🚀 Automatic check for text update

* Option to enable automatic check for text update when you open book in Reader
* Navigates user to BookInfo screen if update is found
* Shows toast(up-to-date) if corresponding setting is enabled and there is not update found

app/src/main/java/ua/acclorite/book_story/presentation/core/constants/DataStoreConstants.kt

@@ -37,6 +37,8 @@ object DataStoreConstants {
     val PERCEPTION_EXPANDER = booleanPreferencesKey("perception_expander")
     val PERCEPTION_EXPANDER_PADDING = intPreferencesKey("perception_expander_padding")
     val PERCEPTION_EXPANDER_THICKNESS = intPreferencesKey("perception_expander_thickness")
+    val CHECK_FOR_TEXT_UPDATE = booleanPreferencesKey("check_for_text_update")
+    val CHECK_FOR_TEXT_UPDATE_TOAST = booleanPreferencesKey("check_for_text_update_toast")
 
     // Browse settings
     val BROWSE_FILES_STRUCTURE = stringPreferencesKey("browse_files_structure")

app/src/main/java/ua/acclorite/book_story/presentation/core/navigation/Navigation.kt

@@ -88,7 +88,8 @@ sealed class Screen : Parcelable {
     @Parcelize
     @Keep
     data class BookInfo(
-        val bookId: Int
+        val bookId: Int,
+        val startUpdate: Boolean
     ) : Screen()
 
     @Parcelize

app/src/main/java/ua/acclorite/book_story/presentation/data/MainEvent.kt

@@ -40,4 +40,6 @@ sealed class MainEvent {
     data class OnChangePerceptionExpander(val bool: Boolean) : MainEvent()
     data class OnChangePerceptionExpanderPadding(val padding: Int) : MainEvent()
     data class OnChangePerceptionExpanderThickness(val thickness: Int) : MainEvent()
+    data class OnChangeCheckForTextUpdate(val bool: Boolean) : MainEvent()
+    data class OnChangeCheckForTextUpdateToast(val bool: Boolean) : MainEvent()
 }

app/src/main/java/ua/acclorite/book_story/presentation/data/MainState.kt

@@ -77,6 +77,8 @@ data class MainState(
     val perceptionExpander: Boolean = provideDefaultValue { false },
     val perceptionExpanderPadding: Int = provideDefaultValue { 5 },
     val perceptionExpanderThickness: Int = provideDefaultValue { 4 },
+    val checkForTextUpdate: Boolean = provideDefaultValue { true },
+    val checkForTextUpdateToast: Boolean = provideDefaultValue { true },
 
     // Browse Settings
     val browseFilesStructure: BrowseFilesStructure = provideDefaultValue {
@@ -254,6 +256,14 @@ data class MainState(
                     perceptionExpanderThickness = provideValue(
                         PERCEPTION_EXPANDER_THICKNESS
                     ) { perceptionExpanderThickness },
+
+                    checkForTextUpdate = provideValue(
+                        CHECK_FOR_TEXT_UPDATE
+                    ) { checkForTextUpdate },
+
+                    checkForTextUpdateToast = provideValue(
+                        CHECK_FOR_TEXT_UPDATE_TOAST
+                    ) { checkForTextUpdateToast },
                 )
             }
         }

app/src/main/java/ua/acclorite/book_story/presentation/data/MainViewModel.kt

@@ -502,6 +502,34 @@ class MainViewModel @Inject constructor(
                     }
                 }
             }
+
+            is MainEvent.OnChangeCheckForTextUpdate -> {
+                viewModelScope.launch(Dispatchers.IO) {
+                    setDatastore.execute(
+                        DataStoreConstants.CHECK_FOR_TEXT_UPDATE,
+                        event.bool
+                    )
+                    updateStateWithSavedHandle {
+                        it.copy(
+                            checkForTextUpdate = event.bool
+                        )
+                    }
+                }
+            }
+
+            is MainEvent.OnChangeCheckForTextUpdateToast -> {
+                viewModelScope.launch(Dispatchers.IO) {
+                    setDatastore.execute(
+                        DataStoreConstants.CHECK_FOR_TEXT_UPDATE_TOAST,
+                        event.bool
+                    )
+                    updateStateWithSavedHandle {
+                        it.copy(
+                            checkForTextUpdateToast = event.bool
+                        )
+                    }
+                }
+            }
         }
     }
 

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/BookInfoScreen.kt

@@ -55,8 +55,8 @@ import ua.acclorite.book_story.presentation.screens.book_info.components.BookInf
 import ua.acclorite.book_story.presentation.screens.book_info.components.BookInfoStatisticSection
 import ua.acclorite.book_story.presentation.screens.book_info.components.BookInfoTopBar
 import ua.acclorite.book_story.presentation.screens.book_info.components.change_cover_bottom_sheet.BookInfoChangeCoverBottomSheet
-import ua.acclorite.book_story.presentation.screens.book_info.components.confirm_update_dialog.BookInfoConfirmUpdateDialog
 import ua.acclorite.book_story.presentation.screens.book_info.components.details_bottom_sheet.BookInfoDetailsBottomSheet
+import ua.acclorite.book_story.presentation.screens.book_info.components.dialog.BookInfoConfirmUpdateDialog
 import ua.acclorite.book_story.presentation.screens.book_info.components.dialog.BookInfoDeleteDialog
 import ua.acclorite.book_story.presentation.screens.book_info.components.dialog.BookInfoMoveDialog
 import ua.acclorite.book_story.presentation.screens.book_info.data.BookInfoEvent
@@ -65,15 +65,22 @@ import ua.acclorite.book_story.presentation.screens.book_info.data.BookInfoEvent
 fun BookInfoScreenRoot(screen: Screen.BookInfo) {
     val viewModel = LocalBookInfoViewModel.current.viewModel
     val onNavigate = LocalOnNavigate.current
+    val context = LocalContext.current
+
+    val snackbarState = remember { SnackbarHostState() }
 
