Handle errors properly in scrobbler selector

app/build.gradle

@@ -90,7 +90,7 @@ dependencies {
 		exclude group: 'org.json', module: 'json'
 	}
 
-	implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.8.0'
+	implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.8.10'
 	implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4'
 
 	implementation "androidx.appcompat:appcompat:1.6.0"

app/src/main/java/org/koitharu/kotatsu/scrobbling/ui/selector/ScrobblingSelectorBottomSheet.kt

@@ -91,6 +91,12 @@ class ScrobblingSelectorBottomSheet :
 		viewModel.onClose.observe(viewLifecycleOwner) {
 			dismiss()
 		}
+		viewModel.selectedScrobblerIndex.observe(viewLifecycleOwner) { index ->
+			val tab = binding.tabs.getTabAt(index)
+			if (tab != null && !tab.isSelected) {
+				tab.select()
+			}
+		}
 		viewModel.searchQuery.observe(viewLifecycleOwner) {
 			binding.headerBar.subtitle = it
 		}
@@ -106,14 +112,16 @@ class ScrobblingSelectorBottomSheet :
 		viewModel.selectedItemId.value = item.id
 	}
 
-	override fun onRetryClick(error: Throwable) = Unit
+	override fun onRetryClick(error: Throwable) {
+		viewModel.retry()
+	}
 
 	override fun onEmptyActionClick() {
 		openSearch()
 	}
 
 	override fun onScrolledToEnd() {
-		viewModel.loadList(append = true)
+		viewModel.loadNextPage()
 	}
 
 	override fun onMenuItemActionExpand(item: MenuItem): Boolean {

app/src/main/java/org/koitharu/kotatsu/scrobbling/ui/selector/ScrobblingSelectorViewModel.kt

@@ -11,18 +11,19 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.filterNotNull
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.base.ui.BaseViewModel
-import org.koitharu.kotatsu.list.ui.model.EmptyHint
 import org.koitharu.kotatsu.list.ui.model.ListModel
 import org.koitharu.kotatsu.list.ui.model.LoadingFooter
 import org.koitharu.kotatsu.list.ui.model.LoadingState
 import org.koitharu.kotatsu.parsers.model.Manga
+import org.koitharu.kotatsu.parsers.util.runCatchingCancellable
 import org.koitharu.kotatsu.scrobbling.domain.Scrobbler
 import org.koitharu.kotatsu.scrobbling.domain.model.ScrobblerManga
+import org.koitharu.kotatsu.scrobbling.ui.selector.model.ScrobblerHint
 import org.koitharu.kotatsu.utils.SingleLiveEvent
 import org.koitharu.kotatsu.utils.ext.asLiveDataDistinct
+import org.koitharu.kotatsu.utils.ext.printStackTraceDebug
 import org.koitharu.kotatsu.utils.ext.requireValue
 
 class ScrobblingSelectorViewModel @AssistedInject constructor(
@@ -34,8 +35,9 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 
 	val selectedScrobblerIndex = MutableLiveData(0)
 
-	private val scrobblerMangaList = MutableStateFlow<List<ScrobblerManga>?>(null)
-	private val hasNextPage = MutableStateFlow(false)
+	private val scrobblerMangaList = MutableStateFlow<List<ScrobblerManga>>(emptyList())
+	private val hasNextPage = MutableStateFlow(true)
+	private val listError = MutableStateFlow<Throwable?>(null)
 	private var loadingJob: Job? = null
 	private var doneJob: Job? = null
 	private var initJob: Job? = null
@@ -44,13 +46,24 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 		get() = availableScrobblers[selectedScrobblerIndex.requireValue()]
 
 	val content: LiveData<List<ListModel>> = combine(
-		scrobblerMangaList.filterNotNull(),
+		scrobblerMangaList,
+		listError,
 		hasNextPage,
-	) { list, isHasNextPage ->
-		when {
-			list.isEmpty() -> listOf(emptyResultsHint())
-			isHasNextPage -> list + LoadingFooter
-			else -> list
+	) { list, error, isHasNextPage ->
+		if (list.isNotEmpty()) {
+			if (isHasNextPage) {
+				list + LoadingFooter
+			} else {
+				list
+			}
+		} else {
+			listOf(
+				when {
+					error != null -> errorHint(error)
+					isHasNextPage -> LoadingFooter
+					else -> emptyResultsHint()
+				},
+			)
 		}
 	}.asLiveDataDistinct(viewModelScope.coroutineContext + Dispatchers.Default, listOf(LoadingState))
 
@@ -59,7 +72,7 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 	val onClose = SingleLiveEvent<Unit>()
 
 	val isEmpty: Boolean
-		get() = scrobblerMangaList.value.isNullOrEmpty()
+		get() = scrobblerMangaList.value.isEmpty()
 
 	init {
 		initialize()
@@ -71,22 +84,39 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 		loadList(append = false)
 	}
 
