Add lifecycle for BasePageHolder

app/src/main/kotlin/org/koitharu/kotatsu/core/ui/list/lifecycle/LifecycleAwareViewHolder.kt

@@ -0,0 +1,88 @@
+package org.koitharu.kotatsu.core.ui.list.lifecycle
+
+import android.view.View
+import androidx.annotation.CallSuper
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LifecycleRegistry
+import androidx.recyclerview.widget.RecyclerView
+
+abstract class LifecycleAwareViewHolder(
+	itemView: View,
+	private val parentLifecycleOwner: LifecycleOwner,
+) : RecyclerView.ViewHolder(itemView), LifecycleOwner {
+
+	@Suppress("LeakingThis")
+	final override val lifecycle = LifecycleRegistry(this)
+	private var isCurrent = false
+
+	init {
+		parentLifecycleOwner.lifecycle.addObserver(ParentLifecycleObserver())
+		if (parentLifecycleOwner.lifecycle.currentState.isAtLeast(Lifecycle.State.CREATED)) {
+			lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
+		}
+	}
+
+	fun setIsCurrent(value: Boolean) {
+		isCurrent = value
+		dispatchResumed()
+	}
+
+	@CallSuper
+	open fun onStart() = lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_START)
+
+	@CallSuper
+	open fun onResume() = lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_RESUME)
+
+	@CallSuper
+	open fun onPause() = lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_PAUSE)
+
+	@CallSuper
+	open fun onStop() = lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_STOP)
+
+	private fun dispatchResumed() {
+		val isParentResumed = parentLifecycleOwner.lifecycle.currentState.isAtLeast(Lifecycle.State.RESUMED)
+		if (isCurrent && isParentResumed) {
+			if (!isResumed()) {
+				onResume()
+			}
+		} else {
+			if (isResumed()) {
+				onPause()
+			}
+		}
+	}
+
+	protected fun isResumed(): Boolean {
+		return lifecycle.currentState.isAtLeast(Lifecycle.State.RESUMED)
+	}
+
+	private inner class ParentLifecycleObserver : DefaultLifecycleObserver {
+
+		override fun onCreate(owner: LifecycleOwner) {
+			lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_CREATE)
+		}
+
+		override fun onStart(owner: LifecycleOwner) {
+			onStart()
+		}
+
+		override fun onResume(owner: LifecycleOwner) {
+			dispatchResumed()
+		}
+
+		override fun onPause(owner: LifecycleOwner) {
+			dispatchResumed()
+		}
+
+		override fun onStop(owner: LifecycleOwner) {
+			onStop()
+		}
+
+		override fun onDestroy(owner: LifecycleOwner) {
+			lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+			owner.lifecycle.removeObserver(this)
+		}
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/ui/list/lifecycle/PagerLifecycleDispatcher.kt

@@ -0,0 +1,19 @@
+package org.koitharu.kotatsu.core.ui.list.lifecycle
+
+import androidx.core.view.children
+import androidx.viewpager2.widget.ViewPager2
+import org.koitharu.kotatsu.core.util.ext.recyclerView
+
+class PagerLifecycleDispatcher(
+	private val pager: ViewPager2,
+) : ViewPager2.OnPageChangeCallback() {
+
+	override fun onPageSelected(position: Int) {
+		super.onPageSelected(position)
+		val rv = pager.recyclerView ?: return
+		for (child in rv.children) {
+			val wh = rv.getChildViewHolder(child) ?: continue
+			(wh as? LifecycleAwareViewHolder)?.setIsCurrent(wh.absoluteAdapterPosition == position)
+		}
+	}
+}

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

@@ -2,13 +2,15 @@ package org.koitharu.kotatsu.reader.ui.pager
 
 import android.content.Context
 import androidx.annotation.CallSuper
-import androidx.recyclerview.widget.RecyclerView
+import androidx.lifecycle.LifecycleOwner
 import androidx.viewbinding.ViewBinding
 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.databinding.LayoutPageInfoBinding
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.config.ReaderSettings
+import org.koitharu.kotatsu.reader.ui.pager.PageHolderDelegate.State
 
 abstract class BasePageHolder<B : ViewBinding>(
 	protected val binding: B,
@@ -16,7 +18,8 @@ abstract class BasePageHolder<B : ViewBinding>(
 	protected val settings: ReaderSettings,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : RecyclerView.ViewHolder(binding.root), PageHolderDelegate.Callback {
+	lifecycleOwner: LifecycleOwner,
+) : LifecycleAwareViewHolder(binding.root, lifecycleOwner), PageHolderDelegate.Callback {
 
 	@Suppress("LeakingThis")
 	protected val delegate = PageHolderDelegate(loader, settings, this, networkState, exceptionResolver)
@@ -43,6 +46,13 @@ abstract class BasePageHolder<B : ViewBinding>(
 
 	protected abstract fun onBind(data: ReaderPage)
 
