Merge pull request #26 from gabrielbmoro/feature/21-side-effects-afte…

…r-adding-paging-supp 21 Side effects after adding paging support
gabrielbmoro · Jul 4, 2023 · adae480 · adae480
2 parents 5c1d153 + 90eccfd
commit adae480
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Showing 3 changed files with 100 additions and 56 deletions.
diff --git a/src/app/src/main/java/com/gabrielbmoro/programmingchallenge/ui/common/widgets/MovieList.kt b/src/app/src/main/java/com/gabrielbmoro/programmingchallenge/ui/common/widgets/MovieList.kt
@@ -2,14 +2,17 @@ package com.gabrielbmoro.programmingchallenge.ui.common.widgets
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.BoxScope
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
+import androidx.paging.LoadState
 import androidx.paging.PagingData
 import androidx.paging.compose.collectAsLazyPagingItems
 import androidx.paging.compose.itemContentType
@@ -34,63 +37,98 @@ private fun MovieListInternal(
 }
 
 @Composable
-fun MoviesListPaginated(
+fun BoxScope.MoviesListPaginated(
     lazyListState: LazyListState,
     pagingDataFlow: Flow<PagingData<Movie>>,
     onSelectMovie: ((Movie) -> Unit),
     modifier: Modifier = Modifier
 ) {
     val lazyPagingItems = pagingDataFlow.collectAsLazyPagingItems()
 
-    MovieListInternal(
-        lazyListState = lazyListState,
-        modifier = modifier,
-        itemFactory = {
-            items(
-                count = lazyPagingItems.itemCount,
-                key = lazyPagingItems.itemKey(),
-                contentType = lazyPagingItems.itemContentType()
-            ) { index ->
-
-                lazyPagingItems[index]?.let { movie ->
-                    MovieCard(
-                        imageUrl = movie.posterImageUrl,
-                        title = movie.title,
-                        votes = movie.votesAverage,
-                        description = movie.overview,
-                        onClick = { onSelectMovie(movie) }
-                    )
-                }
+    if (lazyPagingItems.loadState.refresh == LoadState.Loading) {
+        BubbleLoader(
+            modifier = Modifier.align(Alignment.Center),
+            color = MaterialTheme.colorScheme.secondary
+        )
+    } else {
+        when (lazyPagingItems.itemCount) {
+            0 -> {
+                EmptyState(
+                    modifier = Modifier.align(Alignment.Center),
+                )
+            }
+            else -> {
+                MovieListInternal(
+                    lazyListState = lazyListState,
+                    modifier = modifier,
+                    itemFactory = {
+                        items(
+                            count = lazyPagingItems.itemCount,
+                            key = lazyPagingItems.itemKey(),
+                            contentType = lazyPagingItems.itemContentType()
+                        ) { index ->
+                            lazyPagingItems[index]?.let { movie ->
+                                MovieCard(
+                                    imageUrl = movie.posterImageUrl,
+                                    title = movie.title,
+                                    votes = movie.votesAverage,
+                                    description = movie.overview,
+                                    onClick = { onSelectMovie(movie) }
+                                )
+                            }
+                        }
+                    }
+                )
             }
         }
-    )
+    }
 }
 
 @Composable
-fun MovieList(
-    movies: List<Movie>,
+fun BoxScope.MovieList(
+    movies: List<Movie>?,
     lazyListState: LazyListState,
+    isLoading: Boolean,
     onSelectMovie: (Movie) -> Unit,
     modifier: Modifier = Modifier
 ) {
-    MovieListInternal(
-        modifier = modifier,
-        lazyListState = lazyListState,
-        itemFactory = {
-            items(
-                count = movies.size,
-            ) { index ->
+    if (isLoading) {
+        BubbleLoader(
+            modifier = Modifier.align(Alignment.Center),
+            color = MaterialTheme.colorScheme.secondary
+        )
+    } else {
+        when {
+            movies?.isEmpty() == true -> {
+                EmptyState(
+                    modifier = Modifier.align(Alignment.Center),
+                )
+            }
 
-                movies[index].let { movie ->
-                    MovieCard(
-                        imageUrl = movie.posterImageUrl,
-                        title = movie.title,
-                        votes = movie.votesAverage,
-                        description = movie.overview,
-                        onClick = { onSelectMovie(movie) }
-                    )
-                }
+            else -> {
+                val moviesList = movies ?: emptyList()
+
+                MovieListInternal(
+                    modifier = modifier,
+                    lazyListState = lazyListState,
+                    itemFactory = {
+                        items(
+                            count = moviesList.size,
+                        ) { index ->
+
+                            moviesList[index].let { movie ->
+                                MovieCard(
+                                    imageUrl = movie.posterImageUrl,
+                                    title = movie.title,
+                                    votes = movie.votesAverage,
+                                    description = movie.overview,
+                                    onClick = { onSelectMovie(movie) }
+                                )
+                            }
+                        }
+                    }
+                )
             }
         }
-    )
+    }
 }
diff --git a/.../src/main/java/com/gabrielbmoro/programmingchallenge/ui/screens/home/BaseHomeScreenTab.kt b/.../src/main/java/com/gabrielbmoro/programmingchallenge/ui/screens/home/BaseHomeScreenTab.kt
@@ -8,7 +8,6 @@ import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material3.*
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.*
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
@@ -114,20 +113,13 @@ fun BaseHomeScreenTab(
                         end = 16.dp,
                     )
                 if (uiState.selectedMovieType == MovieListType.FAVORITE) {
-                    if (uiState.isLoading) {
-                        BubbleLoader(
-                            modifier = Modifier.align(Alignment.Center),
-                            color = MaterialTheme.colorScheme.secondary
-                        )
-                    } else {
-                        MovieList(
-                            movies = uiState.favoriteMovies
-                                ?: emptyList(),
-                            onSelectMovie = onSelectMovie,
-                            lazyListState = lazyListState,
-                            modifier = modifier,
-                        )
-                    }
+                    MovieList(
+                        movies = uiState.favoriteMovies,
+                        isLoading = uiState.isLoading,
+                        onSelectMovie = onSelectMovie,
+                        lazyListState = lazyListState,
+                        modifier = modifier,
+                    )
                 } else {
                     MoviesListPaginated(
                         pagingDataFlow = uiState.paginatedMovies,
@@ -154,4 +146,12 @@ fun BaseHomeScreenTab(
             }
         }
     )
+
+
+    LaunchedEffect(
+        key1 = Unit,
+        block = {
+            viewModel.setup()
+        }
+    )
 }
diff --git a/src/app/src/main/java/com/gabrielbmoro/programmingchallenge/ui/screens/home/HomeViewModel.kt b/src/app/src/main/java/com/gabrielbmoro/programmingchallenge/ui/screens/home/HomeViewModel.kt
@@ -14,7 +14,7 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
 class HomeViewModel(
-    movieListType: MovieListType,
+    private val movieListType: MovieListType,
     private val getFavoriteMoviesUseCase: GetFavoriteMoviesUseCase,
     private val getTopRatedMoviesUseCase: GetTopRatedMoviesUseCase,
     private val getPopularMoviesUseCase: GetPopularMoviesUseCase
@@ -41,6 +41,12 @@ class HomeViewModel(
         }
     }
 
+    fun setup() {
+        if(movieListType == MovieListType.FAVORITE) {
+            loadFavoriteMovies()
+        }
+    }
+
     private fun loadFavoriteMovies() {
         viewModelScope.launch {
             _uiState.update {