🚀 Horizontal gesture "Animate visibility" option

* Option to change how much (in %) the visibility animates when using horizontal gesture

app/src/main/java/ua/acclorite/book_story/domain/navigator/Navigator.kt

@@ -17,7 +17,6 @@ import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
-import kotlin.collections.plus
 
 @HiltViewModel(assistedFactory = Navigator.Factory::class)
 class Navigator @AssistedInject constructor(

app/src/main/java/ua/acclorite/book_story/presentation/core/constants/DataStoreConstants.kt

@@ -50,6 +50,7 @@ object DataStoreConstants {
     val HORIZONTAL_GESTURE = stringPreferencesKey("horizontal_gesture")
     val HORIZONTAL_GESTURE_SCROLL = doublePreferencesKey("horizontal_gesture_scroll")
     val HORIZONTAL_GESTURE_SENSITIVITY = doublePreferencesKey("horizontal_gesture_sensitivity")
+    val HORIZONTAL_GESTURE_ALPHA_ANIM = doublePreferencesKey("horizontal_gesture_alpha_anim")
     val BOTTOM_BAR_PADDING = intPreferencesKey("bottom_bar_padding")
     val HIGHLIGHTED_READING = booleanPreferencesKey("highlighted_reading")
     val HIGHLIGHTED_READING_THICKNESS = intPreferencesKey("highlighted_reading_thickness")

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderContent.kt

@@ -57,6 +57,7 @@ fun ReaderContent(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    horizontalGestureAlphaAnim: Float,
     highlightedReading: Boolean,
     highlightedReadingThickness: FontWeight,
     progress: String,
@@ -133,6 +134,7 @@ fun ReaderContent(
             horizontalGesture = horizontalGesture,
             horizontalGestureScroll = horizontalGestureScroll,
             horizontalGestureSensitivity = horizontalGestureSensitivity,
+            horizontalGestureAlphaAnim = horizontalGestureAlphaAnim,
             highlightedReading = highlightedReading,
             highlightedReadingThickness = highlightedReadingThickness,
             progress = progress,

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderHorizontalGesture.kt

@@ -34,11 +34,13 @@ fun Modifier.readerHorizontalGesture(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    horizontalGestureAlphaAnim: Float,
     isLoading: Boolean
 ): Modifier {
     if (horizontalGesture == ReaderHorizontalGesture.OFF || isLoading) return this
     val inverted = rememberUpdatedState(horizontalGesture == ReaderHorizontalGesture.INVERSE)
     val sensitivity = rememberUpdatedState(horizontalGestureSensitivity)
+    val alphaAnim = rememberUpdatedState(horizontalGestureAlphaAnim)
 
     val scope = rememberCoroutineScope()
     val density = LocalDensity.current
@@ -69,7 +71,9 @@ fun Modifier.readerHorizontalGesture(
     @Composable
     fun calculateAlpha(): Float {
         return animateFloatAsState(
-            1f - (abs(with(density) { horizontalOffset.floatValue.toDp() }.value) / sensitivity.value.value)
+            1f - abs(with(density) { horizontalOffset.floatValue.toDp() }.value)
+                .div(sensitivity.value.value)
+                .times(alphaAnim.value)
         ).value
     }
 
@@ -89,7 +93,7 @@ fun Modifier.readerHorizontalGesture(
                 onDragStart = {
                     horizontalOffset.floatValue = 0f
                 },
-                onHorizontalDrag = { change, dragAmount ->
+                onHorizontalDrag = { _, dragAmount ->
                     horizontalOffset.floatValue += (dragAmount * 0.15f)
                 },
                 onDragCancel = {

