update

Author: wzq

app/build.gradle.kts

@@ -80,6 +80,8 @@ dependencies {
     implementation(libs.androidx.room.runtime)
     ksp(libs.androidx.room.compiler)
 
+    implementation("androidx.paging:paging-compose:3.3.0-alpha02")
+
     implementation(libs.ktor.client.core)
     implementation(libs.ktor.client.okhttp)
     implementation(libs.ktor.client.content.negotiation)

app/src/main/java/com/wzq/jd/compose/app/data/ArtclePageSource.kt

@@ -0,0 +1,30 @@
+package com.wzq.jd.compose.app.data
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import com.wzq.jd.compose.app.data.model.ArticleItem
+
+/**
+ * create by wzq on 2023/12/26
+ *
+ */
+class ArticlePageSource : PagingSource<Int, ArticleItem>() {
+    override fun getRefreshKey(state: PagingState<Int, ArticleItem>): Int? {
+        return state.anchorPosition?.let { anchorPosition ->
+            val anchorPage = state.closestPageToPosition(anchorPosition)
+            anchorPage?.prevKey?.plus(1) ?: anchorPage?.nextKey?.minus(1)
+        }
+    }
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, ArticleItem> {
+        val position = params.key ?: 0
+        val resp = DataRepos.remoteRepo.getArticleList(position)
+        return resp.fold({ data ->
+            LoadResult.Page(
+                data = data.data.listData, prevKey = null, nextKey = position + 1
+            )
+        }, {
+            LoadResult.Error(throwable = it)
+        })
+    }
+}

app/src/main/java/com/wzq/jd/compose/app/page/home/HomeIndexPage.kt

@@ -4,7 +4,6 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
-import androidx.compose.foundation.lazy.items
 import androidx.compose.material3.Card
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.MaterialTheme
@@ -13,30 +12,30 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.toArgb
 import androidx.compose.ui.unit.dp
+import androidx.paging.PagingData
+import androidx.paging.compose.collectAsLazyPagingItems
+import androidx.paging.compose.itemKey
 import com.wzq.jd.compose.app.data.model.ArticleItem
-import com.wzq.jd.compose.app.page.LoadScreen
 import com.wzq.jd.compose.app.page.PageState
 import com.wzq.jd.compose.app.ui.widget.HtmlText
 import io.ktor.http.encodeURLPath
+import kotlinx.coroutines.flow.Flow
 
 /**
  * create by wzq on 2023/11/27
  *
  */
 @Composable
-fun HomeIndexPage(state: PageState<List<ArticleItem>>, onItemClick: (String) -> Unit) {
-    when(state) {
-        PageState.Loading -> {
-            LoadScreen()
+fun HomeIndexPage(
+    state: PageState<List<ArticleItem>>,
+    onItemClick: (String) -> Unit,
+    pageData: Flow<PagingData<ArticleItem>>
+) {
+    val lazyPagingItems = pageData.collectAsLazyPagingItems()
+    LazyColumn {
+        items(lazyPagingItems.itemCount, lazyPagingItems.itemKey()) {
+            ArticleItemPage(itemData = lazyPagingItems[it]!!, onItemClick)
         }
-        is PageState.Success -> {
-            LazyColumn(content = {
-                items(state.data) {
-                    ArticleItemPage(itemData = it, onItemClick)
-                }
-            })
-        }
-        else -> {}
     }
 
 }

app/src/main/java/com/wzq/jd/compose/app/page/home/HomeScreen.kt

@@ -57,6 +57,7 @@ fun HomeScreen(viewModel: HomeViewModel, navActions: NavActions) {
             when (currentPagerNum) {
                 0 -> HomeIndexPage(
                     state = viewModel.indexState.value,
+                    pageData = viewModel.pager,
                     onItemClick = { navActions.toWebScreen(it) })
 
                 1 -> HomeProjectPage(

app/src/main/java/com/wzq/jd/compose/app/page/home/HomeViewModel.kt

@@ -4,6 +4,10 @@ import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.cachedIn
+import com.wzq.jd.compose.app.data.ArticlePageSource
 import com.wzq.jd.compose.app.data.DataRepos
 import com.wzq.jd.compose.app.data.local.AppDatabase
 import com.wzq.jd.compose.app.data.model.ArticleItem
@@ -31,12 +35,16 @@ class HomeViewModel : ViewModel() {
         getCategories()
     }
 
+    val pager = Pager(PagingConfig(20), 0) {
+        ArticlePageSource()
+    }.flow.cachedIn(viewModelScope)
+
     private fun getArticleList(pageNum: Int = 0) {
-        viewModelScope.launch {
-            DataRepos.remoteRepo.getArticleList(pageNum)
-                .onSuccess { indexState.value = PageState.Success(it.data.listData) }
-                .onFailure { indexState.value = PageState.Failure(it) }
-        }
+//        viewModelScope.launch {
+//            DataRepos.remoteRepo.getArticleList(pageNum)
+//                .onSuccess { indexState.value = PageState.Success(it.data.listData) }
+//                .onFailure { indexState.value = PageState.Failure(it) }
+//        }
     }
 
     private fun getProjectList() {