Update page state management in reader

app/src/main/kotlin/org/koitharu/kotatsu/core/util/ext/Flow.kt

@@ -61,6 +61,8 @@ inline fun <T, R> Flow<List<T>>.mapItems(crossinline transform: (T) -> R): Flow<
 	return map { list -> list.map(transform) }
 }
 
+fun <T> Flow<T>.throttle(timeoutMillis: Long): Flow<T> = throttle { timeoutMillis }
+
 fun <T> Flow<T>.throttle(timeoutMillis: (T) -> Long): Flow<T> {
 	var lastEmittedAt = 0L
 	return transformLatest { value ->

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

@@ -105,7 +105,7 @@ class ReaderActivity :
 		super.onCreate(savedInstanceState)
 		setContentView(ActivityReaderBinding.inflate(layoutInflater))
 		readerManager = ReaderManager(supportFragmentManager, viewBinding.container, settings)
-		setDisplayHomeAsUp(true, false)
+		setDisplayHomeAsUp(isEnabled = true, showUpAsClose = false)
 		touchHelper = TapGridDispatcher(this, this)
 		scrollTimer = scrollTimerFactory.create(this, this)
 		pageSaveHelper = pageSaveHelperFactory.create(this)
@@ -146,7 +146,7 @@ class ReaderActivity :
 				.setAnchorView(viewBinding.toolbarDocked)
 				.show()
 		}
-		viewModel.readerSettings.observe(this) {
+		viewModel.readerSettingsProducer.observe(this) {
 			viewBinding.infoBar.applyColorScheme(isBlackOnWhite = it.background.isLight(this))
 		}
 		viewModel.isZoomControlsEnabled.observe(this) {

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

@@ -21,6 +21,7 @@ import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.plus
@@ -85,6 +86,7 @@ class ReaderViewModel @Inject constructor(
 	interactor: DetailsInteractor,
 	deleteLocalMangaUseCase: DeleteLocalMangaUseCase,
 	downloadScheduler: DownloadWorker.Scheduler,
+	readerSettingsProducerFactory: ReaderSettings.Producer.Factory,
 ) : ChaptersPagesViewModel(
 	settings = settings,
 	interactor = interactor,
@@ -170,12 +172,8 @@ class ReaderViewModel @Inject constructor(
 		}
 	}.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Lazily, false)
 
-	val readerSettings = ReaderSettings(
-		parentScope = viewModelScope,
-		settings = settings,
-		colorFilterFlow = manga.flatMapLatest {
-			if (it == null) flowOf(null) else dataRepository.observeColorFilter(it.id)
-		}.stateIn(viewModelScope + Dispatchers.Default, SharingStarted.Eagerly, null),
+	val readerSettingsProducer = readerSettingsProducerFactory.create(
+		manga.mapNotNull { it?.id },
 	)
 
 	val isMangaNsfw = manga.map { it?.contentRating == ContentRating.ADULT }

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/config/ReaderSettings.kt

@@ -1,66 +1,69 @@
 package org.koitharu.kotatsu.reader.ui.config
 
-import android.content.SharedPreferences
 import android.graphics.Bitmap
 import android.view.View
 import androidx.annotation.CheckResult
-import androidx.lifecycle.MediatorLiveData
+import androidx.collection.scatterSetOf
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import com.davemorrissey.labs.subscaleview.decoder.SkiaImageDecoder
 import com.davemorrissey.labs.subscaleview.decoder.SkiaImageRegionDecoder
 import com.davemorrissey.labs.subscaleview.decoder.SkiaPooledImageRegionDecoder
-import kotlinx.coroutines.CoroutineScope
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
-import kotlinx.coroutines.flow.FlowCollector
-import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.flatMapLatest
+import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.core.model.ZoomMode
+import org.koitharu.kotatsu.core.parser.MangaDataRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.core.prefs.ReaderBackground
 import org.koitharu.kotatsu.core.prefs.ReaderMode
+import org.koitharu.kotatsu.core.util.MediatorStateFlow
 import org.koitharu.kotatsu.core.util.ext.isLowRamDevice
+import org.koitharu.kotatsu.core.util.ext.processLifecycleScope
 import org.koitharu.kotatsu.reader.domain.ReaderColorFilter
 
-class ReaderSettings(
-	private val parentScope: CoroutineScope,
-	private val settings: AppSettings,
-	private val colorFilterFlow: StateFlow<ReaderColorFilter?>,
-) : MediatorLiveData<ReaderSettings>() {
+data class ReaderSettings(
+	val zoomMode: ZoomMode,
+	val background: ReaderBackground,
+	val colorFilter: ReaderColorFilter?,
+	val isReaderOptimizationEnabled: Boolean,
+	val bitmapConfig: Bitmap.Config,
+	val isPagesNumbersEnabled: Boolean,
+	val isPagesCropEnabledStandard: Boolean,
+	val isPagesCropEnabledWebtoon: Boolean,
+) {
 
-	private val internalObserver = InternalObserver()
-	private var collectJob: Job? = null
-
-	val zoomMode: ZoomMode
-		get() = settings.zoomMode
-
-	val background: ReaderBackground
-		get() = settings.readerBackground
-
-	val colorFilter: ReaderColorFilter?
-		get() = colorFilterFlow.value?.takeUnless { it.isEmpty } ?: settings.readerColorFilter
-
-	val isReaderOptimizationEnabled: Boolean
-		get() = settings.isReaderOptimizationEnabled
-
-	val bitmapConfig: Bitmap.Config
-		get() = if (settings.is32BitColorsEnabled) {
+	private constructor(settings: AppSettings, colorFilterOverride: ReaderColorFilter?) : this(
+		zoomMode = settings.zoomMode,
+		background = settings.readerBackground,
+		colorFilter = colorFilterOverride?.takeUnless { it.isEmpty } ?: settings.readerColorFilter,
+		isReaderOptimizationEnabled = settings.isReaderOptimizationEnabled,
+		bitmapConfig = if (settings.is32BitColorsEnabled) {
 			Bitmap.Config.ARGB_8888
 		} else {
 			Bitmap.Config.RGB_565
-		}
-
-	val isPagesNumbersEnabled: Boolean
-		get() = settings.isPagesNumbersEnabled
+		},
+		isPagesNumbersEnabled = settings.isPagesNumbersEnabled,
+		isPagesCropEnabledStandard = settings.isPagesCropEnabled(ReaderMode.STANDARD),
+		isPagesCropEnabledWebtoon = settings.isPagesCropEnabled(ReaderMode.WEBTOON),
+	)
 
 	fun applyBackground(view: View) {
 		view.background = background.resolve(view.context)
 	}
 