+	override fun onResume() {
+		super.onResume()
+		if (delegate.state == State.ERROR && !delegate.isLoading()) {
+			boundData?.let { delegate.retry(it.toMangaPage(), isFromUser = false) }
+		}
+	}
+
 	@CallSuper
 	open fun onAttachedToWindow() {
 		delegate.onAttachedToWindow()

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

@@ -35,7 +35,8 @@ class PageHolderDelegate(
 ) : DefaultOnImageEventListener, Observer<ReaderSettings> {
 
 	private val scope = loader.loaderScope + Dispatchers.Main.immediate
-	private var state = State.EMPTY
+	var state = State.EMPTY
+		private set
 	private var job: Job? = null
 	private var file: File? = null
 	private var error: Throwable? = null
@@ -44,6 +45,8 @@ class PageHolderDelegate(
 		callback.onConfigChanged()
 	}
 
+	fun isLoading() = job?.isActive == true
+
 	fun onBind(page: MangaPage) {
 		val prevJob = job
 		job = scope.launch {
@@ -52,12 +55,15 @@ class PageHolderDelegate(
 		}
 	}
 
-	fun retry(page: MangaPage) {
+	fun retry(page: MangaPage, isFromUser: Boolean) {
 		val prevJob = job
 		job = scope.launch {
 			prevJob?.cancelAndJoin()
 			val e = error
 			if (e != null && ExceptionResolver.canResolve(e)) {
+				if (!isFromUser) {
+					return@launch
+				}
 				exceptionResolver.resolve(e)
 			}
 			doLoad(page, force = true)
@@ -85,7 +91,7 @@ class PageHolderDelegate(
 	}
 
 	fun reload() {
-		if (state == State.SHOWN ) {
+		if (state == State.SHOWN) {
 			file?.let {
 				callback.onImageReady(it.toUri())
 			}
@@ -166,7 +172,7 @@ class PageHolderDelegate(
 			callback.onError(e)
 			if (e is IOException && !networkState.value) {
 				networkState.awaitForConnection()
-				retry(data)
+				retry(data, isFromUser = false)
 			}
 		}
 	}
@@ -176,7 +182,7 @@ class PageHolderDelegate(
 		.onEach { callback.onProgressChanged((100 * it).toInt()) }
 		.launchIn(scope)
 
-	private enum class State {
+	enum class State {
 		EMPTY, LOADING, LOADED, CONVERTING, CONVERTED, SHOWING, SHOWN, ERROR
 	}
 

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

@@ -30,7 +30,7 @@ open class PageHolder(
 	settings: ReaderSettings,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BasePageHolder<ItemPageBinding>(binding, loader, settings, networkState, exceptionResolver),
+) : BasePageHolder<ItemPageBinding>(binding, loader, settings, networkState, exceptionResolver, owner),
 	View.OnClickListener,
 	ZoomControl.ZoomControlListener {
 
@@ -129,7 +129,7 @@ open class PageHolder(
 
 	final override fun onClick(v: View) {
 		when (v.id) {
-			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return)
+			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return, isFromUser = true)
 			R.id.button_error_details -> delegate.showErrorDetails(boundData?.url)
 		}
 	}

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

@@ -17,6 +17,7 @@ import kotlinx.coroutines.yield
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.prefs.ReaderAnimation
+import org.koitharu.kotatsu.core.ui.list.lifecycle.PagerLifecycleDispatcher
 import org.koitharu.kotatsu.core.util.ext.doOnPageChanged
 import org.koitharu.kotatsu.core.util.ext.findCurrentViewHolder
 import org.koitharu.kotatsu.core.util.ext.observe
@@ -61,6 +62,7 @@ class PagerReaderFragment : BaseReaderFragment<FragmentReaderStandardBinding>(),
 				recyclerView?.defaultFocusHighlightEnabled = false
 			}
 			PagerEventSupplier(this).attach()
+			registerOnPageChangeCallback(PagerLifecycleDispatcher(this))
 		}
 
 		viewModel.pageAnimation.observe(viewLifecycleOwner) {

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

@@ -25,7 +25,7 @@ class WebtoonHolder(
 	settings: ReaderSettings,
 	networkState: NetworkState,
 	exceptionResolver: ExceptionResolver,
-) : BasePageHolder<ItemPageWebtoonBinding>(binding, loader, settings, networkState, exceptionResolver),
+) : BasePageHolder<ItemPageWebtoonBinding>(binding, loader, settings, networkState, exceptionResolver, owner),
 	View.OnClickListener {
 
 	private var scrollToRestore = 0
@@ -107,7 +107,7 @@ class WebtoonHolder(
 
 	override fun onClick(v: View) {
 		when (v.id) {
-			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return)
+			R.id.button_retry -> delegate.retry(boundData?.toMangaPage() ?: return, isFromUser = true)
 			R.id.button_error_details -> delegate.showErrorDetails(boundData?.url)
 		}
 	}