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderLayout.kt

@@ -57,6 +57,7 @@ fun ReaderLayout(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    horizontalGestureAlphaAnim: Float,
     highlightedReading: Boolean,
     highlightedReadingThickness: FontWeight,
     progress: String,
@@ -162,6 +163,7 @@ fun ReaderLayout(
                     horizontalGesture = horizontalGesture,
                     horizontalGestureScroll = horizontalGestureScroll,
                     horizontalGestureSensitivity = horizontalGestureSensitivity,
+                    horizontalGestureAlphaAnim = horizontalGestureAlphaAnim,
                     isLoading = isLoading
                 )
         ) {
@@ -181,7 +183,7 @@ fun ReaderLayout(
             ) {
                 itemsIndexed(
                     text,
-                    key = { index, entry -> index }
+                    key = { index, _ -> index }
                 ) { index, entry ->
                     when {
                         !images && entry is ReaderText.Image -> return@itemsIndexed

app/src/main/java/ua/acclorite/book_story/presentation/reader/ReaderScaffold.kt

@@ -61,6 +61,7 @@ fun ReaderScaffold(
     horizontalGesture: ReaderHorizontalGesture,
     horizontalGestureScroll: Float,
     horizontalGestureSensitivity: Dp,
+    horizontalGestureAlphaAnim: Float,
     highlightedReading: Boolean,
     highlightedReadingThickness: FontWeight,
     progress: String,
@@ -164,6 +165,7 @@ fun ReaderScaffold(
             horizontalGesture = horizontalGesture,
             horizontalGestureScroll = horizontalGestureScroll,
             horizontalGestureSensitivity = horizontalGestureSensitivity,
+            horizontalGestureAlphaAnim = horizontalGestureAlphaAnim,
             highlightedReading = highlightedReading,
             highlightedReadingThickness = highlightedReadingThickness,
             progress = progress,

app/src/main/java/ua/acclorite/book_story/presentation/settings/reader/reading_mode/ReadingModeSubcategory.kt

@@ -15,6 +15,7 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.presentation.settings.components.SettingsSubcategory
+import ua.acclorite.book_story.presentation.settings.reader.reading_mode.components.HorizontalGestureAlphaAnimOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_mode.components.HorizontalGestureOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_mode.components.HorizontalGestureScrollOption
 import ua.acclorite.book_story.presentation.settings.reader.reading_mode.components.HorizontalGestureSensitivityOption
@@ -42,5 +43,9 @@ fun LazyListScope.ReadingModeSubcategory(
         item {
             HorizontalGestureSensitivityOption()
         }
+
+        item {
+            HorizontalGestureAlphaAnimOption()
+        }
     }
 }

app/src/main/java/ua/acclorite/book_story/presentation/settings/reader/reading_mode/components/HorizontalGestureAlphaAnimOption.kt

@@ -0,0 +1,42 @@
+/*
+ * Book's Story — free and open-source Material You eBook reader.
+ * Copyright (C) 2024-2025 Acclorite
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package ua.acclorite.book_story.presentation.settings.reader.reading_mode.components
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.domain.reader.ReaderHorizontalGesture
+import ua.acclorite.book_story.presentation.core.components.settings.SliderWithTitle
+import ua.acclorite.book_story.ui.main.MainEvent
+import ua.acclorite.book_story.ui.main.MainModel
+import ua.acclorite.book_story.ui.theme.ExpandingTransition
+
+@Composable
+fun HorizontalGestureAlphaAnimOption() {
+    val mainModel = hiltViewModel<MainModel>()
+    val state = mainModel.state.collectAsStateWithLifecycle()
+
+    ExpandingTransition(
+        visible = when (state.value.horizontalGesture) {
+            ReaderHorizontalGesture.OFF -> false
+            else -> true
+        }
+    ) {
+        SliderWithTitle(
+            value = state.value.horizontalGestureAlphaAnim to "%",
+            toValue = 100,
+            title = stringResource(id = R.string.horizontal_gesture_alpha_anim_option),
+            onValueChange = {
+                mainModel.onEvent(
+                    MainEvent.OnChangeHorizontalGestureAlphaAnim(it)
+                )
+            }
+        )
+    }
+}

app/src/main/java/ua/acclorite/book_story/ui/browse/BrowseModel.kt

@@ -32,7 +32,6 @@ import ua.acclorite.book_story.domain.use_case.file_system.GetFiles
 import ua.acclorite.book_story.presentation.core.util.showToast
 import ua.acclorite.book_story.ui.library.LibraryScreen
 import javax.inject.Inject
-import kotlin.collections.map
 
