Fix webtoon scrolling

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

@@ -11,10 +11,11 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.model.MangaPage
-import org.koitharu.kotatsu.core.model.MangaState
 import org.koitharu.kotatsu.domain.MangaProviderFactory
 import org.koitharu.kotatsu.ui.common.BaseFragment
-import org.koitharu.kotatsu.ui.reader.*
+import org.koitharu.kotatsu.ui.reader.PageLoader
+import org.koitharu.kotatsu.ui.reader.ReaderListener
+import org.koitharu.kotatsu.ui.reader.ReaderState
 
 abstract class AbstractReader(contentLayoutId: Int) : BaseFragment(contentLayoutId),
 	OnBoundsScrollListener {
@@ -23,7 +24,7 @@ abstract class AbstractReader(contentLayoutId: Int) : BaseFragment(contentLayout
 	protected lateinit var loader: PageLoader
 		private set
 	private lateinit var pages: GroupedList<Long, MangaPage>
-	protected var adapter: BaseReaderAdapter<*>? = null
+	protected var adapter: BaseReaderAdapter? = null
 		private set
 
 	val hasItems: Boolean
@@ -218,7 +219,7 @@ abstract class AbstractReader(contentLayoutId: Int) : BaseFragment(contentLayout
 
 	protected abstract fun setCurrentItem(position: Int, isSmooth: Boolean)
 
-	protected abstract fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter<*>
+	protected abstract fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter
 
 	protected companion object {
 

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

@@ -5,17 +5,17 @@ import androidx.recyclerview.widget.RecyclerView
 import org.koitharu.kotatsu.core.model.MangaPage
 import org.koitharu.kotatsu.ui.common.list.BaseViewHolder
 
-abstract class BaseReaderAdapter<E>(private val pages: GroupedList<Long, MangaPage>) :
+abstract class BaseReaderAdapter(private val pages: GroupedList<Long, MangaPage>) :
-	RecyclerView.Adapter<BaseViewHolder<MangaPage, E>>() {
+	RecyclerView.Adapter<BaseViewHolder<MangaPage, Unit>>() {
 
 	init {
 		@Suppress("LeakingThis")
 		setHasStableIds(true)
 	}
 
-	override fun onBindViewHolder(holder: BaseViewHolder<MangaPage, E>, position: Int) {
+	override fun onBindViewHolder(holder: BaseViewHolder<MangaPage, Unit>, position: Int) {
 		val item = pages[position]
-		holder.bind(item, getExtra(item, position))
+		holder.bind(item, Unit)
 	}
 
 	fun getItem(position: Int) = pages[position]
@@ -40,13 +40,11 @@ abstract class BaseReaderAdapter<E>(private val pages: GroupedList<Long, MangaPa
 
 	final override fun getItemCount() = pages.size
 
-	final override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<MangaPage, E> {
+	final override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<MangaPage, Unit> {
 		return onCreateViewHolder(parent).also(this::onViewHolderCreated)
 	}
 
-	protected abstract fun getExtra(item: MangaPage, position: Int): E
+	protected open fun onViewHolderCreated(holder: BaseViewHolder<MangaPage, Unit>) = Unit
 
-	protected open fun onViewHolderCreated(holder: BaseViewHolder<MangaPage, E>) = Unit
+	protected abstract fun onCreateViewHolder(parent: ViewGroup): BaseViewHolder<MangaPage, Unit>
-
-	protected abstract fun onCreateViewHolder(parent: ViewGroup): BaseViewHolder<MangaPage, E>
 }

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

@@ -30,7 +30,7 @@ class PagerReaderFragment() : AbstractReader(R.layout.fragment_reader_standard)
 		super.onDestroyView()
 	}
 
-	override fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter<*> {
+	override fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter {
 		return PagesAdapter(dataSet, loader)
 	}
 

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

@@ -9,9 +9,7 @@ import org.koitharu.kotatsu.ui.reader.PageLoader
 class PagesAdapter(
 	pages: GroupedList<Long, MangaPage>,
 	private val loader: PageLoader
-) : BaseReaderAdapter<Unit>(pages) {
+) : BaseReaderAdapter(pages) {
 
 	override fun onCreateViewHolder(parent: ViewGroup) = PageHolder(parent, loader)
-
-	override fun getExtra(item: MangaPage, position: Int) = Unit
 }

