Small fix webtoon reader

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

@@ -15,6 +15,7 @@ class MangaGridHolder(parent: ViewGroup) : BaseViewHolder<Manga, MangaHistory?>(
 
 	override fun onBind(data: Manga, extra: MangaHistory?) {
 		coverRequest?.dispose()
+		imageView_cover.setImageDrawable(null)
 		textView_title.text = data.title
 		coverRequest = imageView_cover.load(data.coverUrl) {
 			placeholder(R.drawable.ic_placeholder)

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

@@ -3,7 +3,6 @@ package org.koitharu.kotatsu.ui.reader.wetoon
 import android.os.Bundle
 import android.view.View
 import android.view.animation.AccelerateDecelerateInterpolator
-import androidx.recyclerview.widget.LinearLayoutManager
 import kotlinx.android.synthetic.main.fragment_reader_webtoon.*
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.model.MangaPage
@@ -12,7 +11,7 @@ import org.koitharu.kotatsu.ui.reader.base.AbstractReader
 import org.koitharu.kotatsu.ui.reader.base.BaseReaderAdapter
 import org.koitharu.kotatsu.ui.reader.base.GroupedList
 import org.koitharu.kotatsu.utils.ext.doOnCurrentItemChanged
-import org.koitharu.kotatsu.utils.ext.findMiddleVisibleItemPosition
+import org.koitharu.kotatsu.utils.ext.findCenterViewPosition
 import org.koitharu.kotatsu.utils.ext.firstItem
 import org.koitharu.kotatsu.utils.ext.withArgs
 
@@ -43,7 +42,7 @@ class WebtoonReaderFragment : AbstractReader(R.layout.fragment_reader_webtoon) {
 		get() = adapter?.itemCount ?: 0
 
 	override fun getCurrentItem(): Int {
-		return (recyclerView.layoutManager as LinearLayoutManager).findMiddleVisibleItemPosition()
+		return recyclerView.findCenterViewPosition()
 	}
 
 	override fun setCurrentItem(position: Int, isSmooth: Boolean) {

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

@@ -182,9 +182,8 @@ fun RecyclerView.doOnCurrentItemChanged(callback: (Int) -> Unit) {
 
 		override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
 			super.onScrolled(recyclerView, dx, dy)
-			val item = (recyclerView.layoutManager as? LinearLayoutManager)
-				?.findMiddleVisibleItemPosition()
-			if (item != null && item != RecyclerView.NO_POSITION && item != lastItem) {
+			val item = recyclerView.findCenterViewPosition()
+			if (item != RecyclerView.NO_POSITION && item != lastItem) {
 				lastItem = item
 				callback(item)
 			}
@@ -222,6 +221,14 @@ fun ViewPager2.callOnPageChaneListeners() {
 	}
 }
 
+@Deprecated("")
 fun LinearLayoutManager.findMiddleVisibleItemPosition(): Int {
 	return ((findFirstVisibleItemPosition() + findLastVisibleItemPosition()) / 2.0).roundToInt()
 }
+
+fun RecyclerView.findCenterViewPosition(): Int {
+	val centerX = width / 2f
+	val centerY = height / 2f
+	val view = findChildViewUnder(centerX, centerY) ?: return RecyclerView.NO_POSITION
+	return getChildAdapterPosition(view)
+}