Reader fixes

app/src/main/kotlin/org/koitharu/kotatsu/filter/ui/tags/TagsCatalogSheet.kt

@@ -58,7 +58,7 @@ class TagsCatalogSheet : BaseAdaptiveSheet<SheetTagsBinding>(), OnListItemClickL
 
 	override fun onItemClick(item: TagCatalogItem, view: View) {
 		val filter = (requireActivity() as FilterOwner).filter
-		filter.setTag(item.tag, true)
+		filter.setTag(item.tag, !item.isChecked)
 	}
 
 	override fun onClick(v: View) {

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

@@ -4,6 +4,7 @@ import android.content.Context
 import androidx.annotation.CallSuper
 import androidx.lifecycle.LifecycleOwner
 import androidx.viewbinding.ViewBinding
+import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.os.NetworkState
 import org.koitharu.kotatsu.core.ui.list.lifecycle.LifecycleAwareViewHolder
@@ -69,9 +70,11 @@ abstract class BasePageHolder<B : ViewBinding>(
 		delegate.onRecycle()
 	}
 
-	protected fun getBackgroundDownsampling() = when {
-		!settings.isReaderOptimizationEnabled -> 1
-		context.isLowRamDevice() -> 8
-		else -> 4
+	protected fun SubsamplingScaleImageView.applyDownsampling(isForeground: Boolean) {
+		downsampling = when {
+			isForeground || !settings.isReaderOptimizationEnabled -> 1
+			context.isLowRamDevice() -> 8
+			else -> 4
+		}
 	}
 }

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

@@ -47,12 +47,12 @@ open class PageHolder(
 
 	override fun onResume() {
 		super.onResume()
-		binding.ssiv.downsampling = 1
+		binding.ssiv.applyDownsampling(isForeground = true)
 	}
 
 	override fun onPause() {
 		super.onPause()
-		binding.ssiv.downsampling = getBackgroundDownsampling()
+		binding.ssiv.applyDownsampling(isForeground = false)
 	}
 
 	override fun onConfigChanged() {
@@ -60,7 +60,7 @@ open class PageHolder(
 		if (settings.applyBitmapConfig(binding.ssiv)) {
 			delegate.reload()
 		}
-		binding.ssiv.downsampling = if (isResumed()) 1 else getBackgroundDownsampling()
+		binding.ssiv.applyDownsampling(isResumed())
 	}
 
 	@SuppressLint("SetTextI18n")

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

@@ -5,7 +5,6 @@ import android.view.View
 import androidx.core.view.isVisible
 import androidx.lifecycle.LifecycleOwner
 import com.davemorrissey.labs.subscaleview.ImageSource
-import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.os.NetworkState
@@ -38,22 +37,22 @@ class WebtoonHolder(
 		bindingInfo.buttonErrorDetails.setOnClickListener(this)
 	}
 
+	override fun onResume() {
+		super.onResume()
+		binding.ssiv.applyDownsampling(isForeground = true)
+	}
+
+	override fun onPause() {
+		super.onPause()
+		binding.ssiv.applyDownsampling(isForeground = false)
+	}
+
 	override fun onConfigChanged() {
 		super.onConfigChanged()
 		if (settings.applyBitmapConfig(binding.ssiv)) {
 			delegate.reload()
 		}
-		// FIXME binding.ssiv.downsampling = if (isResumed()) 1 else getBackgroundDownsampling()
-	}
-
-	override fun onResume() {
-		super.onResume()
-		binding.ssiv.downsampling = 1
-	}
-
-	override fun onPause() {
-		super.onPause()
-		// FIXME binding.ssiv.downsampling = getBackgroundDownsampling()
+		binding.ssiv.applyDownsampling(isResumed())
 	}
 
 	override fun onBind(data: ReaderPage) {
@@ -97,9 +96,6 @@ class WebtoonHolder(
 	override fun onImageShowing(settings: ReaderSettings) {
 		binding.ssiv.colorFilter = settings.colorFilter?.toColorFilter()
 		with(binding.ssiv) {
-			minimumScaleType = SubsamplingScaleImageView.SCALE_TYPE_CUSTOM
-			minScale = width / sWidth.toFloat()
-			maxScale = minScale
 			scrollTo(
 				when {
 					scrollToRestore != 0 -> scrollToRestore