     LaunchedEffect(Unit) {
         viewModel.init(
             screen = screen,
-            onNavigate = onNavigate
+            snackbarState = snackbarState,
+            onNavigate = onNavigate,
+            context = context
         )
     }
 
-    BookInfoScreen()
+    BookInfoScreen(
+        snackbarState = snackbarState
+    )
 
     DisposableEffect(Unit) {
         onDispose {
@@ -84,19 +91,18 @@ fun BookInfoScreenRoot(screen: Screen.BookInfo) {
 
 @OptIn(ExperimentalMaterialApi::class)
 @Composable
-private fun BookInfoScreen() {
+private fun BookInfoScreen(snackbarState: SnackbarHostState) {
     val context = LocalContext.current
     val state = LocalBookInfoViewModel.current.state
     val onEvent = LocalBookInfoViewModel.current.onEvent
     val onNavigate = LocalOnNavigate.current
 
     val listState = rememberLazyListState()
-    val snackbarState = remember { SnackbarHostState() }
     val refreshState = rememberPullRefreshState(
-        refreshing = state.value.isRefreshing || state.value.isLoadingUpdate,
+        refreshing = state.value.updating || state.value.checkingForUpdate,
         onRefresh = {
             onEvent(
-                BookInfoEvent.OnLoadUpdate(
+                BookInfoEvent.OnCheckForUpdate(
                     snackbarState,
                     context
                 )
@@ -181,7 +187,7 @@ private fun BookInfoScreen() {
 
             FloatingActionButton(
                 onClick = {
-                    if (!state.value.isRefreshing) {
+                    if (!state.value.updating) {
                         onEvent(BookInfoEvent.OnNavigateToReaderScreen(onNavigate = onNavigate))
                     }
                 },
@@ -221,7 +227,7 @@ private fun BookInfoScreen() {
             )
 
             PullRefreshIndicator(
-                state.value.isRefreshing || state.value.isLoadingUpdate,
+                state.value.updating || state.value.checkingForUpdate,
                 refreshState,
                 Modifier
                     .align(Alignment.TopCenter)
@@ -254,7 +260,7 @@ private fun BookInfoScreen() {
             return@BackHandler
         }
 
-        if (!state.value.isRefreshing) {
+        if (!state.value.updating) {
             onEvent(BookInfoEvent.OnCancelUpdate)
             onNavigate {
                 navigateBack()

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/components/BookInfoMoreDropDown.kt

@@ -38,7 +38,7 @@ fun BookInfoMoreDropDown(snackbarState: SnackbarHostState) {
             contentDescription = R.string.show_dropdown_content_desc,
             disableOnClick = false,
             enabled = !showDropDown &&
-                    !state.value.isRefreshing
+                    !state.value.updating
         ) {
             showDropDown = true
         }

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/components/BookInfoTopBar.kt

@@ -83,7 +83,7 @@ fun BookInfoTopBar(
                     }
                 }
             } else {
-                GoBackButton(onNavigate = onNavigate, enabled = !state.value.isRefreshing) {
+                GoBackButton(onNavigate = onNavigate, enabled = !state.value.updating) {
                     onEvent(BookInfoEvent.OnCancelUpdate)
                 }
             }
@@ -106,10 +106,10 @@ fun BookInfoTopBar(
                 icon = Icons.Outlined.Refresh,
                 contentDescription = R.string.refresh_book_content_desc,
                 disableOnClick = false,
-                enabled = !state.value.isRefreshing && !state.value.isLoadingUpdate
+                enabled = !state.value.updating && !state.value.checkingForUpdate
             ) {
                 onEvent(
-                    BookInfoEvent.OnLoadUpdate(
+                    BookInfoEvent.OnCheckForUpdate(
                         snackbarState,
                         context
                     )
@@ -135,7 +135,7 @@ fun BookInfoTopBar(
                         icon = Icons.Outlined.Done,
                         contentDescription = R.string.apply_changes_content_desc,
                         disableOnClick = true,
-                        enabled = !state.value.isRefreshing &&
+                        enabled = !state.value.updating &&
                                 (state.value.titleValue.isNotBlank() &&
                                         state.value.titleValue.trim() !=
                                         state.value.book.title.trim()) ||

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/components/dialog/BookInfoConfirmUpdateDialog.kt

@@ -1,4 +1,4 @@
-package ua.acclorite.book_story.presentation.screens.book_info.components.confirm_update_dialog
+package ua.acclorite.book_story.presentation.screens.book_info.components.dialog
 
