Store and restore ThemeChooserPreference state

app/src/main/java/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -17,6 +17,7 @@ import org.koitharu.kotatsu.parsers.model.MangaSource
 import org.koitharu.kotatsu.parsers.model.SortOrder
 import org.koitharu.kotatsu.shelf.domain.ShelfSection
 import org.koitharu.kotatsu.utils.ext.connectivityManager
+import org.koitharu.kotatsu.utils.ext.filterToSet
 import org.koitharu.kotatsu.utils.ext.getEnumValue
 import org.koitharu.kotatsu.utils.ext.observe
 import org.koitharu.kotatsu.utils.ext.putEnumValue
@@ -183,7 +184,9 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		}
 
 	var hiddenSources: Set<String>
-		get() = prefs.getStringSet(KEY_SOURCES_HIDDEN, null) ?: emptySet()
+		get() = prefs.getStringSet(KEY_SOURCES_HIDDEN, null)?.filterToSet { name ->
+			remoteSources.any { it.name == name }
+		}.orEmpty()
 		set(value) = prefs.edit { putStringSet(KEY_SOURCES_HIDDEN, value) }
 
 	val isSourcesSelected: Boolean

app/src/main/java/org/koitharu/kotatsu/settings/utils/ThemeChooserPreference.kt

@@ -3,12 +3,17 @@ package org.koitharu.kotatsu.settings.utils
 import android.content.Context
 import android.content.res.TypedArray
 import android.os.Build
+import android.os.Parcel
+import android.os.Parcelable
 import android.util.AttributeSet
 import android.view.LayoutInflater
 import android.view.View
+import android.view.ViewTreeObserver
+import android.widget.HorizontalScrollView
 import android.widget.LinearLayout
 import androidx.appcompat.view.ContextThemeWrapper
 import androidx.core.view.isVisible
+import androidx.customview.view.AbsSavedState
 import androidx.preference.Preference
 import androidx.preference.PreferenceViewHolder
 import org.koitharu.kotatsu.R
@@ -24,10 +29,12 @@ class ThemeChooserPreference @JvmOverloads constructor(
 
 	private val entries = ColorScheme.getAvailableList()
 	private var currentValue: ColorScheme = ColorScheme.default
+	private val lastScrollPosition = intArrayOf(-1)
 	private val itemClickListener = View.OnClickListener {
 		val tag = it.tag as? ColorScheme ?: return@OnClickListener
 		setValueInternal(tag.name, true)
 	}
+	private var scrollPersistListener: ScrollPersistListener? = null
 
 	var value: String
 		get() = currentValue.name
@@ -36,7 +43,9 @@ class ThemeChooserPreference @JvmOverloads constructor(
 	override fun onBindViewHolder(holder: PreferenceViewHolder) {
 		super.onBindViewHolder(holder)
 		val layout = holder.findViewById(R.id.linear) as? LinearLayout ?: return
+		val scrollView = holder.findViewById(R.id.scrollView) as? HorizontalScrollView ?: return
 		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+			scrollView.suppressLayout(true)
 			layout.suppressLayout(true)
 		}
 		layout.removeAllViews()
@@ -52,8 +61,19 @@ class ThemeChooserPreference @JvmOverloads constructor(
 			item.card.setOnClickListener(itemClickListener)
 			layout.addView(item.root)
 		}
+		if (lastScrollPosition[0] >= 0) {
+			val scroller = Scroller(scrollView, lastScrollPosition[0])
+			scroller.run()
+			scrollView.post(scroller)
+		}
+		scrollView.viewTreeObserver.run {
+			scrollPersistListener?.let { removeOnScrollChangedListener(it) }
+			scrollPersistListener = ScrollPersistListener(scrollView, lastScrollPosition)
+			addOnScrollChangedListener(scrollPersistListener)
+		}
 		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
 			layout.suppressLayout(false)
+			scrollView.suppressLayout(false)
 		}
 	}
 
@@ -71,6 +91,24 @@ class ThemeChooserPreference @JvmOverloads constructor(
 		return a.getInt(index, 0)
 	}
 
