Added configuration options to e-ink page flashes (#625)

* Recommit for e-ink pref changes

* Fixed state holder for flash interval

* Detekt

* Refactor suggested by Antsy

* inverted currentDisplayRefresh check for early exit

app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsReaderScreen.kt

@@ -14,6 +14,7 @@ import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.persistentMapOf
 import kotlinx.collections.immutable.toImmutableMap
 import tachiyomi.i18n.MR
+import tachiyomi.presentation.core.i18n.pluralStringResource
 import tachiyomi.presentation.core.i18n.stringResource
 import tachiyomi.presentation.core.util.collectAsState
 import uy.kohesive.injekt.Injekt
@@ -61,12 +62,8 @@ object SettingsReaderScreen : SearchableSettings {
                 pref = readerPref.pageTransitions(),
                 title = stringResource(MR.strings.pref_page_transitions),
             ),
-            Preference.PreferenceItem.SwitchPreference(
-                pref = readerPref.flashOnPageChange(),
-                title = stringResource(MR.strings.pref_flash_page),
-                subtitle = stringResource(MR.strings.pref_flash_page_summ),
-            ),
             getDisplayGroup(readerPreferences = readerPref),
+            getEInkGroup(readerPreferences = readerPref),
             getReadingGroup(readerPreferences = readerPref),
             getPagedGroup(readerPreferences = readerPref),
             getWebtoonGroup(readerPreferences = readerPref),
@@ -122,6 +119,65 @@ object SettingsReaderScreen : SearchableSettings {
         )
     }
 
+    @Composable
+    private fun getEInkGroup(readerPreferences: ReaderPreferences): Preference.PreferenceGroup {
+        val flashPageState by readerPreferences.flashOnPageChange().collectAsState()
+
+        val flashMillisPref = readerPreferences.flashDurationMillis()
+        val flashMillis by flashMillisPref.collectAsState()
+
+        val flashIntervalPref = readerPreferences.flashPageInterval()
+        val flashInterval by flashIntervalPref.collectAsState()
+
+        val flashColorPref = readerPreferences.flashColor()
+
+        return Preference.PreferenceGroup(
+            title = "E-Ink",
+            preferenceItems = persistentListOf(
+                Preference.PreferenceItem.SwitchPreference(
+                    pref = readerPreferences.flashOnPageChange(),
+                    title = stringResource(MR.strings.pref_flash_page),
+                    subtitle = stringResource(MR.strings.pref_flash_page_summ),
+                ),
+                Preference.PreferenceItem.SliderPreference(
+                    value = flashMillis / ReaderPreferences.MILLI_CONVERSION,
+                    min = 1,
+                    max = 15,
+                    title = stringResource(MR.strings.pref_flash_duration),
+                    subtitle = stringResource(MR.strings.pref_flash_duration_summary, flashMillis),
+                    onValueChanged = {
+                        flashMillisPref.set(it * ReaderPreferences.MILLI_CONVERSION)
+                        true
+                    },
+                    enabled = flashPageState,
+                ),
+                Preference.PreferenceItem.SliderPreference(
+                    value = flashInterval,
+                    min = 1,
+                    max = 10,
+                    title = stringResource(MR.strings.pref_flash_page_interval),
+                    subtitle = pluralStringResource(MR.plurals.pref_pages, flashInterval, flashInterval),
+                    onValueChanged = {
+                        flashIntervalPref.set(it)
+                        true
+                    },
+                    enabled = flashPageState,
+                ),
+                Preference.PreferenceItem.ListPreference(
+                    pref = flashColorPref,
+                    title = stringResource(MR.strings.pref_flash_with),
+                    entries = persistentMapOf(
+                        ReaderPreferences.FlashColor.BLACK to stringResource(MR.strings.pref_flash_style_black),
+                        ReaderPreferences.FlashColor.WHITE to stringResource(MR.strings.pref_flash_style_white),
+                        ReaderPreferences.FlashColor.WHITE_BLACK
+                            to stringResource(MR.strings.pref_flash_style_white_black),
+                    ),
+                    enabled = flashPageState,
+                ),
+            ),
+        )
+    }
+
     @Composable
     private fun getReadingGroup(readerPreferences: ReaderPreferences): Preference.PreferenceGroup {
         return Preference.PreferenceGroup(

app/src/main/java/eu/kanade/presentation/reader/DisplayRefreshHost.kt

@@ -7,19 +7,42 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import eu.kanade.tachiyomi.ui.reader.setting.ReaderPreferences
 import kotlinx.coroutines.delay
-import kotlin.time.Duration.Companion.seconds
+import tachiyomi.presentation.core.util.collectAsState
+import uy.kohesive.injekt.Injekt
+import uy.kohesive.injekt.api.get
+import kotlin.time.Duration.Companion.milliseconds
 