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Update

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/data/BookInfoEvent.kt

@@ -101,7 +101,7 @@ sealed class BookInfoEvent {
         val snackbarState: SnackbarHostState
     ) : BookInfoEvent()
 
-    data class OnLoadUpdate(
+    data class OnCheckForUpdate(
         val snackbarState: SnackbarHostState,
         val context: Context
     ) : BookInfoEvent()

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/data/BookInfoState.kt

@@ -10,8 +10,8 @@ import ua.acclorite.book_story.presentation.core.constants.Constants
 data class BookInfoState(
     val book: Book = Constants.EMPTY_BOOK,
 
-    val isLoadingUpdate: Boolean = false,
+    val checkingForUpdate: Boolean = false,
-    val isRefreshing: Boolean = false,
+    val updating: Boolean = false,
 
     val showConfirmUpdateDialog: Boolean = false,
     val updatedText: List<String>? = null,

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/data/BookInfoViewModel.kt

@@ -4,9 +4,11 @@ package ua.acclorite.book_story.presentation.screens.book_info.data
 
 import android.content.ClipData
 import android.content.ClipboardManager
+import android.content.Context
 import android.content.Context.CLIPBOARD_SERVICE
 import android.graphics.BitmapFactory
 import android.os.Build
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.SnackbarResult
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
@@ -451,13 +453,13 @@ class BookInfoViewModel @Inject constructor(
                     }
                 }
 
-                is BookInfoEvent.OnLoadUpdate -> {
+                is BookInfoEvent.OnCheckForUpdate -> {
                     updateJob?.cancel()
                     updateJob = launch(Dispatchers.IO) {
                         _state.update {
                             it.copy(
                                 showConfirmUpdateDialog = false,
-                                isLoadingUpdate = true,
+                                checkingForUpdate = true,
                                 editTitle = false,
                                 editAuthor = false,
                                 editDescription = false
@@ -477,7 +479,7 @@ class BookInfoViewModel @Inject constructor(
                                         action = event.context.getString(R.string.retry),
                                         onAction = {
                                             onEvent(
-                                                BookInfoEvent.OnLoadUpdate(
+                                                BookInfoEvent.OnCheckForUpdate(
                                                     snackbarState = event.snackbarState,
                                                     context = event.context
                                                 )
@@ -491,7 +493,7 @@ class BookInfoViewModel @Inject constructor(
                                 delay(500)
                                 _state.update {
                                     it.copy(
-                                        isLoadingUpdate = false
+                                        checkingForUpdate = false
                                     )
                                 }
                                 return@launch
@@ -508,7 +510,7 @@ class BookInfoViewModel @Inject constructor(
                                         action = event.context.getString(R.string.retry),
                                         onAction = {
                                             onEvent(
-                                                BookInfoEvent.OnLoadUpdate(
+                                                BookInfoEvent.OnCheckForUpdate(
                                                     snackbarState = event.snackbarState,
                                                     context = event.context
                                                 )
@@ -522,7 +524,7 @@ class BookInfoViewModel @Inject constructor(
                                 delay(500)
                                 _state.update {
                                     it.copy(
-                                        isLoadingUpdate = false
+                                        checkingForUpdate = false
                                     )
                                 }
                                 return@launch
@@ -554,7 +556,7 @@ class BookInfoViewModel @Inject constructor(
                             delay(500)
                             _state.update {
                                 it.copy(
-                                    isLoadingUpdate = false
+                                    checkingForUpdate = false
                                 )
                             }
                             return@launch
@@ -571,7 +573,7 @@ class BookInfoViewModel @Inject constructor(
 
                         _state.update {
                             it.copy(
-                                isLoadingUpdate = false
+                                checkingForUpdate = false
                             )
                         }
                     }
@@ -601,7 +603,7 @@ class BookInfoViewModel @Inject constructor(
                     launch(Dispatchers.IO) {
                         _state.update {
                             it.copy(
-                                isRefreshing = true,
+                                updating = true,
                                 showConfirmUpdateDialog = false
                             )
                         }
@@ -615,7 +617,7 @@ class BookInfoViewModel @Inject constructor(
                                     action = event.context.getString(R.string.retry),
                                     onAction = {
                                         onEvent(
-                                            BookInfoEvent.OnLoadUpdate(
+                                            BookInfoEvent.OnCheckForUpdate(
                                                 snackbarState = event.snackbarState,
                                                 context = event.context
                                             )
@@ -629,7 +631,7 @@ class BookInfoViewModel @Inject constructor(
                             delay(500)
                             _state.update {
                                 it.copy(
-                                    isRefreshing = false,
+                                    updating = false,
                                     updatedText = null,
                                     updatedChapters = null
                                 )
@@ -660,7 +662,7 @@ class BookInfoViewModel @Inject constructor(
                                     action = event.context.getString(R.string.retry),
                                     onAction = {
                                         onEvent(
-                                            BookInfoEvent.OnLoadUpdate(
+                                            BookInfoEvent.OnCheckForUpdate(
                                                 snackbarState = event.snackbarState,
                                                 context = event.context
                                             )
@@ -674,7 +676,7 @@ class BookInfoViewModel @Inject constructor(
                             delay(500)
                             _state.update {
                                 it.copy(
-                                    isRefreshing = false,
+                                    updating = false,
                                     updatedText = null,
                                     updatedChapters = null
                                 )
@@ -692,7 +694,7 @@ class BookInfoViewModel @Inject constructor(
                                         action = event.context.getString(R.string.retry),
                                         onAction = {
                                             onEvent(
-                                                BookInfoEvent.OnLoadUpdate(
+                                                BookInfoEvent.OnCheckForUpdate(
                                                     snackbarState = event.snackbarState,
                                                     context = event.context
                                                 )
@@ -706,7 +708,7 @@ class BookInfoViewModel @Inject constructor(
                                 delay(500)
                                 _state.update {
                                     it.copy(
-                                        isRefreshing = false,
+                                        updating = false,
                                         updatedText = null,
                                         updatedChapters = null
                                     )
@@ -735,7 +737,7 @@ class BookInfoViewModel @Inject constructor(
                             delay(500)
                             _state.update {
                                 it.copy(
-                                    isRefreshing = false
+                                    updating = false
                                 )
                             }
                         }
@@ -748,7 +750,7 @@ class BookInfoViewModel @Inject constructor(
 
