Merge #137

137: Add support for refreshing hottest posts r=msfjarvis a=msfjarvis

Fixes #133
bors r+

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

.gitignore

@@ -103,6 +103,7 @@ obj/
 .idea/dynamic.xml
 .idea/uiDesigner.xml
 .idea/assetWizardSettings.xml
+.idea/deploymentTargetDropDown.xml
 
 # OS-specific files
 .DS_Store

app/src/androidTest/java/dev/msfjarvis/lobsters/ui/main/LobstersTopBarTest.kt

@@ -0,0 +1,74 @@
+package dev.msfjarvis.lobsters.ui.main
+
+import androidx.compose.ui.graphics.asAndroidBitmap
+import androidx.compose.ui.test.captureToImage
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onRoot
+import com.karumi.shot.ScreenshotTest
+import dev.msfjarvis.lobsters.ui.DarkTestTheme
+import dev.msfjarvis.lobsters.ui.LightTestTheme
+import dev.msfjarvis.lobsters.ui.navigation.Destination
+import org.junit.Rule
+import org.junit.Test
+
+class LobstersTopBarTest : ScreenshotTest {
+
+  @get:Rule
+  val composeTestRule = createComposeRule()
+
+  @Test
+  fun showsRefreshIconWhenOnHottestPostsScreen_DarkTheme() {
+    composeTestRule.setContent {
+      DarkTestTheme {
+        LobstersTopBar(
+          currentDestination = Destination.Hottest,
+          reloadPosts = { /*TODO*/ }
+        )
+      }
+    }
+
+    compareScreenshot(composeTestRule.onRoot().captureToImage().asAndroidBitmap())
+  }
+
+  @Test
+  fun showsRefreshIconWhenOnHottestPostsScreen_LightTheme() {
+    composeTestRule.setContent {
+      LightTestTheme {
+        LobstersTopBar(
+          currentDestination = Destination.Hottest,
+          reloadPosts = { /*TODO*/ }
+        )
+      }
+    }
+
+    compareScreenshot(composeTestRule.onRoot().captureToImage().asAndroidBitmap())
+  }
+
+  @Test
+  fun doesNotShowRefreshIconWhenOnSavedPostsScreen_DarkTheme() {
+    composeTestRule.setContent {
+      DarkTestTheme {
+        LobstersTopBar(
+          currentDestination = Destination.Saved,
+          reloadPosts = { /*TODO*/ }
+        )
+      }
+    }
+
+    compareScreenshot(composeTestRule.onRoot().captureToImage().asAndroidBitmap())
+  }
+
+  @Test
+  fun doesNotShowRefreshIconWhenOnSavedPostsScreen_LightTheme() {
+    composeTestRule.setContent {
+      LightTestTheme {
+        LobstersTopBar(
+          currentDestination = Destination.Saved,
+          reloadPosts = { /*TODO*/ }
+        )
+      }
+    }
+
+    compareScreenshot(composeTestRule.onRoot().captureToImage().asAndroidBitmap())
+  }
+}

app/src/main/java/dev/msfjarvis/lobsters/data/remote/LobstersPagingSource.kt

@@ -4,9 +4,8 @@ import androidx.paging.PagingSource
 import androidx.paging.PagingState
 import dev.msfjarvis.lobsters.data.repo.LobstersRepository
 import dev.msfjarvis.lobsters.model.LobstersPost
-import javax.inject.Inject
 
-class LobstersPagingSource @Inject constructor(
+class LobstersPagingSource constructor(
   private val lobstersRepository: LobstersRepository,
 ) : PagingSource<Int, LobstersPost>() {
 

