3.判断可见的最后一个itemView的索引，
                // 如果是最后一个，则将下一个itemView设置为第一个，否则设置为当前索引的下一个
                if (lastPos == getItemCount() - 1) {
                    if (looperEnable) {
                        scrap = recycler.getViewForPosition(0);
                    } else {
                        dx = 0;
                    }
                } else {
                    scrap = recycler.getViewForPosition(lastPos + 1);
                }
                if (scrap == null) {
                    return dx;
                }
                //标注4.将新的itemViewadd进来并对其测量和布局
                addView(scrap);
                measureChildWithMargins(scrap, 0, 0);
                RecyclerView.LayoutParams addViewLp = (RecyclerView.LayoutParams) scrap.getLayoutParams();
                RecyclerView.LayoutParams lastViewLp = (RecyclerView.LayoutParams) lastView.getLayoutParams();
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                int lastViewDecoratedRight = getRightDecorationWidth(lastView);
                int left=lastView.getRight()+lastViewDecoratedRight+lastViewLp.rightMargin;
                int right=left+width+addViewLp.rightMargin+addViewLp.leftMargin;
                int top=0;
                int bottom=height+addViewLp.bottomMargin+addViewLp.topMargin;
                layoutDecoratedWithMargins(scrap,left,top,right,bottom);
                return dx;
            }
        } else {
            //向右滚动
            View firstView = getChildAt(0);
            if (firstView == null) {
                return 0;
            }
            int firstPos = getPosition(firstView);

            if (firstView.getLeft() >= 0) {
                View scrap = null;
                if (firstPos == 0) {
                    if (looperEnable) {
                        scrap = recycler.getViewForPosition(getItemCount() - 1);
                    } else {
                        dx = 0;
                    }
                } else {
                    scrap = recycler.getViewForPosition(firstPos - 1);
                }
                if (scrap == null) {
                    return 0;
                }
                addView(scrap, 0);
                measureChildWithMargins(scrap, 0, 0);
                RecyclerView.LayoutParams addViewLp = (RecyclerView.LayoutParams) scrap.getLayoutParams();
                RecyclerView.LayoutParams firstViewLp = (RecyclerView.LayoutParams) firstView.getLayoutParams();
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                int decoratedLeft = getLeftDecorationWidth(firstView);
                int left=firstView.getLeft()-decoratedLeft-firstViewLp.leftMargin-addViewLp.rightMargin-addViewLp.leftMargin-width;
                int right=firstView.getLeft()-decoratedLeft-firstViewLp.leftMargin;
                int top=0;
                int bottom=height+addViewLp.bottomMargin+addViewLp.topMargin;
                layoutDecoratedWithMargins(scrap,left,top,right,bottom);

            }
        }
        return dx;
    }

    /**
     * 回收界面不可见的view
     */
    private void recyclerHideView(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
        for (int i = 0; i < getChildCount(); i++) {
            View view = getChildAt(i);
            if (view == null) {
                continue;
            }
            if (dx > 0) {
                //向左滚动，移除一个左边不在内容里的view
                if (view.getRight() < 0) {
                    removeAndRecycleView(view, recycler);
//                    Log.d(TAG, "循环: 移除 一个view  childCount=" + getChildCount());
                }
            } else {
                //向右滚动，移除一个右边不在内容里的view
                if (view.getLeft() > getWidth()) {
                    removeAndRecycleView(view, recycler);
//                    Log.d(TAG, "循环: 移除 一个view  childCount=" + getChildCount());
                }
            }
        }

    }
}