                         it.copy(
                             showConfirmUpdateDialog = false,
-                            isLoadingUpdate = false,
+                            checkingForUpdate = false,
                             updatedText = null,
                             updatedChapters = null
                         )
@@ -778,7 +780,12 @@ class BookInfoViewModel @Inject constructor(
         }
     }
 
-    fun init(screen: Screen.BookInfo, onNavigate: OnNavigate) {
+    fun init(
+        screen: Screen.BookInfo,
+        snackbarState: SnackbarHostState,
+        context: Context,
+        onNavigate: OnNavigate
+    ) {
         viewModelScope.launch(Dispatchers.IO) {
             val book = getBookById.execute(screen.bookId)
 
@@ -796,6 +803,22 @@ class BookInfoViewModel @Inject constructor(
             }
             clear()
 
+            if (screen.startUpdate) {
+                onEvent(
+                    BookInfoEvent.OnCheckForUpdate(
+                        snackbarState = snackbarState,
+                        context = context
+                    )
+                )
+                onNavigate {
+                    putScreen(
+                        Screen.BookInfo(
+                            screen.bookId,
+                            false
+                        )
+                    )
+                }
+            }
             onEvent(BookInfoEvent.OnCheckCoverReset)
         }
     }

app/src/main/java/ua/acclorite/book_story/presentation/screens/history/HistoryScreen.kt

@@ -214,7 +214,10 @@ private fun HistoryScreen() {
                                 onBodyClick = {
                                     onNavigate {
                                         navigate(
-                                            Screen.BookInfo(it.bookId)
+                                            Screen.BookInfo(
+                                                bookId = it.bookId,
+                                                startUpdate = false
+                                            )
                                         )
                                     }
                                 },

app/src/main/java/ua/acclorite/book_story/presentation/screens/library/LibraryScreen.kt

@@ -174,7 +174,12 @@ private fun LibraryScreen(
                                             onEvent(LibraryEvent.OnSelectBook(it))
                                         } else {
                                             onNavigate {
-                                                navigate(Screen.BookInfo(it.first.id))
+                                                navigate(
+                                                    Screen.BookInfo(
+                                                        bookId = it.first.id,
+                                                        startUpdate = false
+                                                    )
+                                                )
                                             }
                                         }
                                     },

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/ReaderScreen.kt

@@ -81,6 +81,7 @@ import ua.acclorite.book_story.presentation.screens.reader.components.ReaderChap
 import ua.acclorite.book_story.presentation.screens.reader.components.ReaderChaptersDrawer
 import ua.acclorite.book_story.presentation.screens.reader.components.ReaderPerceptionExpander
 import ua.acclorite.book_story.presentation.screens.reader.components.ReaderTextParagraph
+import ua.acclorite.book_story.presentation.screens.reader.components.ReaderUpdateDialog
 import ua.acclorite.book_story.presentation.screens.reader.components.app_bar.ReaderBottomBar
 import ua.acclorite.book_story.presentation.screens.reader.components.app_bar.ReaderTopBar
 import ua.acclorite.book_story.presentation.screens.reader.components.readerFastColorPresetChange
@@ -117,6 +118,15 @@ fun ReaderScreenRoot(screen: Screen.Reader) {
             screen = screen,
             onNavigate = onNavigate,
             fullscreenMode = mainState.value.fullscreen,
+            checkForTextUpdate = mainState.value.checkForTextUpdate,
+            checkForTextUpdateToast = {
+                if (mainState.value.checkForTextUpdateToast) {
+                    context.getString(R.string.nothing_changed).showToast(
+                        context = context,
+                        longToast = false
+                    )
+                }
+            },
             activity = context,
             refreshList = {
                 onLibraryEvent(LibraryEvent.OnUpdateBook(it))
@@ -350,6 +360,9 @@ private fun ReaderScreen(lazyListState: LazyListState) {
     if (state.value.showSettingsBottomSheet) {
         ReaderSettingsBottomSheet()
     }
+    if (state.value.showUpdateDialog) {
+        ReaderUpdateDialog()
+    }
 