-	fun loadList(append: Boolean) {
+	fun loadNextPage() {
+		if (scrobblerMangaList.value.isNotEmpty() && hasNextPage.value) {
+			loadList(append = true)
+		}
+	}
+
+	fun retry() {
+		loadingJob?.cancel()
+		hasNextPage.value = true
+		scrobblerMangaList.value = emptyList()
+		loadList(append = false)
+	}
+
+	private fun loadList(append: Boolean) {
 		if (loadingJob?.isActive == true) {
 			return
 		}
-		if (append && !hasNextPage.value) {
-			return
-		}
 		loadingJob = launchLoadingJob(Dispatchers.Default) {
-			val offset = if (append) scrobblerMangaList.value?.size ?: 0 else 0
-			val list = currentScrobbler.findManga(checkNotNull(searchQuery.value), offset)
-			if (!append) {
-				scrobblerMangaList.value = list
-			} else if (list.isNotEmpty()) {
-				scrobblerMangaList.value = scrobblerMangaList.value?.plus(list) ?: list
+			listError.value = null
+			val offset = if (append) scrobblerMangaList.value.size else 0
+			runCatchingCancellable {
+				currentScrobbler.findManga(checkNotNull(searchQuery.value), offset)
+			}.onSuccess { list ->
+				if (!append) {
+					scrobblerMangaList.value = list
+				} else if (list.isNotEmpty()) {
+					scrobblerMangaList.value = scrobblerMangaList.value + list
+				}
+				hasNextPage.value = list.isNotEmpty()
+			}.onFailure { error ->
+				error.printStackTraceDebug()
+				listError.value = error
 			}
-			hasNextPage.value = list.isNotEmpty()
 		}
 	}
 
@@ -113,8 +143,8 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 	private fun initialize() {
 		initJob?.cancel()
 		loadingJob?.cancel()
-		hasNextPage.value = false
-		scrobblerMangaList.value = null
+		hasNextPage.value = true
+		scrobblerMangaList.value = emptyList()
 		initJob = launchJob(Dispatchers.Default) {
 			try {
 				val info = currentScrobbler.getScrobblingInfoOrNull(manga.id)
@@ -127,13 +157,22 @@ class ScrobblingSelectorViewModel @AssistedInject constructor(
 		}
 	}
 
-	private fun emptyResultsHint() = EmptyHint(
+	private fun emptyResultsHint() = ScrobblerHint(
 		icon = R.drawable.ic_empty_history,
 		textPrimary = R.string.nothing_found,
 		textSecondary = R.string.text_search_holder_secondary,
+		error = null,
 		actionStringRes = R.string.search,
 	)
 
+	private fun errorHint(e: Throwable) = ScrobblerHint(
+		icon = R.drawable.ic_error_large,
+		textPrimary = R.string.error_occurred,
+		error = e,
+		textSecondary = 0,
+		actionStringRes = R.string.try_again,
+	)
+
 	@AssistedFactory
 	interface Factory {
 

app/src/main/java/org/koitharu/kotatsu/scrobbling/ui/selector/adapter/ScrobblerHintAD.kt

@@ -0,0 +1,37 @@
+package org.koitharu.kotatsu.scrobbling.ui.selector.adapter
+
+import com.hannesdorfmann.adapterdelegates4.dsl.adapterDelegateViewBinding
+import org.koitharu.kotatsu.databinding.ItemEmptyHintBinding
+import org.koitharu.kotatsu.list.ui.adapter.ListStateHolderListener
+import org.koitharu.kotatsu.list.ui.model.ListModel
+import org.koitharu.kotatsu.scrobbling.ui.selector.model.ScrobblerHint
+import org.koitharu.kotatsu.utils.ext.getDisplayMessage
+import org.koitharu.kotatsu.utils.ext.setTextAndVisible
+import org.koitharu.kotatsu.utils.ext.textAndVisible
+
+fun scrobblerHintAD(
+	listener: ListStateHolderListener,
+) = adapterDelegateViewBinding<ScrobblerHint, ListModel, ItemEmptyHintBinding>(
+	{ inflater, parent -> ItemEmptyHintBinding.inflate(inflater, parent, false) },
+) {
+
+	binding.buttonRetry.setOnClickListener {
+		val e = item.error
+		if (e != null) {
+			listener.onRetryClick(e)
+		} else {
+			listener.onEmptyActionClick()
+		}
+	}
+
+	bind {
+		binding.icon.setImageResource(item.icon)
+		binding.textPrimary.setText(item.textPrimary)
+		if (item.error != null) {
+			binding.textSecondary.textAndVisible = item.error?.getDisplayMessage(context.resources)
+		} else {
+			binding.textSecondary.setTextAndVisible(item.textSecondary)
+		}
+		binding.buttonRetry.setTextAndVisible(item.actionStringRes)
+	}
+}

app/src/main/java/org/koitharu/kotatsu/scrobbling/ui/selector/adapter/ShikimoriSelectorAdapter.kt