-	fun isPagesCropEnabled(isWebtoon: Boolean) = settings.isPagesCropEnabled(
-		if (isWebtoon) ReaderMode.WEBTOON else ReaderMode.STANDARD,
-	)
+	fun isPagesCropEnabled(isWebtoon: Boolean) = if (isWebtoon) {
+		isPagesCropEnabledWebtoon
+	} else {
+		isPagesCropEnabledStandard
+	}
 
 	@CheckResult
 	fun applyBitmapConfig(ssiv: SubsamplingScaleImageView): Boolean {
@@ -78,33 +81,13 @@ class ReaderSettings(
 		}
 	}
 
-	override fun onInactive() {
-		super.onInactive()
-		settings.unsubscribe(internalObserver)
-		collectJob?.cancel()
-		collectJob = null
-	}
+	class Producer @AssistedInject constructor(
+		@Assisted private val mangaId: Flow<Long>,
+		private val settings: AppSettings,
+		private val mangaDataRepository: MangaDataRepository,
+	) : MediatorStateFlow<ReaderSettings>(ReaderSettings(settings, null)) {
 
-	override fun onActive() {
-		super.onActive()
-		settings.subscribe(internalObserver)
-		collectJob?.cancel()
-		collectJob = parentScope.launch {
-			colorFilterFlow.collect(internalObserver)
-		}
-	}
-
-	override fun getValue() = this
-
-	private fun notifyChanged() {
-		value = value
-	}
-
-	private inner class InternalObserver :
-		FlowCollector<ReaderColorFilter?>,
-		SharedPreferences.OnSharedPreferenceChangeListener {
-
-		private val settingsKeys = setOf(
+		private val settingsKeys = scatterSetOf(
 			AppSettings.KEY_ZOOM_MODE,
 			AppSettings.KEY_PAGES_NUMBERS,
 			AppSettings.KEY_READER_BACKGROUND,
@@ -114,18 +97,38 @@ class ReaderSettings(
 			AppSettings.KEY_CF_BRIGHTNESS,
 			AppSettings.KEY_CF_INVERTED,
 			AppSettings.KEY_CF_GRAYSCALE,
+			AppSettings.KEY_READER_CROP,
 		)
+		private var job: Job? = null
 
-		override suspend fun emit(value: ReaderColorFilter?) {
-			withContext(Dispatchers.Main.immediate) {
-				notifyChanged()
+		override fun onActive() {
+			assert(job?.isActive != true)
+			job?.cancel()
+			job = processLifecycleScope.launch(Dispatchers.Default) {
+				observeImpl()
 			}
 		}
 
-		override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
-			if (key in settingsKeys) {
-				notifyChanged()
+		override fun onInactive() {
+			job?.cancel()
+			job = null
+		}
+
+		private suspend fun observeImpl() {
+			combine(
+				mangaId.flatMapLatest { mangaDataRepository.observeColorFilter(it) },
+				settings.observe().filter { x -> x == null || x in settingsKeys }.onStart { emit(null) },
+			) { mangaCf, settingsKey ->
+				ReaderSettings(settings, mangaCf)
+			}.collect {
+				publishValue(it)
 			}
 		}
+
+		@AssistedFactory
+		interface Factory {
+
+			fun create(mangaId: Flow<Long>): Producer
+		}
 	}
 }

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

@@ -1,40 +1,56 @@
 package org.koitharu.kotatsu.reader.ui.pager
 
 import android.content.Context
+import android.view.View
 import androidx.annotation.CallSuper
+import androidx.core.view.isGone
+import androidx.core.view.isVisible
 import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.lifecycleScope
 import androidx.viewbinding.ViewBinding
+import com.davemorrissey.labs.subscaleview.DefaultOnImageEventListener
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import org.koitharu.kotatsu.BuildConfig
+import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.ui.list.lifecycle.LifecycleAwareViewHolder
+import org.koitharu.kotatsu.core.util.ext.getDisplayMessage
 import org.koitharu.kotatsu.core.util.ext.isLowRamDevice
+import org.koitharu.kotatsu.core.util.ext.isSerializable
+import org.koitharu.kotatsu.core.util.ext.observe
+import org.koitharu.kotatsu.core.util.ext.showOrHide
 import org.koitharu.kotatsu.databinding.LayoutPageInfoBinding
+import org.koitharu.kotatsu.parsers.util.ifZero
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.config.ReaderSettings
-import org.koitharu.kotatsu.reader.ui.pager.PageHolderDelegate.State
+import org.koitharu.kotatsu.reader.ui.pager.vm.PageState
+import org.koitharu.kotatsu.reader.ui.pager.vm.PageViewModel
 import org.koitharu.kotatsu.reader.ui.pager.webtoon.WebtoonHolder
 
 abstract class BasePageHolder<B : ViewBinding>(
 	protected val binding: B,
 	loader: PageLoader,
-	protected val settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
 	lifecycleOwner: LifecycleOwner,
-) : LifecycleAwareViewHolder(binding.root, lifecycleOwner), PageHolderDelegate.Callback {
+) : LifecycleAwareViewHolder(binding.root, lifecycleOwner), DefaultOnImageEventListener {
 
-	@Suppress("LeakingThis")
-	protected val delegate = PageHolderDelegate(
+	protected val viewModel = PageViewModel(
 		loader = loader,
-		readerSettings = settings,
-		callback = this,
+		settingsProducer = readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 		isWebtoon = this is WebtoonHolder,
 	)
 	protected val bindingInfo = LayoutPageInfoBinding.bind(binding.root)
+	protected abstract val ssiv: SubsamplingScaleImageView
+
+	protected val settings: ReaderSettings
+		get() = viewModel.settingsProducer.value
 
 	val context: Context
 		get() = itemView.context
@@ -42,51 +58,128 @@ abstract class BasePageHolder<B : ViewBinding>(
 	var boundData: ReaderPage? = null
 		private set
 
