Merge #53

53: Fix pagination and extract UrlLauncherAmbient r=msfjarvis a=msfjarvis

Our pagination hack currently does not update the last index field which has now been fixed. While here we also take the time to extract UrlLauncherAmbient and prepare the post list composables for tweaking from the root UI

bors r+

Co-authored-by: Harsh Shandilya <me@msfjarvis.dev>

app/src/main/java/dev/msfjarvis/lobsters/MainActivity.kt

@@ -9,8 +9,6 @@ import androidx.compose.material.BottomNavigationItem
 import androidx.compose.material.Scaffold
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Providers
-import androidx.compose.runtime.ambientOf
-import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.platform.setContent
 import androidx.navigation.compose.KEY_ROUTE
@@ -27,10 +25,9 @@ import dev.msfjarvis.lobsters.ui.HottestPosts
 import dev.msfjarvis.lobsters.ui.LobstersTheme
 import dev.msfjarvis.lobsters.ui.SavedPosts
 import dev.msfjarvis.lobsters.urllauncher.UrlLauncher
+import dev.msfjarvis.lobsters.urllauncher.UrlLauncherAmbient
 import javax.inject.Inject
 
-val UrlLauncherAmbient = ambientOf<UrlLauncher> { error("Needs to be provided") }
-
 @AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
   @Inject lateinit var urlLauncher: UrlLauncher
@@ -53,8 +50,6 @@ fun LobstersApp(
   viewModel: LobstersViewModel
 ) {
   val urlLauncher = UrlLauncherAmbient.current
-  val posts = viewModel.posts.collectAsState()
-  val lastIndex = posts.value.lastIndex
   val navController = rememberNavController()
   val destinations = arrayOf(Destination.Hottest, Destination.Saved)
 
@@ -92,10 +87,10 @@ fun LobstersApp(
   ) {
     NavHost(navController, startDestination = Destination.Hottest.route) {
       composable(Destination.Hottest.route) {
-        HottestPosts(lastIndex = lastIndex, urlLauncher = urlLauncher , viewModel = viewModel)
+        HottestPosts(viewModel = viewModel)
       }
       composable(Destination.Saved.route) {
-        SavedPosts(urlLauncher = urlLauncher, viewModel = viewModel)
+        SavedPosts(viewModel = viewModel)
       }
     }
   }

app/src/main/java/dev/msfjarvis/lobsters/ui/HottestPosts.kt

@@ -9,16 +9,16 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import dev.msfjarvis.lobsters.data.LobstersViewModel
-import dev.msfjarvis.lobsters.urllauncher.UrlLauncher
+import dev.msfjarvis.lobsters.urllauncher.UrlLauncherAmbient
 
 @Composable
 fun HottestPosts(
-  lastIndex: Int,
-  urlLauncher: UrlLauncher,
   viewModel: LobstersViewModel,
+  modifier: Modifier = Modifier,
 ) {
   val posts by viewModel.posts.collectAsState()
   val listState = rememberLazyListState()
+  val urlLauncher = UrlLauncherAmbient.current
 
   if (posts.isEmpty()) {
     EmptyList(saved = false)
@@ -26,9 +26,9 @@ fun HottestPosts(
     LazyColumnForIndexed(
       items = posts,
       state = listState,
-      modifier = Modifier.padding(horizontal = 8.dp)
+      modifier = Modifier.padding(horizontal = 8.dp).then(modifier)
     ) { index, item ->
-      if (lastIndex == index) {
+      if (posts.lastIndex == index) {
         viewModel.getMorePosts()
       }
       LobstersItem(

app/src/main/java/dev/msfjarvis/lobsters/ui/SavedPosts.kt

@@ -9,15 +9,16 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import dev.msfjarvis.lobsters.data.LobstersViewModel
-import dev.msfjarvis.lobsters.urllauncher.UrlLauncher
+import dev.msfjarvis.lobsters.urllauncher.UrlLauncherAmbient
 
 @Composable
 fun SavedPosts(
-  urlLauncher: UrlLauncher,
   viewModel: LobstersViewModel,
+  modifier: Modifier = Modifier,
 ) {
   val posts by viewModel.savedPosts.collectAsState()
   val listState = rememberLazyListState()
+  val urlLauncher = UrlLauncherAmbient.current
 
   if (posts.isEmpty()) {
     EmptyList(saved = true)
@@ -25,7 +26,7 @@ fun SavedPosts(
     LazyColumnFor(
       items = posts,
       state = listState,
-      modifier = Modifier.padding(horizontal = 8.dp)
+      modifier = Modifier.padding(horizontal = 8.dp).then(modifier)
     ) { item ->
       LobstersItem(
         post = item,

app/src/main/java/dev/msfjarvis/lobsters/urllauncher/UrlLauncherAmbient.kt

@@ -0,0 +1,5 @@
+package dev.msfjarvis.lobsters.urllauncher
+
+import androidx.compose.runtime.ambientOf
+
+val UrlLauncherAmbient = ambientOf<UrlLauncher> { error("Needs to be provided") }