 @Stable
 class DisplayRefreshHost {
 
     internal var currentDisplayRefresh by mutableStateOf(false)
+    private val readerPreferences = Injekt.get<ReaderPreferences>()
+
+    internal val flashMillis = readerPreferences.flashDurationMillis()
+    internal val flashMode = readerPreferences.flashColor()
+
+    internal val flashIntervalPref = readerPreferences.flashPageInterval()
+
+    // Internal State for Flash
+    private var flashInterval = flashIntervalPref.get()
+    private var timesCalled = 0
 
     fun flash() {
-        currentDisplayRefresh = true
+        if (timesCalled % flashInterval == 0) {
+            currentDisplayRefresh = true
+        }
+        timesCalled += 1
+    }
+
+    fun setInterval(interval: Int) {
+        flashInterval = interval
+        timesCalled = 0
     }
 }
 
@@ -29,18 +52,39 @@ fun DisplayRefreshHost(
     modifier: Modifier = Modifier,
 ) {
     val currentDisplayRefresh = hostState.currentDisplayRefresh
+    val refreshDuration by hostState.flashMillis.collectAsState()
+    val flashMode by hostState.flashMode.collectAsState()
+    val flashInterval by hostState.flashIntervalPref.collectAsState()
+
+    var currentColor by remember { mutableStateOf<Color?>(null) }
+
     LaunchedEffect(currentDisplayRefresh) {
-        if (currentDisplayRefresh) {
+        if (!currentDisplayRefresh) {
-            delay(1.5.seconds)
+            currentColor = null
-            hostState.currentDisplayRefresh = false
+            return@LaunchedEffect
         }
+
+        val refreshDurationHalf = refreshDuration.milliseconds / 2
+        currentColor = if (flashMode == ReaderPreferences.FlashColor.BLACK) {
+            Color.Black
+        } else {
+            Color.White
+        }
+        delay(refreshDurationHalf)
+        if (flashMode == ReaderPreferences.FlashColor.WHITE_BLACK) {
+            currentColor = Color.Black
+        }
+        delay(refreshDurationHalf)
+        hostState.currentDisplayRefresh = false
+    }
+
+    LaunchedEffect(flashInterval) {
+        hostState.setInterval(flashInterval)
     }
 
     Canvas(
         modifier = modifier.fillMaxSize(),
     ) {
-        if (currentDisplayRefresh) {
+        currentColor?.let { drawRect(it) }
-            drawRect(Color.Black)
-        }
     }
 }

app/src/main/java/eu/kanade/presentation/reader/settings/GeneralSettingsPage.kt

@@ -5,10 +5,13 @@ import androidx.compose.material3.FilterChip
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import eu.kanade.tachiyomi.ui.reader.setting.ReaderPreferences
 import eu.kanade.tachiyomi.ui.reader.setting.ReaderSettingsScreenModel
 import tachiyomi.i18n.MR
 import tachiyomi.presentation.core.components.CheckboxItem
 import tachiyomi.presentation.core.components.SettingsChipRow
+import tachiyomi.presentation.core.components.SliderItem
+import tachiyomi.presentation.core.i18n.pluralStringResource
 import tachiyomi.presentation.core.i18n.stringResource
 import tachiyomi.presentation.core.util.collectAsState
 
@@ -19,9 +22,27 @@ private val themes = listOf(
     MR.strings.automatic_background to 3,
 )
 
