Yellow color filter in reader

app/src/main/kotlin/org/koitharu/kotatsu/core/db/MangaDatabase.kt

@@ -42,6 +42,7 @@ import org.koitharu.kotatsu.core.db.migrations.Migration23To24
 import org.koitharu.kotatsu.core.db.migrations.Migration24To23
 import org.koitharu.kotatsu.core.db.migrations.Migration24To25
 import org.koitharu.kotatsu.core.db.migrations.Migration25To26
+import org.koitharu.kotatsu.core.db.migrations.Migration26To27
 import org.koitharu.kotatsu.core.db.migrations.Migration2To3
 import org.koitharu.kotatsu.core.db.migrations.Migration3To4
 import org.koitharu.kotatsu.core.db.migrations.Migration4To5
@@ -69,7 +70,7 @@ import org.koitharu.kotatsu.tracker.data.TrackEntity
 import org.koitharu.kotatsu.tracker.data.TrackLogEntity
 import org.koitharu.kotatsu.tracker.data.TracksDao
 
-const val DATABASE_VERSION = 26
+const val DATABASE_VERSION = 27
 
 @Database(
 	entities = [
@@ -140,6 +141,7 @@ fun getDatabaseMigrations(context: Context): Array<Migration> = arrayOf(
 	Migration24To23(),
 	Migration24To25(),
 	Migration25To26(),
+	Migration26To27(),
 )
 
 fun MangaDatabase(context: Context): MangaDatabase = Room

app/src/main/kotlin/org/koitharu/kotatsu/core/db/entity/MangaPrefsEntity.kt

@@ -26,6 +26,7 @@ data class MangaPrefsEntity(
 	@ColumnInfo(name = "cf_contrast") val cfContrast: Float,
 	@ColumnInfo(name = "cf_invert") val cfInvert: Boolean,
 	@ColumnInfo(name = "cf_grayscale") val cfGrayscale: Boolean,
+	@ColumnInfo(name = "cf_book") val cfBookEffect: Boolean,
 	@ColumnInfo(name = "title_override") val titleOverride: String?,
 	@ColumnInfo(name = "cover_override") val coverUrlOverride: String?,
 	@ColumnInfo(name = "content_rating_override") val contentRatingOverride: String?,

app/src/main/kotlin/org/koitharu/kotatsu/core/db/migrations/Migration26To27.kt

@@ -0,0 +1,11 @@
+package org.koitharu.kotatsu.core.db.migrations
+
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+
+class Migration26To27 : Migration(26, 27) {
+
+	override fun migrate(db: SupportSQLiteDatabase) {
+		db.execSQL("ALTER TABLE preferences ADD COLUMN cf_book INTEGER NOT NULL DEFAULT 0")
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/parser/MangaDataRepository.kt

@@ -197,8 +197,14 @@ class MangaDataRepository @Inject constructor(
 	}
 
 	private fun MangaPrefsEntity.getColorFilterOrNull(): ReaderColorFilter? {
-		return if (cfBrightness != 0f || cfContrast != 0f || cfInvert || cfGrayscale) {
+		return if (cfBrightness != 0f || cfContrast != 0f || cfInvert || cfGrayscale || cfBookEffect) {
-			ReaderColorFilter(cfBrightness, cfContrast, cfInvert, cfGrayscale)
+			ReaderColorFilter(
+				brightness = cfBrightness,
+				contrast = cfContrast,
+				isInverted = cfInvert,
+				isGrayscale = cfGrayscale,
+				isBookBackground = cfBookEffect
+			)
 		} else {
 			null
 		}
@@ -219,10 +225,11 @@ class MangaDataRepository @Inject constructor(
 	private fun newEntity(mangaId: Long) = MangaPrefsEntity(
 		mangaId = mangaId,
 		mode = -1,
-		cfBrightness = 0f,
+		cfBrightness = ReaderColorFilter.EMPTY.brightness,
-		cfContrast = 0f,
+		cfContrast = ReaderColorFilter.EMPTY.contrast,
-		cfInvert = false,
+		cfInvert = ReaderColorFilter.EMPTY.isInverted,
-		cfGrayscale = false,
+		cfGrayscale = ReaderColorFilter.EMPTY.isGrayscale,
+		cfBookEffect = ReaderColorFilter.EMPTY.isBookBackground,
 		titleOverride = null,
 		coverUrlOverride = null,
 		contentRatingOverride = null,