     Scaffold(
         Modifier

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/ReaderUpdateDialog.kt

@@ -0,0 +1,47 @@
+package ua.acclorite.book_story.presentation.screens.reader.components
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.rounded.Upgrade
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.LocalReaderViewModel
+import ua.acclorite.book_story.presentation.core.components.custom_dialog.CustomDialogWithContent
+import ua.acclorite.book_story.presentation.core.navigation.LocalOnNavigate
+import ua.acclorite.book_story.presentation.core.navigation.Screen
+import ua.acclorite.book_story.presentation.screens.reader.data.ReaderEvent
+
+/**
+ * Reader Update Dialog.
+ * Navigates user to BookInfo and starts book update.
+ */
+@Composable
+fun ReaderUpdateDialog() {
+    val state = LocalReaderViewModel.current.state
+    val onEvent = LocalReaderViewModel.current.onEvent
+    val onNavigate = LocalOnNavigate.current
+
+    CustomDialogWithContent(
+        title = stringResource(id = R.string.update_book),
+        imageVectorIcon = Icons.Rounded.Upgrade,
+        description = stringResource(
+            id = R.string.update_book_description
+        ),
+        actionText = stringResource(id = R.string.proceed),
+        isActionEnabled = true,
+        onDismiss = { onEvent(ReaderEvent.OnShowHideUpdateDialog(false)) },
+        onAction = {
+            onNavigate {
+                navigate(
+                    Screen.BookInfo(
+                        bookId = state.value.book.id,
+                        startUpdate = true
+                    ),
+                    useBackAnimation = true,
+                    saveInBackStack = false
+                )
+            }
+        },
+        withDivider = false
+    )
+}

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/app_bar/ReaderTopBar.kt

@@ -2,15 +2,23 @@ package ua.acclorite.book_story.presentation.screens.reader.components.app_bar
 
 import androidx.activity.ComponentActivity
 import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.shrinkHorizontally
 import androidx.compose.foundation.background
 import androidx.compose.foundation.basicMarquee
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.outlined.ArrowBack
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.rounded.Menu
+import androidx.compose.material.icons.rounded.Upgrade
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.LinearProgressIndicator
 import androidx.compose.material3.MaterialTheme
@@ -18,14 +26,17 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.CustomAnimatedVisibility
 import ua.acclorite.book_story.presentation.core.components.CustomIconButton
 import ua.acclorite.book_story.presentation.core.components.LocalHistoryViewModel
 import ua.acclorite.book_story.presentation.core.components.LocalLibraryViewModel
@@ -92,8 +103,10 @@ fun ReaderTopBar() {
                         fontSize = 20.sp,
                         lineHeight = 20.sp,
                         color = MaterialTheme.colorScheme.onSurface,
+                        overflow = TextOverflow.Ellipsis,
                         maxLines = 1,
                         modifier = Modifier
+                            .padding(end = 8.dp)
                             .noRippleClickable(
                                 enabled = !state.value.lockMenu,
                                 onClick = {
@@ -107,7 +120,10 @@ fun ReaderTopBar() {
                                             navigate = {
                                                 onNavigate {
                                                     navigate(
-                                                        Screen.BookInfo(state.value.book.id),
+                                                        Screen.BookInfo(
+                                                            bookId = state.value.book.id,
+                                                            startUpdate = false
+                                                        ),
                                                         useBackAnimation = true,
                                                         saveInBackStack = false
                                                     )
@@ -117,8 +133,9 @@ fun ReaderTopBar() {
                                     )
                                 }
                             )
-                            .basicMarquee(
+                            .then(
-                                iterations = Int.MAX_VALUE
+                                if (state.value.checkingForUpdate || state.value.updateFound) Modifier
+                                else Modifier.basicMarquee(iterations = Int.MAX_VALUE)
                             )
                     )
                     Text(
@@ -132,6 +149,40 @@ fun ReaderTopBar() {
                 }
             },
             actions = {
+                CustomAnimatedVisibility(
+                    visible = state.value.checkingForUpdate || state.value.updateFound,
+                    enter = fadeIn(),
+                    exit = shrinkHorizontally() + fadeOut()
+                ) {
+                    Box(
+                        modifier = Modifier.size(40.dp),
+                        contentAlignment = Alignment.Center
+                    ) {
+                        if (state.value.updateFound) {
+                            CustomIconButton(
+                                icon = Icons.Rounded.Upgrade,
+                                contentDescription = R.string.update_text_content_desc,
+                                color = MaterialTheme.colorScheme.primary,
+                                disableOnClick = false,
+                                enabled = !state.value.lockMenu &&
+                                        state.value.updateFound &&
+                                        !state.value.checkingForUpdate
+                            ) {
+                                onEvent(ReaderEvent.OnShowHideUpdateDialog(true))
+                            }
+                        } else {
+                            CircularProgressIndicator(
+                                modifier = Modifier
+                                    .size(19.dp)
+                                    .noRippleClickable {
+                                        onEvent(ReaderEvent.OnCancelCheckTextForUpdate)
+                                    },
+                                strokeWidth = 2.4.dp
+                            )
+                        }
+                    }
+                }
+
                 if (state.value.currentChapter != null) {
                     CustomIconButton(
                         icon = Icons.Rounded.Menu,