-	override fun onConfigChanged() {
-		settings.applyBackground(itemView)
+	init {
+		lifecycleScope.launch(Dispatchers.Main) {
+			ssiv.bindToLifecycle(this@BasePageHolder)
+			ssiv.isEagerLoadingEnabled = !context.isLowRamDevice()
+			ssiv.addOnImageEventListener(viewModel)
+			ssiv.addOnImageEventListener(this@BasePageHolder)
+		}
+		val clickListener = View.OnClickListener { v ->
+			when (v.id) {
+				R.id.button_retry -> viewModel.retry(
+					page = boundData?.toMangaPage() ?: return@OnClickListener,
+					isFromUser = true,
+				)
+
+				R.id.button_error_details -> viewModel.showErrorDetails(boundData?.url)
+			}
+		}
+		bindingInfo.buttonRetry.setOnClickListener(clickListener)
+		bindingInfo.buttonErrorDetails.setOnClickListener(clickListener)
 	}
 
-	fun requireData(): ReaderPage {
-		return checkNotNull(boundData) { "Calling requireData() before bind()" }
+	@CallSuper
+	protected open fun onConfigChanged(settings: ReaderSettings) {
+		settings.applyBackground(itemView)
+		if (viewModel.state.value is PageState.Shown) {
+			onReady()
+		}
+	}
+
+	fun reloadImage() {
+		val source = (viewModel.state.value as? PageState.Shown)?.source ?: return
+		ssiv.setImage(source)
 	}
 
 	fun bind(data: ReaderPage) {
 		boundData = data
+		viewModel.onBind(data.toMangaPage())
 		onBind(data)
 	}
 
-	protected abstract fun onBind(data: ReaderPage)
+	@CallSuper
+	protected open fun onBind(data: ReaderPage) = Unit
 
 	override fun onCreate() {
 		super.onCreate()
-		context.registerComponentCallbacks(delegate)
+		context.registerComponentCallbacks(viewModel)
+		viewModel.state.observe(this, ::onStateChanged)
+		viewModel.settingsProducer.observe(this, ::onConfigChanged)
 	}
 
 	override fun onResume() {
 		super.onResume()
-		if (delegate.state == State.ERROR && !delegate.isLoading()) {
-			boundData?.let { delegate.retry(it.toMangaPage(), isFromUser = false) }
+		ssiv.applyDownSampling(isForeground = true)
+		if (viewModel.state.value is PageState.Error && !viewModel.isLoading()) {
+			boundData?.let { viewModel.retry(it.toMangaPage(), isFromUser = false) }
 		}
 	}
 
+	override fun onPause() {
+		super.onPause()
+		ssiv.applyDownSampling(isForeground = false)
+	}
+
 	override fun onDestroy() {
-		context.unregisterComponentCallbacks(delegate)
+		context.unregisterComponentCallbacks(viewModel)
 		super.onDestroy()
 	}
 
-	@CallSuper
-	open fun onAttachedToWindow() {
-		delegate.onAttachedToWindow()
-	}
+	open fun onAttachedToWindow() = Unit
 
-	@CallSuper
-	open fun onDetachedFromWindow() {
-		delegate.onDetachedFromWindow()
-	}
+	open fun onDetachedFromWindow() = Unit
 
 	@CallSuper
 	open fun onRecycled() {
-		delegate.onRecycle()
+		viewModel.onRecycle()
+		ssiv.recycle()
+	}
+
+	protected open fun onStateChanged(state: PageState) {
+		bindingInfo.layoutError.isVisible = state is PageState.Error
+		bindingInfo.progressBar.showOrHide(!state.isFinalState())
+		bindingInfo.textViewStatus.isGone = state.isFinalState()
+		val progress = (state as? PageState.Loading)?.progress ?: -1
+		if (progress in 0..100) {
+			bindingInfo.progressBar.isIndeterminate = false
+			bindingInfo.progressBar.setProgressCompat(progress, true)
+			bindingInfo.textViewStatus.text = context.getString(R.string.percent_string_pattern, progress.toString())
+		} else {
+			bindingInfo.progressBar.isIndeterminate = true
+			bindingInfo.textViewStatus.setText(R.string.loading_)
+		}
+		when (state) {
+			is PageState.Converting -> {
+				bindingInfo.textViewStatus.setText(R.string.processing_)
+			}
+
+			is PageState.Empty -> Unit
+
+			is PageState.Error -> {
+				val e = state.error
+				bindingInfo.textViewError.text = e.getDisplayMessage(context.resources)
+				bindingInfo.buttonRetry.setText(
+					ExceptionResolver.getResolveStringId(e).ifZero { R.string.try_again },
+				)
+				bindingInfo.buttonErrorDetails.isVisible = e.isSerializable()
+				bindingInfo.layoutError.isVisible = true
+				bindingInfo.progressBar.hide()
+			}
+
+			is PageState.Loaded -> {
+				bindingInfo.textViewStatus.setText(R.string.processing_)
+				ssiv.setImage(state.source)
+			}
+
+			is PageState.Loading -> {
+				if (state.preview != null && ssiv.getState() == null) {
+					ssiv.setImage(state.preview)
+				}
+			}
+
+			is PageState.Shown -> Unit
+		}
 	}
 
 	protected fun SubsamplingScaleImageView.applyDownSampling(isForeground: Boolean) {

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/BasePagerReaderFragment.kt

@@ -142,7 +142,7 @@ abstract class BasePagerReaderFragment : BaseReaderFragment<FragmentReaderPagerB
 	override fun onCreateAdapter(): BaseReaderAdapter<*> = PagesAdapter(
 		lifecycleOwner = viewLifecycleOwner,
 		loader = pageLoader,
-		settings = viewModel.readerSettings,
+		readerSettingsProducer = viewModel.readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

