Refactor reader

app/build.gradle

@@ -67,8 +67,8 @@ dependencies {
 	implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.4.2'
 
 	implementation 'androidx.core:core-ktx:1.5.0-alpha05'
-	implementation 'androidx.activity:activity-ktx:1.2.0-beta01'
+	implementation 'androidx.activity:activity-ktx:1.2.0-beta02'
-	implementation 'androidx.fragment:fragment-ktx:1.3.0-beta01'
+	implementation 'androidx.fragment:fragment-ktx:1.3.0-beta02'
 	implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.0-beta01'
 	implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.0-beta01'
 	implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.3.0-beta01'
@@ -76,7 +76,7 @@ dependencies {
 	implementation 'androidx.lifecycle:lifecycle-process:2.3.0-beta01'
 	implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
 	implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.1.0'
-	implementation 'androidx.recyclerview:recyclerview:1.2.0-alpha06'
+	implementation 'androidx.recyclerview:recyclerview:1.2.0-beta01'
 	implementation 'androidx.viewpager2:viewpager2:1.1.0-alpha01'
 	implementation 'androidx.preference:preference-ktx:1.1.1'
 	implementation 'androidx.work:work-runtime-ktx:2.4.0'

app/src/main/java/org/koitharu/kotatsu/base/ui/BaseFragment.kt

@@ -32,12 +32,14 @@ abstract class BaseFragment<B : ViewBinding> : Fragment() {
 
 	open fun getTitle(): CharSequence? = null
 
-	protected abstract fun onInflateView(inflater: LayoutInflater, container: ViewGroup?): B
-
 	override fun onAttach(context: Context) {
 		super.onAttach(context)
 		getTitle()?.let {
 			activity?.title = it
 		}
 	}
+
+	protected fun bindingOrNull() = viewBinding
+
+	protected abstract fun onInflateView(inflater: LayoutInflater, container: ViewGroup?): B
 }

app/src/main/java/org/koitharu/kotatsu/base/ui/list/BaseViewHolder.kt

@@ -4,6 +4,7 @@ import androidx.recyclerview.widget.RecyclerView
 import androidx.viewbinding.ViewBinding
 import org.koin.core.component.KoinComponent
 
+@Deprecated("")
 abstract class BaseViewHolder<T, E, B : ViewBinding> protected constructor(val binding: B) :
 	RecyclerView.ViewHolder(binding.root), KoinComponent {
 

app/src/main/java/org/koitharu/kotatsu/details/ui/ChaptersFragment.kt

@@ -20,6 +20,7 @@ import org.koitharu.kotatsu.details.ui.adapter.ChaptersSelectionDecoration
 import org.koitharu.kotatsu.details.ui.model.ChapterListItem
 import org.koitharu.kotatsu.download.DownloadService
 import org.koitharu.kotatsu.reader.ui.ReaderActivity
+import org.koitharu.kotatsu.reader.ui.ReaderState
 
 class ChaptersFragment : BaseFragment<FragmentChaptersBinding>(),
 	OnListItemClickListener<MangaChapter>, ActionMode.Callback {
@@ -84,9 +85,9 @@ class ChaptersFragment : BaseFragment<FragmentChaptersBinding>(),
 		)
 		startActivity(
 			ReaderActivity.newIntent(
-				context ?: return,
+				view.context,
 				viewModel.manga.value ?: return,
-				item.id
+				ReaderState(item.id, 0, 0)
 			), options.toBundle()
 		)
 	}

app/src/main/java/org/koitharu/kotatsu/details/ui/DetailsActivity.kt

@@ -209,12 +209,14 @@ class DetailsActivity : BaseActivity<ActivityDetailsBinding>(),
 
 		const val ACTION_MANGA_VIEW = "${BuildConfig.APPLICATION_ID}.action.VIEW_MANGA"
 
-		fun newIntent(context: Context, manga: Manga) =
+		fun newIntent(context: Context, manga: Manga): Intent {
-			Intent(context, DetailsActivity::class.java)
+			return Intent(context, DetailsActivity::class.java)
 				.putExtra(MangaIntent.KEY_MANGA, manga)
+		}
 
-		fun newIntent(context: Context, mangaId: Long) =
+		fun newIntent(context: Context, mangaId: Long): Intent {
-			Intent(context, DetailsActivity::class.java)
+			return Intent(context, DetailsActivity::class.java)
 				.putExtra(MangaIntent.KEY_ID, mangaId)
 		}
 	}
+}

app/src/main/java/org/koitharu/kotatsu/details/ui/DetailsFragment.kt

@@ -22,6 +22,7 @@ import org.koitharu.kotatsu.core.model.MangaHistory
 import org.koitharu.kotatsu.databinding.FragmentDetailsBinding
 import org.koitharu.kotatsu.favourites.ui.categories.select.FavouriteCategoriesDialog
 import org.koitharu.kotatsu.reader.ui.ReaderActivity
+import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.utils.FileSizeUtils
 import org.koitharu.kotatsu.utils.ext.*
 import kotlin.math.roundToInt
@@ -138,7 +139,7 @@ class DetailsFragment : BaseFragment<FragmentDetailsBinding>(), View.OnClickList
 					ReaderActivity.newIntent(
 						context ?: return,
 						manga ?: return,
-						viewModel.readingHistory.value
+						null
 					)
 				)
 			}
@@ -157,7 +158,10 @@ class DetailsFragment : BaseFragment<FragmentDetailsBinding>(), View.OnClickList
 							startActivity(
 								ReaderActivity.newIntent(
 									context ?: return@showPopupMenu false,
-									viewModel.manga.value ?: return@showPopupMenu false
+									viewModel.manga.value ?: return@showPopupMenu false,
+									viewModel.chapters.value?.firstOrNull()?.let { c ->
+										ReaderState(c.chapter.id, 0, 0)
+									}
 								)
 							)
 							true

app/src/main/java/org/koitharu/kotatsu/details/ui/DetailsViewModel.kt

@@ -4,6 +4,7 @@ import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.plus
 import org.koitharu.kotatsu.base.domain.MangaDataRepository
 import org.koitharu.kotatsu.base.domain.MangaIntent
 import org.koitharu.kotatsu.base.ui.BaseViewModel
@@ -34,28 +35,28 @@ class DetailsViewModel(
 		.distinctUntilChanged()
 		.flatMapLatest { mangaId ->
 			historyRepository.observeOne(mangaId)
-		}.stateIn(viewModelScope, SharingStarted.Eagerly, null)
+		}.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Eagerly, null)
 
 	private val favourite = mangaData.mapNotNull { it?.id }
 		.distinctUntilChanged()
 		.flatMapLatest { mangaId ->
 			favouritesRepository.observeCategoriesIds(mangaId).map { it.isNotEmpty() }
-		}.stateIn(viewModelScope, SharingStarted.Eagerly, false)
+		}.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Eagerly, false)
 
 	private val newChapters = mangaData.mapNotNull { it?.id }
 		.distinctUntilChanged()
 		.mapLatest { mangaId ->
 			trackingRepository.getNewChaptersCount(mangaId)
-		}.stateIn(viewModelScope, SharingStarted.Eagerly, 0)
+		}.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Eagerly, 0)
 
 	val manga = mangaData.filterNotNull()
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.asLiveData(viewModelScope.coroutineContext)
 	val favouriteCategories = favourite
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.asLiveData(viewModelScope.coroutineContext)
 	val newChaptersCount = newChapters
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.asLiveData(viewModelScope.coroutineContext)
 	val readingHistory = history
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.asLiveData(viewModelScope.coroutineContext)
 
 	val onMangaRemoved = SingleLiveEvent<Manga>()
 
@@ -76,7 +77,7 @@ class DetailsViewModel(
 				}
 			)
 		}
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
 
 	init {
 		launchLoadingJob(Dispatchers.Default) {

app/src/main/java/org/koitharu/kotatsu/favourites/ui/FavouritesContainerFragment.kt

@@ -30,7 +30,6 @@ class FavouritesContainerFragment : BaseFragment<FragmentFavouritesBinding>(),
 	override fun onCreate(savedInstanceState: Bundle?) {
 		super.onCreate(savedInstanceState)
 		setHasOptionsMenu(true)
-		adapterState = savedInstanceState?.getParcelable(KEY_ADAPTER_STATE) ?: adapterState
 	}
 
 	override fun onInflateView(
@@ -41,7 +40,6 @@ class FavouritesContainerFragment : BaseFragment<FragmentFavouritesBinding>(),
 	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
 		super.onViewCreated(view, savedInstanceState)
 		val adapter = FavouritesPagerAdapter(this, this)
-		adapterState?.let(adapter::restoreState)
 		binding.pager.adapter = adapter
 		TabLayoutMediator(binding.tabs, binding.pager, adapter).attach()
 
@@ -49,6 +47,13 @@ class FavouritesContainerFragment : BaseFragment<FragmentFavouritesBinding>(),
 		viewModel.onError.observe(viewLifecycleOwner, ::onError)
 	}
 
+	override fun onViewStateRestored(savedInstanceState: Bundle?) {
+		super.onViewStateRestored(savedInstanceState)
+		(savedInstanceState?.getParcelable(KEY_ADAPTER_STATE) ?: adapterState)?.let {
+			(binding.pager.adapter as FavouritesPagerAdapter).restoreState(it)
+		}
+	}
+
 	override fun onDestroyView() {
 		adapterState = (binding.pager.adapter as? FavouritesPagerAdapter)?.saveState()
 		super.onDestroyView()
@@ -56,6 +61,8 @@ class FavouritesContainerFragment : BaseFragment<FragmentFavouritesBinding>(),
 
 	override fun onSaveInstanceState(outState: Bundle) {
 		super.onSaveInstanceState(outState)
+		adapterState = (bindingOrNull()?.pager?.adapter as? FavouritesPagerAdapter)?.saveState()
+			?: adapterState
 		outState.putParcelable(KEY_ADAPTER_STATE, adapterState)
 	}
 

app/src/main/java/org/koitharu/kotatsu/favourites/ui/categories/FavouritesCategoriesViewModel.kt

@@ -4,6 +4,7 @@ import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.base.ui.BaseViewModel
 import org.koitharu.kotatsu.favourites.domain.FavouritesRepository
 
@@ -14,7 +15,7 @@ class FavouritesCategoriesViewModel(
 	private var reorderJob: Job? = null
 
 	val categories = repository.observeCategories()
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
 
 	fun createCategory(name: String) {
 		launchJob(Dispatchers.Default) {

app/src/main/java/org/koitharu/kotatsu/favourites/ui/categories/select/MangaCategoriesViewModel.kt

@@ -4,6 +4,7 @@ import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.base.ui.BaseViewModel
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.favourites.domain.FavouritesRepository
@@ -25,7 +26,7 @@ class MangaCategoriesViewModel(
 				isChecked = it.id in checked
 			)
 		}
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
 
 	fun setChecked(categoryId: Long, isChecked: Boolean) {
 		launchJob(Dispatchers.Default) {

app/src/main/java/org/koitharu/kotatsu/favourites/ui/list/FavouritesListViewModel.kt

@@ -1,11 +1,10 @@
 package org.koitharu.kotatsu.favourites.ui.list
 
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.prefs.AppSettings
@@ -15,6 +14,7 @@ import org.koitharu.kotatsu.list.ui.model.EmptyState
 import org.koitharu.kotatsu.list.ui.model.LoadingState
 import org.koitharu.kotatsu.list.ui.model.toErrorState
 import org.koitharu.kotatsu.list.ui.model.toUi
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import org.koitharu.kotatsu.utils.ext.onFirst
 
 class FavouritesListViewModel(
@@ -41,11 +41,9 @@ class FavouritesListViewModel(
 		}
 	}.onFirst {
 		isLoading.postValue(false)
-	}.onStart {
-		emit(listOf(LoadingState))
 	}.catch {
 		emit(listOf(it.toErrorState(canRetry = false)))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
 
 	override fun onRefresh() = Unit
 

app/src/main/java/org/koitharu/kotatsu/history/ui/HistoryListViewModel.kt

@@ -3,7 +3,6 @@ package org.koitharu.kotatsu.history.ui
 import android.content.Context
 import android.os.Build
 import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.*
@@ -18,6 +17,7 @@ import org.koitharu.kotatsu.list.ui.MangaListViewModel
 import org.koitharu.kotatsu.list.ui.model.*
 import org.koitharu.kotatsu.utils.MangaShortcut
 import org.koitharu.kotatsu.utils.SingleLiveEvent
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import org.koitharu.kotatsu.utils.ext.daysDiff
 import org.koitharu.kotatsu.utils.ext.onFirst
 import java.util.*
@@ -51,11 +51,9 @@ class HistoryListViewModel(
 		}
 	}.onFirst {
 		isLoading.postValue(false)
-	}.onStart {
-		emit(listOf(LoadingState))
 	}.catch {
 		it.toErrorState(canRetry = false)
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
 
 	override fun onRefresh() = Unit
 

app/src/main/java/org/koitharu/kotatsu/list/ui/MangaListViewModel.kt

@@ -22,7 +22,8 @@ abstract class MangaListViewModel(
 		.filter { it == AppSettings.KEY_GRID_SIZE }
 		.map { settings.gridSize / 100f }
 		.onStart { emit(settings.gridSize / 100f) }
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.IO)
+		.flowOn(Dispatchers.IO)
+		.asLiveData(viewModelScope.coroutineContext)
 
 	protected fun createListModeFlow() = settings.observe()
 		.filter { it == AppSettings.KEY_LIST_MODE }

app/src/main/java/org/koitharu/kotatsu/local/ui/LocalListViewModel.kt

@@ -8,6 +8,7 @@ import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.R
@@ -52,7 +53,7 @@ class LocalListViewModel(
 		}
 	}.onStart {
 		emit(listOf(LoadingState))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
 
 	init {
 		onRefresh()

app/src/main/java/org/koitharu/kotatsu/main/ui/MainActivity.kt

@@ -18,6 +18,7 @@ import com.google.android.material.snackbar.Snackbar
 import org.koin.androidx.viewmodel.ext.android.viewModel
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.base.ui.BaseActivity
+import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.model.MangaSource
 import org.koitharu.kotatsu.core.prefs.AppSection
 import org.koitharu.kotatsu.databinding.ActivityMainBinding
@@ -26,7 +27,6 @@ import org.koitharu.kotatsu.history.ui.HistoryListFragment
 import org.koitharu.kotatsu.local.ui.LocalListFragment
 import org.koitharu.kotatsu.main.ui.protect.AppProtectHelper
 import org.koitharu.kotatsu.reader.ui.ReaderActivity
-import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.remotelist.ui.RemoteListFragment
 import org.koitharu.kotatsu.search.ui.SearchHelper
 import org.koitharu.kotatsu.settings.AppUpdateChecker
@@ -159,7 +159,7 @@ class MainActivity : BaseActivity<ActivityMainBinding>(),
 		return true
 	}
 