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderEvent.kt

@@ -11,6 +11,7 @@ sealed class ReaderEvent {
     data object OnTextIsEmpty : ReaderEvent()
 
     data class OnLoadText(
+        val checkForUpdate: () -> Unit,
         val refreshList: (Book) -> Unit,
         val onError: (UIText) -> Unit,
         val onTextIsEmpty: () -> Unit
@@ -86,4 +87,14 @@ sealed class ReaderEvent {
         val context: ComponentActivity,
         val noAppsFound: () -> Unit
     ) : ReaderEvent()
+
+    data class OnCheckTextForUpdate(
+        val noUpdateFound: () -> Unit
+    ) : ReaderEvent()
+
+    data class OnShowHideUpdateDialog(
+        val show: Boolean
+    ) : ReaderEvent()
+
+    data object OnCancelCheckTextForUpdate : ReaderEvent()
 }

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderState.kt

@@ -24,6 +24,10 @@ data class ReaderState(
     val checkpoint: Pair<Int, Int> = 0 to 0,
     val lockMenu: Boolean = false,
 
+    val checkingForUpdate: Boolean = false,
+    val updateFound: Boolean = false,
+    val showUpdateDialog: Boolean = false,
+
     val showSettingsBottomSheet: Boolean = false,
     val currentPage: Int = 0,
 )

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderViewModel.kt

@@ -22,18 +22,22 @@ import kotlinx.coroutines.flow.debounce
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import kotlinx.coroutines.yield
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.domain.model.Book
 import ua.acclorite.book_story.domain.use_case.GetBookById
 import ua.acclorite.book_story.domain.use_case.GetLatestHistory
 import ua.acclorite.book_story.domain.use_case.GetText
+import ua.acclorite.book_story.domain.use_case.ParseText
 import ua.acclorite.book_story.domain.use_case.UpdateBook
 import ua.acclorite.book_story.domain.util.OnNavigate
+import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import ua.acclorite.book_story.presentation.core.navigation.Screen
 import ua.acclorite.book_story.presentation.core.util.BaseViewModel
 import ua.acclorite.book_story.presentation.core.util.launchActivity
+import java.io.File
 import javax.inject.Inject
 import kotlin.math.roundToInt
 
@@ -43,7 +47,8 @@ class ReaderViewModel @Inject constructor(
     private val updateBook: UpdateBook,
     private val getText: GetText,
     private val getLatestHistory: GetLatestHistory,
-    private val getBookById: GetBookById
+    private val getBookById: GetBookById,
+    private val parseText: ParseText
 ) : BaseViewModel<ReaderState, ReaderEvent>() {
 
     private val _state = MutableStateFlow(ReaderState())
@@ -51,6 +56,7 @@ class ReaderViewModel @Inject constructor(
 
     private var eventJob = SupervisorJob()
     private var scrollJob: Job? = null
+    private var updateJob: Job? = null
 
     override fun onEvent(event: ReaderEvent) {
         viewModelScope.launch(eventJob + Dispatchers.Main) {
@@ -95,6 +101,8 @@ class ReaderViewModel @Inject constructor(
                                     _state.value.book.scrollOffset
                                 )
 
+                                event.checkForUpdate()
+
                                 delay(100)
                                 _state.update {
                                     it.copy(
@@ -399,6 +407,97 @@ class ReaderViewModel @Inject constructor(
                         event.noAppsFound()
                     }
                 }
+
+                is ReaderEvent.OnCheckTextForUpdate -> {
+                    updateJob?.cancel()
+                    updateJob = launch(Dispatchers.IO) {
+                        _state.update {
+                            it.copy(
+                                checkingForUpdate = true,
+                                updateFound = false,
+                                showUpdateDialog = false
+                            )
+                        }
+
+                        yield()
+
+                        val currentBook = _state.value.book.apply {
+                            if (!File(filePath).exists()) {
+                                _state.update {
+                                    it.copy(
+                                        checkingForUpdate = false,
+                                        updateFound = false
+                                    )
+                                }
+                                return@launch
+                            }
+                        }
+                        val updatedBook = parseText.execute(File(currentBook.filePath)).apply {
+                            if (this is Resource.Error || data == null) {
+                                _state.update {
+                                    it.copy(
+                                        checkingForUpdate = false,
+                                        updateFound = false
+                                    )
+                                }
+                                return@launch
+                            }
+                        }.data!!
+
+                        yield()
+
+                        val updatedText = updatedBook.map { it.text }.flatten()
+                        val text = getText.execute(currentBook.textPath)
+
+                        val updatedChapters = updatedBook.map { it.chapter }.run {
+                            if (size < 2) return@run emptyList()
+                            return@run this
+                        }
+                        val chapters = currentBook.chapters
+
+                        yield()
+
+                        if (updatedText == text && updatedChapters == chapters) {
+                            withContext(Dispatchers.Main) {
+                                event.noUpdateFound()
+                            }
+                            _state.update {
+                                it.copy(
+                                    checkingForUpdate = false,
+                                    updateFound = false
+                                )
+                            }
+                            return@launch
+                        }
+
+                        _state.update {
+                            it.copy(
+                                updateFound = true,
+                                checkingForUpdate = false
+                            )
+                        }
+                        onEvent(ReaderEvent.OnShowHideUpdateDialog(true))
+                    }
+                }
+
+                is ReaderEvent.OnShowHideUpdateDialog -> {
+                    _state.update {
+                        it.copy(
+                            showUpdateDialog = event.show
+                        )
+                    }
+                }
+
+                is ReaderEvent.OnCancelCheckTextForUpdate -> {
+                    _state.update {
+                        updateJob?.cancel()
+
+                        it.copy(
+                            showUpdateDialog = false,
+                            checkingForUpdate = false
+                        )
+                    }
+                }
             }
         }
     }
@@ -407,6 +506,8 @@ class ReaderViewModel @Inject constructor(
         screen: Screen.Reader,
         onNavigate: OnNavigate,
         fullscreenMode: Boolean,
+        checkForTextUpdate: Boolean,
+        checkForTextUpdateToast: () -> Unit,
         activity: ComponentActivity,
         refreshList: (Book) -> Unit,
         onError: (UIText) -> Unit
@@ -437,6 +538,15 @@ class ReaderViewModel @Inject constructor(
                 )
                 onEvent(
                     ReaderEvent.OnLoadText(
+                        checkForUpdate = {
+                            if (checkForTextUpdate) {
+                                onEvent(
+                                    ReaderEvent.OnCheckTextForUpdate {
+                                        checkForTextUpdateToast()
+                                    }
+                                )
+                            }
+                        },
                         refreshList = { refreshList(it) },
                         onError = {
                             onError(it)