 @HiltViewModel
 class BrowseModel @Inject constructor(

app/src/main/java/ua/acclorite/book_story/ui/main/MainEvent.kt

@@ -65,4 +65,5 @@ sealed class MainEvent {
     data class OnChangeBrowsePinnedPaths(val value: String) : MainEvent()
     data class OnChangeFontThickness(val value: String) : MainEvent()
     data class OnChangeProgressCount(val value: String) : MainEvent()
+    data class OnChangeHorizontalGestureAlphaAnim(val value: Float) : MainEvent()
 }

app/src/main/java/ua/acclorite/book_story/ui/main/MainModel.kt

@@ -499,6 +499,14 @@ class MainModel @Inject constructor(
                     it.copy(progressCount = this.toProgressCount())
                 }
             )
+
+            is MainEvent.OnChangeHorizontalGestureAlphaAnim -> handleDatastoreUpdate(
+                key = DataStoreConstants.HORIZONTAL_GESTURE_ALPHA_ANIM,
+                value = event.value.toDouble(),
+                updateState = {
+                    it.copy(horizontalGestureAlphaAnim = this.toFloat())
+                }
+            )
         }
     }
 

app/src/main/java/ua/acclorite/book_story/ui/main/MainState.kt

@@ -101,6 +101,7 @@ data class MainState(
     },
     val horizontalGestureScroll: Float = provideDefaultValue { 0.7f },
     val horizontalGestureSensitivity: Float = provideDefaultValue { 0.6f },
+    val horizontalGestureAlphaAnim: Float = provideDefaultValue { 1f },
     val bottomBarPadding: Int = provideDefaultValue { 0 },
     val highlightedReading: Boolean = provideDefaultValue { false },
     val highlightedReadingThickness: Int = provideDefaultValue { 2 },
@@ -365,6 +366,10 @@ data class MainState(
                     progressCount = provideValue(
                         PROGRESS_COUNT, convert = { toProgressCount() }
                     ) { progressCount },
+
+                    horizontalGestureAlphaAnim = provideValue(
+                        HORIZONTAL_GESTURE_ALPHA_ANIM, convert = { toFloat() }
+                    ) { horizontalGestureAlphaAnim },
                 )
             }
         }

app/src/main/java/ua/acclorite/book_story/ui/reader/ReaderScreen.kt

@@ -425,6 +425,7 @@ data class ReaderScreen(val bookId: Int) : Screen, Parcelable {
             horizontalGesture = mainState.value.horizontalGesture,
             horizontalGestureScroll = mainState.value.horizontalGestureScroll,
             horizontalGestureSensitivity = horizontalGestureSensitivity,
+            horizontalGestureAlphaAnim = mainState.value.horizontalGestureAlphaAnim,
             highlightedReading = mainState.value.highlightedReading,
             highlightedReadingThickness = highlightedReadingThickness,
             progress = progress,

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

@@ -186,6 +186,7 @@
     <string name="horizontal_gesture_option">Горизонтальний жест</string>
     <string name="horizontal_gesture_scroll_option">Частка прокрутки</string>
     <string name="horizontal_gesture_sensitivity_option">Чутливість</string>
+    <string name="horizontal_gesture_alpha_anim_option">Анімувати видимість</string>
     <string name="bottom_bar_padding_option">Відступ нижньої панелі</string>
     <string name="highlighted_reading_option">Підсвічування слів</string>
     <string name="highlighted_reading_option_desc">Підсвічувати початок кожного слова</string>

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

@@ -217,6 +217,7 @@
     <string name="horizontal_gesture_option">Horizontal gesture</string>
     <string name="horizontal_gesture_scroll_option">Scroll fraction</string>
     <string name="horizontal_gesture_sensitivity_option">Sensitivity</string>
+    <string name="horizontal_gesture_alpha_anim_option">Animate visibility</string>
     <string name="bottom_bar_padding_option">Bottom bar margin</string>
     <string name="highlighted_reading_option">Highlight words</string>
     <string name="highlighted_reading_option_desc">Highlight the beginning of each word</string>