解决ViewPager2内嵌套其他滑动组件冲突问题的解决

解决ViewPager2内嵌套其他滑动组件冲突问题的解决

比如开发时遇到的两层ViewPager2嵌套，内部ViewPager2无法滑动，可在内部的ViewPager2外套一层下方的NestedScrollableHost，这时可滑动内部的ViewPager2，并且滑到第一个或最后一个时，可直接带动外层ViewPager2继续滑动，可解决滑动冲突问题。
这个是Google官方提供的解决方案地址

/*
 * Copyright 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.viewpager2.integration.testapp

import android.content.Context
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
import android.view.ViewConfiguration
import android.widget.FrameLayout
import androidx.viewpager2.widget.ViewPager2
import androidx.viewpager2.widget.ViewPager2.ORIENTATION_HORIZONTAL
import kotlin.math.absoluteValue
import kotlin.math.sign

/**
 * Layout to wrap a scrollable component inside a ViewPager2. Provided as a solution to the problem
 * where pages of ViewPager2 have nested scrollable elements that scroll in the same direction as
 * ViewPager2. The scrollable element needs to be the immediate and only child of this host layout.
 *
 * This solution has limitations when using multiple levels of nested scrollable elements
 * (e.g. a horizontal RecyclerView in a vertical RecyclerView in a horizontal ViewPager2).
 */
class NestedScrollableHost : FrameLayout {
   
   
    constru