app/src/main/java/ua/acclorite/book_story/presentation/screens/settings/nested/reader/components/settings/CheckForTextUpdateSetting.kt

@@ -0,0 +1,31 @@
+package ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.LocalMainViewModel
+import ua.acclorite.book_story.presentation.data.MainEvent
+import ua.acclorite.book_story.presentation.screens.settings.components.SwitchWithTitle
+
+/**
+ * Check for Text Update setting.
+ * If true, automatically checks whether there is book's text update.
+ */
+@Composable
+fun CheckForTextUpdateSetting() {
+    val state = LocalMainViewModel.current.state
+    val onMainEvent = LocalMainViewModel.current.onEvent
+
+    SwitchWithTitle(
+        selected = state.value.checkForTextUpdate,
+        title = stringResource(id = R.string.check_for_text_update_option),
+        description = stringResource(id = R.string.check_for_text_update_option_desc),
+        onClick = {
+            onMainEvent(
+                MainEvent.OnChangeCheckForTextUpdate(
+                    !state.value.checkForTextUpdate
+                )
+            )
+        }
+    )
+}

app/src/main/java/ua/acclorite/book_story/presentation/screens/settings/nested/reader/components/settings/CheckForTextUpdateToastSetting.kt

@@ -0,0 +1,33 @@
+package ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.LocalMainViewModel
+import ua.acclorite.book_story.presentation.data.MainEvent
+import ua.acclorite.book_story.presentation.screens.settings.components.SwitchWithTitle
+import ua.acclorite.book_story.presentation.ui.ExpandingTransition
+
+/**
+ * Check for Text Update Toast setting.
+ * If true, shows a toast when the text is up-to-date.
+ */
+@Composable
+fun CheckForTextUpdateToastSetting() {
+    val state = LocalMainViewModel.current.state
+    val onMainEvent = LocalMainViewModel.current.onEvent
+
+    ExpandingTransition(visible = state.value.checkForTextUpdate) {
+        SwitchWithTitle(
+            selected = state.value.checkForTextUpdateToast,
+            title = stringResource(id = R.string.check_for_text_update_toast_option),
+            onClick = {
+                onMainEvent(
+                    MainEvent.OnChangeCheckForTextUpdateToast(
+                        !state.value.checkForTextUpdateToast
+                    )
+                )
+            }
+        )
+    }
+}

app/src/main/java/ua/acclorite/book_story/presentation/screens/settings/nested/reader/components/subcategories/MiscSubcategory.kt

@@ -10,6 +10,8 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.Dp
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.presentation.screens.settings.components.SettingsSubcategory
+import ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings.CheckForTextUpdateSetting
+import ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings.CheckForTextUpdateToastSetting
 import ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings.FullscreenSetting
 import ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings.HideBarsOnFastScrollSetting
 import ua.acclorite.book_story.presentation.screens.settings.nested.reader.components.settings.KeepScreenOnSetting
@@ -34,6 +36,14 @@ fun LazyListScope.MiscSubcategory(
         topPadding = topPadding,
         bottomPadding = bottomPadding
     ) {
+        item {
+            CheckForTextUpdateSetting()
+        }
+
+        item {
+            CheckForTextUpdateToastSetting()
+        }
+
         item {
             FullscreenSetting()
         }

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

@@ -29,6 +29,7 @@
     <string name="delete_history">Видалити історію читання?</string>
     <string name="confirm_update">Підтвердити оновлення?</string>
     <string name="enable_check_for_updates">Увімнкути перевірку на оновлення?</string>
+    <string name="update_book">Оновити книгу?</string>
 