-	private fun onOpenReader(state: ReaderState) {
+	private fun onOpenReader(manga: Manga) {
 		val options = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
 			ActivityOptions.makeClipRevealAnimation(
 				binding.fab, 0, 0, binding.fab.measuredWidth, binding.fab.measuredHeight
@@ -169,7 +169,7 @@ class MainActivity : BaseActivity<ActivityMainBinding>(),
 				binding.fab, 0, 0, binding.fab.measuredWidth, binding.fab.measuredHeight
 			)
 		}
-		startActivity(ReaderActivity.newIntent(this, state), options?.toBundle())
+		startActivity(ReaderActivity.newIntent(this, manga, null), options?.toBundle())
 	}
 
 	private fun onError(e: Throwable) {

app/src/main/java/org/koitharu/kotatsu/main/ui/MainViewModel.kt

@@ -3,16 +3,13 @@ package org.koitharu.kotatsu.main.ui
 import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.*
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.onStart
 import org.koitharu.kotatsu.base.domain.MangaProviderFactory
 import org.koitharu.kotatsu.base.ui.BaseViewModel
 import org.koitharu.kotatsu.core.exceptions.EmptyHistoryException
+import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.history.domain.HistoryRepository
-import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 
 class MainViewModel(
@@ -20,7 +17,7 @@ class MainViewModel(
 	settings: AppSettings
 ) : BaseViewModel() {
 
-	val onOpenReader = SingleLiveEvent<ReaderState>()
+	val onOpenReader = SingleLiveEvent<Manga>()
 	var defaultSection by settings::defaultSection
 
 	val remoteSources = settings.observe()
@@ -28,18 +25,14 @@ class MainViewModel(
 		.onStart { emit("") }
 		.map { MangaProviderFactory.getSources(settings, includeHidden = false) }
 		.distinctUntilChanged()
-		.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+		.flowOn(Dispatchers.Default)
+		.asLiveData(viewModelScope.coroutineContext)
 
 	fun openLastReader() {
 		launchLoadingJob {
 			val manga = historyRepository.getList(0, 1).firstOrNull()
 				?: throw EmptyHistoryException()
-			val history = historyRepository.getOne(manga) ?: throw EmptyHistoryException()
+			onOpenReader.call(manga)
-			val state = ReaderState(
-				manga.source.repository.getDetails(manga),
-				history.chapterId, history.page, history.scroll
-			)
-			onOpenReader.call(state)
 		}
 	}
 }

app/src/main/java/org/koitharu/kotatsu/main/ui/protect/AppProtectHelper.kt

@@ -7,6 +7,7 @@ import org.koin.core.component.inject
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.main.ui.MainActivity
 
+@Deprecated("TODO not object")
 object AppProtectHelper : KoinComponent {
 
 	val settings by inject<AppSettings>()

app/src/main/java/org/koitharu/kotatsu/reader/ReaderControlDelegate.kt

@@ -0,0 +1,95 @@
+package org.koitharu.kotatsu.reader
+
+import android.view.KeyEvent
+import androidx.lifecycle.LifecycleCoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.*
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.utils.GridTouchHelper
+
+@Suppress("UNUSED_PARAMETER")
+class ReaderControlDelegate(
+	private val scope: LifecycleCoroutineScope,
+	private val settings: AppSettings,
+	private val listener: OnInteractionListener
+) {
+
+	private var isTapSwitchEnabled: Boolean = true
+	private var isVolumeKeysSwitchEnabled: Boolean = false
+
+	init {
+		settings.observe()
+			.filter { it == AppSettings.KEY_READER_SWITCHERS }
+			.map { settings.readerPageSwitch }
+			.onStart { emit(settings.readerPageSwitch) }
+			.distinctUntilChanged()
+			.flowOn(Dispatchers.IO)
+			.onEach {
+				isTapSwitchEnabled = AppSettings.PAGE_SWITCH_TAPS in it
+				isVolumeKeysSwitchEnabled = AppSettings.PAGE_SWITCH_VOLUME_KEYS in it
+			}.launchIn(scope)
+	}
+
+	fun onGridTouch(area: Int) {
+		when (area) {
+			GridTouchHelper.AREA_CENTER -> {
+				listener.toggleUiVisibility()
+			}
+			GridTouchHelper.AREA_TOP,
+			GridTouchHelper.AREA_LEFT -> if (isTapSwitchEnabled) {
+				listener.switchPageBy(-1)
+			}
+			GridTouchHelper.AREA_BOTTOM,
+			GridTouchHelper.AREA_RIGHT -> if (isTapSwitchEnabled) {
+				listener.switchPageBy(1)
+			}
+		}
+	}
+
+	fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean = when (keyCode) {
+		KeyEvent.KEYCODE_VOLUME_UP -> if (isVolumeKeysSwitchEnabled) {
+			listener.switchPageBy(-1)
+			true
+		} else {
+			false
+		}
+		KeyEvent.KEYCODE_VOLUME_DOWN -> if (isVolumeKeysSwitchEnabled) {
+			listener.switchPageBy(1)
+			true
+		} else {
+			false
+		}
+		KeyEvent.KEYCODE_SPACE,
+		KeyEvent.KEYCODE_PAGE_DOWN,
+		KeyEvent.KEYCODE_SYSTEM_NAVIGATION_DOWN,
+		KeyEvent.KEYCODE_DPAD_DOWN,
+		KeyEvent.KEYCODE_DPAD_RIGHT -> {
+			listener.switchPageBy(1)
+			true
+		}
+		KeyEvent.KEYCODE_PAGE_UP,
+		KeyEvent.KEYCODE_SYSTEM_NAVIGATION_UP,
+		KeyEvent.KEYCODE_DPAD_UP,
+		KeyEvent.KEYCODE_DPAD_LEFT -> {
+			listener.switchPageBy(-1)
+			true
+		}
+		KeyEvent.KEYCODE_DPAD_CENTER -> {
+			listener.toggleUiVisibility()
+			true
+		}
+		else -> false
+	}
+
+	fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
+		return (isVolumeKeysSwitchEnabled &&
+				(keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_UP))
+	}
+
+	interface OnInteractionListener {
+
+		fun switchPageBy(delta: Int)
+
+		fun toggleUiVisibility()
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ReaderModule.kt

@@ -3,7 +3,9 @@ package org.koitharu.kotatsu.reader
 import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
 import org.koitharu.kotatsu.base.domain.MangaDataRepository
+import org.koitharu.kotatsu.base.domain.MangaIntent
 import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.reader.ui.ReaderViewModel
 
 val readerModule
@@ -12,5 +14,7 @@ val readerModule
 		single { MangaDataRepository(get()) }
 		single { PagesCache(get()) }
 
-		viewModel { ReaderViewModel(get(), get()) }
+		viewModel { (intent: MangaIntent, state: ReaderState?) ->
+			ReaderViewModel(intent, state, get(), get(), get())
+		}
 	}

app/src/main/java/org/koitharu/kotatsu/reader/ui/PageLoader.kt

@@ -9,26 +9,21 @@ import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import okhttp3.OkHttpClient
 import okhttp3.Request
-import org.koin.core.component.KoinComponent
-import org.koin.core.component.inject
 import org.koitharu.kotatsu.local.data.PagesCache
 import org.koitharu.kotatsu.utils.CacheUtils
 import org.koitharu.kotatsu.utils.ext.await
 import java.io.File
 import java.util.zip.ZipFile
-import kotlin.coroutines.CoroutineContext
 
-class PageLoader : KoinComponent, CoroutineScope, DisposableHandle {
+class PageLoader(
+	scope: CoroutineScope,
+	private val okHttp: OkHttpClient,
+	private val cache: PagesCache
+) : CoroutineScope by scope {
 
-	private val job = SupervisorJob()
 	private val tasks = ArrayMap<String, Deferred<File>>()
-	private val okHttp by inject<OkHttpClient>()
-	private val cache by inject<PagesCache>()
 	private val convertLock = Mutex()
 
-	override val coroutineContext: CoroutineContext
-		get() = job + Dispatchers.Main.immediate
-
 	@Suppress("BlockingMethodInNonBlockingContext")
 	suspend fun loadFile(url: String, force: Boolean): File {
 		if (!force) {
@@ -74,7 +69,7 @@ class PageLoader : KoinComponent, CoroutineScope, DisposableHandle {
 
 	suspend fun convertInPlace(file: File) {
 		convertLock.withLock(file) {
-			withContext(Dispatchers.IO) {
+			withContext(Dispatchers.Default) {
 				val image = BitmapFactory.decodeFile(file.absolutePath)
 				try {
 					file.outputStream().use { out ->
@@ -86,9 +81,4 @@ class PageLoader : KoinComponent, CoroutineScope, DisposableHandle {
 			}
 		}
 	}
-
-	override fun dispose() {
-		job.cancelChildren()
-		tasks.clear()
-	}
 }

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderActivity.kt

@@ -3,10 +3,8 @@ package org.koitharu.kotatsu.reader.ui
 import android.Manifest
 import android.content.Context
 import android.content.Intent
-import android.content.SharedPreferences
 import android.content.pm.PackageManager
 import android.net.Uri
-import android.os.Build
 import android.os.Bundle
 import android.view.*
 import android.widget.Toast
@@ -20,53 +18,54 @@ import androidx.fragment.app.commit
 import androidx.lifecycle.lifecycleScope
 import com.google.android.material.snackbar.Snackbar
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
-import org.koin.android.ext.android.inject
+import kotlinx.coroutines.withContext
+import org.koin.android.ext.android.get
 import org.koin.androidx.viewmodel.ext.android.viewModel
+import org.koin.core.parameter.parametersOf
 import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.base.domain.MangaIntent
 import org.koitharu.kotatsu.base.ui.BaseFullscreenActivity
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.model.MangaChapter
-import org.koitharu.kotatsu.core.model.MangaHistory
 import org.koitharu.kotatsu.core.model.MangaPage
-import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.core.prefs.ReaderMode
 import org.koitharu.kotatsu.databinding.ActivityReaderBinding
-import org.koitharu.kotatsu.reader.ui.base.AbstractReader
+import org.koitharu.kotatsu.reader.ReaderControlDelegate
-import org.koitharu.kotatsu.reader.ui.reversed.ReversedReaderFragment
+import org.koitharu.kotatsu.reader.ui.pager.BaseReader
-import org.koitharu.kotatsu.reader.ui.standard.PagerReaderFragment
+import org.koitharu.kotatsu.reader.ui.pager.ReaderUiState
+import org.koitharu.kotatsu.reader.ui.pager.reversed.ReversedReaderFragment
+import org.koitharu.kotatsu.reader.ui.pager.standard.PagerReaderFragment
+import org.koitharu.kotatsu.reader.ui.pager.wetoon.WebtoonReaderFragment
 import org.koitharu.kotatsu.reader.ui.thumbnails.OnPageSelectListener
 import org.koitharu.kotatsu.reader.ui.thumbnails.PagesThumbnailsSheet
-import org.koitharu.kotatsu.reader.ui.wetoon.WebtoonReaderFragment
 import org.koitharu.kotatsu.utils.GridTouchHelper
-import org.koitharu.kotatsu.utils.MangaShortcut
 import org.koitharu.kotatsu.utils.ScreenOrientationHelper
 import org.koitharu.kotatsu.utils.ShareHelper
 import org.koitharu.kotatsu.utils.anim.Motion
-import org.koitharu.kotatsu.utils.ext.*
+import org.koitharu.kotatsu.utils.ext.hasGlobalPoint
+import org.koitharu.kotatsu.utils.ext.hideAnimated
+import org.koitharu.kotatsu.utils.ext.hitTest
+import org.koitharu.kotatsu.utils.ext.showAnimated
 
 class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 	ChaptersDialog.OnChapterChangeListener,
 	GridTouchHelper.OnGridTouchListener, OnPageSelectListener, ReaderConfigDialog.Callback,
-	ReaderListener, SharedPreferences.OnSharedPreferenceChangeListener,
+	ActivityResultCallback<Boolean>, OnApplyWindowInsetsListener,
-	ActivityResultCallback<Boolean>, OnApplyWindowInsetsListener {
+	ReaderControlDelegate.OnInteractionListener {
 
-	private val viewModel by viewModel<ReaderViewModel>()
+	private val viewModel by viewModel<ReaderViewModel> {
-	private val settings by inject<AppSettings>()
+		parametersOf(MangaIntent.from(intent), intent?.getParcelableExtra<ReaderState>(EXTRA_STATE))
-
+	}
-	lateinit var state: ReaderState
-		private set
 
 	private lateinit var touchHelper: GridTouchHelper
 	private lateinit var orientationHelper: ScreenOrientationHelper
-	private var isTapSwitchEnabled = true
+	private lateinit var controlDelegate: ReaderControlDelegate
-	private var isVolumeKeysSwitchEnabled = false
 
 	private val reader
-		get() = supportFragmentManager.findFragmentById(R.id.container) as? AbstractReader<*>
+		get() = supportFragmentManager.findFragmentById(R.id.container) as? BaseReader<*>
 
 	override fun onCreate(savedInstanceState: Bundle?) {
 		super.onCreate(savedInstanceState)
@@ -74,63 +73,43 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 		supportActionBar?.setDisplayHomeAsUpEnabled(true)
 		touchHelper = GridTouchHelper(this, this)
 		orientationHelper = ScreenOrientationHelper(this)
+		controlDelegate = ReaderControlDelegate(lifecycleScope, get(), this)
 		binding.toolbarBottom.inflateMenu(R.menu.opt_reader_bottom)
 		binding.toolbarBottom.setOnMenuItemClickListener(::onOptionsItemSelected)
 
-		@Suppress("RemoveExplicitTypeArguments")
-		state = savedInstanceState?.getParcelable<ReaderState>(EXTRA_STATE)
-			?: intent.getParcelableExtra<ReaderState>(EXTRA_STATE)
-					?: let {
-				Toast.makeText(this, R.string.error_occurred, Toast.LENGTH_SHORT).show()
-				finishAfterTransition()
-				return
-			}
-
-		title = state.chapter?.name ?: state.manga.title
-		state.manga.chapters?.run {
-			supportActionBar?.subtitle =
-				getString(R.string.chapter_d_of_d, state.chapter?.number ?: 0, size)
-		}
-
 		ViewCompat.setOnApplyWindowInsetsListener(binding.rootLayout, this)
 
-		settings.subscribe(this)
-		loadSwitchSettings()
 		orientationHelper.observeAutoOrientation()
 			.onEach {
 				binding.toolbarBottom.menu.findItem(R.id.action_screen_rotate).isVisible = !it
 			}.launchIn(lifecycleScope)
 
-		if (savedInstanceState == null) {
-			viewModel.init(state.manga)
-			if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N_MR1) {
-				GlobalScope.launch(Dispatchers.Main + IgnoreErrors) {
-					MangaShortcut(state.manga).addAppShortcut(applicationContext)
-				}
-			}
-		}
-
 		viewModel.onError.observe(this, this::onError)
-		viewModel.reader.observe(this) { (manga, mode) -> onInitReader(manga, mode) }
+		viewModel.readerMode.observe(this, this::onInitReader)
 		viewModel.onPageSaved.observe(this, this::onPageSaved)
+		viewModel.uiState.observe(this, this::onUiStateChanged)
+		viewModel.isLoading.observe(this, this::onLoadingStateChanged)
+		viewModel.content.observe(this) {
+			onLoadingStateChanged(viewModel.isLoading.value == true)
+		}
 	}
 
-	private fun onInitReader(manga: Manga, mode: ReaderMode) {
+	private fun onInitReader(mode: ReaderMode) {
 		val currentReader = reader
 		when (mode) {
 			ReaderMode.WEBTOON -> if (currentReader !is WebtoonReaderFragment) {
 				supportFragmentManager.commit {
-					replace(R.id.container, WebtoonReaderFragment.newInstance(state))
+					replace(R.id.container, WebtoonReaderFragment())
 				}
 			}
 			ReaderMode.REVERSED -> if (currentReader !is ReversedReaderFragment) {
 				supportFragmentManager.commit {
-					replace(R.id.container, ReversedReaderFragment.newInstance(state))
+					replace(R.id.container, ReversedReaderFragment())
 				}
 			}
 			ReaderMode.STANDARD -> if (currentReader !is PagerReaderFragment) {
 				supportFragmentManager.commit {
-					replace(R.id.container, PagerReaderFragment.newInstance(state))
+					replace(R.id.container, PagerReaderFragment())
 				}
 			}
 		}
@@ -146,9 +125,9 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 		}
 	}
 