+private val flashColors = listOf(
+    MR.strings.pref_flash_style_black to ReaderPreferences.FlashColor.BLACK,
+    MR.strings.pref_flash_style_white to ReaderPreferences.FlashColor.WHITE,
+    MR.strings.pref_flash_style_white_black to ReaderPreferences.FlashColor.WHITE_BLACK,
+)
+
 @Composable
 internal fun ColumnScope.GeneralPage(screenModel: ReaderSettingsScreenModel) {
     val readerTheme by screenModel.preferences.readerTheme().collectAsState()
+
+    val flashPageState by screenModel.preferences.flashOnPageChange().collectAsState()
+
+    val flashMillisPref = screenModel.preferences.flashDurationMillis()
+    val flashMillis by flashMillisPref.collectAsState()
+
+    val flashIntervalPref = screenModel.preferences.flashPageInterval()
+    val flashInterval by flashIntervalPref.collectAsState()
+
+    val flashColorPref = screenModel.preferences.flashColor()
+    val flashColor by flashColorPref.collectAsState()
+
     SettingsChipRow(MR.strings.pref_reader_theme) {
         themes.map { (labelRes, value) ->
             FilterChip(
@@ -73,4 +94,33 @@ internal fun ColumnScope.GeneralPage(screenModel: ReaderSettingsScreenModel) {
         label = stringResource(MR.strings.pref_flash_page),
         pref = screenModel.preferences.flashOnPageChange(),
     )
+    if (flashPageState) {
+        SliderItem(
+            value = flashMillis / ReaderPreferences.MILLI_CONVERSION,
+            label = stringResource(MR.strings.pref_flash_duration),
+            valueText = stringResource(MR.strings.pref_flash_duration_summary, flashMillis),
+            onChange = { flashMillisPref.set(it * ReaderPreferences.MILLI_CONVERSION) },
+            min = 1,
+            max = 15,
+        )
+        SliderItem(
+            value = flashInterval,
+            label = stringResource(MR.strings.pref_flash_page_interval),
+            valueText = pluralStringResource(MR.plurals.pref_pages, flashInterval, flashInterval),
+            onChange = {
+                flashIntervalPref.set(it)
+            },
+            min = 1,
+            max = 10,
+        )
+        SettingsChipRow(MR.strings.pref_flash_with) {
+            flashColors.map { (labelRes, value) ->
+                FilterChip(
+                    selected = flashColor == value,
+                    onClick = { flashColorPref.set(value) },
+                    label = { Text(stringResource(labelRes)) },
+                )
+            }
+        }
+    }
 }

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

@@ -17,6 +17,12 @@ class ReaderPreferences(
 
     fun flashOnPageChange() = preferenceStore.getBoolean("pref_reader_flash", false)
 
+    fun flashDurationMillis() = preferenceStore.getInt("pref_reader_flash_duration", MILLI_CONVERSION)
+
+    fun flashPageInterval() = preferenceStore.getInt("pref_reader_flash_interval", 1)
+
+    fun flashColor() = preferenceStore.getEnum("pref_reader_flash_mode", FlashColor.BLACK)
+
     fun doubleTapAnimSpeed() = preferenceStore.getInt("pref_double_tap_anim_speed", 500)
 
     fun showPageNumber() = preferenceStore.getBoolean("pref_show_page_number_key", true)
@@ -133,6 +139,12 @@ class ReaderPreferences(
 
     // endregion
 
+    enum class FlashColor {
+        BLACK,
+        WHITE,
+        WHITE_BLACK
+    }
+
     enum class TappingInvertMode(
         val titleRes: StringResource,
         val shouldInvertHorizontal: Boolean = false,
@@ -155,6 +167,8 @@ class ReaderPreferences(
         const val WEBTOON_PADDING_MIN = 0
         const val WEBTOON_PADDING_MAX = 25
 
+        const val MILLI_CONVERSION = 100
+
         val TapZones = listOf(
             MR.strings.label_default,
             MR.strings.l_nav,

i18n/src/commonMain/moko-resources/base/plurals.xml

@@ -40,6 +40,11 @@
         <item quantity="other">%d days</item>
     </plurals>
 
+    <plurals name="pref_pages">
+        <item quantity="one">1 page</item>
+        <item quantity="other">%1$s pages</item>
+    </plurals>
+
     <!-- Manga info -->
     <plurals name="missing_chapters">
         <item quantity="one">Missing %1$s chapter</item>

i18n/src/commonMain/moko-resources/base/strings.xml

@@ -366,6 +366,13 @@
     <string name="pref_page_transitions">Animate page transitions</string>
     <string name="pref_flash_page">Flash on page change</string>
     <string name="pref_flash_page_summ">Reduces ghosting on e-ink displays</string>
+    <string name="pref_flash_duration">Flash duration</string>
+    <string name="pref_flash_duration_summary">%1$s ms</string>
+    <string name="pref_flash_page_interval">Flash every</string>
+    <string name="pref_flash_with">Flash with</string>
+    <string name="pref_flash_style_black">Black</string>
+    <string name="pref_flash_style_white">White</string>
+    <string name="pref_flash_style_white_black">White and Black</string>
     <string name="pref_double_tap_anim_speed">Double tap animation speed</string>
     <string name="pref_show_page_number">Show page number</string>
     <string name="pref_show_reading_mode">Show reading mode</string>