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

@@ -15,7 +15,7 @@ import kotlin.coroutines.suspendCoroutine
 @Suppress("LeakingThis")
 abstract class BaseReaderAdapter<H : BasePageHolder<*>>(
 	private val loader: PageLoader,
-	private val readerSettings: ReaderSettings,
+	private val readerSettingsProducer: ReaderSettings.Producer,
 	private val networkState: NetworkState,
 	private val exceptionResolver: ExceptionResolver,
 ) : RecyclerView.Adapter<H>() {
@@ -58,7 +58,7 @@ abstract class BaseReaderAdapter<H : BasePageHolder<*>>(
 	final override fun onCreateViewHolder(
 		parent: ViewGroup,
 		viewType: Int,
-	): H = onCreateViewHolder(parent, loader, readerSettings, networkState, exceptionResolver)
+	): H = onCreateViewHolder(parent, loader, readerSettingsProducer, networkState, exceptionResolver)
 
 	suspend fun setItems(items: List<ReaderPage>) = suspendCoroutine { cont ->
 		differ.submitList(items) {
@@ -69,7 +69,7 @@ abstract class BaseReaderAdapter<H : BasePageHolder<*>>(
 	protected abstract fun onCreateViewHolder(
 		parent: ViewGroup,
 		loader: PageLoader,
-		settings: ReaderSettings,
+		readerSettingsProducer: ReaderSettings.Producer,
 		networkState: NetworkState,
 		exceptionResolver: ExceptionResolver,
 	): H

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/doublepage/DoublePageHolder.kt

@@ -17,10 +17,17 @@ class DoublePageHolder(
 	owner: LifecycleOwner,
 	binding: ItemPageBinding,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : PageHolder(owner, binding, loader, settings, networkState, exceptionResolver) {
+) : PageHolder(
+	owner = owner,
+	binding = binding,
+	loader = loader,
+	readerSettingsProducer = readerSettingsProducer,
+	networkState = networkState,
+	exceptionResolver = exceptionResolver,
+) {
 
 	private val isEven: Boolean
 		get() = bindingAdapterPosition and 1 == 0
@@ -35,7 +42,7 @@ class DoublePageHolder(
 			.gravity = (if (isEven) Gravity.START else Gravity.END) or Gravity.BOTTOM
 	}
 
-	override fun onImageShowing(settings: ReaderSettings, isPreview: Boolean) {
+	override fun onReady() {
 		with(binding.ssiv) {
 			maxScale = 2f * maxOf(
 				width / sWidth.toFloat(),

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/doublepage/DoublePagesAdapter.kt

@@ -13,22 +13,22 @@ import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 class DoublePagesAdapter(
 	private val lifecycleOwner: LifecycleOwner,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BaseReaderAdapter<DoublePageHolder>(loader, settings, networkState, exceptionResolver) {
+) : BaseReaderAdapter<DoublePageHolder>(loader, readerSettingsProducer, networkState, exceptionResolver) {
 
 	override fun onCreateViewHolder(
 		parent: ViewGroup,
 		loader: PageLoader,
-		settings: ReaderSettings,
+		readerSettingsProducer: ReaderSettings.Producer,
 		networkState: NetworkState,
 		exceptionResolver: ExceptionResolver,
 	) = DoublePageHolder(
 		owner = lifecycleOwner,
 		binding = ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false),
 		loader = loader,
-		settings = settings,
+		readerSettingsProducer = readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/doublepage/DoubleReaderFragment.kt

@@ -90,7 +90,7 @@ open class DoubleReaderFragment : BaseReaderFragment<FragmentReaderDoubleBinding
 	override fun onCreateAdapter() = DoublePagesAdapter(
 		lifecycleOwner = viewLifecycleOwner,
 		loader = pageLoader,
-		settings = viewModel.readerSettings,
+		readerSettingsProducer = viewModel.readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

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

@@ -17,17 +17,24 @@ class ReversedPageHolder(
 	owner: LifecycleOwner,
 	binding: ItemPageBinding,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : PageHolder(owner, binding, loader, settings, networkState, exceptionResolver) {
+) : PageHolder(
+	owner = owner,
+	binding = binding,
+	loader = loader,
+	readerSettingsProducer = readerSettingsProducer,
+	networkState = networkState,
+	exceptionResolver = exceptionResolver,
+) {
 
 	init {
 		(binding.textViewNumber.layoutParams as FrameLayout.LayoutParams)
 			.gravity = Gravity.START or Gravity.BOTTOM
 	}
 
-	override fun onImageShowing(settings: ReaderSettings, isPreview: Boolean) {
+	override fun onReady() {
 		with(binding.ssiv) {
 			maxScale = 2f * maxOf(
 				width / sWidth.toFloat(),

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

@@ -13,22 +13,22 @@ import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 class ReversedPagesAdapter(
 	private val lifecycleOwner: LifecycleOwner,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BaseReaderAdapter<ReversedPageHolder>(loader, settings, networkState, exceptionResolver) {
+) : BaseReaderAdapter<ReversedPageHolder>(loader, readerSettingsProducer, networkState, exceptionResolver) {
 
 	override fun onCreateViewHolder(
 		parent: ViewGroup,
 		loader: PageLoader,
-		settings: ReaderSettings,
+		readerSettingsProducer: ReaderSettings.Producer,
 		networkState: NetworkState,
 		exceptionResolver: ExceptionResolver,
 	) = ReversedPageHolder(
 		owner = lifecycleOwner,
 		binding = ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false),
 		loader = loader,
-		settings = settings,
+		readerSettingsProducer = readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

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

@@ -19,7 +19,7 @@ class ReversedReaderFragment : BasePagerReaderFragment() {
 	override fun onCreateAdapter() = ReversedPagesAdapter(
 		lifecycleOwner = viewLifecycleOwner,
 		loader = pageLoader,
-		settings = viewModel.readerSettings,
+		readerSettingsProducer = viewModel.readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