-	override fun onDestroy() {
+	override fun onPause() {
-		settings.unsubscribe(this)
+		viewModel.saveCurrentState(reader?.getCurrentState())
-		super.onDestroy()
+		super.onPause()
 	}
 
 	override fun onCreateOptionsMenu(menu: Menu?): Boolean {
@@ -156,11 +135,6 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 		return super.onCreateOptionsMenu(menu)
 	}
 
-	override fun onSaveInstanceState(outState: Bundle) {
-		super.onSaveInstanceState(outState)
-		outState.putParcelable(EXTRA_STATE, state)
-	}
-
 	override fun onOptionsItemSelected(item: MenuItem): Boolean {
 		when (item.itemId) {
 			R.id.action_reader_mode -> {
@@ -182,30 +156,28 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 			R.id.action_chapters -> {
 				ChaptersDialog.show(
 					supportFragmentManager,
-					state.manga.chapters.orEmpty(),
+					viewModel.manga?.chapters.orEmpty(),
-					state.chapterId
+					viewModel.getCurrentState()?.chapterId ?: 0L
 				)
 			}
 			R.id.action_screen_rotate -> {
 				orientationHelper.toggleOrientation()
 			}
 			R.id.action_pages_thumbs -> {
-				if (reader?.hasItems == true) {
+				val pages = viewModel.getCurrentChapterPages()
-					val pages = reader?.getPages()
 				if (!pages.isNullOrEmpty()) {
 					PagesThumbnailsSheet.show(
-							supportFragmentManager, pages,
+						supportFragmentManager,
-							state.chapter?.name ?: title?.toString().orEmpty()
+						pages,
+						title?.toString().orEmpty(),
+						reader?.getCurrentState()?.page ?: -1
 					)
 				} else {
 					showWaitWhileLoading()
 				}
-				} else {
-					showWaitWhileLoading()
-				}
 			}
 			R.id.action_save_page -> {
-				if (reader?.hasItems == true) {
+				if (!viewModel.content.value?.pages.isNullOrEmpty()) {
 					if (ContextCompat.checkSelfPermission(
 							this,
 							Manifest.permission.WRITE_EXTERNAL_STORAGE
@@ -229,30 +201,22 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 
 	override fun onActivityResult(result: Boolean) {
 		if (result) {
-			viewModel.savePage(
+			viewModel.saveCurrentPage(contentResolver)
-				resolver = contentResolver,
-				page = reader?.currentPage ?: return
-			)
 		}
 	}
 
-	override fun saveState(chapterId: Long, page: Int, scroll: Int) {
+	private fun onLoadingStateChanged(isLoading: Boolean) {
-		state = state.copy(chapterId = chapterId, page = page, scroll = scroll)
+		val hasPages = !viewModel.content.value?.pages.isNullOrEmpty()
-		ReaderViewModel.saveState(state)
-	}
-
-	override fun onLoadingStateChanged(isLoading: Boolean) {
-		val hasPages = reader?.hasItems == true
 		binding.layoutLoading.isVisible = isLoading && !hasPages
 		binding.progressBarBottom.isVisible = isLoading && hasPages
 	}
 
-	override fun onError(e: Throwable) {
+	private fun onError(e: Throwable) {
 		val dialog = AlertDialog.Builder(this)
 			.setTitle(R.string.error_occurred)
 			.setMessage(e.message)
 			.setPositiveButton(R.string.close, null)
-		if (reader?.hasItems != true) {
+		if (viewModel.content.value?.pages.isNullOrEmpty()) {
 			dialog.setOnDismissListener {
 				finish()
 			}
@@ -261,19 +225,7 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 	}
 
 	override fun onGridTouch(area: Int) {
-		when (area) {
+		controlDelegate.onGridTouch(area)
-			GridTouchHelper.AREA_CENTER -> {
-				setUiIsVisible(!binding.appbarTop.isVisible)
-			}
-			GridTouchHelper.AREA_TOP,
-			GridTouchHelper.AREA_LEFT -> if (isTapSwitchEnabled) {
-				reader?.switchPageBy(-1)
-			}
-			GridTouchHelper.AREA_BOTTOM,
-			GridTouchHelper.AREA_RIGHT -> if (isTapSwitchEnabled) {
-				reader?.switchPageBy(1)
-			}
-		}
 	}
 
 	override fun onProcessTouch(rawX: Int, rawY: Int): Boolean {
@@ -292,61 +244,32 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 		return super.dispatchTouchEvent(ev)
 	}
 
-	override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean = when (keyCode) {
+	override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
-		KeyEvent.KEYCODE_VOLUME_UP -> if (isVolumeKeysSwitchEnabled) {
+		return controlDelegate.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event)
-			reader?.switchPageBy(-1)
-			true
-		} else {
-			super.onKeyDown(keyCode, event)
-		}
-		KeyEvent.KEYCODE_VOLUME_DOWN -> if (isVolumeKeysSwitchEnabled) {
-			reader?.switchPageBy(1)
-			true
-		} else {
-			super.onKeyDown(keyCode, event)
-		}
-		KeyEvent.KEYCODE_SPACE,
-		KeyEvent.KEYCODE_PAGE_DOWN,
-		KeyEvent.KEYCODE_DPAD_DOWN,
-		KeyEvent.KEYCODE_DPAD_RIGHT -> {
-			reader?.switchPageBy(1)
-			true
-		}
-		KeyEvent.KEYCODE_PAGE_UP,
-		KeyEvent.KEYCODE_DPAD_UP,
-		KeyEvent.KEYCODE_DPAD_LEFT -> {
-			reader?.switchPageBy(-1)
-			true
-		}
-		KeyEvent.KEYCODE_DPAD_CENTER -> {
-			setUiIsVisible(!binding.appbarTop.isVisible)
-			true
-		}
-		else -> super.onKeyDown(keyCode, event)
 	}
 
 	override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
-		return (isVolumeKeysSwitchEnabled &&
+		return controlDelegate.onKeyUp(keyCode, event) || super.onKeyUp(keyCode, event)
-				(keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_UP))
-				|| super.onKeyUp(keyCode, event)
 	}
 
 	override fun onChapterChanged(chapter: MangaChapter) {
-		state = state.copy(
+		viewModel.switchChapter(chapter.id)
-			chapterId = chapter.id,
-			page = 0,
-			scroll = 0
-		)
-		reader?.updateState(chapterId = chapter.id)
 	}
 
 	override fun onPageSelected(page: MangaPage) {
-		reader?.updateState(pageId = page.id)
+		lifecycleScope.launch(Dispatchers.Default) {
+			val pages = viewModel.content.value?.pages ?: return@launch
+			val index = pages.indexOfFirst { it.id == page.id }
+			if (index != -1) {
+				withContext(Dispatchers.Main) {
+					reader?.switchPageTo(index, true)
+				}
+			}
+		}
 	}
 
 	override fun onReaderModeChanged(mode: ReaderMode) {
-		//TODO save state
+		viewModel.switchMode(mode)
-		viewModel.setMode(state.manga, mode)
 	}
 
 	private fun onPageSaved(uri: Uri?) {
@@ -363,22 +286,6 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 		}
 	}
 
-	override fun onPageChanged(chapter: MangaChapter, page: Int) {
-		title = chapter.name
-		state.manga.chapters?.run {
-			supportActionBar?.subtitle =
-				getString(R.string.chapter_d_of_d, chapter.number, size)
-		}
-	}
-
-	override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
-		when (key) {
-			AppSettings.KEY_READER_SWITCHERS -> loadSwitchSettings()
-			AppSettings.KEY_READER_ANIMATION,
-			AppSettings.KEY_ZOOM_MODE -> reader?.recreateAdapter()
-		}
-	}
-
 	private fun showWaitWhileLoading() {
 		Toast.makeText(this, R.string.wait_for_loading_finish, Toast.LENGTH_SHORT).apply {
 			setGravity(Gravity.CENTER, 0, 0)
@@ -416,10 +323,20 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 			.build()
 	}
 
-	private fun loadSwitchSettings() {
+	override fun switchPageBy(delta: Int) {
-		settings.readerPageSwitch.let {
+		reader?.switchPageBy(delta)
-			isTapSwitchEnabled = it.contains(AppSettings.PAGE_SWITCH_TAPS)
+	}
-			isVolumeKeysSwitchEnabled = it.contains(AppSettings.PAGE_SWITCH_VOLUME_KEYS)
+
+	override fun toggleUiVisibility() {
+		setUiIsVisible(!binding.appbarTop.isVisible)
+	}
+
+	private fun onUiStateChanged(uiState: ReaderUiState) {
+		title = uiState.chapterName ?: uiState.mangaName ?: getString(R.string.loading_)
+		supportActionBar?.subtitle = if (uiState.chapterNumber in 1..uiState.chaptersTotal) {
+			getString(R.string.chapter_d_of_d, uiState.chapterNumber, uiState.chaptersTotal)
+		} else {
+			null
 		}
 	}
 
@@ -427,32 +344,16 @@ class ReaderActivity : BaseFullscreenActivity<ActivityReaderBinding>(),
 
 		private const val EXTRA_STATE = "state"
 
-		fun newIntent(context: Context, state: ReaderState) =
+		fun newIntent(context: Context, manga: Manga, state: ReaderState?): Intent {
-			Intent(context, ReaderActivity::class.java)
+			return Intent(context, ReaderActivity::class.java)
+				.putExtra(MangaIntent.KEY_MANGA, manga)
 				.putExtra(EXTRA_STATE, state)
+		}
 
-		fun newIntent(context: Context, manga: Manga, chapterId: Long = -1) = newIntent(
+		fun newIntent(context: Context, mangaId: Long, state: ReaderState?): Intent {
-			context, ReaderState(
+			return Intent(context, ReaderActivity::class.java)
-				manga = manga,
+				.putExtra(MangaIntent.KEY_ID, mangaId)
-				chapterId = if (chapterId == -1L) manga.chapters?.firstOrNull()?.id
+				.putExtra(EXTRA_STATE, state)
-					?: -1 else chapterId,
-				page = 0,
-				scroll = 0
-			)
-		)
-
-		fun newIntent(context: Context, manga: Manga, history: MangaHistory?) =
-			if (history == null) {
-				newIntent(context, manga)
-			} else {
-				newIntent(
-					context, ReaderState(
-						manga = manga,
-						chapterId = history.chapterId,
-						page = history.page,
-						scroll = history.scroll
-					)
-				)
 		}
 	}
 }

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderConfigDialog.kt

@@ -1,5 +1,6 @@
 package org.koitharu.kotatsu.reader.ui
 
+import android.content.DialogInterface
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
@@ -31,6 +32,7 @@ class ReaderConfigDialog : AlertDialogFragment<DialogReaderConfigBinding>(),
 
 	override fun onBuildDialog(builder: AlertDialog.Builder) {
 		builder.setTitle(R.string.read_mode)
+			.setPositiveButton(R.string.done, null)
 			.setCancelable(true)
 	}
 
@@ -40,19 +42,19 @@ class ReaderConfigDialog : AlertDialogFragment<DialogReaderConfigBinding>(),
 		binding.buttonReversed.isChecked = mode == ReaderMode.REVERSED
 		binding.buttonWebtoon.isChecked = mode == ReaderMode.WEBTOON
 
-		binding.buttonOk.setOnClickListener(this)
 		binding.buttonStandard.setOnClickListener(this)
 		binding.buttonReversed.setOnClickListener(this)
 		binding.buttonWebtoon.setOnClickListener(this)
 	}
 
-	override fun onClick(v: View) {
+	override fun onDismiss(dialog: DialogInterface) {
-		when (v.id) {
-			R.id.button_ok -> {
 		((parentFragment as? Callback)
 			?: (activity as? Callback))?.onReaderModeChanged(mode)
-				dismiss()
+		super.onDismiss(dialog)
 	}
+
+	override fun onClick(v: View) {
+		when (v.id) {
 			R.id.button_standard -> mode = ReaderMode.STANDARD
 			R.id.button_webtoon -> mode = ReaderMode.WEBTOON
 			R.id.button_reversed -> mode = ReaderMode.REVERSED

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderContent.kt

@@ -0,0 +1,8 @@
+package org.koitharu.kotatsu.reader.ui
+
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+
+data class ReaderContent(
+	val pages: List<ReaderPage>,
+	val state: ReaderState?
+)

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderListener.kt

@@ -1,14 +0,0 @@
-package org.koitharu.kotatsu.reader.ui
-
-import org.koitharu.kotatsu.core.model.MangaChapter
-
-interface ReaderListener {
-
-	fun onPageChanged(chapter: MangaChapter, page: Int)
-
-	fun saveState(chapterId: Long, page: Int, scroll: Int)
-
-	fun onLoadingStateChanged(isLoading: Boolean)
-
-	fun onError(error: Throwable)
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderState.kt

@@ -1,21 +1,29 @@
 package org.koitharu.kotatsu.reader.ui
 
 import android.os.Parcelable
-import kotlinx.android.parcel.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
 import org.koitharu.kotatsu.core.model.Manga
-import org.koitharu.kotatsu.core.model.MangaChapter
+import org.koitharu.kotatsu.core.model.MangaHistory
 
 @Parcelize
 data class ReaderState(
-	val manga: Manga,
 	val chapterId: Long,
 	val page: Int,
 	val scroll: Int
 ) : Parcelable {
 
-	@IgnoredOnParcel
+	companion object {
-	val chapter: MangaChapter? by lazy {
+
-		manga.chapters?.find { it.id == chapterId }
+		fun from(history: MangaHistory) = ReaderState(
+			chapterId = history.chapterId,
+			page = history.page,
+			scroll = history.scroll
+		)
+
+		fun initial(manga: Manga) = ReaderState(
+			chapterId = manga.chapters?.firstOrNull()?.id ?: error("Cannot find first chapter"),
+			page = 0,
+			scroll = 0
+		)
 	}
 }

app/src/main/java/org/koitharu/kotatsu/reader/ui/ReaderViewModel.kt

@@ -2,74 +2,145 @@ package org.koitharu.kotatsu.reader.ui
 
 import android.content.ContentResolver
 import android.net.Uri
+import android.util.LongSparseArray
 import android.webkit.URLUtil
 import androidx.lifecycle.MutableLiveData
-import kotlinx.coroutines.CancellationException
+import androidx.lifecycle.asLiveData
-import kotlinx.coroutines.Dispatchers
+import androidx.lifecycle.viewModelScope
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.*
-import kotlinx.coroutines.withContext
+import kotlinx.coroutines.flow.*
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.get
 import org.koitharu.kotatsu.base.domain.MangaDataRepository
+import org.koitharu.kotatsu.base.domain.MangaIntent
 import org.koitharu.kotatsu.base.domain.MangaUtils
 import org.koitharu.kotatsu.base.ui.BaseViewModel
+import org.koitharu.kotatsu.core.exceptions.MangaNotFoundException
 import org.koitharu.kotatsu.core.model.Manga
+import org.koitharu.kotatsu.core.model.MangaChapter
 import org.koitharu.kotatsu.core.model.MangaPage
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.core.prefs.ReaderMode
 import org.koitharu.kotatsu.history.domain.HistoryRepository
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.reader.ui.pager.ReaderUiState
 import org.koitharu.kotatsu.utils.MediaStoreCompat
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.ext.*
 
 class ReaderViewModel(
+	intent: MangaIntent,
+	state: ReaderState?,
 	private val dataRepository: MangaDataRepository,
+	private val historyRepository: HistoryRepository,
 	private val settings: AppSettings
 ) : BaseViewModel() {
 
