Add DB cleaning after refreshing the character list.

Change Pagers configurations.
Recompile apk-file.

README.md

@@ -9,5 +9,4 @@ The application uses the modern Material Design 3 component library, and because
 https://gitlab.fel.cvut.cz/barysole/ackee-test-task/-/blob/master/apk/app-release.apk
 
 ## KNOWING ISSUES
-- Problem: The characters list doesn't save its scrolling position after navigating to the character detail screen and back.
-Analysis: LazyColumn gets the characters list from the ViewModel flow by using the ".collectAsLazyPagingItems()" method, and this method retrieves only part of the characters list after navigation.
+- Problem: The characters list doesn't accurately save its scrolling position after navigating to the character detail, add it to favorite and navigate back due to list recomposition.

app/src/main/java/cz/fel/barysole/ackeetesttask/db/room/dao/CharacterDao.kt

@@ -31,4 +31,7 @@ interface CharacterDao {
                 "ORDER BY id ASC"
     )
     fun getCharactersByName(characterName: String): PagingSource<Int, CharacterInfo>
+
+    @Query("DELETE FROM CharacterInfo WHERE isFavorite = 0")
+    suspend fun deleteNotFavorite()
 }
\ No newline at end of file

app/src/main/java/cz/fel/barysole/ackeetesttask/repository/characters/CharacterRemoteMediator.kt

@@ -65,6 +65,9 @@ class CharacterRemoteMediator(
             val response = rickAndMortyApi.getAllCharacters(requiredPage)
             val endOfPaginationReached = response.paginationInfo?.next == null
             appDatabase.withTransaction {
+                if (loadType == LoadType.REFRESH) {
+                    appDatabase.characterDao().deleteNotFavorite()
+                }
                 appDatabase.paginationDao().insert(
                     PaginationInfo(
                         PaginationDataType.SearchCharacterPagination.paginationName,

app/src/main/java/cz/fel/barysole/ackeetesttask/repository/characters/CharacterRepositoryImpl.kt

@@ -26,7 +26,8 @@ class CharacterRepositoryImpl @Inject constructor(
         return Pager(
             config = PagingConfig(
                 pageSize = NETWORK_PAGE_SIZE,
-                enablePlaceholders = false
+                prefetchDistance = NETWORK_PAGE_SIZE,
+                initialLoadSize = NETWORK_PAGE_SIZE
             ),
             pagingSourceFactory = {
                 CharactersSearchPagingSource(
@@ -40,7 +41,9 @@ class CharacterRepositoryImpl @Inject constructor(
     override fun getCharactersFlow(): Flow<PagingData<CharacterInfo>> {
         @OptIn(ExperimentalPagingApi::class)
         return Pager(
-            config = PagingConfig(pageSize = NETWORK_PAGE_SIZE, enablePlaceholders = false),
+            config = PagingConfig(pageSize = NETWORK_PAGE_SIZE,
+                prefetchDistance = NETWORK_PAGE_SIZE,
+                initialLoadSize = NETWORK_PAGE_SIZE),
             remoteMediator = CharacterRemoteMediator(
                 rickAndMortyApi,
                 appDatabase
@@ -53,7 +56,8 @@ class CharacterRepositoryImpl @Inject constructor(
         return Pager(
             config = PagingConfig(
                 pageSize = NETWORK_PAGE_SIZE,
-                enablePlaceholders = false
+                prefetchDistance = NETWORK_PAGE_SIZE,
+                initialLoadSize = NETWORK_PAGE_SIZE
             ),
             pagingSourceFactory = { appDatabase.characterDao().getFavorite() }
         ).flow

app/src/main/java/cz/fel/barysole/ackeetesttask/ui/screen/favorite/FavoriteCharacterListScreen.kt

@@ -21,12 +21,11 @@ fun FavoriteCharacterListScreen(
     onSelectItem: (id: Long) -> Unit,
     favoriteCharacterListViewModel: FavoriteCharacterListViewModel = hiltViewModel()
 ) {
-    favoriteCharacterListViewModel.refreshList()
-    val favoriteCharacters =
-        favoriteCharacterListViewModel.favoriteCharactersPDFlow.collectAsLazyPagingItems()
     Surface(
         color = MaterialTheme.colorScheme.background
     ) {
+        val favoriteCharacters =
+            favoriteCharacterListViewModel.favoriteCharactersPDFlow.collectAsLazyPagingItems()
         if (favoriteCharacters.itemCount == 0) {
             Column(
                 modifier = Modifier

app/src/main/java/cz/fel/barysole/ackeetesttask/ui/uielement/character/CharacterList.kt

 package cz.fel.barysole.ackeetesttask.ui.uielement.character
 
-import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.runtime.Composable
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.dp
 import androidx.paging.compose.LazyPagingItems
 import cz.fel.barysole.ackeetesttask.model.CharacterInfo
 
-
 @Composable
 fun CharacterList(
     characterList: LazyPagingItems<CharacterInfo>,
     onSelectItem: (id: Long) -> Unit
 ) {
-    LazyColumn(modifier = Modifier.padding(vertical = 4.dp)) {
+    LazyColumn() {
         items(
             count = characterList.itemCount,
             contentType = { if (characterList[it] == null) 1 else 0 }