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

@@ -2,23 +2,15 @@ package org.koitharu.kotatsu.reader.ui.pager.standard
 
 import android.annotation.SuppressLint
 import android.graphics.PointF
-import android.view.View
 import android.view.animation.DecelerateInterpolator
 import androidx.core.view.isVisible
 import androidx.lifecycle.LifecycleOwner
-import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
-import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.model.ZoomMode
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.ui.widgets.ZoomControl
-import org.koitharu.kotatsu.core.util.ext.getDisplayMessage
-import org.koitharu.kotatsu.core.util.ext.isLowRamDevice
-import org.koitharu.kotatsu.core.util.ext.isSerializable
-import org.koitharu.kotatsu.core.util.ext.setTextAndVisible
 import org.koitharu.kotatsu.databinding.ItemPageBinding
-import org.koitharu.kotatsu.parsers.util.ifZero
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.config.ReaderSettings
 import org.koitharu.kotatsu.reader.ui.pager.BasePageHolder
@@ -28,37 +20,25 @@ open class PageHolder(
 	owner: LifecycleOwner,
 	binding: ItemPageBinding,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BasePageHolder<ItemPageBinding>(binding, loader, settings, networkState, exceptionResolver, owner),
-	View.OnClickListener,
+) : BasePageHolder<ItemPageBinding>(
+	binding = binding,
+	loader = loader,
+	readerSettingsProducer = readerSettingsProducer,
+	networkState = networkState,
+	exceptionResolver = exceptionResolver,
+	lifecycleOwner = owner,
+),
 	ZoomControl.ZoomControlListener {
 
-	init {
-		binding.ssiv.bindToLifecycle(owner)
-		binding.ssiv.isEagerLoadingEnabled = !context.isLowRamDevice()
-		binding.ssiv.addOnImageEventListener(delegate)
-		@Suppress("LeakingThis")
-		bindingInfo.buttonRetry.setOnClickListener(this)
-		@Suppress("LeakingThis")
-		bindingInfo.buttonErrorDetails.setOnClickListener(this)
-	}
+	override val ssiv = binding.ssiv
 
-	override fun onResume() {
-		super.onResume()
-		binding.ssiv.applyDownSampling(isForeground = true)
-	}
-
-	override fun onPause() {
-		super.onPause()
-		binding.ssiv.applyDownSampling(isForeground = false)
-	}
-
-	override fun onConfigChanged() {
-		super.onConfigChanged()
+	override fun onConfigChanged(settings: ReaderSettings) {
+		super.onConfigChanged(settings)
 		if (settings.applyBitmapConfig(binding.ssiv)) {
-			delegate.reload()
+			reloadImage()
 		}
 		binding.ssiv.applyDownSampling(isResumed())
 		binding.textViewNumber.isVisible = settings.isPagesNumbersEnabled
@@ -66,7 +46,7 @@ open class PageHolder(
 
 	@SuppressLint("SetTextI18n")
 	override fun onBind(data: ReaderPage) {
-		delegate.onBind(data.toMangaPage())
+		super.onBind(data)
 		binding.textViewNumber.text = (data.index + 1).toString()
 	}
 
@@ -75,33 +55,7 @@ open class PageHolder(
 		binding.ssiv.recycle()
 	}
 
-	override fun onLoadingStarted() {
-		bindingInfo.layoutError.isVisible = false
-		bindingInfo.progressBar.show()
-		binding.ssiv.recycle()
-		bindingInfo.textViewStatus.setTextAndVisible(R.string.loading_)
-	}
-
-	override fun onProgressChanged(progress: Int) {
-		if (progress in 0..100) {
-			bindingInfo.progressBar.isIndeterminate = false
-			bindingInfo.progressBar.setProgressCompat(progress, true)
-			bindingInfo.textViewStatus.text = context.getString(R.string.percent_string_pattern, progress.toString())
-		} else {
-			bindingInfo.progressBar.isIndeterminate = true
-			bindingInfo.textViewStatus.setText(R.string.loading_)
-		}
-	}
-
-	override fun onPreviewReady(source: ImageSource) {
-		binding.ssiv.setImage(source)
-	}
-
-	override fun onImageReady(source: ImageSource) {
-		binding.ssiv.setImage(source)
-	}
-
-	override fun onImageShowing(settings: ReaderSettings, isPreview: Boolean) {
+	override fun onReady() {
 		binding.ssiv.maxScale = 2f * maxOf(
 			binding.ssiv.width / binding.ssiv.sWidth.toFloat(),
 			binding.ssiv.height / binding.ssiv.sHeight.toFloat(),
@@ -141,34 +95,6 @@ open class PageHolder(
 		}
 	}
 
-	override fun onImageShown(isPreview: Boolean) {
-		if (!isPreview) {
-			bindingInfo.progressBar.hide()
-		}
-		bindingInfo.textViewStatus.isVisible = false
-	}
-
-	override fun onTrimMemory() {
-		// TODO https://developer.android.com/topic/performance/memory
-	}
-
-	final override fun onClick(v: View) {
-		when (v.id) {
-			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return, isFromUser = true)
-			R.id.button_error_details -> delegate.showErrorDetails(boundData?.url)
-		}
-	}
-
-	override fun onError(e: Throwable) {
-		bindingInfo.textViewError.text = e.getDisplayMessage(context.resources)
-		bindingInfo.buttonRetry.setText(
-			ExceptionResolver.getResolveStringId(e).ifZero { R.string.try_again },
-		)
-		bindingInfo.buttonErrorDetails.isVisible = e.isSerializable()
-		bindingInfo.layoutError.isVisible = true
-		bindingInfo.progressBar.hide()
-	}
-
 	override fun onZoomIn() {
 		scaleBy(1.2f)
 	}

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

@@ -13,22 +13,27 @@ import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 class PagesAdapter(
 	private val lifecycleOwner: LifecycleOwner,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BaseReaderAdapter<PageHolder>(loader, settings, networkState, exceptionResolver) {
+) : BaseReaderAdapter<PageHolder>(
+	loader = loader,
+	readerSettingsProducer = readerSettingsProducer,
+	networkState = networkState,
+	exceptionResolver = exceptionResolver,
+) {
 
 	override fun onCreateViewHolder(
 		parent: ViewGroup,
 		loader: PageLoader,
-		settings: ReaderSettings,
+		readerSettingsProducer: ReaderSettings.Producer,
 		networkState: NetworkState,
 		exceptionResolver: ExceptionResolver,
 	) = PageHolder(
 		owner = lifecycleOwner,
 		binding = ItemPageBinding.inflate(LayoutInflater.from(parent.context), parent, false),
 		loader = loader,
-		settings = settings,
+		readerSettingsProducer = readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/vm/PageState.kt

