Fix smooth page switching

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

@@ -12,7 +12,9 @@ import org.koitharu.kotatsu.reader.ui.ReaderState
 import org.koitharu.kotatsu.reader.ui.pager.BaseReader
 import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.reader.ui.pager.standard.PagerReaderFragment
 import org.koitharu.kotatsu.utils.ext.*
+import kotlin.math.absoluteValue
 
 class ReversedReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
 
@@ -58,7 +60,10 @@ class ReversedReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
 	}
 
 	override fun switchPageTo(position: Int, smooth: Boolean) {
-		binding.pager.setCurrentItem(reversed(position), smooth)
+		binding.pager.setCurrentItem(
+			reversed(position),
+			smooth && (binding.pager.currentItem - position).absoluteValue < PagerReaderFragment.SMOOTH_SCROLL_LIMIT
+		)
 	}
 
 	override fun onPagesChanged(pages: List<ReaderPage>, pendingState: ReaderState?) {

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

@@ -13,6 +13,7 @@ import org.koitharu.kotatsu.reader.ui.pager.BaseReader
 import org.koitharu.kotatsu.reader.ui.pager.BaseReaderAdapter
 import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 import org.koitharu.kotatsu.utils.ext.*
+import kotlin.math.absoluteValue
 
 class PagerReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
 
@@ -78,7 +79,10 @@ class PagerReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
 	}
 
 	override fun switchPageTo(position: Int, smooth: Boolean) {
-		binding.pager.setCurrentItem(position, smooth)
+		binding.pager.setCurrentItem(
+			position,
+			smooth && (binding.pager.currentItem - position).absoluteValue < SMOOTH_SCROLL_LIMIT
+		)
 	}
 
 	override fun getCurrentState(): ReaderState? = bindingOrNull()?.run {
@@ -94,4 +98,9 @@ class PagerReaderFragment : BaseReader<FragmentReaderStandardBinding>() {
 	private fun notifyPageChanged(page: Int) {
 		viewModel.onCurrentPageChanged(page)
 	}
+
+	companion object {
+
+		const val SMOOTH_SCROLL_LIMIT = 3
+	}
 }

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

@@ -88,10 +88,6 @@ class WebtoonReaderFragment : BaseReader<FragmentReaderWebtoonBinding>() {
 	}
 
 	override fun switchPageTo(position: Int, smooth: Boolean) {
-		if (smooth) {
+		binding.recyclerView.firstItem = position
-			binding.recyclerView.smoothScrollToPosition(position)
-		} else {
-			binding.recyclerView.firstItem = position
-		}
 	}
 }