RecycleView横向来回自动滚动

以下做出两处改动
1.添加每次滚动距离设置
2.实现来回滚动
3.代码使用kotlin

import android.content.Context
import android.os.Build
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.animation.LinearInterpolator
import androidx.annotation.RequiresApi
import androidx.recyclerview.widget.RecyclerView
import java.lang.ref.WeakReference

class AutoPollRecyclerView(context: Context, attrs: AttributeSet?) : RecyclerView(context, attrs) {
    internal var autoPollTask: AutoPollTask
    private var running: Boolean = false //标示是否正在自动轮询
    private var canRun: Boolean = false//标示是否可以自动轮询,可在不需要的是否置false
    //改动1:添加每次滚动距离设置
    var distanceOnce = 550
        set(value) {
            autoPollTask = AutoPollTask(this, value)
        }

    init {
        autoPollTask = AutoPollTask(this, distanceOnce)
    }

    internal class AutoPollTask//使用弱引用持有外部类引用->防止内存泄漏
    (reference: AutoPollRecyclerView, private val distanceOnce: Int) : Runnable {
        private val mReference: WeakReference<AutoPollRecyclerView> = WeakReference(reference)
        private var isScrollToEnd = false

        @RequiresApi(Build.VERSION_CODES.M)
        override fun run() {
            val recyclerView = mReference.get()
            if (recyclerView != null && recyclerView.running && recyclerView.canRun) {
        		//改动2:实现来回滚动
                if (recyclerView.computeHorizontalScrollExtent() + recyclerView.computeHorizontalScrollOffset() >= recyclerView.computeHorizontalScrollRange()) {
                    isScrollToEnd = true
                } else if (recyclerView.computeHorizontalScrollOffset() == 0) {
                    isScrollToEnd = false
                }
                recyclerView.smoothScrollBy(if (isScrollToEnd) {
                    -distanceOnce
                } else {
                    distanceOnce
                }, 0, LinearInterpolator())
                recyclerView.postDelayed(recyclerView.autoPollTask, TIME_AUTO_POLL)
            }
        }
    }

    //开启:如果正在运行,先停止->再开启
    fun start() {
        if (running)
            stop()
        canRun = true
        running = true
        postDelayed(autoPollTask, TIME_AUTO_POLL)
    }

    fun stop() {
        running = false
        removeCallbacks(autoPollTask)
    }

    override fun onTouchEvent(e: MotionEvent): Boolean {
        when (e.action) {
            MotionEvent.ACTION_DOWN -> if (running)
                stop()
            MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL, MotionEvent.ACTION_OUTSIDE -> if (canRun)
                start()
        }
        return super.onTouchEvent(e)
    }

    companion object {
        private val TIME_AUTO_POLL: Long = 2000
    }
}

感谢
参考文档:https://blog.csdn.net/merbn/article/details/97146937