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

@@ -88,6 +88,18 @@ class WebtoonImageView @JvmOverloads constructor(
 		setMeasuredDimension(width, height)
 	}
 
+	override fun onDownsamplingChanged() {
+		super.onDownsamplingChanged()
+		adjustScale()
+		computeScrollRange()
+		ancestors.firstNotNullOfOrNull { it as? WebtoonRecyclerView }?.updateChildrenScroll()
+	}
+
+	override fun onReady() {
+		super.onReady()
+		adjustScale()
+	}
+
 	override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
 		super.onSizeChanged(w, h, oldw, oldh)
 		if (oldh == h || oldw == 0 || oldh == 0 || scrollRange == SCROLL_UNKNOWN) return
@@ -101,6 +113,8 @@ class WebtoonImageView @JvmOverloads constructor(
 	}
 
 	private fun scrollToInternal(pos: Int) {
+		minScale = width / sWidth.toFloat()
+		maxScale = minScale
 		scrollPos = pos
 		ct.set(sWidth / 2f, (height / 2f + pos.toFloat()) / minScale)
 		setScaleAndCenter(minScale, ct)
@@ -114,6 +128,12 @@ class WebtoonImageView @JvmOverloads constructor(
 		scrollRange = (totalHeight - height).coerceAtLeast(0)
 	}
 
+	private fun adjustScale() {
+		minScale = width / sWidth.toFloat()
+		maxScale = minScale
+		minimumScaleType = SCALE_TYPE_CUSTOM
+	}
+
 	private fun parentHeight(): Int {
 		return ancestors.firstNotNullOfOrNull { it as? RecyclerView }?.height ?: 0
 	}

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

@@ -3,9 +3,11 @@ package org.koitharu.kotatsu.reader.ui.pager.webtoon
 import android.content.Context
 import android.util.AttributeSet
 import android.view.View
+import android.widget.Toast
 import androidx.core.view.ViewCompat.TYPE_TOUCH
 import androidx.core.view.forEach
 import androidx.recyclerview.widget.RecyclerView
+import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.core.util.ext.findCenterViewPosition
 import java.util.LinkedList
 import java.util.WeakHashMap
@@ -104,12 +106,16 @@ class WebtoonRecyclerView @JvmOverloads constructor(
 	}
 
 	private fun notifyScrollChanged(dy: Int) {
+		updateChildrenScroll()
 		val listeners = onPageScrollListeners
 		if (listeners.isNullOrEmpty()) {
 			return
 		}
 		val centerPosition = findCenterViewPosition()
 		listeners.forEach { it.dispatchScroll(this, dy, centerPosition) }
+		if (BuildConfig.DEBUG) {
+			validateLayout()
+		}
 	}
 
 	fun relayoutChildren() {
@@ -121,6 +127,32 @@ class WebtoonRecyclerView @JvmOverloads constructor(
 		}
 	}
 
+	fun updateChildrenScroll() {
+		forEach { child ->
+			val ssiv = (child as WebtoonFrameLayout).target
+			when {
+				child.top < 0 -> ssiv.scrollTo(ssiv.getScrollRange())
+				child.top > 0 -> ssiv.scrollTo(0)
+				else -> ssiv.scrollBy(0)
+			}
+		}
+	}
+
+	private fun validateLayout() {
+		forEach { child ->
+			val ssiv = (child as WebtoonFrameLayout).target
+			val scroll = ssiv.getScroll()
+			val assertion = when {
+				child.top < 0 -> scroll == ssiv.getScrollRange()
+				child.top > 0 -> scroll == 0
+				else -> true
+			}
+			if (!assertion) {
+				Toast.makeText(context, "Scroll = $scroll for view with top: ${child.top}", Toast.LENGTH_SHORT).show()
+			}
+		}
+	}
+
 	abstract class OnPageScrollListener {
 
 		private var lastPosition = NO_POSITION