Yet another attempt to make webtoon reader great again

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

@@ -7,6 +7,8 @@ import android.view.View
 import androidx.core.view.isVisible
 import com.davemorrissey.labs.subscaleview.ImageSource
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.asExecutor
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.exceptions.resolve.ExceptionResolver
 import org.koitharu.kotatsu.core.model.ZoomMode
@@ -26,6 +28,8 @@ open class PageHolder(
 	View.OnClickListener {
 
 	init {
+		binding.ssiv.setExecutor(Dispatchers.Default.asExecutor())
+		binding.ssiv.setEagerLoadingEnabled(!isLowRamDevice(context))
 		binding.ssiv.setOnImageEventListener(delegate)
 		@Suppress("LeakingThis")
 		bindingInfo.buttonRetry.setOnClickListener(this)

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

@@ -3,13 +3,16 @@ package org.koitharu.kotatsu.reader.ui.pager.webtoon
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.FrameLayout
+import androidx.annotation.AttrRes
 import org.koitharu.kotatsu.R
 
 class WebtoonFrameLayout @JvmOverloads constructor(
-	context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
+	context: Context,
+	attrs: AttributeSet? = null,
+	@AttrRes defStyleAttr: Int = 0,
 ) : FrameLayout(context, attrs, defStyleAttr) {
 
-	private val target by lazy {
+	private val target by lazy(LazyThreadSafetyMode.NONE) {
 		findViewById<WebtoonImageView>(R.id.ssiv)
 	}
 

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

@@ -13,14 +13,14 @@ import org.koitharu.kotatsu.databinding.ItemPageWebtoonBinding
 import org.koitharu.kotatsu.reader.domain.PageLoader
 import org.koitharu.kotatsu.reader.ui.pager.BasePageHolder
 import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.utils.GoneOnInvisibleListener
 import org.koitharu.kotatsu.utils.ext.*
 
-
 class WebtoonHolder(
 	binding: ItemPageWebtoonBinding,
 	loader: PageLoader,
 	settings: AppSettings,
-	exceptionResolver: ExceptionResolver
+	exceptionResolver: ExceptionResolver,
 ) : BasePageHolder<ItemPageWebtoonBinding>(binding, loader, settings, exceptionResolver),
 	View.OnClickListener {
 
@@ -29,6 +29,7 @@ class WebtoonHolder(
 	init {
 		binding.ssiv.setOnImageEventListener(delegate)
 		bindingInfo.buttonRetry.setOnClickListener(this)
+		GoneOnInvisibleListener(bindingInfo.progressBar).attach()
 	}
 
 	override fun onBind(data: ReaderPage) {
@@ -61,9 +62,9 @@ class WebtoonHolder(
 
 	override fun onImageShowing(zoom: ZoomMode) {
 		with(binding.ssiv) {
-			maxScale = 2f * width / sWidth.toFloat()
 			setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CUSTOM)
 			minScale = width / sWidth.toFloat()
+			maxScale = minScale
 			scrollTo(
 				when {
 					scrollToRestore != 0 -> scrollToRestore

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

@@ -1,11 +1,15 @@
 package org.koitharu.kotatsu.reader.ui.pager.webtoon
 
-import android.app.Activity
 import android.content.Context
 import android.graphics.PointF
 import android.util.AttributeSet
+import androidx.recyclerview.widget.RecyclerView
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.asExecutor
 import org.koitharu.kotatsu.parsers.util.toIntUp
+import org.koitharu.kotatsu.utils.ext.isLowRamDevice
+import org.koitharu.kotatsu.utils.ext.parents
 
 private const val SCROLL_UNKNOWN = -1
 
@@ -15,15 +19,15 @@ class WebtoonImageView @JvmOverloads constructor(
 ) : SubsamplingScaleImageView(context, attr) {
 
 	private val ct = PointF()
-	private val displayHeight = if (context is Activity) {
-		context.window.decorView.height
-	} else {
-		context.resources.displayMetrics.heightPixels
-	}
 
 	private var scrollPos = 0
 	private var scrollRange = SCROLL_UNKNOWN
 
+	init {
+		setExecutor(Dispatchers.Default.asExecutor())
+		setEagerLoadingEnabled(!isLowRamDevice(context))
+	}
+
 	fun scrollBy(delta: Int) {
 		val maxScroll = getScrollRange()
 		if (maxScroll == 0) {
@@ -36,6 +40,7 @@ class WebtoonImageView @JvmOverloads constructor(
 	fun scrollTo(y: Int) {
 		val maxScroll = getScrollRange()
 		if (maxScroll == 0) {
+			resetScaleAndCenter()
 			return
 		}
 		scrollToInternal(y.coerceIn(0, maxScroll))
@@ -58,8 +63,11 @@ class WebtoonImageView @JvmOverloads constructor(
 
 	override fun getSuggestedMinimumHeight(): Int {
 		var desiredHeight = super.getSuggestedMinimumHeight()
-		if (sHeight == 0 && desiredHeight < displayHeight) {
-			desiredHeight = displayHeight
+		if (sHeight == 0) {
+			val parentHeight = parentHeight()
+			if (desiredHeight < parentHeight) {
+				desiredHeight = parentHeight
+			}
 		}
 		return desiredHeight
 	}
@@ -84,7 +92,7 @@ class WebtoonImageView @JvmOverloads constructor(
 			}
 		}
 		width = width.coerceAtLeast(suggestedMinimumWidth)
-		height = height.coerceIn(suggestedMinimumHeight, displayHeight)
+		height = height.coerceIn(suggestedMinimumHeight, parentHeight())
 		setMeasuredDimension(width, height)
 	}
 