     <!-- Dialog Descriptions -->
     <string name="storage_permission_description">
@@ -75,6 +76,13 @@
         з «api.github.com» кожен раз, коли застосунок запускається.
         Хочете продовжити та увімкнути «Перевіряти на оновлення»?
     </string>
+    <string name="update_book_description">
+        Знайдено оновлення тексту книги.
+        Оновлення необхідне для того, щоб забезпечити використання найновіших методів парсингу.
+        Це автономний процес і в більшості випадків пов\'язаний з оновленням парсеру текста.
+        Ваш прогрес не постраждає, якщо не відбудуться значні зміни.
+        Чи бажаєте ви продовжити оновлення?
+    </string>
 
     <!-- Errors -->
     <string name="error_permission">
@@ -153,6 +161,7 @@
     <string name="enable">Увімкнути</string>
     <string name="web_search">Веб-пошук</string>
     <string name="share">Поділитися</string>
+    <string name="proceed">Продовжити</string>
 
     <!-- Items -->
     <string name="files">файли</string>
@@ -250,6 +259,9 @@
     </string>
     <string name="perception_expander_padding_option">Відступи лінії розширення сприйняття</string>
     <string name="perception_expander_thickness_option">Товщина лінії розширення сприйняття</string>
+    <string name="check_for_text_update_option">Перевіряти на оновлення тексту</string>
+    <string name="check_for_text_update_option_desc">Автоматично перевіряти чи є оновлення тексту</string>
+    <string name="check_for_text_update_toast_option">Показувати \"текст актуальний\" повідомлення</string>
 
     <!-- Browse -->
     <string name="browse_files_structure_option">Структура файлів</string>
@@ -340,7 +352,7 @@
     <string name="history_element_deleted">Елемент історії був успішно видалений.</string>
     <string name="file_not_found">Файл \"%1$s\" не знайдено.</string>
     <string name="book_updated">Текст книги був успішно оновлений.</string>
-    <string name="nothing_changed">Текст книги актуальний.</string>
+    <string name="nothing_changed">Текст актуальний.</string>
 
     <!-- DropDown properties -->
     <string name="move_this_book">Перемістити</string>
@@ -606,5 +618,6 @@
     <string name="checkpoint_back_content_desc">Чекпоінт назад</string>
     <string name="checkpoint_forward_content_desc">Чекпоінт вперед</string>
     <string name="chapters_content_desc">Розділи</string>
+    <string name="update_text_content_desc">Оновити текст</string>
 
 </resources>

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

@@ -32,6 +32,7 @@
     <string name="delete_history">Delete reading history?</string>
     <string name="confirm_update">Confirm update?</string>
     <string name="enable_check_for_updates">Enable check for updates?</string>
+    <string name="update_book">Update book?</string>
 
     <!-- Dialog Descriptions -->
     <string name="storage_permission_description">
@@ -65,7 +66,7 @@
     </string>
     <string name="confirm_update_description">
         Update this book\'s text and chapters.
-        The progress should remain unchanged unless order of paragraphs was changed.
+        The progress should remain unchanged unless the order of paragraphs was changed.
     </string>
     <string name="update_app_description">
         New version of Book\'s Story was found.
@@ -79,6 +80,13 @@
         when app starts.
         Do you want to proceed and enable «Check for updates»?
     </string>
+    <string name="update_book_description">
+        Update of the text has been found.
+        Update is needed to ensure latest parser methods are used.
+        It is offline process.
+        Your progress will not be affected unless big changes occur.
+        Do you want to proceed with update?
+    </string>
 
     <!-- Errors -->
     <string name="error_permission">
@@ -156,6 +164,7 @@
     <string name="enable">Enable</string>
     <string name="web_search">Web search</string>
     <string name="share">Share</string>
+    <string name="proceed">Proceed</string>
 
     <!-- Items -->
     <string name="files">files</string>
@@ -253,6 +262,9 @@
     </string>
     <string name="perception_expander_padding_option">Perception expander line padding</string>
     <string name="perception_expander_thickness_option">Perception expander line thickness</string>
+    <string name="check_for_text_update_option">Check for text update</string>
+    <string name="check_for_text_update_option_desc">Automatically check whether there is text update</string>
+    <string name="check_for_text_update_toast_option">Show \"text is up-to-date\" toast</string>
 
     <!-- Browse -->
     <string name="browse_files_structure_option">Files structure</string>
@@ -343,7 +355,7 @@
     <string name="history_element_deleted">History element was successfully deleted.</string>
     <string name="file_not_found">File \"%1$s\" was not found.</string>
     <string name="book_updated">Book\'s text was successfully updated.</string>
-    <string name="nothing_changed">Book\'s text is up to date.</string>
+    <string name="nothing_changed">Text is up-to-date.</string>
 
     <!-- DropDown properties -->
     <string name="move_this_book">Move</string>
@@ -611,5 +623,6 @@
     <string name="checkpoint_back_content_desc">Checkpoint back</string>
     <string name="checkpoint_forward_content_desc">Checkpoint forward</string>
     <string name="chapters_content_desc">Chapters</string>
+    <string name="update_text_content_desc">Update text</string>
 
 </resources>