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

@@ -1,11 +1,14 @@
 package dev.msfjarvis.lobsters.ui.main
 
+import androidx.compose.animation.ExperimentalAnimationApi
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.BottomNavigation
 import androidx.compose.material.BottomNavigationItem
 import androidx.compose.material.Scaffold
 import androidx.compose.material.Text
+import androidx.compose.material.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
@@ -13,6 +16,7 @@ import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.compose.KEY_ROUTE
 import androidx.navigation.compose.NavHost
@@ -21,6 +25,7 @@ import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.compose.navigate
 import androidx.navigation.compose.rememberNavController
 import androidx.paging.compose.collectAsLazyPagingItems
+import dev.msfjarvis.lobsters.R
 import dev.msfjarvis.lobsters.ui.navigation.Destination
 import dev.msfjarvis.lobsters.ui.posts.HottestPosts
 import dev.msfjarvis.lobsters.ui.posts.SavedPosts
@@ -51,6 +56,12 @@ fun LobstersApp() {
   }
 
   Scaffold(
+    topBar = {
+      LobstersTopBar(
+        currentDestination = currentDestination,
+        reloadPosts = { viewModel.reloadPosts() },
+      )
+    },
     bottomBar = {
       LobstersBottomNav(
         currentDestination,
@@ -80,6 +91,33 @@ fun LobstersApp() {
   }
 }
 
+@OptIn(ExperimentalAnimationApi::class)
+@Composable
+fun LobstersTopBar(
+  currentDestination: Destination,
+  reloadPosts: () -> Unit,
+) {
+  TopAppBar(
+    title = {
+      Text(
+        text = stringResource(id = R.string.app_name),
+        modifier = Modifier.padding(vertical = 8.dp),
+      )
+    },
+    actions = {
+      if (currentDestination == Destination.Hottest) {
+        IconResource(
+          resourceId = R.drawable.ic_refresh_24px,
+          contentDescription = stringResource(id = R.string.refresh_posts_content_description),
+          modifier = Modifier
+            .padding(horizontal = 8.dp, vertical = 8.dp)
+            .clickable { reloadPosts() },
+        )
+      }
+    }
+  )
+}
+
 @Composable
 fun LobstersBottomNav(
   currentDestination: Destination,

app/src/main/java/dev/msfjarvis/lobsters/ui/viewmodel/LobstersViewModel.kt

@@ -19,13 +19,13 @@ import kotlinx.coroutines.launch
 @HiltViewModel
 class LobstersViewModel @Inject constructor(
   private val lobstersRepository: LobstersRepository,
-  private val pagingSource: LobstersPagingSource,
 ) : ViewModel() {
   private val _savedPosts = MutableStateFlow<List<SavedPost>>(emptyList())
   val savedPosts = _savedPosts.asStateFlow()
   val posts = Pager(PagingConfig(25)) {
-    pagingSource
+    LobstersPagingSource(lobstersRepository).also { pagingSource = it }
   }.flow.cachedIn(viewModelScope)
+  private var pagingSource: LobstersPagingSource? = null
 
   init {
     lobstersRepository.isCacheReady.onEach { ready ->
@@ -35,6 +35,10 @@ class LobstersViewModel @Inject constructor(
     }.launchIn(viewModelScope)
   }
 
+  fun reloadPosts() {
+    pagingSource?.invalidate()
+  }
+
   fun toggleSave(post: SavedPost) {
     viewModelScope.launch {
       val isSaved = lobstersRepository.isPostSaved(post.shortId)

app/src/main/res/drawable/ic_refresh_24px.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+  android:width="24dp"
+  android:height="24dp"
+  android:viewportWidth="24"
+  android:viewportHeight="24">
+  <path
+    android:fillColor="#FF000000"
+    android:pathData="M17.65,6.35C16.2,4.9 14.21,4 12,4c-4.42,0 -7.99,3.58 -7.99,8s3.57,8 7.99,8c3.73,0 6.84,-2.55 7.73,-6h-2.08c-0.82,2.33 -3.04,4 -5.65,4 -3.31,0 -6,-2.69 -6,-6s2.69,-6 6,-6c1.66,0 3.14,0.69 4.22,1.78L13,11h7V4l-2.35,2.35z" />
+</vector>

app/src/main/res/values/strings.xml

@@ -8,4 +8,5 @@
   <string name="avatar_content_description">%1$s\'s avatar</string>
   <string name="add_to_saved_posts">Add to saved posts</string>
   <string name="remove_from_saved_posts">Remove from saved posts</string>
+  <string name="refresh_posts_content_description">Refresh posts</string>
 </resources>