-	val reader = MutableLiveData<Pair<Manga, ReaderMode>>()
+	private var loadingJob: Job? = null
+	private val currentState = MutableStateFlow(state)
+	private val mangaData = MutableStateFlow<Manga?>(intent.manga)
+	private val chapters = LongSparseArray<MangaChapter>()
+
+	val readerMode = MutableLiveData<ReaderMode>()
 	val onPageSaved = SingleLiveEvent<Uri?>()
+	val uiState = combine(
+		mangaData,
+		currentState
+	) { manga, state ->
+		val chapter = state?.chapterId?.let(chapters::get)
+		ReaderUiState(
+			mangaName = manga?.title,
+			chapterName = chapter?.name,
+			chapterNumber = chapter?.number ?: 0,
+			chaptersTotal = chapters.size()
+		)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
+
+	val content = MutableLiveData<ReaderContent>(ReaderContent(emptyList(), null))
+	val manga: Manga?
+		get() = mangaData.value
+
+	val readerAnimation = settings.observe()
+		.filter { it == AppSettings.KEY_READER_ANIMATION }
+		.map { settings.readerAnimation }
+		.onStart { emit(settings.readerAnimation) }
+		.distinctUntilChanged()
+		.flowOn(Dispatchers.IO)
+		.asLiveData(viewModelScope.coroutineContext)
+
+	val onZoomChanged = settings.observe()
+		.filter { it == AppSettings.KEY_ZOOM_MODE }
+		.flowOn(Dispatchers.IO)
+		.asLiveEvent(viewModelScope.coroutineContext)
 
-	fun init(manga: Manga) {
+	init {
-		launchLoadingJob {
+		loadingJob = launchLoadingJob(Dispatchers.Default) {
-			val mode = withContext(Dispatchers.Default) {
+			var manga = dataRepository.resolveIntent(intent)
+				?: throw MangaNotFoundException("Cannot find manga")
+			mangaData.value = manga
 			val repo = manga.source.repository
-				val chapter =
+			manga = repo.getDetails(manga)
-					(manga.chapters ?: throw RuntimeException("Chapters is null")).random()
+			manga.chapters?.forEach {
-				var mode = dataRepository.getReaderMode(manga.id)
+				chapters.put(it.id, it)
-				if (mode == null) {
+			}
-					val pages = repo.getPages(chapter)
+			mangaData.value = manga
+			// determine mode
+			val mode =
+				dataRepository.getReaderMode(manga.id) ?: manga.chapters?.randomOrNull()?.let {
+					val pages = repo.getPages(it)
 					val isWebtoon = MangaUtils.determineMangaIsWebtoon(pages)
-					mode = getReaderMode(isWebtoon)
+					val newMode = getReaderMode(isWebtoon)
 					if (isWebtoon != null) {
-						dataRepository.savePreferences(
+						dataRepository.savePreferences(manga, newMode)
-							manga = manga,
-							mode = mode
-						)
-					}
 					}
-				mode
+					newMode
+				} ?: error("There are no chapters in this manga")
+			// obtain state
+			if (state == null) {
+				currentState.value = historyRepository.getOne(manga)?.let {
+					ReaderState.from(it)
+				} ?: ReaderState.initial(manga)
 			}
-			reader.value = manga to mode
+			readerMode.postValue(mode)
+
+			val pages = loadChapter(checkNotNull(manga.chapters?.firstOrNull()).id)
+			content.postValue(ReaderContent(pages, currentState.value))
 		}
 	}
 
-	fun setMode(manga: Manga, mode: ReaderMode) {
+	fun switchMode(newMode: ReaderMode) {
 		launchJob {
+			val manga = checkNotNull(mangaData.value)
 			dataRepository.savePreferences(
 				manga = manga,
-				mode = mode
+				mode = newMode
 			)
-			reader.value = manga to mode
+			readerMode.value = newMode
 		}
 	}
 
-	fun savePage(resolver: ContentResolver, page: MangaPage) {
+	fun saveCurrentState(state: ReaderState? = null) {
-		launchJob {
+		saveState(
-			withContext(Dispatchers.Default) {
+			mangaData.value ?: return,
+			state ?: currentState.value ?: return
+		)
+	}
+
+	fun getCurrentState() = currentState.value
+
+	fun getCurrentChapterPages(): List<MangaPage>? {
+		val chapterId = currentState.value?.chapterId ?: return null
+		val pages = content.value?.pages ?: return null
+		return pages.filter { it.chapterId == chapterId }.map { it.toMangaPage() }
+	}
+
+	fun saveCurrentPage(resolver: ContentResolver) {
+		launchJob(Dispatchers.Default) {
 			try {
+				val page =
+					content.value?.pages?.randomOrNull()?.toMangaPage() ?: return@launchJob //TODO
 				val repo = page.source.repository
 				val url = repo.getPageFullUrl(page)
 				val request = Request.Builder()
@@ -84,7 +155,7 @@ class ReaderViewModel(
 							response.mimeType
 						)
 					MediaStoreCompat.insertImage(resolver, fileName) {
-							response.body!!.byteStream().copyTo(it)
+						checkNotNull(response.body).byteStream().copyTo(it)
 					}
 				}
 				onPageSaved.postCall(uri)
@@ -94,6 +165,37 @@ class ReaderViewModel(
 			}
 		}
 	}
+
+	fun switchChapter(id: Long) {
+		val prevJob = loadingJob
+		loadingJob = launchLoadingJob(Dispatchers.Default) {
+			prevJob?.cancelAndJoin()
+			content.postValue(ReaderContent(emptyList(), null))
+			val newPages = loadChapter(id)
+			content.postValue(ReaderContent(newPages, ReaderState(id, 0, 0)))
+		}
+	}
+
+	fun onCurrentPageChanged(position: Int) {
+		val pages = content.value?.pages ?: return
+		pages.getOrNull(position)?.let {
+			val currentValue = currentState.value
+			if (currentValue != null && currentValue.chapterId != it.chapterId) {
+				currentState.value = currentValue.copy(chapterId = it.chapterId)
+			}
+		}
+		when {
+			loadingJob?.isActive == true -> return
+			pages.isEmpty() -> return
+			position <= BOUNDS_PAGE_OFFSET -> {
+				val chapterId = pages.first().chapterId
+				loadPrevNextChapter(chapterId, -1)
+			}
+			position >= pages.size - BOUNDS_PAGE_OFFSET -> {
+				val chapterId = pages.last().chapterId
+				loadPrevNextChapter(chapterId, 1)
+			}
+		}
 	}
 
 	private fun getReaderMode(isWebtoon: Boolean?) = when {
@@ -102,12 +204,56 @@ class ReaderViewModel(
 		else -> ReaderMode.STANDARD
 	}
 
-	companion object : KoinComponent {
+	private suspend fun loadChapter(chapterId: Long): List<ReaderPage> {
+		val manga = checkNotNull(mangaData.value) { "Manga is null" }
+		val chapter = checkNotNull(chapters.get(chapterId)) { "Chapter $chapterId not found" }
+		val repo = manga.source.repository
+		return repo.getPages(chapter).mapIndexed { index, page ->
+			ReaderPage.from(page, index, chapterId)
+		}
+	}
+
+	private fun loadPrevNextChapter(currentId: Long, delta: Int) {
+		loadingJob = launchLoadingJob(Dispatchers.Default) {
+			val chapters = mangaData.value?.chapters ?: return@launchLoadingJob
+			val predicate: (MangaChapter) -> Boolean = { it.id == currentId }
+			val index =
+				if (delta < 0) chapters.indexOfLast(predicate) else chapters.indexOfFirst(predicate)
+			if (index == -1) return@launchLoadingJob
+			val newChapter = chapters.getOrNull(index + delta) ?: return@launchLoadingJob
+			val newPages = loadChapter(newChapter.id)
+			var currentPages = content.value?.pages ?: return@launchLoadingJob
+			// trim pages
+			if (currentPages.size > PAGES_TRIM_THRESHOLD) {
+				val firstChapterId = currentPages.first().chapterId
+				val lastChapterId = currentPages.last().chapterId
+				if (firstChapterId != lastChapterId) {
+					currentPages = when (delta) {
+						1 -> currentPages.dropWhile { it.chapterId == firstChapterId }
+						-1 -> currentPages.dropLastWhile { it.chapterId == lastChapterId }
+						else -> currentPages
+					}
+				}
+			}
+			val pages = when (delta) {
+				0 -> newPages
+				-1 -> newPages + currentPages
+				1 -> currentPages + newPages
+				else -> error("Invalid delta $delta")
+			}
+			content.postValue(ReaderContent(pages, null))
+		}
+	}
+
+	private companion object : KoinComponent {
 
-		fun saveState(state: ReaderState) {
+		const val BOUNDS_PAGE_OFFSET = 2
+		const val PAGES_TRIM_THRESHOLD = 120
+
+		fun saveState(manga: Manga, state: ReaderState) {
 			processLifecycleScope.launch(Dispatchers.Default + IgnoreErrors) {
 				get<HistoryRepository>().addOrUpdate(
-					manga = state.manga,
+					manga = manga,
 					chapterId = state.chapterId,
 					page = state.page,
 					scroll = state.scroll

app/src/main/java/org/koitharu/kotatsu/reader/ui/base/AbstractReader.kt

@@ -1,267 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.base
-
-import android.content.Context
-import android.os.Bundle
-import android.view.View
-import androidx.annotation.CallSuper
-import androidx.collection.LongSparseArray
-import androidx.core.view.postDelayed
-import androidx.viewbinding.ViewBinding
-import kotlinx.coroutines.CancellationException
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
-import org.koitharu.kotatsu.base.ui.BaseFragment
-import org.koitharu.kotatsu.core.model.Manga
-import org.koitharu.kotatsu.core.model.MangaChapter
-import org.koitharu.kotatsu.core.model.MangaPage
-import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.ReaderListener
-import org.koitharu.kotatsu.reader.ui.ReaderState
-import org.koitharu.kotatsu.utils.ext.associateByLong
-import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
-
-abstract class AbstractReader<B : ViewBinding> : BaseFragment<B>(), OnBoundsScrollListener {
-
-	protected lateinit var manga: Manga
-		private set
-	private lateinit var chapters: LongSparseArray<MangaChapter>
-	protected val loader by lazy(LazyThreadSafetyMode.NONE) {
-		PageLoader()
-	}
-	protected val pages = ArrayDeque<ReaderPage>()
-	protected var readerAdapter: BaseReaderAdapter? = null
-		private set
-
-	val itemsCount: Int
-		get() = readerAdapter?.itemCount ?: 0
-
-	val hasItems: Boolean
-		get() = itemsCount != 0
-
-	val currentPage: MangaPage?
-		get() = pages.getOrNull(getCurrentItem())?.toMangaPage()
-
-	private var readerListener: ReaderListener? = null
-
-	override fun onCreate(savedInstanceState: Bundle?) {
-		super.onCreate(savedInstanceState)
-		manga = requireNotNull(requireArguments().getParcelable<ReaderState>(ARG_STATE)).manga
-		chapters = requireNotNull(manga.chapters).associateByLong { it.id }
-	}
-
-	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-		super.onViewCreated(view, savedInstanceState)
-		readerAdapter = onCreateAdapter(pages)
-		@Suppress("RemoveExplicitTypeArguments")
-		val state = savedInstanceState?.getParcelable<ReaderState>(ARG_STATE)
-			?: requireArguments().getParcelable<ReaderState>(ARG_STATE)!!
-		loadChapter(state.chapterId) {
-			pages.clear()
-			it.mapIndexedTo(pages) { i, p ->
-				ReaderPage.from(p, i, state.chapterId)
-			}
-			readerAdapter?.notifyDataSetChanged()
-			setCurrentItem(state.page, false)
-			if (state.scroll != 0) {
-				restorePageScroll(state.page, state.scroll)
-			}
-		}
-	}
-
-	override fun onAttach(context: Context) {
-		super.onAttach(context)
-		readerListener = activity as? ReaderListener
-	}
-
-	override fun onDetach() {
-		readerListener = null
-		super.onDetach()
-	}
-
-	override fun onSaveInstanceState(outState: Bundle) {
-		super.onSaveInstanceState(outState)
-		val page = pages.getOrNull(getCurrentItem()) ?: return
-		outState.putParcelable(
-			ARG_STATE, ReaderState(
-				manga = manga,
-				chapterId = page.chapterId,
-				page = page.index,
-				scroll = getCurrentPageScroll()
-			)
-		)
-	}
-
-	override fun onScrolledToStart() {
-		val chapterId = getFirstPage()?.chapterId ?: return
-		val index = manga.chapters?.indexOfFirst { it.id == chapterId } ?: return
-		val prevChapterId = manga.chapters!!.getOrNull(index - 1)?.id ?: return
-		loadChapter(prevChapterId) {
-			pages.addAll(0, it.mapIndexed { i, p ->
-				ReaderPage.from(p, i, prevChapterId)
-			})
-			readerAdapter?.notifyItemsPrepended(it.size)
-			view?.postDelayed(500) {
-				trimEnd()
-			}
-		}
-	}
-
-	override fun onScrolledToEnd() {
-		val chapterId = getLastPage()?.chapterId ?: return
-		val index = manga.chapters?.indexOfLast { it.id == chapterId } ?: return
-		val nextChapterId = manga.chapters!!.getOrNull(index + 1)?.id ?: return
-		loadChapter(nextChapterId) {
-			pages.addAll(it.mapIndexed { i, p ->
-				ReaderPage.from(p, i, nextChapterId)
-			})
-			readerAdapter?.notifyItemsAppended(it.size)
-			view?.postDelayed(500) {
-				trimStart()
-			}
-		}
-	}
-
-	override fun onDestroyView() {
-		readerAdapter = null
-		super.onDestroyView()
-	}
-
-	override fun onDestroy() {
-		loader.dispose()
-		super.onDestroy()
-	}
-
-	@CallSuper
-	open fun recreateAdapter() {
-		readerAdapter = onCreateAdapter(pages)
-	}
-
-	fun getPages(): List<MangaPage>? {
-		val chapterId = (pages.getOrNull(getCurrentItem()) ?: return null).chapterId
-		// TODO optimize
-		return pages.filter { it.chapterId == chapterId }.map { it.toMangaPage() }
-	}
-
-	override fun onPause() {
-		saveState()
-		super.onPause()
-	}
-
-	private fun loadChapter(chapterId: Long, callback: suspend (List<MangaPage>) -> Unit) {
-		viewLifecycleScope.launch {
-			readerListener?.onLoadingStateChanged(isLoading = true)
-			try {
-				val pages = withContext(Dispatchers.Default) {
-					val chapter = chapters.get(chapterId)
-						?: throw RuntimeException("Chapter $chapterId not found")
-					val repo = manga.source.repository
-					repo.getPages(chapter)
-				}
-				callback(pages)
-			} catch (_: CancellationException) {
-			} catch (e: Throwable) {
-				readerListener?.onError(e)
-			} finally {
-				readerListener?.onLoadingStateChanged(isLoading = false)
-			}
-		}
-	}
-
-	private fun trimStart() {
-		/*var removed = 0
-		while (pages.groupCount > 3 && pages.size > 8) {
-			removed += pages.removeFirst().size
-		}
-		if (removed != 0) {
-			adapter?.notifyItemsRemovedStart(removed)
-			Log.i(TAG, "Removed $removed pages from start")
-		}*/
-	}
-
-	private fun trimEnd() {
-		/*var removed = 0
-		while (pages.groupCount > 3 && pages.size > 8) {
-			removed += pages.removeLast().size
-		}
-		if (removed != 0) {
-			adapter?.notifyItemsRemovedEnd(removed)
-			Log.i(TAG, "Removed $removed pages from end")
-		}*/
-	}
-
-	protected fun notifyPageChanged(position: Int) {
-		val page = pages.getOrNull(position) ?: return
-		val chapter = chapters.get(page.chapterId) ?: return
-		readerListener?.onPageChanged(
-			chapter = chapter,
-			page = page.index
-		)
-	}
-
-	private fun saveState() {
-		val page = pages.getOrNull(getCurrentItem()) ?: return
-		readerListener?.saveState(page.chapterId, page.index, getCurrentPageScroll())
-	}
-
-	open fun switchPageBy(delta: Int) {
-		setCurrentItem(getCurrentItem() + delta, true)
-	}
-
-	fun updateState(chapterId: Long = 0, pageId: Long = 0) {
-		val currentChapterId = pages.getOrNull(getCurrentItem())?.chapterId ?: 0L
-		if (chapterId != 0L && chapterId != currentChapterId) {
-			pages.clear()
-			readerAdapter?.notifyDataSetChanged()
-			loadChapter(chapterId) {
-				pages.clear()
-				it.mapIndexedTo(pages) { i, p ->
-					ReaderPage.from(p, i, chapterId)
-				}
-				readerAdapter?.notifyDataSetChanged()
-				setCurrentItem(
-					if (pageId == 0L) {
-						0
-					} else {
-						it.indexOfFirst { x -> x.id == pageId }.coerceAtLeast(0)
-					}, false
-				)
-			}
-		} else {
-			var index = 0
-			if (pageId != 0L) {
-				index = pages.indexOfFirst {
-					it.chapterId == currentChapterId && it.id == pageId
-				}
-				if (index == -1) { // try to find chapter at least
-					index = pages.indexOfFirst {
-						it.chapterId == currentChapterId
-					}
-				}
-				if (index == -1) {
-					index = 0
-				}
-			}
-			setCurrentItem(index, false)
-		}
-	}
-
-	protected open fun getLastPage() = pages.lastOrNull()
-
-	protected open fun getFirstPage() = pages.firstOrNull()
-
-	protected abstract fun getCurrentItem(): Int
-
-	protected abstract fun getCurrentPageScroll(): Int
-
-	protected abstract fun restorePageScroll(position: Int, scroll: Int)
-
-	protected abstract fun setCurrentItem(position: Int, isSmooth: Boolean)
-
-	protected abstract fun onCreateAdapter(dataSet: List<ReaderPage>): BaseReaderAdapter
-
-	protected companion object {
-
-		const val ARG_STATE = "state"
-	}
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/base/BaseReaderAdapter.kt