@@ -0,0 +1,31 @@
+package org.koitharu.kotatsu.reader.ui.pager.vm
+
+import com.davemorrissey.labs.subscaleview.ImageSource
+
+sealed class PageState {
+
+	data object Empty : PageState()
+
+	data class Loading(
+		val preview: ImageSource?,
+		val progress: Int,
+	) : PageState()
+
+	data class Loaded(
+		val source: ImageSource,
+		val isConverted: Boolean,
+	) : PageState()
+
+	class Converting() : PageState()
+
+	data class Shown(
+		val source: ImageSource,
+		val isConverted: Boolean,
+	) : PageState()
+
+	data class Error(
+		val error: Throwable,
+	) : PageState()
+
+	fun isFinalState(): Boolean = this is Error || this is Shown
+}

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/vm/PageViewModel.kt

@@ -1,10 +1,10 @@
-package org.koitharu.kotatsu.reader.ui.pager
+package org.koitharu.kotatsu.reader.ui.pager.vm
 
 import android.content.ComponentCallbacks2
 import android.content.res.Configuration
 import android.graphics.Rect
 import android.net.Uri
-import androidx.lifecycle.Observer
+import androidx.annotation.WorkerThread
 import com.davemorrissey.labs.subscaleview.DefaultOnImageEventListener
 import com.davemorrissey.labs.subscaleview.ImageSource
 import kotlinx.coroutines.CancellationException
@@ -14,41 +14,38 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.cancelAndJoin
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.debounce
+import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.plus
-import kotlinx.coroutines.withContext
+import okio.IOException
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.util.ext.printStackTraceDebug
-import org.koitharu.kotatsu.core.util.ext.toFileOrNull
+import org.koitharu.kotatsu.core.util.ext.throttle
 import org.koitharu.kotatsu.parsers.model.MangaPage
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.config.ReaderSettings
-import java.io.IOException
 
-class PageHolderDelegate(
+class PageViewModel(
 	private val loader: PageLoader,
-	private val readerSettings: ReaderSettings,
-	private val callback: Callback,
+	val settingsProducer: ReaderSettings.Producer,
 	private val networkState: NetworkState,
 	private val exceptionResolver: ExceptionResolver,
 	private val isWebtoon: Boolean,
-) : DefaultOnImageEventListener, Observer<ReaderSettings>, ComponentCallbacks2 {
+) : DefaultOnImageEventListener, ComponentCallbacks2 {
 
 	private val scope = loader.loaderScope + Dispatchers.Main.immediate
-	var state = State.EMPTY
-		private set
 	private var job: Job? = null
-	private var uri: Uri? = null
 	private var cachedBounds: Rect? = null
-	private var error: Throwable? = null
+
+	val state = MutableStateFlow<PageState>(PageState.Empty)
 
 	init {
 		scope.launch(Dispatchers.Main) { // the same as post() -- wait until child fields init
-			callback.onConfigChanged()
+			// callback.onConfigChanged()
 		}
 	}
 
@@ -56,7 +53,7 @@ class PageHolderDelegate(
 
 	fun onBind(page: MangaPage) {
 		val prevJob = job
-		job = scope.launch {
+		job = scope.launch(Dispatchers.Default) {
 			prevJob?.cancelAndJoin()
 			doLoad(page, force = false)
 		}
@@ -66,8 +63,8 @@ class PageHolderDelegate(
 		val prevJob = job
 		job = scope.launch {
 			prevJob?.cancelAndJoin()
-			val e = error
-			if (e != null && ExceptionResolver.canResolve(e)) {
+			val e = (state.value as? PageState.Error)?.error
+			if (e != null && ExceptionResolver.Companion.canResolve(e)) {
 				if (!isFromUser) {
 					return@launch
 				}
@@ -78,75 +75,38 @@ class PageHolderDelegate(
 	}
 
 	fun showErrorDetails(url: String?) {
-		val e = error ?: return
+		val e = (state.value as? PageState.Error)?.error ?: return
 		exceptionResolver.showErrorDetails(e, url)
 	}
 
-	fun onAttachedToWindow() {
-		readerSettings.observeForever(this)
-	}
-
-	fun onDetachedFromWindow() {
-		readerSettings.removeObserver(this)
-	}
-
 	fun onRecycle() {
-		state = State.EMPTY
-		uri = null
+		state.value = PageState.Empty
 		cachedBounds = null
-		error = null
 		job?.cancel()
 	}
 
-	fun reload() {
-		if (state == State.SHOWN) {
-			uri?.let {
-				callback.onImageReady(it.toImageSource(cachedBounds))
-			}
-		}
-	}
-
-	override fun onReady() {
-		if (state >= State.LOADED) {
-			state = State.SHOWING
-			error = null
-			callback.onImageShowing(readerSettings, isPreview = false)
-		} else if (state == State.LOADING_WITH_PREVIEW) {
-			callback.onImageShowing(readerSettings, isPreview = true)
-		}
-	}
-
 	override fun onImageLoaded() {
-		if (state >= State.LOADED) {
-			state = State.SHOWN
-			error = null
-			callback.onImageShown(isPreview = false)
-		} else if (state == State.LOADING_WITH_PREVIEW) {
-			callback.onImageShown(isPreview = true)
+		state.update {
+			if (it is PageState.Loaded) PageState.Shown(it.source, it.isConverted) else it
 		}
 	}
 
 	override fun onImageLoadError(e: Throwable) {
 		e.printStackTraceDebug()
-		if (state < State.LOADED) {
-			// ignore preview error
-			return
-		}
-		val uri = this.uri
-		error = e
-		if (state == State.LOADED && e is IOException && uri != null && uri.toFileOrNull()?.exists() != false) {
-			tryConvert(uri, e)
-		} else {
-			state = State.ERROR
-			callback.onError(e)
-		}
-	}
 