+	override fun onSaveInstanceState(): Parcelable? {
+		val superState = super.onSaveInstanceState() ?: return null
+		return SavedState(
+			superState = superState,
+			scrollPosition = lastScrollPosition[0],
+		)
+	}
+
+	override fun onRestoreInstanceState(state: Parcelable?) {
+		if (state !is SavedState) {
+			super.onRestoreInstanceState(state)
+			return
+		}
+		super.onRestoreInstanceState(state.superState)
+		lastScrollPosition[0] = state.scrollPosition
+		// notifyChanged()
+	}
+
 	private fun setValueInternal(enumName: String, notifyChanged: Boolean) {
 		val newValue = ColorScheme.safeValueOf(enumName) ?: return
 		if (newValue != currentValue) {
@@ -81,4 +119,55 @@ class ThemeChooserPreference @JvmOverloads constructor(
 			}
 		}
 	}
+
+	private class SavedState : AbsSavedState {
+
+		val scrollPosition: Int
+
+		constructor(
+			superState: Parcelable,
+			scrollPosition: Int
+		) : super(superState) {
+			this.scrollPosition = scrollPosition
+		}
+
+		constructor(source: Parcel, classLoader: ClassLoader?) : super(source, classLoader) {
+			scrollPosition = source.readInt()
+		}
+
+		override fun writeToParcel(out: Parcel, flags: Int) {
+			super.writeToParcel(out, flags)
+			out.writeInt(scrollPosition)
+		}
+
+		companion object {
+			@Suppress("unused")
+			@JvmField
+			val CREATOR: Parcelable.Creator<SavedState> = object : Parcelable.Creator<SavedState> {
+				override fun createFromParcel(`in`: Parcel) = SavedState(`in`, SavedState::class.java.classLoader)
+
+				override fun newArray(size: Int): Array<SavedState?> = arrayOfNulls(size)
+			}
+		}
+	}
+
+	private class ScrollPersistListener(
+		private val scrollView: HorizontalScrollView,
+		private val lastScrollPosition: IntArray,
+	) : ViewTreeObserver.OnScrollChangedListener {
+
+		override fun onScrollChanged() {
+			lastScrollPosition[0] = scrollView.scrollX
+		}
+	}
+
+	private class Scroller(
+		private val scrollView: HorizontalScrollView,
+		private val position: Int,
+	) : Runnable {
+
+		override fun run() {
+			scrollView.scrollTo(position, 0)
+		}
+	}
 }

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

@@ -1,7 +1,7 @@
 package org.koitharu.kotatsu.utils.ext
 
 import androidx.collection.ArraySet
-import java.util.*
+import java.util.Collections
 
 fun <T> MutableList<T>.move(sourceIndex: Int, targetIndex: Int) {
 	if (sourceIndex <= targetIndex) {
@@ -11,14 +11,12 @@ fun <T> MutableList<T>.move(sourceIndex: Int, targetIndex: Int) {
 	}
 }
 
-@Suppress("FunctionName")
 inline fun <T> MutableSet(size: Int, init: (index: Int) -> T): MutableSet<T> {
 	val set = ArraySet<T>(size)
 	repeat(size) { index -> set.add(init(index)) }
 	return set
 }
 
-@Suppress("FunctionName")
 inline fun <T> Set(size: Int, init: (index: Int) -> T): Set<T> = when (size) {
 	0 -> emptySet()
 	1 -> Collections.singleton(init(0))
@@ -39,3 +37,7 @@ fun <K, V> Map<K, V>.findKeyByValue(value: V): K? {
 	}
 	return null
 }
+
+inline fun <T> Collection<T>.filterToSet(predicate: (T) -> Boolean): Set<T> {
+	return filterTo(ArraySet(size), predicate)
+}

app/src/main/res/layout/preference_theme.xml

@@ -55,6 +55,7 @@
 		</LinearLayout>
 
 		<HorizontalScrollView
+			android:id="@+id/scrollView"
 			android:layout_width="match_parent"
 			android:layout_height="wrap_content"
 			android:layout_marginTop="2dp"