@@ -1,52 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.base
-
-import android.view.ViewGroup
-import androidx.recyclerview.widget.RecyclerView
-import org.koitharu.kotatsu.base.ui.list.BaseViewHolder
-
-abstract class BaseReaderAdapter(protected val pages: List<ReaderPage>) :
-	RecyclerView.Adapter<BaseViewHolder<ReaderPage, Unit, *>>() {
-
-	init {
-		@Suppress("LeakingThis")
-		setHasStableIds(true)
-	}
-
-	override fun onBindViewHolder(holder: BaseViewHolder<ReaderPage, Unit, *>, position: Int) {
-		val item = pages[position]
-		holder.bind(item, Unit)
-	}
-
-	open fun getItem(position: Int) = pages[position]
-
-	open fun notifyItemsAppended(count: Int) {
-		notifyItemRangeInserted(pages.size - count, count)
-	}
-
-	open fun notifyItemsPrepended(count: Int) {
-		notifyItemRangeInserted(0, count)
-	}
-
-	open fun notifyItemsRemovedStart(count: Int) {
-		notifyItemRangeRemoved(0, count)
-	}
-
-	open fun notifyItemsRemovedEnd(count: Int) {
-		notifyItemRangeRemoved(pages.size - count, count)
-	}
-
-	override fun getItemId(position: Int) = pages[position].id
-
-	final override fun getItemCount() = pages.size
-
-	final override fun onCreateViewHolder(
-		parent: ViewGroup,
-		viewType: Int
-	): BaseViewHolder<ReaderPage, Unit, *> {
-		return onCreateViewHolder(parent).also(this::onViewHolderCreated)
-	}
-
-	protected open fun onViewHolderCreated(holder: BaseViewHolder<ReaderPage, Unit, *>) = Unit
-
-	protected abstract fun onCreateViewHolder(parent: ViewGroup): BaseViewHolder<ReaderPage, Unit, *>
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/BasePageHolder.kt

@@ -0,0 +1,35 @@
+package org.koitharu.kotatsu.reader.ui.pager
+
+import android.content.Context
+import androidx.recyclerview.widget.RecyclerView
+import androidx.viewbinding.ViewBinding
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.reader.ui.PageLoader
+
+abstract class BasePageHolder<B : ViewBinding>(
+	protected val binding: B,
+	loader: PageLoader,
+	settings: AppSettings
+) : RecyclerView.ViewHolder(binding.root), PageHolderDelegate.Callback {
+
+	protected val delegate = PageHolderDelegate(loader, settings, this)
+
+	val context: Context
+		get() = itemView.context
+
+	var boundData: ReaderPage? = null
+		private set
+
+	fun requireData(): ReaderPage {
+		return checkNotNull(boundData) { "Calling requireData() before bind()" }
+	}
+
+	fun bind(data: ReaderPage) {
+		boundData = data
+		onBind(data)
+	}
+
+	protected abstract fun onBind(data: ReaderPage)
+
+	protected open fun onRecycled() = Unit
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/BaseReader.kt

@@ -0,0 +1,57 @@
+package org.koitharu.kotatsu.reader.ui.pager
+
+import android.os.Bundle
+import android.view.View
+import androidx.lifecycle.lifecycleScope
+import androidx.viewbinding.ViewBinding
+import org.koin.android.ext.android.get
+import org.koin.androidx.viewmodel.ext.android.sharedViewModel
+import org.koitharu.kotatsu.base.ui.BaseFragment
+import org.koitharu.kotatsu.reader.ui.PageLoader
+import org.koitharu.kotatsu.reader.ui.ReaderState
+import org.koitharu.kotatsu.reader.ui.ReaderViewModel
+
+abstract class BaseReader<B : ViewBinding> : BaseFragment<B>() {
+
+	protected val viewModel by sharedViewModel<ReaderViewModel>()
+	protected val loader by lazy(LazyThreadSafetyMode.NONE) {
+		PageLoader(lifecycleScope, get(), get())
+	}
+	private var lastReaderState: ReaderState? = null
+
+	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+		super.onViewCreated(view, savedInstanceState)
+		lastReaderState = savedInstanceState?.getParcelable(KEY_STATE) ?: lastReaderState
+
+		viewModel.content.observe(viewLifecycleOwner) {
+			onPagesChanged(it.pages, lastReaderState ?: it.state)
+			lastReaderState = null
+		}
+	}
+
+	override fun onDestroyView() {
+		lastReaderState = getCurrentState()
+		super.onDestroyView()
+	}
+
+	override fun onSaveInstanceState(outState: Bundle) {
+		super.onSaveInstanceState(outState)
+		getCurrentState()?.let {
+			lastReaderState = it
+		}
+		outState.putParcelable(KEY_STATE, lastReaderState)
+	}
+
+	abstract fun switchPageBy(delta: Int)
+
+	abstract fun switchPageTo(position: Int, smooth: Boolean)
+
+	abstract fun getCurrentState(): ReaderState?
+
+	protected abstract fun onPagesChanged(pages: List<ReaderPage>, pendingState: ReaderState?)
+
+	private companion object {
+
+		const val KEY_STATE = "state"
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/BaseReaderAdapter.kt

@@ -0,0 +1,69 @@
+package org.koitharu.kotatsu.reader.ui.pager
+
+import android.view.ViewGroup
+import androidx.recyclerview.widget.AsyncListDiffer
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.RecyclerView
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.reader.ui.PageLoader
+import kotlin.coroutines.resume
+import kotlin.coroutines.suspendCoroutine
+
+abstract class BaseReaderAdapter<H : BasePageHolder<*>>(
+	private val loader: PageLoader,
+	private val settings: AppSettings
+) : RecyclerView.Adapter<H>() {
+
+	private val differ = AsyncListDiffer(this, DiffCallback())
+
+	init {
+		setHasStableIds(true)
+	}
+
+	override fun onBindViewHolder(holder: H, position: Int) {
+		holder.bind(differ.currentList[position])
+	}
+
+	open fun getItem(position: Int): ReaderPage = differ.currentList[position]
+
+	open fun getItemOrNull(position: Int) = differ.currentList.getOrNull(position)
+
+	override fun getItemId(position: Int) = differ.currentList[position].id
+
+	final override fun getItemCount() = differ.currentList.size
+
+	final override fun onCreateViewHolder(
+		parent: ViewGroup,
+		viewType: Int
+	): H = onCreateViewHolder(parent, loader, settings).also(this::onViewHolderCreated)
+
+	fun setItems(items: List<ReaderPage>, callback: Runnable) {
+		differ.submitList(items, callback)
+	}
+
+	suspend fun setItems(items: List<ReaderPage>) = suspendCoroutine<Unit> { cont ->
+		differ.submitList(items) {
+			cont.resume(Unit)
+		}
+	}
+
+	protected open fun onViewHolderCreated(holder: H) = Unit
+
+	protected abstract fun onCreateViewHolder(
+		parent: ViewGroup,
+		loader: PageLoader,
+		settings: AppSettings
+	): H
+
+	private class DiffCallback : DiffUtil.ItemCallback<ReaderPage>() {
+
+		override fun areItemsTheSame(oldItem: ReaderPage, newItem: ReaderPage): Boolean {
+			return oldItem.id == newItem.id
+		}
+
+		override fun areContentsTheSame(oldItem: ReaderPage, newItem: ReaderPage): Boolean {
+			return oldItem == newItem
+		}
+
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/OnBoundsScrollListener.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.base
+package org.koitharu.kotatsu.reader.ui.pager
 
 interface OnBoundsScrollListener {
 

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/PageHolderDelegate.kt

@@ -1,10 +1,9 @@
-package org.koitharu.kotatsu.reader.ui.base
+package org.koitharu.kotatsu.reader.ui.pager
 
 import android.net.Uri
 import androidx.core.net.toUri
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import kotlinx.coroutines.*
-import org.koin.core.component.inject
 import org.koitharu.kotatsu.core.model.MangaPage
 import org.koitharu.kotatsu.core.model.ZoomMode
 import org.koitharu.kotatsu.core.prefs.AppSettings
@@ -16,11 +15,11 @@ import java.io.IOException
 
 class PageHolderDelegate(
 	private val loader: PageLoader,
+	private val settings: AppSettings,
 	private val callback: Callback
 ) : SubsamplingScaleImageView.DefaultOnImageEventListener(),
 	CoroutineScope by loader {
 
-	private val settings by loader.inject<AppSettings>()
 	private var state = State.EMPTY
 	private var job: Job? = null
 	private var file: File? = null

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/ReaderPage.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.base
+package org.koitharu.kotatsu.reader.ui.pager
 
 import android.os.Parcelable
 import kotlinx.parcelize.Parcelize

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/ReaderUiState.kt

@@ -0,0 +1,8 @@
+package org.koitharu.kotatsu.reader.ui.pager
+
+data class ReaderUiState(
+	val mangaName: String?,
+	val chapterName: String?,
+	val chapterNumber: Int,
+	val chaptersTotal: Int
+)

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageAnimTransformer.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.reversed
+package org.koitharu.kotatsu.reader.ui.pager.reversed
 
 import android.view.View
 import androidx.viewpager2.widget.ViewPager2

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPageHolder.kt

@@ -1,13 +1,18 @@
-package org.koitharu.kotatsu.reader.ui.reversed
+package org.koitharu.kotatsu.reader.ui.pager.reversed
 
 import android.graphics.PointF
-import android.view.ViewGroup
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import org.koitharu.kotatsu.core.model.ZoomMode
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.databinding.ItemPageBinding
 import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.standard.PageHolder
+import org.koitharu.kotatsu.reader.ui.pager.standard.PageHolder
 
-class ReversedPageHolder(parent: ViewGroup, loader: PageLoader) : PageHolder(parent, loader) {
+class ReversedPageHolder(
+	binding: ItemPageBinding,
+	loader: PageLoader,
+	settings: AppSettings
+) : PageHolder(binding, loader, settings) {
 
 	override fun onImageShowing(zoom: ZoomMode) {
 		with(binding.ssiv) {

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedPagesAdapter.kt

@@ -0,0 +1,24 @@
+package org.koitharu.kotatsu.reader.ui.pager.reversed
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.databinding.ItemPageBinding
+import org.koitharu.kotatsu.reader.ui.PageLoader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+
+class ReversedPagesAdapter(
+	loader: PageLoader,
+	settings: AppSettings
+) : BaseReaderAdapter<ReversedPageHolder>(loader, settings) {
+
+	override fun onCreateViewHolder(
+		parent: ViewGroup,
+		loader: PageLoader,
+		settings: AppSettings
+	) = ReversedPageHolder(
+		binding = ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false),
+		loader = loader,
+		settings = settings
+	)
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/reversed/ReversedReaderFragment.kt

@@ -0,0 +1,78 @@
+package org.koitharu.kotatsu.reader.ui.pager.reversed
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import org.koin.android.ext.android.get
+import org.koitharu.kotatsu.databinding.FragmentReaderStandardBinding
+import org.koitharu.kotatsu.reader.ui.ReaderState
+import org.koitharu.kotatsu.reader.ui.pager.BaseReader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.utils.ext.doOnPageChanged
+
+class ReversedReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
+
+	private var pagerAdapter: ReversedPagesAdapter? = null
+
+	override fun onInflateView(
+		inflater: LayoutInflater,
+		container: ViewGroup?
+	) = FragmentReaderStandardBinding.inflate(inflater, container, false)
+
+	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+		super.onViewCreated(view, savedInstanceState)
+		pagerAdapter = ReversedPagesAdapter(loader, get())
+		with(binding.pager) {
+			adapter = pagerAdapter
+			offscreenPageLimit = 2
+			doOnPageChanged(::notifyPageChanged)
+		}
+	}
+
+	override fun onDestroyView() {
+		pagerAdapter = null
+		super.onDestroyView()
+	}
+
+	override fun switchPageBy(delta: Int) {
+		with(binding.pager) {
+			setCurrentItem(currentItem - delta, true)
+		}
+	}
+
+	override fun switchPageTo(position: Int, smooth: Boolean) {
+		binding.pager.setCurrentItem(reversed(position), smooth)
+	}
+
+	override fun onPagesChanged(pages: List<ReaderPage>, pendingState: ReaderState?) {
+		pagerAdapter?.setItems(pages.asReversed()) {
+			if (pendingState != null) {
+				val position = pages.indexOfFirst {
+					it.chapterId == pendingState.chapterId && it.index == pendingState.page
+				}
+				if (position == -1) return@setItems
+				binding.pager.setCurrentItem(position, false)
+			}
+		}
+	}
+
+	override fun getCurrentState(): ReaderState? = bindingOrNull()?.run {
+		val adapter = pager.adapter as? BaseReaderAdapter<*>
+		val page = adapter?.getItemOrNull(pager.currentItem) ?: return@run null
+		ReaderState(
+			chapterId = page.chapterId,
+			page = page.index,
+			scroll = 0
+		)
+	}
+
+	private fun notifyPageChanged(page: Int) {
+		viewModel.onCurrentPageChanged(reversed(page))
+	}
+
+	private fun reversed(position: Int): Int {
+		return ((pagerAdapter?.itemCount ?: 0) - position - 1).coerceAtLeast(0)
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageAnimTransformer.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.standard
+package org.koitharu.kotatsu.reader.ui.pager.standard
 
 import android.view.View
 import androidx.viewpager2.widget.ViewPager2

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PageHolder.kt

@@ -1,35 +1,32 @@
-package org.koitharu.kotatsu.reader.ui.standard
+package org.koitharu.kotatsu.reader.ui.pager.standard
 
 import android.graphics.PointF
 import android.net.Uri
-import android.view.LayoutInflater
 import android.view.View
-import android.view.ViewGroup
 import androidx.core.view.isVisible
 import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import org.koitharu.kotatsu.R
-import org.koitharu.kotatsu.base.ui.list.BaseViewHolder
 import org.koitharu.kotatsu.core.model.ZoomMode
+import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.databinding.ItemPageBinding
 import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.base.PageHolderDelegate
+import org.koitharu.kotatsu.reader.ui.pager.BasePageHolder
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 import org.koitharu.kotatsu.utils.ext.getDisplayMessage
 