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

@@ -1,20 +1,15 @@
 package org.koitharu.kotatsu.ui.reader.wetoon
 
-import android.view.Gravity
 import android.view.ViewGroup
 import org.koitharu.kotatsu.core.model.MangaPage
+import org.koitharu.kotatsu.ui.reader.PageLoader
 import org.koitharu.kotatsu.ui.reader.base.BaseReaderAdapter
 import org.koitharu.kotatsu.ui.reader.base.GroupedList
-import org.koitharu.kotatsu.ui.reader.PageLoader
 
 class WebtoonAdapter(
 	pages: GroupedList<Long, MangaPage>,
 	private val loader: PageLoader
-) : BaseReaderAdapter<Int>(pages) {
+) : BaseReaderAdapter(pages) {
-
-	var pageGravity: Int = Gravity.TOP
 
 	override fun onCreateViewHolder(parent: ViewGroup) = WebtoonHolder(parent, loader)
-
-	override fun getExtra(item: MangaPage, position: Int) = pageGravity
 }

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

@@ -19,9 +19,6 @@ class WebtoonFrameLayout @JvmOverloads constructor(
 	}
 
 	fun dispatchVerticalScroll(dy: Int): Int {
-		if (!target.isImageLoaded) {
-			return dy //consume all scrolling
-		}
 		target.getPanRemaining(pan)
 		val c = target.center ?: return 0
 		val s = target.scale

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

@@ -1,7 +1,6 @@
 package org.koitharu.kotatsu.ui.reader.wetoon
 
 import android.graphics.PointF
-import android.view.Gravity
 import android.view.ViewGroup
 import androidx.core.net.toUri
 import androidx.core.view.isVisible
@@ -17,11 +16,10 @@ import org.koitharu.kotatsu.utils.ext.getDisplayMessage
 
 
 class WebtoonHolder(parent: ViewGroup, private val loader: PageLoader) :
-	BaseViewHolder<MangaPage, Int>(parent, R.layout.item_page_webtoon),
+	BaseViewHolder<MangaPage, Unit>(parent, R.layout.item_page_webtoon),
 	SubsamplingScaleImageView.OnImageEventListener, CoroutineScope by loader {
 
 	private var job: Job? = null
-	private var yFactor = 0f
 
 	init {
 		ssiv.setOnImageEventListener(this)
@@ -30,12 +28,7 @@ class WebtoonHolder(parent: ViewGroup, private val loader: PageLoader) :
 		}
 	}
 
-	override fun onBind(data: MangaPage, extra: Int) {
+	override fun onBind(data: MangaPage, extra: Unit) {
-		yFactor = when(extra) {
-			Gravity.TOP -> 0f
-			Gravity.BOTTOM -> 1f
-			else -> 0.5f
-		}
 		doLoad(data, force = false)
 	}
 
@@ -63,7 +56,14 @@ class WebtoonHolder(parent: ViewGroup, private val loader: PageLoader) :
 		ssiv.minScale = ssiv.width / ssiv.sWidth.toFloat()
 		ssiv.setScaleAndCenter(
 			ssiv.minScale,
-			PointF(ssiv.sWidth / 2f, ssiv.sHeight * yFactor)
+			PointF(
+				ssiv.sWidth / 2f,
+				if (itemView.top < 0) {
+					ssiv.sHeight.toFloat()
+				} else {
+					0f
+				}
+			)
 		)
 	}
 

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

@@ -31,7 +31,7 @@ class WebtoonReaderFragment : AbstractReader(R.layout.fragment_reader_webtoon) {
 		recyclerView.doOnCurrentItemChanged(::notifyPageChanged)
 	}
 
-	override fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter<*> {
+	override fun onCreateAdapter(dataSet: GroupedList<Long, MangaPage>): BaseReaderAdapter {
 		return WebtoonAdapter(dataSet, loader)
 	}
 

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

@@ -12,8 +12,6 @@ class WebtoonRecyclerView @JvmOverloads constructor(
 	context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
 ) : RecyclerView(context, attrs, defStyleAttr) {
 
-	private var lastScrollDirection = 0
-
 	override fun dispatchNestedPreScroll(
 		dx: Int,
 		dy: Int,
@@ -49,18 +47,4 @@ class WebtoonRecyclerView @JvmOverloads constructor(
 		scrollY -= (child as WebtoonFrameLayout).dispatchVerticalScroll(scrollY)
 		return dy - scrollY
 	}
-
-	override fun onScrolled(dx: Int, dy: Int) {
-		val direction = dy.sign
-		if (direction != lastScrollDirection) {
-			(adapter as? WebtoonAdapter)?.let {
-				it.pageGravity = if (dy < 0) {
-					Gravity.BOTTOM
-				} else {
-					Gravity.TOP
-				}
-				lastScrollDirection = direction
-			}
-		}
-	}
 }