Use enum instead of boolean

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferenceValues.kt

@@ -30,4 +30,11 @@ object PreferenceValues {
         COMFORTABLE_GRID,
         LIST,
     }
+
+    enum class TappingInvertMode {
+        NONE,
+        HORIZONTAL,
+        VERTICAL,
+        BOTH
+    }
 }

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -121,7 +121,7 @@ class PreferencesHelper(val context: Context) {
 
     fun readWithTapping() = flowPrefs.getBoolean(Keys.readWithTapping, true)
 
-    fun readWithTappingInverted() = flowPrefs.getBoolean(Keys.readWithTappingInverted, false)
+    fun readWithTappingInverted() = flowPrefs.getEnum(Keys.readWithTappingInverted, Values.TappingInvertMode.NONE)
 
     fun readWithLongTap() = flowPrefs.getBoolean(Keys.readWithLongTap, true)
 

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/ViewerConfig.kt

@@ -1,6 +1,7 @@
 package eu.kanade.tachiyomi.ui.reader.viewer
 
 import com.tfcporciuncula.flow.Preference
+import eu.kanade.tachiyomi.data.preference.PreferenceValues.TappingInvertMode
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -20,7 +21,7 @@ abstract class ViewerConfig(preferences: PreferencesHelper) {
 
     var tappingEnabled = true
     var longTapEnabled = true
-    var tappingInverted = false
+    var tappingInverted = TappingInvertMode.NONE
     var doubleTapAnimDuration = 500
     var volumeKeysEnabled = false
     var volumeKeysInverted = false

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt

@@ -7,6 +7,7 @@ import android.view.View
 import android.view.ViewGroup.LayoutParams
 import androidx.viewpager.widget.ViewPager
 import eu.kanade.tachiyomi.R
+import eu.kanade.tachiyomi.data.preference.PreferenceValues.TappingInvertMode
 import eu.kanade.tachiyomi.ui.reader.ReaderActivity
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -80,10 +81,11 @@ abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
             }
         })
         pager.tapListener = { event ->
-            val tappingInverted = config.tappingInverted
+            val invertMode = config.tappingInverted
 
             if (this is VerticalPagerViewer) {
                 val positionY = event.y
+                val tappingInverted = invertMode == TappingInvertMode.VERTICAL || invertMode == TappingInvertMode.BOTH
                 val topSideTap = positionY < pager.height * 0.33f && config.tappingEnabled
                 val bottomSideTap = positionY > pager.height * 0.66f && config.tappingEnabled
 
@@ -94,6 +96,7 @@ abstract class PagerViewer(val activity: ReaderActivity) : BaseViewer {
                 }
             } else {
                 val positionX = event.x
+                val tappingInverted = invertMode == TappingInvertMode.HORIZONTAL || invertMode == TappingInvertMode.BOTH
                 val leftSideTap = positionX < pager.width * 0.33f && config.tappingEnabled
                 val rightSideTap = positionX > pager.width * 0.66f && config.tappingEnabled
 

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonViewer.kt

@@ -7,6 +7,7 @@ import android.view.ViewGroup
 import android.view.ViewGroup.LayoutParams.MATCH_PARENT
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.WebtoonLayoutManager
+import eu.kanade.tachiyomi.data.preference.PreferenceValues.TappingInvertMode
 import eu.kanade.tachiyomi.ui.reader.ReaderActivity
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
 import eu.kanade.tachiyomi.ui.reader.model.ReaderPage
@@ -14,10 +15,10 @@ import eu.kanade.tachiyomi.ui.reader.model.ViewerChapters
 import eu.kanade.tachiyomi.ui.reader.viewer.BaseViewer
 import eu.kanade.tachiyomi.util.view.gone
 import eu.kanade.tachiyomi.util.view.visible
-import kotlin.math.max
-import kotlin.math.min
 import rx.subscriptions.CompositeSubscription
 import timber.log.Timber
+import kotlin.math.max
+import kotlin.math.min
 
 /**
  * Implementation of a [BaseViewer] to display pages with a [RecyclerView].
@@ -94,10 +95,12 @@ class WebtoonViewer(val activity: ReaderActivity, val isContinuous: Boolean = tr
         })
         recycler.tapListener = { event ->
             val positionY = event.rawY
-            val tappingInverted = config.tappingInverted
+            val invertMode = config.tappingInverted
             val topSideTap = positionY < recycler.height * 0.33f && config.tappingEnabled
             val bottomSideTap = positionY > recycler.height * 0.66f && config.tappingEnabled
 
+            val tappingInverted = invertMode == TappingInvertMode.VERTICAL || invertMode == TappingInvertMode.BOTH
+
             when {
                 topSideTap && !tappingInverted || bottomSideTap && tappingInverted -> scrollUp()
                 bottomSideTap && !tappingInverted || topSideTap && tappingInverted -> scrollDown()

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsReaderController.kt

@@ -4,9 +4,11 @@ import android.os.Build
 import androidx.preference.PreferenceScreen
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.preference.PreferenceKeys as Keys
+import eu.kanade.tachiyomi.data.preference.PreferenceValues.TappingInvertMode
 import eu.kanade.tachiyomi.util.preference.defaultValue
 import eu.kanade.tachiyomi.util.preference.entriesRes
 import eu.kanade.tachiyomi.util.preference.intListPreference
+import eu.kanade.tachiyomi.util.preference.listPreference
 import eu.kanade.tachiyomi.util.preference.preferenceCategory
 import eu.kanade.tachiyomi.util.preference.summaryRes
 import eu.kanade.tachiyomi.util.preference.switchPreference
@@ -190,10 +192,23 @@ class SettingsReaderController : SettingsController() {
                 titleRes = R.string.pref_read_with_tapping
                 defaultValue = true
             }
-            switchPreference {
+            listPreference {
                 key = Keys.readWithTappingInverted
                 titleRes = R.string.pref_read_with_tapping_inverted
-                defaultValue = false
+                entriesRes = arrayOf(
+                    R.string.tapping_inverted_none,
+                    R.string.tapping_inverted_horizontal,
+                    R.string.tapping_inverted_vertical,
+                    R.string.tapping_inverted_both
+                )
+                entryValues = arrayOf(
+                    TappingInvertMode.NONE.name,
+                    TappingInvertMode.HORIZONTAL.name,
+                    TappingInvertMode.VERTICAL.name,
+                    TappingInvertMode.BOTH.name
+                )
+                defaultValue = TappingInvertMode.NONE.name
+                summary = "%s"
             }.apply { dependency = Keys.readWithTapping }
             switchPreference {
                 key = Keys.readWithLongTap