-open class PageHolder(parent: ViewGroup, loader: PageLoader) :
+open class PageHolder(
-	BaseViewHolder<ReaderPage, Unit, ItemPageBinding>(
+	binding: ItemPageBinding,
-		ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false)
+	loader: PageLoader,
-	), PageHolderDelegate.Callback, View.OnClickListener {
+	settings: AppSettings
-
+) : BasePageHolder<ItemPageBinding>(binding, loader, settings), View.OnClickListener {
-	private val delegate = PageHolderDelegate(loader, this)
 
 	init {
 		binding.ssiv.setOnImageEventListener(delegate)
 		binding.buttonRetry.setOnClickListener(this)
 	}
 
-	override fun onBind(data: ReaderPage, extra: Unit) {
+	override fun onBind(data: ReaderPage) {
 		delegate.onBind(data.toMangaPage())
 	}
 

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PagerPaginationListener.kt

@@ -1,8 +1,8 @@
-package org.koitharu.kotatsu.reader.ui.standard
+package org.koitharu.kotatsu.reader.ui.pager.standard
 
 import androidx.recyclerview.widget.RecyclerView
 import androidx.viewpager2.widget.ViewPager2
-import org.koitharu.kotatsu.reader.ui.base.OnBoundsScrollListener
+import org.koitharu.kotatsu.reader.ui.pager.OnBoundsScrollListener
 
 class PagerPaginationListener(
 	private val adapter: RecyclerView.Adapter<*>,

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PagerReaderFragment.kt

@@ -0,0 +1,93 @@
+package org.koitharu.kotatsu.reader.ui.pager.standard
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import kotlinx.coroutines.async
+import org.koin.android.ext.android.get
+import org.koitharu.kotatsu.databinding.FragmentReaderStandardBinding
+import org.koitharu.kotatsu.reader.ui.ReaderState
+import org.koitharu.kotatsu.reader.ui.pager.BaseReader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.utils.ext.doOnPageChanged
+import org.koitharu.kotatsu.utils.ext.swapAdapter
+import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
+
+class PagerReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
+
+	private var pagesAdapter: PagesAdapter? = null
+
+	override fun onInflateView(
+		inflater: LayoutInflater,
+		container: ViewGroup?
+	) = FragmentReaderStandardBinding.inflate(inflater, container, false)
+
+	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+		super.onViewCreated(view, savedInstanceState)
+		pagesAdapter = PagesAdapter(loader, get())
+		with(binding.pager) {
+			adapter = pagesAdapter
+			offscreenPageLimit = 2
+			doOnPageChanged(::notifyPageChanged)
+		}
+
+		viewModel.readerAnimation.observe(viewLifecycleOwner) {
+			val transformer = if (it) PageAnimTransformer() else null
+			binding.pager.setPageTransformer(transformer)
+		}
+		viewModel.onZoomChanged.observe(viewLifecycleOwner) {
+			pagesAdapter = PagesAdapter(loader, get())
+			binding.pager.swapAdapter(pagesAdapter)
+		}
+	}
+
+	override fun onDestroyView() {
+		pagesAdapter = null
+		super.onDestroyView()
+	}
+
+	override fun onPagesChanged(pages: List<ReaderPage>, pendingState: ReaderState?) {
+		viewLifecycleScope.launchWhenCreated {
+			val items = async {
+				pagesAdapter?.setItems(pages)
+			}
+			if (pendingState != null) {
+				val position = pages.indexOfFirst {
+					it.chapterId == pendingState.chapterId && it.index == pendingState.page
+				}
+				items.await() ?: return@launchWhenCreated
+				if (position != -1) {
+					binding.pager.setCurrentItem(position, false)
+				}
+			} else {
+				items.await()
+			}
+		}
+	}
+
+	override fun switchPageBy(delta: Int) {
+		with(binding.pager) {
+			setCurrentItem(currentItem + delta, true)
+		}
+	}
+
+	override fun switchPageTo(position: Int, smooth: Boolean) {
+		binding.pager.setCurrentItem(position, smooth)
+	}
+
+	override fun getCurrentState(): ReaderState? = bindingOrNull()?.run {
+		val adapter = pager.adapter as? BaseReaderAdapter<*>
+		val page = adapter?.getItemOrNull(pager.currentItem) ?: return@run null
+		ReaderState(
+			chapterId = page.chapterId,
+			page = page.index,
+			scroll = 0
+		)
+	}
+
+	private fun notifyPageChanged(page: Int) {
+		viewModel.onCurrentPageChanged(page)
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/standard/PagesAdapter.kt

@@ -0,0 +1,24 @@
+package org.koitharu.kotatsu.reader.ui.pager.standard
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.databinding.ItemPageBinding
+import org.koitharu.kotatsu.reader.ui.PageLoader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+
+class PagesAdapter(
+	loader: PageLoader,
+	settings: AppSettings
+) : BaseReaderAdapter<PageHolder>(loader, settings) {
+
+	override fun onCreateViewHolder(
+		parent: ViewGroup,
+		loader: PageLoader,
+		settings: AppSettings
+	) = PageHolder(
+		binding = ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false),
+		loader = loader,
+		settings = settings
+	)
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/ListPaginationListener.kt

@@ -1,8 +1,8 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
 
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
-import org.koitharu.kotatsu.reader.ui.base.OnBoundsScrollListener
+import org.koitharu.kotatsu.reader.ui.pager.OnBoundsScrollListener
 
 class ListPaginationListener(
 	private val offset: Int,

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonAdapter.kt

@@ -0,0 +1,28 @@
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.databinding.ItemPageWebtoonBinding
+import org.koitharu.kotatsu.reader.ui.PageLoader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+
+class WebtoonAdapter(
+	loader: PageLoader,
+	settings: AppSettings
+) : BaseReaderAdapter<WebtoonHolder>(loader, settings) {
+
+	override fun onCreateViewHolder(
+		parent: ViewGroup,
+		loader: PageLoader,
+		settings: AppSettings
+	) = WebtoonHolder(
+		binding = ItemPageWebtoonBinding.inflate(
+			LayoutInflater.from(parent.context),
+			parent,
+			false
+		),
+		loader = loader,
+		settings = settings
+	)
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonFrameLayout.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
 
 import android.content.Context
 import android.util.AttributeSet

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonHolder.kt

@@ -1,28 +1,26 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
 
 import android.net.Uri
-import android.view.LayoutInflater
 import android.view.View
-import android.view.ViewGroup
 import androidx.core.view.isVisible
 import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import org.koitharu.kotatsu.R
-import org.koitharu.kotatsu.base.ui.list.BaseViewHolder
 import org.koitharu.kotatsu.core.model.ZoomMode
+import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.databinding.ItemPageWebtoonBinding
 import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.base.PageHolderDelegate
+import org.koitharu.kotatsu.reader.ui.pager.BasePageHolder
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 import org.koitharu.kotatsu.utils.ext.getDisplayMessage
 
 
-class WebtoonHolder(parent: ViewGroup, private val loader: PageLoader) :
+class WebtoonHolder(
-	BaseViewHolder<ReaderPage, Unit, ItemPageWebtoonBinding>(
+	binding: ItemPageWebtoonBinding,
-		ItemPageWebtoonBinding.inflate(LayoutInflater.from(parent.context), parent, false)
+	loader: PageLoader,
-	), PageHolderDelegate.Callback, View.OnClickListener {
+	settings: AppSettings
+) : BasePageHolder<ItemPageWebtoonBinding>(binding, loader, settings), View.OnClickListener {
 
-	private val delegate = PageHolderDelegate(loader, this)
 	private var scrollToRestore = 0
 
 	init {
@@ -30,7 +28,7 @@ class WebtoonHolder(parent: ViewGroup, private val loader: PageLoader) :
 		binding.buttonRetry.setOnClickListener(this)
 	}
 
-	override fun onBind(data: ReaderPage, extra: Unit) {
+	override fun onBind(data: ReaderPage) {
 		delegate.onBind(data.toMangaPage())
 	}
 

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonImageView.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
 
 import android.content.Context
 import android.graphics.PointF

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonReaderFragment.kt

@@ -0,0 +1,96 @@
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.view.animation.AccelerateDecelerateInterpolator
+import kotlinx.coroutines.async
+import org.koin.android.ext.android.get
+import org.koitharu.kotatsu.databinding.FragmentReaderWebtoonBinding
+import org.koitharu.kotatsu.reader.ui.ReaderState
+import org.koitharu.kotatsu.reader.ui.pager.BaseReader
+import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
+import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.utils.ext.doOnCurrentItemChanged
+import org.koitharu.kotatsu.utils.ext.findCenterViewPosition
+import org.koitharu.kotatsu.utils.ext.firstItem
+import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
+
+class WebtoonReaderFragment : BaseReader<FragmentReaderWebtoonBinding>() {
+
+	private val scrollInterpolator = AccelerateDecelerateInterpolator()
+	private var webtoonAdapter: WebtoonAdapter? = null
+
+	override fun onInflateView(
+		inflater: LayoutInflater,
+		container: ViewGroup?
+	) = FragmentReaderWebtoonBinding.inflate(inflater, container, false)
+
+	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+		super.onViewCreated(view, savedInstanceState)
+		webtoonAdapter = WebtoonAdapter(loader, get())
+		with(binding.recyclerView) {
+			setHasFixedSize(true)
+			adapter = webtoonAdapter
+			doOnCurrentItemChanged(::notifyPageChanged)
+		}
+	}
+
+	override fun onDestroyView() {
+		webtoonAdapter = null
+		super.onDestroyView()
+	}
+
+	override fun onPagesChanged(pages: List<ReaderPage>, pendingState: ReaderState?) {
+		viewLifecycleScope.launchWhenCreated {
+			val setItems = async { webtoonAdapter?.setItems(pages) }
+			if (pendingState != null) {
+				val position = pages.indexOfFirst {
+					it.chapterId == pendingState.chapterId && it.index == pendingState.page
+				}
+				setItems.await() ?: return@launchWhenCreated
+				if (position != -1) {
+					binding.recyclerView.firstItem = position
+					// TODO check
+					(binding.recyclerView.findViewHolderForAdapterPosition(position) as? WebtoonHolder)
+						?.restoreScroll(pendingState.scroll)
+				}
+			} else {
+				setItems.await()
+			}
+		}
+	}
+
+	override fun getCurrentState(): ReaderState? = bindingOrNull()?.run {
+		val currentItem = recyclerView.findCenterViewPosition()
+		val adapter = recyclerView.adapter as? BaseReaderAdapter<*>
+		val page = adapter?.getItemOrNull(currentItem) ?: return@run null
+		ReaderState(
+			chapterId = page.chapterId,
+			page = page.index,
+			scroll = (recyclerView.findViewHolderForAdapterPosition(currentItem) as? WebtoonHolder)
+				?.getScrollY() ?: 0
+		)
+	}
+
+	private fun notifyPageChanged(page: Int) {
+		viewModel.onCurrentPageChanged(page)
+	}
+
+	override fun switchPageBy(delta: Int) {
+		binding.recyclerView.smoothScrollBy(
+			0,
+			(binding.recyclerView.height * 0.9).toInt() * delta,
+			scrollInterpolator
+		)
+	}
+
+	override fun switchPageTo(position: Int, smooth: Boolean) {
+		if (smooth) {
+			binding.recyclerView.smoothScrollToPosition(position)
+		} else {
+			binding.recyclerView.firstItem = position
+		}
+	}
+}

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/wetoon/WebtoonRecyclerView.kt

@@ -1,4 +1,4 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
+package org.koitharu.kotatsu.reader.ui.pager.wetoon
 
 import android.content.Context
 import android.util.AttributeSet

app/src/main/java/org/koitharu/kotatsu/reader/ui/reversed/ReversedPagesAdapter.kt

@@ -1,45 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.reversed
-
-import android.view.ViewGroup
-import org.koitharu.kotatsu.base.ui.list.BaseViewHolder
-import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-
-class ReversedPagesAdapter(
-	pages: List<ReaderPage>,
-	private val loader: PageLoader
-) : BaseReaderAdapter(pages) {
-
-	override fun onCreateViewHolder(parent: ViewGroup) = ReversedPageHolder(parent, loader)
-
-	override fun onBindViewHolder(holder: BaseViewHolder<ReaderPage, Unit, *>, position: Int) {
-		super.onBindViewHolder(holder, reversed(position))
-	}
-
-	override fun getItem(position: Int): ReaderPage {
-		return super.getItem(reversed(position))
-	}
-
-	override fun getItemId(position: Int): Long {
-		return super.getItemId(reversed(position))
-	}
-
-	override fun notifyItemsAppended(count: Int) {
-		super.notifyItemsPrepended(count)
-	}
-
-	override fun notifyItemsPrepended(count: Int) {
-		super.notifyItemsAppended(count)
-	}
-
-	override fun notifyItemsRemovedStart(count: Int) {
-		super.notifyItemsRemovedEnd(count)
-	}
-
-	override fun notifyItemsRemovedEnd(count: Int) {
-		super.notifyItemsRemovedStart(count)
-	}
-
-	private fun reversed(position: Int) = pages.size - position - 1
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/reversed/ReversedReaderFragment.kt