-	override fun onChanged(value: ReaderSettings) {
-		if (state == State.SHOWN) {
-			callback.onImageShowing(readerSettings, isPreview = false)
+		state.update { currentState ->
+			if (currentState is PageState.Loaded) {
+				val uri = (currentState.source as? ImageSource.Uri)?.uri
+				if (!currentState.isConverted && uri != null && e is IOException) {
+					tryConvert(uri, e)
+					PageState.Converting()
+				} else {
+					PageState.Error(e)
+				}
+			} else {
+				currentState
+			}
 		}
-		callback.onConfigChanged()
 	}
 
 	override fun onConfigurationChanged(newConfig: Configuration) = Unit
@@ -155,68 +115,58 @@ class PageHolderDelegate(
 	override fun onLowMemory() = Unit
 
 	override fun onTrimMemory(level: Int) {
-		callback.onTrimMemory()
+		// callback.onTrimMemory()
 	}
 
 	private fun tryConvert(uri: Uri, e: Exception) {
 		val prevJob = job
 		job = scope.launch {
 			prevJob?.join()
-			state = State.CONVERTING
+			state.value = PageState.Converting()
 			try {
 				val newUri = loader.convertBimap(uri)
-				cachedBounds = if (readerSettings.isPagesCropEnabled(isWebtoon)) {
+				cachedBounds = if (settingsProducer.value.isPagesCropEnabled(isWebtoon)) {
 					loader.getTrimmedBounds(newUri)
 				} else {
 					null
 				}
-				state = State.CONVERTED
-				callback.onImageReady(newUri.toImageSource(cachedBounds))
+				state.value = PageState.Loaded(uri.toImageSource(cachedBounds), isConverted = true)
 			} catch (ce: CancellationException) {
 				throw ce
 			} catch (e2: Throwable) {
 				e2.printStackTrace()
 				e.addSuppressed(e2)
-				state = State.ERROR
-				callback.onError(e)
+				state.value = PageState.Error(e)
 			}
 		}
 	}
 
+	@WorkerThread
 	private suspend fun doLoad(data: MangaPage, force: Boolean) = coroutineScope {
-		state = State.LOADING
-		error = null
-		callback.onLoadingStarted()
+		state.value = PageState.Loading(null/* TODO */, -1)
 		val previewJob = launch {
-			val preview = loader.loadPreview(data)
-			if (preview != null && state == State.LOADING) {
-				state = State.LOADING_WITH_PREVIEW
-				callback.onPreviewReady(preview)
+			val preview = loader.loadPreview(data) ?: return@launch
+			state.update {
+				if (it is PageState.Loading) it.copy(preview = preview) else it
 			}
 		}
 		try {
-			val task = withContext(Dispatchers.Default) {
-				loader.loadPageAsync(data, force)
-			}
+			val task = loader.loadPageAsync(data, force)
 			val progressObserver = observeProgress(this, task.progressAsFlow())
-			val file = task.await()
+			val uri = task.await()
 			progressObserver.cancelAndJoin()
 			previewJob.cancel()
-			uri = file
-			state = State.LOADED
-			cachedBounds = if (readerSettings.isPagesCropEnabled(isWebtoon)) {
-				loader.getTrimmedBounds(checkNotNull(uri))
+			cachedBounds = if (settingsProducer.value.isPagesCropEnabled(isWebtoon)) {
+				loader.getTrimmedBounds(uri)
 			} else {
 				null
 			}
-			callback.onImageReady(checkNotNull(uri).toImageSource(cachedBounds))
+			state.value = PageState.Loaded(uri.toImageSource(cachedBounds), isConverted = false)
 		} catch (e: CancellationException) {
 			throw e
 		} catch (e: Throwable) {
 			e.printStackTraceDebug()
-			state = State.ERROR
-			error = e
-			callback.onError(e)
+			state.value = PageState.Error(e)
 			if (e is IOException && !networkState.value) {
 				networkState.awaitForConnection()
 				retry(data, isFromUser = false)
@@ -225,9 +175,17 @@ class PageHolderDelegate(
 	}
 
 	private fun observeProgress(scope: CoroutineScope, progress: Flow<Float>) = progress
-		.debounce(250)
-		.onEach { callback.onProgressChanged((100 * it).toInt()) }
-		.launchIn(scope)
+		.throttle(250)
+		.onEach {
+			val progressValue = (100 * it).toInt()
+			state.update { currentState ->
+				if (currentState is PageState.Loading) {
+					currentState.copy(progress = progressValue)
+				} else {
+					currentState
+				}
+			}
+		}.launchIn(scope)
 
 	private fun Uri.toImageSource(bounds: Rect?): ImageSource {
 		val source = ImageSource.uri(this)
@@ -237,29 +195,4 @@ class PageHolderDelegate(
 			source
 		}
 	}
-
-	enum class State {
-		EMPTY, LOADING, LOADING_WITH_PREVIEW, LOADED, CONVERTING, CONVERTED, SHOWING, SHOWN, ERROR
-	}
-
-	interface Callback {
-
-		fun onLoadingStarted()
-
-		fun onError(e: Throwable)
-
-		fun onPreviewReady(source: ImageSource)
-
-		fun onImageReady(source: ImageSource)
-
-		fun onImageShowing(settings: ReaderSettings, isPreview: Boolean)
-
-		fun onImageShown(isPreview: Boolean)
-
-		fun onProgressChanged(progress: Int)
-
-		fun onConfigChanged()
-
-		fun onTrimMemory()
-	}
 }

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/webtoon/WebtoonAdapter.kt

@@ -13,15 +13,15 @@ import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 class WebtoonAdapter(
 	private val lifecycleOwner: LifecycleOwner,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BaseReaderAdapter<WebtoonHolder>(loader, settings, networkState, exceptionResolver) {
+) : BaseReaderAdapter<WebtoonHolder>(loader, readerSettingsProducer, networkState, exceptionResolver) {
 
 	override fun onCreateViewHolder(
 		parent: ViewGroup,
 		loader: PageLoader,
-		settings: ReaderSettings,
+		readerSettingsProducer: ReaderSettings.Producer,
 		networkState: NetworkState,
 		exceptionResolver: ExceptionResolver,
 	) = WebtoonHolder(
@@ -32,7 +32,7 @@ class WebtoonAdapter(
 			false,
 		),
 		loader = loader,
-		settings = settings,
+		readerSettingsProducer = readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/webtoon/WebtoonHolder.kt