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

@@ -401,19 +401,29 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 
 	var readerColorFilter: ReaderColorFilter?
 		get() = runCatching {
-			val brightness = prefs.getFloat(KEY_CF_BRIGHTNESS, ReaderColorFilter.EMPTY.brightness)
+			ReaderColorFilter(
-			val contrast = prefs.getFloat(KEY_CF_CONTRAST, ReaderColorFilter.EMPTY.contrast)
+				brightness = prefs.getFloat(KEY_CF_BRIGHTNESS, ReaderColorFilter.EMPTY.brightness),
-			val inverted = prefs.getBoolean(KEY_CF_INVERTED, ReaderColorFilter.EMPTY.isInverted)
+				contrast = prefs.getFloat(KEY_CF_CONTRAST, ReaderColorFilter.EMPTY.contrast),
-			val grayscale = prefs.getBoolean(KEY_CF_GRAYSCALE, ReaderColorFilter.EMPTY.isGrayscale)
+				isInverted = prefs.getBoolean(KEY_CF_INVERTED, ReaderColorFilter.EMPTY.isInverted),
-			ReaderColorFilter(brightness, contrast, inverted, grayscale).takeUnless { it.isEmpty }
+				isGrayscale = prefs.getBoolean(KEY_CF_GRAYSCALE, ReaderColorFilter.EMPTY.isGrayscale),
+				isBookBackground = prefs.getBoolean(KEY_CF_BOOK, ReaderColorFilter.EMPTY.isBookBackground),
+			).takeUnless { it.isEmpty }
 		}.getOrNull()
 		set(value) {
 			prefs.edit {
-				val cf = value ?: ReaderColorFilter.EMPTY
+				if (value != null) {
-				putFloat(KEY_CF_BRIGHTNESS, cf.brightness)
+					putFloat(KEY_CF_BRIGHTNESS, value.brightness)
-				putFloat(KEY_CF_CONTRAST, cf.contrast)
+					putFloat(KEY_CF_CONTRAST, value.contrast)
-				putBoolean(KEY_CF_INVERTED, cf.isInverted)
+					putBoolean(KEY_CF_INVERTED, value.isInverted)
-				putBoolean(KEY_CF_GRAYSCALE, cf.isGrayscale)
+					putBoolean(KEY_CF_GRAYSCALE, value.isGrayscale)
+					putBoolean(KEY_CF_BOOK, value.isBookBackground)
+				} else {
+					remove(KEY_CF_BRIGHTNESS)
+					remove(KEY_CF_CONTRAST)
+					remove(KEY_CF_INVERTED)
+					remove(KEY_CF_GRAYSCALE)
+					remove(KEY_CF_BOOK)
+				}
 			}
 		}
 
@@ -740,6 +750,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val KEY_CF_CONTRAST = "cf_contrast"
 		const val KEY_CF_INVERTED = "cf_inverted"
 		const val KEY_CF_GRAYSCALE = "cf_grayscale"
+		const val KEY_CF_BOOK = "cf_book"
 		const val KEY_PAGES_TAB = "pages_tab"
 		const val KEY_DETAILS_TAB = "details_tab"
 		const val KEY_DETAILS_LAST_TAB = "details_last_tab"

app/src/main/kotlin/org/koitharu/kotatsu/reader/domain/ReaderColorFilter.kt

@@ -1,5 +1,7 @@
 package org.koitharu.kotatsu.reader.domain
 
+import android.content.res.ColorStateList
+import android.graphics.Color
 import android.graphics.ColorMatrix
 import android.graphics.ColorMatrixColorFilter
 
@@ -8,10 +10,11 @@ data class ReaderColorFilter(
 	val contrast: Float,
 	val isInverted: Boolean,
 	val isGrayscale: Boolean,
+	val isBookBackground: Boolean,
 ) {
 
 	val isEmpty: Boolean
-		get() = !isGrayscale && !isInverted && brightness == 0f && contrast == 0f
+		get() = !isGrayscale && !isInverted && !isBookBackground && brightness == 0f && contrast == 0f
 
 	fun toColorFilter(): ColorMatrixColorFilter {
 		val cm = ColorMatrix()
@@ -23,9 +26,19 @@ data class ReaderColorFilter(
 		}
 		cm.setBrightness(brightness)
 		cm.setContrast(contrast)
+		if (isBookBackground) {
+			cm.addBookEffect()
+		}
 		return ColorMatrixColorFilter(cm)
 	}
 
+	fun getBackgroundTint(): ColorStateList? = if (isBookBackground) {
+		val color = Color.rgb(255, 255, (255 * BOOK_BLUE_FACTOR).toInt())
+		ColorStateList.valueOf(color)
+	} else {
+		null
+	}
+
 	private fun ColorMatrix.setBrightness(brightness: Float) {
 		val scale = brightness + 1f
 		val matrix = ColorMatrix()
@@ -60,13 +73,26 @@ data class ReaderColorFilter(
 		setSaturation(0f)
 	}
 
+	private fun ColorMatrix.addBookEffect() {
+		val removeBlueMatrix = floatArrayOf(
+			1f, 0f, 0f, 0f, 0f,
+			0f, 1f, 0f, 0f, 0f,
+			0f, 0f, BOOK_BLUE_FACTOR, 0f, 0f,
+			0f, 0f, 0f, 1f, 0f,
+		)
+		postConcat(ColorMatrix(removeBlueMatrix))
+	}
+
 	companion object {
 
+		private const val BOOK_BLUE_FACTOR = 0.92f
+
 		val EMPTY = ReaderColorFilter(
 			brightness = 0.0f,
 			contrast = 0.0f,
 			isInverted = false,
 			isGrayscale = false,
+			isBookBackground = false,
 		)
 	}
 }

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/colorfilter/ColorFilterConfigActivity.kt