@@ -1,107 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.reversed
-
-import android.content.Context
-import android.content.SharedPreferences
-import android.os.Bundle
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import org.koin.android.ext.android.inject
-import org.koitharu.kotatsu.core.prefs.AppSettings
-import org.koitharu.kotatsu.databinding.FragmentReaderStandardBinding
-import org.koitharu.kotatsu.reader.ui.ReaderState
-import org.koitharu.kotatsu.reader.ui.base.AbstractReader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-import org.koitharu.kotatsu.reader.ui.standard.PageAnimTransformer
-import org.koitharu.kotatsu.reader.ui.standard.PagerPaginationListener
-import org.koitharu.kotatsu.utils.ext.doOnPageChanged
-import org.koitharu.kotatsu.utils.ext.swapAdapter
-import org.koitharu.kotatsu.utils.ext.withArgs
-
-class ReversedReaderFragment : AbstractReader<FragmentReaderStandardBinding>(),
-	SharedPreferences.OnSharedPreferenceChangeListener {
-
-	private var paginationListener: PagerPaginationListener? = null
-	private val settings by inject<AppSettings>()
-
-	override fun onInflateView(
-		inflater: LayoutInflater,
-		container: ViewGroup?
-	) = FragmentReaderStandardBinding.inflate(inflater, container, false)
-
-	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-		super.onViewCreated(view, savedInstanceState)
-		paginationListener = PagerPaginationListener(readerAdapter!!, 2, this)
-		with(binding.pager) {
-			adapter = readerAdapter
-			if (settings.readerAnimation) {
-				setPageTransformer(ReversedPageAnimTransformer())
-			}
-			offscreenPageLimit = 2
-			registerOnPageChangeCallback(paginationListener!!)
-			doOnPageChanged {
-				notifyPageChanged(reversed(it))
-			}
-		}
-	}
-
-	override fun onAttach(context: Context) {
-		super.onAttach(context)
-		settings.subscribe(this)
-	}
-
-	override fun onDetach() {
-		settings.unsubscribe(this)
-		super.onDetach()
-	}
-
-	override fun onDestroyView() {
-		paginationListener = null
-		super.onDestroyView()
-	}
-
-	override fun onCreateAdapter(dataSet: List<ReaderPage>): BaseReaderAdapter {
-		return ReversedPagesAdapter(dataSet, loader)
-	}
-
-	override fun recreateAdapter() {
-		super.recreateAdapter()
-		binding.pager.swapAdapter(readerAdapter)
-	}
-
-	override fun getCurrentItem() = reversed(binding.pager.currentItem)
-
-	override fun setCurrentItem(position: Int, isSmooth: Boolean) {
-		binding.pager.setCurrentItem(reversed(position), isSmooth)
-	}
-
-	override fun getCurrentPageScroll() = 0
-
-	override fun restorePageScroll(position: Int, scroll: Int) = Unit
-
-	override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
-		when (key) {
-			AppSettings.KEY_READER_ANIMATION -> {
-				if (settings.readerAnimation) {
-					binding.pager.setPageTransformer(PageAnimTransformer())
-				} else {
-					binding.pager.setPageTransformer(null)
-				}
-			}
-		}
-	}
-
-	override fun getLastPage() = pages.firstOrNull()
-
-	override fun getFirstPage() = pages.lastOrNull()
-
-	private fun reversed(position: Int) = (itemsCount - position - 1).coerceAtLeast(0)
-
-	companion object {
-
-		fun newInstance(state: ReaderState) = ReversedReaderFragment().withArgs(1) {
-			putParcelable(ARG_STATE, state)
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/standard/PagerReaderFragment.kt

@@ -1,97 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.standard
-
-import android.content.Context
-import android.content.SharedPreferences
-import android.os.Bundle
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import org.koin.android.ext.android.inject
-import org.koitharu.kotatsu.core.prefs.AppSettings
-import org.koitharu.kotatsu.databinding.FragmentReaderStandardBinding
-import org.koitharu.kotatsu.reader.ui.ReaderState
-import org.koitharu.kotatsu.reader.ui.base.AbstractReader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-import org.koitharu.kotatsu.utils.ext.doOnPageChanged
-import org.koitharu.kotatsu.utils.ext.swapAdapter
-import org.koitharu.kotatsu.utils.ext.withArgs
-
-class PagerReaderFragment : AbstractReader<FragmentReaderStandardBinding>(),
-	SharedPreferences.OnSharedPreferenceChangeListener {
-
-	private var paginationListener: PagerPaginationListener? = null
-	private val settings by inject<AppSettings>()
-
-	override fun onInflateView(
-		inflater: LayoutInflater,
-		container: ViewGroup?
-	) = FragmentReaderStandardBinding.inflate(inflater, container, false)
-
-	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-		super.onViewCreated(view, savedInstanceState)
-		paginationListener = PagerPaginationListener(readerAdapter!!, 2, this)
-		with(binding.pager) {
-			adapter = readerAdapter
-			if (settings.readerAnimation) {
-				setPageTransformer(PageAnimTransformer())
-			}
-			offscreenPageLimit = 2
-			registerOnPageChangeCallback(paginationListener!!)
-			doOnPageChanged(::notifyPageChanged)
-		}
-	}
-
-	override fun onAttach(context: Context) {
-		super.onAttach(context)
-		settings.subscribe(this)
-	}
-
-	override fun onDetach() {
-		settings.unsubscribe(this)
-		super.onDetach()
-	}
-
-	override fun onDestroyView() {
-		paginationListener = null
-		super.onDestroyView()
-	}
-
-	override fun onCreateAdapter(dataSet: List<ReaderPage>): BaseReaderAdapter {
-		return PagesAdapter(dataSet, loader)
-	}
-
-	override fun recreateAdapter() {
-		super.recreateAdapter()
-		binding.pager.swapAdapter(readerAdapter)
-	}
-
-	override fun getCurrentItem() = binding.pager.currentItem
-
-	override fun setCurrentItem(position: Int, isSmooth: Boolean) {
-		binding.pager.setCurrentItem(position, isSmooth)
-	}
-
-	override fun getCurrentPageScroll() = 0
-
-	override fun restorePageScroll(position: Int, scroll: Int) = Unit
-
-	override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
-		when (key) {
-			AppSettings.KEY_READER_ANIMATION -> {
-				if (settings.readerAnimation) {
-					binding.pager.setPageTransformer(PageAnimTransformer())
-				} else {
-					binding.pager.setPageTransformer(null)
-				}
-			}
-		}
-	}
-
-	companion object {
-
-		fun newInstance(state: ReaderState) = PagerReaderFragment().withArgs(1) {
-			putParcelable(ARG_STATE, state)
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/standard/PagesAdapter.kt

@@ -1,14 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.standard
-
-import android.view.ViewGroup
-import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-
-class PagesAdapter(
-	pages: List<ReaderPage>,
-	private val loader: PageLoader
-) : BaseReaderAdapter(pages) {
-
-	override fun onCreateViewHolder(parent: ViewGroup) = PageHolder(parent, loader)
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/thumbnails/PageThumbnail.kt

@@ -0,0 +1,11 @@
+package org.koitharu.kotatsu.reader.ui.thumbnails
+
+import org.koitharu.kotatsu.core.model.MangaPage
+import org.koitharu.kotatsu.core.parser.MangaRepository
+
+data class PageThumbnail(
+	val number: Int,
+	val isCurrent: Boolean,
+	val repository: MangaRepository,
+	val page: MangaPage
+)

app/src/main/java/org/koitharu/kotatsu/reader/ui/thumbnails/PagesThumbnailsSheet.kt

@@ -14,9 +14,10 @@ import org.koitharu.kotatsu.base.ui.BaseBottomSheet
 import org.koitharu.kotatsu.base.ui.list.OnListItemClickListener
 import org.koitharu.kotatsu.base.ui.list.decor.SpacingItemDecoration
 import org.koitharu.kotatsu.core.model.MangaPage
+import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.databinding.SheetPagesBinding
+import org.koitharu.kotatsu.list.ui.MangaListSpanResolver
 import org.koitharu.kotatsu.reader.ui.thumbnails.adapter.PageThumbnailAdapter
-import org.koitharu.kotatsu.utils.UiUtils
 import org.koitharu.kotatsu.utils.ext.resolveDp
 import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
 import org.koitharu.kotatsu.utils.ext.withArgs
@@ -24,34 +25,58 @@ import org.koitharu.kotatsu.utils.ext.withArgs
 class PagesThumbnailsSheet : BaseBottomSheet<SheetPagesBinding>(),
 	OnListItemClickListener<MangaPage> {
 
+	private lateinit var thumbnails: List<PageThumbnail>
+	private val spanResolver = MangaListSpanResolver()
+
+	override fun onCreate(savedInstanceState: Bundle?) {
+		super.onCreate(savedInstanceState)
+		val pages = arguments?.getParcelableArrayList<MangaPage>(ARG_PAGES)
+		if (pages.isNullOrEmpty()) {
+			dismissAllowingStateLoss()
+			return
+		}
+		val current = arguments?.getInt(ARG_CURRENT, -1) ?: -1
+		val repository = pages.first().source.repository
+		thumbnails = pages.mapIndexed { i, x ->
+			PageThumbnail(
+				number = i + 1,
+				isCurrent = i == current,
+				repository = repository,
+				page = x
+			)
+		}
+	}
+
 	override fun onInflateView(inflater: LayoutInflater, container: ViewGroup?): SheetPagesBinding {
 		return SheetPagesBinding.inflate(inflater, container, false)
 	}
 
 	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
 		super.onViewCreated(view, savedInstanceState)
-		binding.recyclerView.addItemDecoration(SpacingItemDecoration(view.resources.resolveDp(8)))
+		with(binding.recyclerView) {
-		val pages = arguments?.getParcelableArrayList<MangaPage>(ARG_PAGES)
+			addItemDecoration(SpacingItemDecoration(view.resources.resolveDp(8)))
-		if (pages == null) {
+			adapter = PageThumbnailAdapter(
-			dismissAllowingStateLoss()
+				thumbnails,
-			return
+				get(),
-		}
+				viewLifecycleScope,
-		binding.recyclerView.adapter =
+				get(),
-			PageThumbnailAdapter(get(), viewLifecycleScope, get(), this).apply {
+				this@PagesThumbnailsSheet
-				items = pages
+			)
+			addOnLayoutChangeListener(spanResolver)
+			spanResolver.setGridSize(get<AppSettings>().gridSize / 100f, this)
 		}
+
 		val title = arguments?.getString(ARG_TITLE)
 		binding.toolbar.title = title
 		binding.toolbar.setNavigationOnClickListener { dismiss() }
 		binding.toolbar.subtitle =
-			resources.getQuantityString(R.plurals.pages, pages.size, pages.size)
+			resources.getQuantityString(R.plurals.pages, thumbnails.size, thumbnails.size)
 		binding.textViewTitle.text = title
 		if (dialog !is BottomSheetDialog) {
 			binding.toolbar.isVisible = true
 			binding.textViewTitle.isVisible = false
 			binding.appbar.elevation = resources.getDimension(R.dimen.elevation_large)
 		}
-		binding.recyclerView.addOnLayoutChangeListener(UiUtils.SpanCountResolver)
 	}
 
 	override fun onCreateDialog(savedInstanceState: Bundle?) =
@@ -77,11 +102,6 @@ class PagesThumbnailsSheet : BaseBottomSheet<SheetPagesBinding>(),
 
 		}
 
-	override fun onDestroyView() {
-		binding.recyclerView.adapter = null
-		super.onDestroyView()
-	}
-
 	override fun onItemClick(item: MangaPage, view: View) {
 		((parentFragment as? OnPageSelectListener)
 			?: (activity as? OnPageSelectListener))?.run {
@@ -94,13 +114,15 @@ class PagesThumbnailsSheet : BaseBottomSheet<SheetPagesBinding>(),
 
 		private const val ARG_PAGES = "pages"
 		private const val ARG_TITLE = "title"
+		private const val ARG_CURRENT = "current"
 
 		private const val TAG = "PagesThumbnailsSheet"
 
-		fun show(fm: FragmentManager, pages: List<MangaPage>, title: String) =
+		fun show(fm: FragmentManager, pages: List<MangaPage>, title: String, currentPage: Int) =
-			PagesThumbnailsSheet().withArgs(2) {
+			PagesThumbnailsSheet().withArgs(3) {
 				putParcelableArrayList(ARG_PAGES, ArrayList<MangaPage>(pages))
 				putString(ARG_TITLE, title)
+				putInt(ARG_CURRENT, currentPage)
 			}.show(fm, TAG)
 
 	}

app/src/main/java/org/koitharu/kotatsu/reader/ui/thumbnails/adapter/PageThumbnailAD.kt

@@ -11,6 +11,7 @@ import org.koitharu.kotatsu.base.ui.list.OnListItemClickListener
 import org.koitharu.kotatsu.core.model.MangaPage
 import org.koitharu.kotatsu.databinding.ItemPageThumbBinding
 import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.reader.ui.thumbnails.PageThumbnail
 import org.koitharu.kotatsu.utils.ext.IgnoreErrors
 
 fun pageThumbnailAD(
@@ -18,7 +19,7 @@ fun pageThumbnailAD(
 	scope: CoroutineScope,
 	cache: PagesCache,
 	clickListener: OnListItemClickListener<MangaPage>
-) = adapterDelegateViewBinding<MangaPage, MangaPage, ItemPageThumbBinding>(
+) = adapterDelegateViewBinding<PageThumbnail, PageThumbnail, ItemPageThumbBinding>(
 	{ inflater, parent -> ItemPageThumbBinding.inflate(inflater, parent, false) }
 ) {
 
@@ -30,16 +31,19 @@ fun pageThumbnailAD(
 	)
 
 	binding.handle.setOnClickListener {
-		clickListener.onItemClick(item, itemView)
+		clickListener.onItemClick(item.page, itemView)
 	}
 
 	bind {
 		job?.cancel()
 		binding.imageViewThumb.setImageDrawable(null)
-		binding.textViewNumber.text = (bindingAdapterPosition + 1).toString()
+		with(binding.textViewNumber) {
+			setBackgroundResource(if (item.isCurrent) R.drawable.bg_badge_accent else R.drawable.bg_badge_default)
+			text = (item.number).toString()
+		}
 		job = scope.launch(Dispatchers.Default + IgnoreErrors) {
-			val url = item.preview ?: item.url.let {
+			val url = item.page.preview ?: item.page.url.let {
-				val pageUrl = item.source.repository.getPageFullUrl(item)
+				val pageUrl = item.repository.getPageFullUrl(item.page)
 				cache[pageUrl]?.toUri()?.toString() ?: pageUrl
 			}
 			val drawable = coil.execute(

app/src/main/java/org/koitharu/kotatsu/reader/ui/thumbnails/adapter/PageThumbnailAdapter.kt

