android: move Pager into a ViewModel

android/build.gradle.kts

@@ -17,6 +17,7 @@ dependencies {
   implementation(libs.androidx.activity.compose)
   implementation(libs.androidx.appcompat)
   implementation(libs.androidx.coreKtx)
+  implementation(libs.androidx.lifecycle.compose)
   implementation(libs.androidx.paging.compose)
   implementation(libs.dagger.hilt.android)
   implementation(libs.retrofit.moshiConverter)

android/src/main/kotlin/dev/msfjarvis/claw/android/MainActivity.kt

@@ -4,29 +4,22 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.core.view.WindowCompat
-import androidx.paging.Pager
-import androidx.paging.PagingConfig
 import dagger.hilt.android.AndroidEntryPoint
-import dev.msfjarvis.claw.android.paging.LobstersPagingSource
 import dev.msfjarvis.claw.android.ui.LobstersApp
-import dev.msfjarvis.claw.api.LobstersApi
 import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
 import javax.inject.Inject
 
 @AndroidEntryPoint
 class MainActivity : ComponentActivity() {
-  @Inject lateinit var api: LobstersApi
 
   @Inject lateinit var urlLauncher: UrlLauncher
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     WindowCompat.setDecorFitsSystemWindows(window, false)
-    val pager = Pager(PagingConfig(20)) { LobstersPagingSource(api::getHottestPosts) }
     setContent {
       LobstersApp(
-        pager,
-        urlLauncher,
+        urlLauncher = urlLauncher,
       )
     }
   }

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt

@@ -15,19 +15,19 @@ import androidx.compose.runtime.SideEffect
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
+import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.paging.LoadState
-import androidx.paging.Pager
 import androidx.paging.compose.collectAsLazyPagingItems
 import com.google.accompanist.insets.ProvideWindowInsets
 import com.google.accompanist.insets.statusBarsPadding
 import com.google.accompanist.systemuicontroller.rememberSystemUiController
-import dev.msfjarvis.claw.api.model.LobstersPost
+import dev.msfjarvis.claw.android.viewmodel.ClawViewModel
 import dev.msfjarvis.claw.common.theme.LobstersTheme
 import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
 
 @Composable
 fun LobstersApp(
-  pager: Pager<Int, LobstersPost>,
+  viewModel: ClawViewModel = viewModel(),
   urlLauncher: UrlLauncher,
 ) {
   val systemUiController = rememberSystemUiController()
@@ -40,7 +40,7 @@ fun LobstersApp(
       SideEffect {
         systemUiController.setSystemBarsColor(color = systemBarsColor, darkIcons = useDarkIcons)
       }
-      val items = pager.flow.collectAsLazyPagingItems()
+      val items = viewModel.pagerFlow.collectAsLazyPagingItems()
       Scaffold(
         scaffoldState = scaffoldState,
         topBar = { ClawAppBar(modifier = Modifier.statusBarsPadding()) },
@@ -49,7 +49,7 @@ fun LobstersApp(
         if (items.loadState.refresh != LoadState.Loading) {
           NetworkPosts(
             items = items,
-            urlLauncher = urlLauncher,
+            launchUrl = urlLauncher::launch,
             modifier = Modifier.padding(top = 16.dp),
           )
         } else {

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/NetworkPosts.kt

@@ -15,7 +15,7 @@ import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
 @Composable
 fun NetworkPosts(
   items: LazyPagingItems<LobstersPost>,
-  urlLauncher: UrlLauncher,
+  launchUrl: (String) -> Unit,
   modifier: Modifier = Modifier,
 ) {
   LazyColumn(
@@ -26,8 +26,8 @@ fun NetworkPosts(
         LobstersCard(
           post = item.toDbModel(),
           isSaved = false,
-          viewPost = { urlLauncher.launch(item.url.ifEmpty { item.commentsUrl }) },
-          viewComments = { urlLauncher.launch(item.commentsUrl) },
+          viewPost = { launchUrl(item.url.ifEmpty { item.commentsUrl }) },
+          viewComments = { launchUrl(item.commentsUrl) },
           toggleSave = {},
           modifier = Modifier.padding(bottom = 16.dp, start = 16.dp, end = 16.dp),
         )

android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt

@@ -0,0 +1,19 @@
+package dev.msfjarvis.claw.android.viewmodel
+
+import androidx.lifecycle.ViewModel
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import dagger.hilt.android.lifecycle.HiltViewModel
+import dev.msfjarvis.claw.android.paging.LobstersPagingSource
+import dev.msfjarvis.claw.api.LobstersApi
+import javax.inject.Inject
+
+@HiltViewModel
+class ClawViewModel @Inject constructor(
+  api: LobstersApi,
+) : ViewModel() {
+  private val pager = Pager(PagingConfig(20)) { LobstersPagingSource(api::getHottestPosts) }
+
+  val pagerFlow
+    get() = pager.flow
+}