@@ -53,6 +53,7 @@ class ColorFilterConfigActivity :
 		viewBinding.sliderBrightness.setLabelFormatter(formatter)
 		viewBinding.switchInvert.setOnCheckedChangeListener(this)
 		viewBinding.switchGrayscale.setOnCheckedChangeListener(this)
+		viewBinding.switchBook.setOnCheckedChangeListener(this)
 		viewBinding.buttonDone.setOnClickListener(this)
 		viewBinding.buttonReset.setOnClickListener(this)
 
@@ -93,6 +94,7 @@ class ColorFilterConfigActivity :
 		when (buttonView.id) {
 			R.id.switch_invert -> viewModel.setInversion(isChecked)
 			R.id.switch_grayscale -> viewModel.setGrayscale(isChecked)
+			R.id.switch_book -> viewModel.setBookEffect(isChecked)
 		}
 	}
 
@@ -120,6 +122,7 @@ class ColorFilterConfigActivity :
 		viewBinding.sliderContrast.setValueRounded(readerColorFilter?.contrast ?: 0f)
 		viewBinding.switchInvert.setChecked(readerColorFilter?.isInverted == true, false)
 		viewBinding.switchGrayscale.setChecked(readerColorFilter?.isGrayscale == true, false)
+		viewBinding.switchBook.setChecked(readerColorFilter?.isBookBackground == true, false)
 		viewBinding.imageViewAfter.colorFilter = readerColorFilter?.toColorFilter()
 	}
 

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/colorfilter/ColorFilterConfigViewModel.kt

@@ -56,6 +56,10 @@ class ColorFilterConfigViewModel @Inject constructor(
 		updateColorFilter { it.copy(isGrayscale = grayscale) }
 	}
 
+	fun setBookEffect(book: Boolean) {
+		updateColorFilter { it.copy(isBookBackground = book) }
+	}
+
 	fun reset() {
 		colorFilter.value = null
 	}

app/src/main/kotlin/org/koitharu/kotatsu/reader/ui/config/ReaderSettings.kt

@@ -57,6 +57,11 @@ data class ReaderSettings(
 
 	fun applyBackground(view: View) {
 		view.background = background.resolve(view.context)
+		view.backgroundTintList = if (background.isLight(view.context)) {
+			colorFilter?.getBackgroundTint()
+		} else {
+			null
+		}
 	}
 
 	fun isPagesCropEnabled(isWebtoon: Boolean) = if (isWebtoon) {

app/src/main/res/layout-w600dp-land/activity_color_filter.xml

@@ -191,6 +191,18 @@
 				app:layout_constraintStart_toEndOf="@id/guideline_vertical"
 				app:layout_constraintTop_toBottomOf="@id/textView_contrast" />
 
+			<com.google.android.material.materialswitch.MaterialSwitch
+				android:id="@+id/switch_book"
+				android:layout_width="0dp"
+				android:layout_height="wrap_content"
+				android:layout_marginStart="@dimen/margin_normal"
+				android:layout_marginTop="8dp"
+				android:text="@string/book_effect"
+				android:textAppearance="?textAppearanceTitleMedium"
+				app:layout_constraintEnd_toEndOf="parent"
+				app:layout_constraintStart_toEndOf="@id/guideline_vertical"
+				app:layout_constraintTop_toBottomOf="@id/slider_contrast" />
+
 		</androidx.constraintlayout.widget.ConstraintLayout>
 
 	</ScrollView>

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

@@ -170,15 +170,26 @@
 				app:layout_constraintStart_toStartOf="parent"
 				app:layout_constraintTop_toBottomOf="@id/textView_contrast" />
 
+			<com.google.android.material.materialswitch.MaterialSwitch
+				android:id="@+id/switch_book"
+				android:layout_width="0dp"
+				android:layout_height="wrap_content"
+				android:layout_marginTop="8dp"
+				android:text="@string/book_effect"
+				android:textAppearance="?textAppearanceTitleMedium"
+				app:layout_constraintEnd_toEndOf="parent"
+				app:layout_constraintStart_toStartOf="parent"
+				app:layout_constraintTop_toBottomOf="@id/slider_contrast" />
+
 			<Button
 				android:id="@+id/button_reset"
 				style="?materialButtonOutlinedStyle"
 				android:layout_width="wrap_content"
 				android:layout_height="wrap_content"
-				android:layout_marginTop="8dp"
+				android:layout_marginTop="16dp"
 				android:text="@string/reset"
 				app:layout_constraintEnd_toEndOf="parent"
-				app:layout_constraintTop_toBottomOf="@id/slider_contrast" />
+				app:layout_constraintTop_toBottomOf="@id/switch_book" />
 
 		</androidx.constraintlayout.widget.ConstraintLayout>
 

app/src/main/res/values/strings.xml

@@ -853,4 +853,5 @@
 	<string name="reader_multitask_summary">Allows you to keep multiple readers with different manga open at the same time</string>
 	<string name="theme_name_itsuka">Itsuka</string>
 	<string name="theme_name_totoro">Totoro</string>
+	<string name="book_effect">Yellowish background (blue filter)</string>
 </resources>