@@ -6,15 +6,18 @@ import kotlinx.coroutines.CoroutineScope
 import org.koitharu.kotatsu.base.ui.list.OnListItemClickListener
 import org.koitharu.kotatsu.core.model.MangaPage
 import org.koitharu.kotatsu.local.data.PagesCache
+import org.koitharu.kotatsu.reader.ui.thumbnails.PageThumbnail
 
 class PageThumbnailAdapter(
+	dataSet: List<PageThumbnail>,
 	coil: ImageLoader,
 	scope: CoroutineScope,
 	cache: PagesCache,
 	clickListener: OnListItemClickListener<MangaPage>
-) : ListDelegationAdapter<List<MangaPage>>() {
+) : ListDelegationAdapter<List<PageThumbnail>>() {
 
 	init {
 		delegatesManager.addDelegate(pageThumbnailAD(coil, scope, cache, clickListener))
+		setItems(dataSet)
 	}
 }

app/src/main/java/org/koitharu/kotatsu/reader/ui/wetoon/WebtoonAdapter.kt

@@ -1,14 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
-
-import android.view.ViewGroup
-import org.koitharu.kotatsu.reader.ui.PageLoader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-
-class WebtoonAdapter(
-	pages: List<ReaderPage>,
-	private val loader: PageLoader
-) : BaseReaderAdapter(pages) {
-
-	override fun onCreateViewHolder(parent: ViewGroup) = WebtoonHolder(parent, loader)
-}

app/src/main/java/org/koitharu/kotatsu/reader/ui/wetoon/WebtoonReaderFragment.kt

@@ -1,91 +0,0 @@
-package org.koitharu.kotatsu.reader.ui.wetoon
-
-import android.os.Bundle
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import android.view.animation.AccelerateDecelerateInterpolator
-import org.koitharu.kotatsu.databinding.FragmentReaderWebtoonBinding
-import org.koitharu.kotatsu.reader.ui.ReaderState
-import org.koitharu.kotatsu.reader.ui.base.AbstractReader
-import org.koitharu.kotatsu.reader.ui.base.BaseReaderAdapter
-import org.koitharu.kotatsu.reader.ui.base.ReaderPage
-import org.koitharu.kotatsu.utils.ext.doOnCurrentItemChanged
-import org.koitharu.kotatsu.utils.ext.findCenterViewPosition
-import org.koitharu.kotatsu.utils.ext.firstItem
-import org.koitharu.kotatsu.utils.ext.withArgs
-
-class WebtoonReaderFragment : AbstractReader<FragmentReaderWebtoonBinding>() {
-
-	private val scrollInterpolator = AccelerateDecelerateInterpolator()
-	private var paginationListener: ListPaginationListener? = null
-
-	override fun onInflateView(
-		inflater: LayoutInflater,
-		container: ViewGroup?
-	) = FragmentReaderWebtoonBinding.inflate(inflater, container, false)
-
-	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-		super.onViewCreated(view, savedInstanceState)
-		paginationListener = ListPaginationListener(2, this)
-		with(binding.recyclerView) {
-			setHasFixedSize(true)
-			adapter = readerAdapter
-			addOnScrollListener(paginationListener!!)
-			doOnCurrentItemChanged(::notifyPageChanged)
-		}
-	}
-
-	override fun onCreateAdapter(dataSet: List<ReaderPage>): BaseReaderAdapter {
-		return WebtoonAdapter(dataSet, loader)
-	}
-
-	override fun recreateAdapter() {
-		super.recreateAdapter()
-		binding.recyclerView.swapAdapter(readerAdapter, true)
-	}
-
-	override fun onDestroyView() {
-		paginationListener = null
-		super.onDestroyView()
-	}
-
-	override fun getCurrentItem(): Int {
-		return binding.recyclerView.findCenterViewPosition()
-	}
-
-	override fun setCurrentItem(position: Int, isSmooth: Boolean) {
-		if (isSmooth) {
-			binding.recyclerView.smoothScrollToPosition(position)
-		} else {
-			binding.recyclerView.firstItem = position
-		}
-	}
-
-	override fun switchPageBy(delta: Int) {
-		binding.recyclerView.smoothScrollBy(
-			0,
-			(binding.recyclerView.height * 0.9).toInt() * delta,
-			scrollInterpolator
-		)
-	}
-
-	override fun getCurrentPageScroll(): Int {
-		return (binding.recyclerView.findViewHolderForAdapterPosition(getCurrentItem()) as? WebtoonHolder)
-			?.getScrollY() ?: 0
-	}
-
-	override fun restorePageScroll(position: Int, scroll: Int) {
-		binding.recyclerView.post {
-			val holder = binding.recyclerView.findViewHolderForAdapterPosition(position) ?: return@post
-			(holder as WebtoonHolder).restoreScroll(scroll)
-		}
-	}
-
-	companion object {
-
-		fun newInstance(state: ReaderState) = WebtoonReaderFragment().withArgs(1) {
-			putParcelable(ARG_STATE, state)
-		}
-	}
-}

app/src/main/java/org/koitharu/kotatsu/remotelist/ui/RemoteListViewModel.kt

@@ -1,12 +1,11 @@
 package org.koitharu.kotatsu.remotelist.ui
 
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.model.Manga
@@ -16,6 +15,7 @@ import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.list.ui.MangaFilterConfig
 import org.koitharu.kotatsu.list.ui.MangaListViewModel
 import org.koitharu.kotatsu.list.ui.model.*
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import java.util.*
 
 class RemoteListViewModel(
@@ -49,9 +49,7 @@ class RemoteListViewModel(
 				result
 			}
 		}
-	}.onStart {
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
-		emit(listOf(LoadingState))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
 
 	init {
 		loadList(false)

app/src/main/java/org/koitharu/kotatsu/search/ui/SearchViewModel.kt

@@ -1,18 +1,18 @@
 package org.koitharu.kotatsu.search.ui
 
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.parser.MangaRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.list.ui.MangaListViewModel
 import org.koitharu.kotatsu.list.ui.model.*
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import java.util.*
 
 class SearchViewModel(
@@ -46,9 +46,7 @@ class SearchViewModel(
 				result
 			}
 		}
-	}.onStart {
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
-		emit(listOf(LoadingState))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
 
 	init {
 		loadList(append = false)

app/src/main/java/org/koitharu/kotatsu/search/ui/global/GlobalSearchViewModel.kt

@@ -1,6 +1,5 @@
 package org.koitharu.kotatsu.search.ui.global
 
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -12,6 +11,7 @@ import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.list.ui.MangaListViewModel
 import org.koitharu.kotatsu.list.ui.model.*
 import org.koitharu.kotatsu.search.domain.MangaSearchRepository
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import org.koitharu.kotatsu.utils.ext.onFirst
 import java.util.*
 
@@ -46,9 +46,7 @@ class GlobalSearchViewModel(
 				result
 			}
 		}
-	}.onStart {
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
-		emit(listOf(LoadingState))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
 
 	init {
 		onRefresh()

app/src/main/java/org/koitharu/kotatsu/tracker/ui/FeedViewModel.kt

@@ -2,20 +2,20 @@ package org.koitharu.kotatsu.tracker.ui
 
 import android.content.Context
 import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.filterNotNull
-import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.base.ui.BaseViewModel
 import org.koitharu.kotatsu.core.model.TrackingLogItem
 import org.koitharu.kotatsu.list.ui.model.LoadingFooter
 import org.koitharu.kotatsu.list.ui.model.LoadingState
 import org.koitharu.kotatsu.tracker.domain.TrackingRepository
 import org.koitharu.kotatsu.tracker.ui.model.toFeedItem
+import org.koitharu.kotatsu.utils.ext.asLiveData
 import org.koitharu.kotatsu.utils.ext.mapItems
 
 class FeedViewModel(
@@ -35,9 +35,7 @@ class FeedViewModel(
 		hasNextPage
 	) { list, isHasNextPage ->
 		if (isHasNextPage && list.isNotEmpty()) list + LoadingFooter else list
-	}.onStart {
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext, listOf(LoadingState))
-		emit(listOf(LoadingState))
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
 
 	init {
 		loadList(append = false)

app/src/main/java/org/koitharu/kotatsu/utils/BufferedObserver.kt

@@ -0,0 +1,6 @@
+package org.koitharu.kotatsu.utils
+
+fun interface BufferedObserver<T> {
+
+	fun onChanged(t: T, previous: T?)
+}

app/src/main/java/org/koitharu/kotatsu/utils/FlowLiveEvent.kt

@@ -0,0 +1,54 @@
+package org.koitharu.kotatsu.utils
+
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.coroutines.CoroutineContext
+
+class FlowLiveEvent<T>(
+	private val source: Flow<T>,
+	private val context: CoroutineContext
+) : LiveData<T>() {
+
+	private val scope = CoroutineScope(
+		Dispatchers.Main.immediate + context + SupervisorJob(context[Job])
+	)
+	private val pending = AtomicBoolean(false)
+	private var collectJob: Job? = null
+
+	override fun observe(owner: LifecycleOwner, observer: Observer<in T>) {
+		super.observe(owner) {
+			if (pending.compareAndSet(true, false)) {
+				observer.onChanged(it)
+			}
+		}
+	}
+
+	override fun onActive() {
+		super.onActive()
+		if (collectJob == null) {
+			collectJob = source.onEach {
+				setValue(it)
+			}.launchIn(scope)
+		}
+	}
+
+	override fun onInactive() {
+		collectJob?.cancel()
+		collectJob = null
+		super.onInactive()
+	}
+
+	override fun setValue(value: T) {
+		pending.set(true)
+		super.setValue(value)
+	}
+}

app/src/main/java/org/koitharu/kotatsu/utils/UiUtils.kt

@@ -26,6 +26,7 @@ object UiUtils : KoinComponent {
 
 	fun isTablet(context: Context) = context.resources.getBoolean(R.bool.is_tablet)
 
+	@Deprecated("Use MangaListSpanResolver")
 	object SpanCountResolver : View.OnLayoutChangeListener {
 		override fun onLayoutChange(
 			v: View?, left: Int, top: Int, right: Int, bottom: Int,

app/src/main/java/org/koitharu/kotatsu/utils/ext/LiveDataExt.kt

@@ -3,6 +3,13 @@ package org.koitharu.kotatsu.utils.ext
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.Observer
+import androidx.lifecycle.liveData
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
+import org.koitharu.kotatsu.utils.BufferedObserver
+import org.koitharu.kotatsu.utils.FlowLiveEvent
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
 
 fun <T> LiveData<T?>.observeNotNull(owner: LifecycleOwner, observer: Observer<T>) {
 	this.observe(owner) {
@@ -11,3 +18,27 @@ fun <T> LiveData<T?>.observeNotNull(owner: LifecycleOwner, observer: Observer<T>
 		}
 	}
 }
+
+fun <T> LiveData<T>.observeWithPrevious(owner: LifecycleOwner, observer: BufferedObserver<T>) {
+	var previous: T? = null
+	this.observe(owner) {
+		observer.onChanged(it, previous)
+		previous = it
+	}
+}
+
+fun <T> Flow<T>.asLiveData(
+	context: CoroutineContext = EmptyCoroutineContext,
+	defaultValue: T
+): LiveData<T> = liveData(context) {
+	if (latestValue == null) {
+		emit(defaultValue)
+	}
+	collect {
+		emit(it)
+	}
+}
+
+fun <T> Flow<T>.asLiveEvent(
+	context: CoroutineContext = EmptyCoroutineContext
+): LiveData<T> = FlowLiveEvent(this, context)

app/src/main/java/org/koitharu/kotatsu/utils/ext/ViewExt.kt

@@ -206,6 +206,6 @@ fun ViewPager2.swapAdapter(newAdapter: RecyclerView.Adapter<*>?) {
 	val position = currentItem
 	adapter = newAdapter
 	if (adapter != null && position != RecyclerView.NO_POSITION) {
-		currentItem = position
+		setCurrentItem(position, false)
 	}
 }

app/src/main/java/org/koitharu/kotatsu/widget/shelf/ShelfConfigViewModel.kt

@@ -5,6 +5,7 @@ import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flowOn
 import org.koitharu.kotatsu.base.ui.BaseViewModel
 import org.koitharu.kotatsu.favourites.domain.FavouritesRepository
 import org.koitharu.kotatsu.widget.shelf.model.CategoryItem
@@ -26,7 +27,7 @@ class ShelfConfigViewModel(
 			CategoryItem(it.id, it.title, selectedId == it.id)
 		}
 		list
-	}.asLiveData(viewModelScope.coroutineContext + Dispatchers.Default)
+	}.flowOn(Dispatchers.Default).asLiveData(viewModelScope.coroutineContext)
 
 	var checkedId: Long by selectedCategoryId::value
 }

app/src/main/res/layout/dialog_reader_config.xml

@@ -4,8 +4,8 @@
 	xmlns:app="http://schemas.android.com/apk/res-auto"
 	android:layout_width="match_parent"
 	android:layout_height="wrap_content"
-	android:padding="16dp"
+	android:orientation="vertical"
-	android:orientation="vertical">
+	android:padding="16dp">
 
 	<com.google.android.material.button.MaterialButtonToggleGroup
 		android:layout_width="match_parent"
@@ -40,12 +40,11 @@
 
 	</com.google.android.material.button.MaterialButtonToggleGroup>
 
-	<com.google.android.material.button.MaterialButton
+	<TextView
-		android:id="@+id/button_ok"
+		android:layout_width="match_parent"
-		style="@style/Widget.MaterialComponents.Button"
-		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:layout_marginTop="16dp"
+		android:layout_marginTop="8dp"
-		android:layout_gravity="center_horizontal"
+		android:text="@string/reader_mode_hint"
-		android:text="@android:string/ok" />
+		android:textAppearance="@style/TextAppearance.MaterialComponents.Caption" />
+
 </LinearLayout>

app/src/main/res/layout/fragment_reader_webtoon.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<org.koitharu.kotatsu.reader.ui.wetoon.WebtoonRecyclerView
+<org.koitharu.kotatsu.reader.ui.pager.wetoon.WebtoonRecyclerView
 	xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:app="http://schemas.android.com/apk/res-auto"
 	android:id="@+id/recyclerView"

app/src/main/res/layout/item_page_thumb.xml

@@ -25,13 +25,13 @@
 		android:layout_height="wrap_content"
 		android:layout_gravity="bottom|end"
 		android:layout_margin="8dp"
-		android:background="@drawable/bg_badge_default"
 		android:ellipsize="none"
 		android:gravity="center"
 		android:minWidth="26dp"
 		android:singleLine="true"
 		android:textAlignment="center"
 		android:textColor="?android:textColorSecondaryInverse"
+		tools:background="@drawable/bg_badge_default"
 		tools:text="2" />
 
 </FrameLayout>

app/src/main/res/layout/item_page_webtoon.xml

@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<org.koitharu.kotatsu.reader.ui.wetoon.WebtoonFrameLayout
+<org.koitharu.kotatsu.reader.ui.pager.wetoon.WebtoonFrameLayout
 	xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:app="http://schemas.android.com/apk/res-auto"
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="match_parent">
 
-	<org.koitharu.kotatsu.reader.ui.wetoon.WebtoonImageView
+	<org.koitharu.kotatsu.reader.ui.pager.wetoon.WebtoonImageView
 		android:id="@+id/ssiv"
 		android:layout_width="match_parent"
 		android:layout_height="match_parent"
@@ -52,4 +52,4 @@
 
 	</LinearLayout>
 
-</org.koitharu.kotatsu.reader.ui.wetoon.WebtoonFrameLayout>
+</org.koitharu.kotatsu.reader.ui.pager.wetoon.WebtoonFrameLayout>

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

@@ -186,4 +186,5 @@
 	<string name="group">Группировать</string>
 	<string name="today">Сегодня</string>
 	<string name="tap_to_try_again">Tap to try again</string>
+	<string name="reader_mode_hint">Chosen configuration will be remembered for this manga</string>
 </resources>

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

@@ -188,4 +188,5 @@
 	<string name="group">Group</string>
 	<string name="today">Today</string>
 	<string name="tap_to_try_again">Tap to try again</string>
+	<string name="reader_mode_hint">Chosen configuration will be remembered for this manga</string>
 </resources>

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

@@ -32,4 +32,8 @@
 		<item name="background">@color/grey</item>
 	</style>
 
+	<style name="AppBadge" parent="Widget.MaterialComponents.Badge">
+		<item name="backgroundColor">?attr/colorAccent</item>
+	</style>
+
 </resources>

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

@@ -5,6 +5,7 @@
 		<item name="actionModeCloseDrawable">@drawable/ic_cross</item>
 		<item name="actionModeStyle">@style/AppActionMode</item>
 		<item name="preferenceTheme">@style/PreferenceThemeOverlay</item>
+		<item name="badgeStyle">@style/Widget.MaterialComponents.Badge</item>
 	</style>
 
 	<style name="AppTheme" parent="BaseAppTheme">

build.gradle

@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
-	ext.kotlin_version = '1.4.20'
+	ext.kotlin_version = '1.4.21'
 	repositories {
 		google()
 		jcenter()