loop vp adapter

app/src/main/java/com/gamedog/vididin/main/fragments/HomeFragment.kt

@@ -33,6 +33,7 @@ class HomeFragment : AppViewsFragment<ViewBinding, UiState, ViewModel>(), OnSwit
 
 
 
+    //private val mViewPagerAdapter by lazy { HomeFragmentStateAdapter(this) }
     private val mViewPagerAdapter by lazy { HomeFragmentStateAdapter(this) }
 
     override fun inflateViewBinding(

app/src/main/java/com/gamedog/vididin/main/fragments/home/HomeVpLoopAdapter.kt

@@ -0,0 +1,28 @@
+package com.gamedog.vididin.main.fragments.home
+
+
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentActivity
+import androidx.viewpager2.adapter.FragmentStateAdapter
+
+
+class HomeVpLoopAdapter<T>(
+    private val activity: FragmentActivity,
+    private val dataList: List<T>,
+    private val fragmentCreatorFun: (List<T>, Int) -> Fragment
+) : FragmentStateAdapter(activity) {
+
+    companion object {
+        private const val LOOP_FRAGMENT_COUNT = 3
+    }
+
+    private val mRealPageCount = LOOP_FRAGMENT_COUNT
+
+    override fun getItemCount(): Int = Int.MAX_VALUE
+
+    override fun createFragment(position: Int): Fragment {
+        val fragmentPosition = position % mRealPageCount
+        return fragmentCreatorFun(dataList, fragmentPosition)
+    }
+
+}

app/src/main/java/com/gamedog/vididin/widget/loopViewpager/LoopPagerAdapter.kt

@@ -7,7 +7,7 @@ import androidx.viewpager2.adapter.FragmentStateAdapter
 class LoopPagerAdapter<T>(
     private val activity: FragmentActivity,
     private val dataList: List<T>,
-    private val fragmentCreatorFun: (List<T>, Int) -> Fragment // 修改点1：传入整个数据列表和真实位置, 接收一个创建Fragment的lambda，传入数据和在ViewPager中的真实位置
+    private val fragmentCreatorFun: (List<T>, Int) -> Fragment
 ) : FragmentStateAdapter(activity) {
 
     private val mRealPageCount = 3

core/architecture/src/main/java/com/ama/core/architecture/base/views/adapter/BaseFragmentStateAdapter.kt

@@ -38,16 +38,13 @@ abstract class BaseFragmentStateAdapter<T : BaseFragmentStateDiffItem>(
 
     override fun createFragment(position: Int): Fragment {
         return createFragment(position, getItem(position))
-            // 设置Fragment是否是懒加载初始化
             .setFragmentIsLazyInit(isFragmentLazyInit)
     }
 
-    // 返回对应位置的，数据项的唯一ID。
     override fun getItemId(position: Int): Long {
         return getItem(position).getItemId()
     }
 
-    // 判断给定的itemId，是否在当前数据集中。
     override fun containsItem(itemId: Long): Boolean {
         return getCurrentList().any { it.getItemId() == itemId }
     }
@@ -58,7 +55,6 @@ abstract class BaseFragmentStateAdapter<T : BaseFragmentStateDiffItem>(
         mDiffer.submitList(list)
     }
 
-    // 文章：https://blog.csdn.net/cxz200367/article/details/115032032
     fun getFragmentByIndex(position: Int) =
         if (position in 0..<itemCount) fragmentManager.findFragmentByTag("f" + getItemId(position)) else null
 

core/architecture/src/main/java/com/ama/core/architecture/util/ViewPager2Ext.kt

@@ -8,25 +8,19 @@ import kotlin.collections.isNullOrEmpty
 
 
 
-/**
+
- * 设置[list]数据和[createAdapter]创建的Adapter。
- * [offscreenPageLimit]设置预加载数量，null或小于等于0的值为无预加载、[Int.MAX_VALUE]为预加载全部、其他值为固定预加载数量。
- * 说明：使用此方法是为了解决，因为配置变更而导致的页面销毁后的还原（如：ViewPager2原来的位置等）问题，
- * ViewPager2会在setAdapter()的时候进行上次的还原，如果以先setAdapter()，后再全部通过拿到数据之后再adapter.setData()进行刷新数据，则此ViewPager2的还原则会失效。
- */
 fun <T : BaseFragmentStateDiffItem> ViewPager2.setDataOrAdapter(
-    list: List<T>?,
+    dataList: List<T>?,
     offscreenPageLimit: Int?,
     createAdapter: () -> BaseFragmentStateAdapter<T>,
 ) {
-    // 设置预加载
     setOffscreenPageLimit(
         if (offscreenPageLimit == null || offscreenPageLimit <= 0) {
             // 小值，用默认的。
             ViewPager2.OFFSCREEN_PAGE_LIMIT_DEFAULT
         } else if (offscreenPageLimit == Int.MAX_VALUE) {
             // 大值，用全部的。
-            val itemCount = (list?.size ?: 0)
+            val itemCount = (dataList?.size ?: 0)
             if (itemCount >= 2) {
                 // 2个及以上
                 itemCount - 1
@@ -41,14 +35,13 @@ fun <T : BaseFragmentStateDiffItem> ViewPager2.setDataOrAdapter(
     )
 
     if (adapter == null) {
-        // create adapter
+        if (dataList.isNullOrEmpty()) return
-        if (list.isNullOrEmpty()) return // 初始化状态，不设置下面的，防止没恢复之前保持的数据。不能使用adapter.setStateRestorationPolicy(PREVENT_WHEN_EMPTY)来替代实现，因为此ViewPager2是通过setAdapter进行恢复的。
         val fragmentStateAdapter = createAdapter()
-        fragmentStateAdapter.submitList(list)
+        fragmentStateAdapter.submitList(dataList)
-        // set adapter
+
         adapter = fragmentStateAdapter
     } else {
         // update adapter
-        adapter.asUnsafe<BaseFragmentStateAdapter<T>>().submitList(list)
+        adapter.asUnsafe<BaseFragmentStateAdapter<T>>().submitList(dataList)
     }
 }