@@ -6,11 +6,11 @@ import coil.ImageLoader
 import com.hannesdorfmann.adapterdelegates4.AsyncListDifferDelegationAdapter
 import org.koitharu.kotatsu.base.ui.list.OnListItemClickListener
 import org.koitharu.kotatsu.list.ui.adapter.ListStateHolderListener
-import org.koitharu.kotatsu.list.ui.adapter.emptyHintAD
 import org.koitharu.kotatsu.list.ui.adapter.loadingFooterAD
 import org.koitharu.kotatsu.list.ui.adapter.loadingStateAD
 import org.koitharu.kotatsu.list.ui.model.ListModel
 import org.koitharu.kotatsu.scrobbling.domain.model.ScrobblerManga
+import org.koitharu.kotatsu.scrobbling.ui.selector.model.ScrobblerHint
 import kotlin.jvm.internal.Intrinsics
 
 class ShikimoriSelectorAdapter(
@@ -24,7 +24,7 @@ class ShikimoriSelectorAdapter(
 		delegatesManager.addDelegate(loadingStateAD())
 			.addDelegate(scrobblingMangaAD(lifecycleOwner, coil, clickListener))
 			.addDelegate(loadingFooterAD())
-			.addDelegate(emptyHintAD(stateHolderListener))
+			.addDelegate(scrobblerHintAD(stateHolderListener))
 	}
 
 	private class DiffCallback : DiffUtil.ItemCallback<ListModel>() {
@@ -33,6 +33,7 @@ class ShikimoriSelectorAdapter(
 			return when {
 				oldItem === newItem -> true
 				oldItem is ScrobblerManga && newItem is ScrobblerManga -> oldItem.id == newItem.id
+				oldItem is ScrobblerHint && newItem is ScrobblerHint -> oldItem.textPrimary == newItem.textPrimary
 				else -> false
 			}
 		}

app/src/main/java/org/koitharu/kotatsu/scrobbling/ui/selector/model/ScrobblerHint.kt

@@ -0,0 +1,38 @@
+package org.koitharu.kotatsu.scrobbling.ui.selector.model
+
+import androidx.annotation.DrawableRes
+import androidx.annotation.StringRes
+import org.koitharu.kotatsu.list.ui.model.ListModel
+
+class ScrobblerHint(
+	@DrawableRes val icon: Int,
+	@StringRes val textPrimary: Int,
+	@StringRes val textSecondary: Int,
+	val error: Throwable?,
+	@StringRes val actionStringRes: Int,
+) : ListModel {
+
+	override fun equals(other: Any?): Boolean {
+		if (this === other) return true
+		if (javaClass != other?.javaClass) return false
+
+		other as ScrobblerHint
+
+		if (icon != other.icon) return false
+		if (textPrimary != other.textPrimary) return false
+		if (textSecondary != other.textSecondary) return false
+		if (error != other.error) return false
+		if (actionStringRes != other.actionStringRes) return false
+
+		return true
+	}
+
+	override fun hashCode(): Int {
+		var result = icon
+		result = 31 * result + textPrimary
+		result = 31 * result + textSecondary
+		result = 31 * result + (error?.hashCode() ?: 0)
+		result = 31 * result + actionStringRes
+		return result
+	}
+}

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

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+	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="wrap_content"
+	android:padding="@dimen/margin_normal">
+
+	<ImageView
+		android:id="@+id/icon"
+		android:layout_width="120dp"
+		android:layout_height="120dp"
+		android:contentDescription="@null"
+		android:scaleType="fitCenter"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent"
+		tools:src="@drawable/ic_empty_favourites" />
+
+	<TextView
+		android:id="@+id/textPrimary"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="@dimen/margin_small"
+		android:textAppearance="?attr/textAppearanceTitleLarge"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@id/icon"
+		app:layout_constraintTop_toTopOf="parent"
+		tools:text="@tools:sample/lorem[3]" />
+
+	<TextView
+		android:id="@+id/textSecondary"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		android:layout_marginStart="@dimen/margin_small"
+		android:layout_marginTop="@dimen/margin_small"
+		android:textAppearance="?attr/textAppearanceBodyMedium"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@id/icon"
+		app:layout_constraintTop_toBottomOf="@id/textPrimary"
+		tools:text="@tools:sample/lorem[15]" />
+
+	<Button
+		android:id="@+id/button_retry"
+		style="@style/Widget.Material3.Button.TonalButton"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:layout_marginTop="@dimen/margin_small"
+		android:visibility="gone"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintTop_toBottomOf="@id/textSecondary"
+		tools:text="@string/try_again"
+		tools:visibility="visible" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>