@@ -1,65 +1,43 @@
 package org.koitharu.kotatsu.reader.ui.pager.webtoon
 
-import android.view.View
-import androidx.core.view.isVisible
 import androidx.lifecycle.LifecycleOwner
-import com.davemorrissey.labs.subscaleview.ImageSource
-import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.util.GoneOnInvisibleListener
-import org.koitharu.kotatsu.core.util.ext.getDisplayMessage
-import org.koitharu.kotatsu.core.util.ext.isSerializable
-import org.koitharu.kotatsu.core.util.ext.setTextAndVisible
 import org.koitharu.kotatsu.databinding.ItemPageWebtoonBinding
-import org.koitharu.kotatsu.parsers.util.ifZero
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.config.ReaderSettings
 import org.koitharu.kotatsu.reader.ui.pager.BasePageHolder
-import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 
 class WebtoonHolder(
 	owner: LifecycleOwner,
 	binding: ItemPageWebtoonBinding,
 	loader: PageLoader,
-	settings: ReaderSettings,
+	readerSettingsProducer: ReaderSettings.Producer,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BasePageHolder<ItemPageWebtoonBinding>(binding, loader, settings, networkState, exceptionResolver, owner),
-	View.OnClickListener {
+) : BasePageHolder<ItemPageWebtoonBinding>(
+	binding = binding,
+	loader = loader,
+	readerSettingsProducer = readerSettingsProducer,
+	networkState = networkState,
+	exceptionResolver = exceptionResolver,
+	lifecycleOwner = owner,
+) {
+
+	override val ssiv = binding.ssiv
 
 	private var scrollToRestore = 0
 	private val goneOnInvisibleListener = GoneOnInvisibleListener(bindingInfo.progressBar)
 
-	init {
-		binding.ssiv.bindToLifecycle(owner)
-		binding.ssiv.addOnImageEventListener(delegate)
-		bindingInfo.buttonRetry.setOnClickListener(this)
-		bindingInfo.buttonErrorDetails.setOnClickListener(this)
-	}
-
-	override fun onResume() {
-		super.onResume()
-		binding.ssiv.applyDownSampling(isForeground = true)
-	}
-
-	override fun onPause() {
-		super.onPause()
-		binding.ssiv.applyDownSampling(isForeground = false)
-	}
-
-	override fun onConfigChanged() {
-		super.onConfigChanged()
+	override fun onConfigChanged(settings: ReaderSettings) {
+		super.onConfigChanged(settings)
 		if (settings.applyBitmapConfig(binding.ssiv)) {
-			delegate.reload()
+			reloadImage()
 		}
 		binding.ssiv.applyDownSampling(isResumed())
 	}
 
-	override fun onBind(data: ReaderPage) {
-		delegate.onBind(data.toMangaPage())
-	}
-
 	override fun onRecycled() {
 		super.onRecycled()
 		binding.ssiv.recycle()
@@ -75,31 +53,7 @@ class WebtoonHolder(
 		goneOnInvisibleListener.detach()
 	}
 
-	override fun onLoadingStarted() {
-		bindingInfo.layoutError.isVisible = false
-		bindingInfo.progressBar.show()
-		binding.ssiv.recycle()
-		bindingInfo.textViewStatus.setTextAndVisible(R.string.loading_)
-	}
-
-	override fun onProgressChanged(progress: Int) {
-		if (progress in 0..100) {
-			bindingInfo.progressBar.isIndeterminate = false
-			bindingInfo.progressBar.setProgressCompat(progress, true)
-			bindingInfo.textViewStatus.text = context.getString(R.string.percent_string_pattern, progress.toString())
-		} else {
-			bindingInfo.progressBar.isIndeterminate = true
-			bindingInfo.textViewStatus.setText(R.string.loading_)
-		}
-	}
-
-	override fun onPreviewReady(source: ImageSource) = Unit
-
-	override fun onImageReady(source: ImageSource) {
-		binding.ssiv.setImage(source)
-	}
-
-	override fun onImageShowing(settings: ReaderSettings, isPreview: Boolean) {
+	override fun onReady() {
 		binding.ssiv.colorFilter = settings.colorFilter?.toColorFilter()
 		with(binding.ssiv) {
 			scrollTo(
@@ -113,32 +67,6 @@ class WebtoonHolder(
 		}
 	}
 
-	override fun onImageShown(isPreview: Boolean) {
-		bindingInfo.progressBar.hide()
-		bindingInfo.textViewStatus.isVisible = false
-	}
-
-	override fun onTrimMemory() {
-		// TODO
-	}
-
-	override fun onClick(v: View) {
-		when (v.id) {
-			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return, isFromUser = true)
-			R.id.button_error_details -> delegate.showErrorDetails(boundData?.url)
-		}
-	}
-
-	override fun onError(e: Throwable) {
-		bindingInfo.textViewError.text = e.getDisplayMessage(context.resources)
-		bindingInfo.buttonRetry.setText(
-			ExceptionResolver.getResolveStringId(e).ifZero { R.string.try_again },
-		)
-		bindingInfo.buttonErrorDetails.isVisible = e.isSerializable()
-		bindingInfo.layoutError.isVisible = true
-		bindingInfo.progressBar.hide()
-	}
-
 	fun getScrollY() = binding.ssiv.getScroll()
 
 	fun restoreScroll(scroll: Int) {

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/pager/webtoon/WebtoonReaderFragment.kt

@@ -67,7 +67,7 @@ class WebtoonReaderFragment : BaseReaderFragment<FragmentReaderWebtoonBinding>()
 				rv.addItemDecoration(WebtoonGapsDecoration())
 			}
 		}
-		viewModel.readerSettings.observe(viewLifecycleOwner) {
+		viewModel.readerSettingsProducer.observe(viewLifecycleOwner) {
 			it.applyBackground(binding.root)
 		}
 	}
@@ -81,7 +81,7 @@ class WebtoonReaderFragment : BaseReaderFragment<FragmentReaderWebtoonBinding>()
 	override fun onCreateAdapter() = WebtoonAdapter(
 		lifecycleOwner = viewLifecycleOwner,
 		loader = pageLoader,
-		settings = viewModel.readerSettings,
+		readerSettingsProducer = viewModel.readerSettingsProducer,
 		networkState = networkState,
 		exceptionResolver = exceptionResolver,
 	)

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

@@ -31,7 +31,7 @@
 	<string name="add">Add</string>
 	<string name="save">Save</string>
 	<string name="share">Share</string>
-	<string name="create_shortcut">Create shortcut…</string>
+	<string name="create_shortcut">Create shortcut</string>
 	<string name="share_s">Share %s</string>
 	<string name="search">Search</string>
 	<string name="search_manga">Search manga</string>