@@ -101,4 +109,8 @@ class WebtoonImageView @JvmOverloads constructor(
 		val totalHeight = (sHeight * minScale).toIntUp()
 		scrollRange = (totalHeight - height).coerceAtLeast(0)
 	}
+
+	private fun parentHeight(): Int {
+		return parents.firstNotNullOfOrNull { it as? RecyclerView }?.height ?: 0
+	}
 }

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/webtoon/WebtoonLayoutManager.kt

@@ -6,6 +6,7 @@ import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import kotlin.math.sign
 
+@Suppress("unused")
 class WebtoonLayoutManager : LinearLayoutManager {
 
 	private var scrollDirection: Int = 0

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

@@ -23,7 +23,7 @@ class WebtoonReaderFragment : BaseReader<FragmentReaderWebtoonBinding>() {
 
 	override fun onInflateView(
 		inflater: LayoutInflater,
-		container: ViewGroup?
+		container: ViewGroup?,
 	) = FragmentReaderWebtoonBinding.inflate(inflater, container, false)
 
 	override fun onViewCreated(view: View, savedInstanceState: Bundle?) {

app/src/main/java/org/koitharu/kotatsu/reader/ui/thumbnails/adapter/PageThumbnailAD.kt

@@ -3,6 +3,7 @@ package org.koitharu.kotatsu.reader.ui.thumbnails.adapter
 import android.graphics.drawable.Drawable
 import coil.ImageLoader
 import coil.request.ImageRequest
+import coil.size.Scale
 import coil.size.Size
 import com.google.android.material.R as materialR
 import com.hannesdorfmann.adapterdelegates4.dsl.adapterDelegateViewBinding
@@ -24,7 +25,6 @@ fun pageThumbnailAD(
 ) = adapterDelegateViewBinding<PageThumbnail, PageThumbnail, ItemPageThumbBinding>(
 	{ inflater, parent -> ItemPageThumbBinding.inflate(inflater, parent, false) }
 ) {
-
 	var job: Job? = null
 	val gridWidth = itemView.context.resources.getDimensionPixelSize(R.dimen.preferred_grid_width)
 	val thumbSize = Size(
@@ -39,6 +39,7 @@ fun pageThumbnailAD(
 					.data(url)
 					.referer(item.page.referer)
 					.size(thumbSize)
+					.scale(Scale.FILL)
 					.allowRgb565(true)
 					.build()
 			).drawable

app/src/main/java/org/koitharu/kotatsu/utils/GoneOnInvisibleListener.kt

@@ -0,0 +1,23 @@
+package org.koitharu.kotatsu.utils
+
+import android.view.View
+import android.view.ViewTreeObserver
+
+/**
+ * ProgressIndicator become INVISIBLE instead of GONE by hide() call.
+ * It`s final so we need this workaround
+ */
+class GoneOnInvisibleListener(
+	private val view: View,
+) : ViewTreeObserver.OnGlobalLayoutListener {
+
+	override fun onGlobalLayout() {
+		if (view.visibility == View.INVISIBLE) {
+			view.visibility = View.GONE
+		}
+	}
+
+	fun attach() {
+		view.viewTreeObserver.addOnGlobalLayoutListener(this)
+	}
+}

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

@@ -1,6 +1,8 @@
 package org.koitharu.kotatsu.utils.ext
 
+import android.app.ActivityManager
 import android.content.Context
+import android.content.Context.ACTIVITY_SERVICE
 import android.content.SharedPreferences
 import android.content.pm.ResolveInfo
 import android.net.ConnectivityManager
@@ -27,6 +29,9 @@ import kotlinx.coroutines.suspendCancellableCoroutine
 val Context.connectivityManager: ConnectivityManager
 	get() = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
 
+val Context.activityManager: ActivityManager?
+	get() = getSystemService(ACTIVITY_SERVICE) as? ActivityManager
+
 suspend fun ConnectivityManager.waitForNetwork(): Network {
 	val request = NetworkRequest.Builder().build()
 	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
@@ -92,4 +97,8 @@ fun Lifecycle.postDelayed(runnable: Runnable, delay: Long) {
 		delay(delay)
 		runnable.run()
 	}
+}
+
+fun isLowRamDevice(context: Context): Boolean {
+	return context.activityManager?.isLowRamDevice ?: false
 }

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

@@ -4,6 +4,7 @@ import android.app.Activity
 import android.graphics.Rect
 import android.view.View
 import android.view.ViewGroup
+import android.view.ViewParent
 import android.view.inputmethod.InputMethodManager
 import androidx.core.view.children
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -138,4 +139,13 @@ fun <T : View> ViewGroup.findViewsByType(clazz: Class<T>): Sequence<T> {
 			}
 		}
 	}
-}
+}
+
+val View.parents: Sequence<ViewParent>
+	get() = sequence {
+		var p: ViewParent? = parent
+		while (p != null) {
+			yield(p)
+			p = p.parent
+		}
+	}