Introduce ReadYou swipe animation

app/src/main/java/com/capyreader/app/preferences/AppPreferences.kt

@@ -98,16 +98,10 @@ class AppPreferences(context: Context) {
         val fontFamily: Preference<FontOption>
             get() = preferenceStore.getEnum("article_font_family", FontOption.default)
 
-        val topSwipeGesture: Preference<ArticleVerticalSwipe>
-            get() = preferenceStore.getEnum(
-                "article_top_swipe_gesture",
-                ArticleVerticalSwipe.topSwipeDefault
-            )
-
-        val bottomSwipeGesture: Preference<ArticleVerticalSwipe>
-            get() = preferenceStore.getEnum(
-                "article_bottom_swipe_gesture",
-                ArticleVerticalSwipe.bottomSwipeDefault
+        val enableSwipeNavigation: Preference<Boolean>
+            get() = preferenceStore.getBoolean(
+                "enable_swipe_navigation",
+                true
             )
 
         val imageVisibility: Preference<ReaderImageVisibility>
@@ -120,7 +114,7 @@ class AppPreferences(context: Context) {
             get() = preferenceStore.getBoolean("article_enable_paging_tap_gesture", false)
 
         val enableHorizontaPagination: Preference<Boolean>
-            get() = preferenceStore.getBoolean("article_enable_horizontal_pagination", true)
+            get() = preferenceStore.getBoolean("article_enable_horizontal_pagination", false)
 
         val improveTalkback: Preference<Boolean>
             get() = preferenceStore.getBoolean("article_improve_talkback", false)

app/src/main/java/com/capyreader/app/preferences/ArticleVerticalSwipe.kt

@@ -5,17 +5,13 @@ import com.capyreader.app.R
 enum class ArticleVerticalSwipe {
     DISABLED,
     PREVIOUS_ARTICLE,
-    NEXT_ARTICLE,
-    LOAD_FULL_CONTENT,
-    OPEN_ARTICLE_IN_BROWSER;
+    NEXT_ARTICLE;
 
     val translationKey: Int
         get() = when (this) {
             DISABLED -> R.string.article_vertical_swipe_disabled
             PREVIOUS_ARTICLE -> R.string.article_vertical_swipe_previous_article
             NEXT_ARTICLE -> R.string.article_vertical_swipe_next_article
-            LOAD_FULL_CONTENT -> R.string.article_vertical_swipe_full_content
-            OPEN_ARTICLE_IN_BROWSER -> R.string.article_vertical_open_article_in_browser
         }
 
     val enabled: Boolean
@@ -27,19 +23,16 @@ enum class ArticleVerticalSwipe {
     companion object {
         val topOptions = listOf(
             DISABLED,
-            LOAD_FULL_CONTENT,
             PREVIOUS_ARTICLE,
         )
 
         val bottomOptions = listOf(
             DISABLED,
-            OPEN_ARTICLE_IN_BROWSER,
             NEXT_ARTICLE,
-            LOAD_FULL_CONTENT,
         )
 
-        val topSwipeDefault = LOAD_FULL_CONTENT
+        val topSwipeDefault = PREVIOUS_ARTICLE
 
-        val bottomSwipeDefault = OPEN_ARTICLE_IN_BROWSER
+        val bottomSwipeDefault = NEXT_ARTICLE
     }
 }

app/src/main/java/com/capyreader/app/ui/articles/detail/ArticleReader.kt

@@ -37,6 +37,7 @@ import kotlin.math.roundToInt
 fun ArticleReader(
     article: Article,
     onSelectMedia: (media: Media) -> Unit,
+    modifier: Modifier = Modifier,
 ) {
     val (shareLink, setShareLink) = rememberSaveableShareLink()
     val linkOpener = LocalLinkOpener.current
@@ -53,15 +54,18 @@ fun ArticleReader(
 
     if (improveTalkback) {
         Column(
-            Modifier.fillMaxSize()
+            modifier = modifier.fillMaxSize()
         ) {
             WebView(
                 modifier = Modifier.fillMaxSize(),
                 state = webViewState,
             )
         }
     } else {
-        ScrollableWebView(webViewState)
+        ScrollableWebView(
+            webViewState = webViewState,
+            modifier = modifier
+        )
     }
 
     LaunchedEffect(article.id, article.content) {
@@ -87,7 +91,10 @@ fun ArticleReader(
 }
 
 @Composable
-fun ScrollableWebView(webViewState: WebViewState) {
+fun ScrollableWebView(
+    webViewState: WebViewState,
+    modifier: Modifier = Modifier,
+) {
     var maxHeight by remember { mutableFloatStateOf(0f) }
     val scrollState = rememberSaveable(saver = ScrollState.Saver) {
         ScrollState(initial = 0)
@@ -101,7 +108,7 @@ fun ScrollableWebView(webViewState: WebViewState) {
     ) {
         ColumnScrollbar(state = scrollState) {
             Column(
-                modifier = Modifier
+                modifier = modifier
                     .fillMaxSize()
                     .verticalScroll(scrollState)
                     .onGloballyPositioned { coordinates ->

app/src/main/java/com/capyreader/app/ui/articles/detail/ArticleTransition.kt

@@ -0,0 +1,70 @@
+package com.capyreader.app.ui.articles.detail
+
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.core.Spring
+import androidx.compose.animation.core.spring
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideInVertically
+import androidx.compose.animation.slideOutVertically
+import androidx.compose.animation.togetherWith
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.unit.IntOffset
+
+enum class ArticleDirection {
+    UPWARD,
+    DOWNWARD,
+    NONE
+}
+
+@Composable
+fun ArticleTransition(
+    article: ArticleTransitionState,
+    content: @Composable (ArticleTransitionState) -> Unit,
+) {
+    AnimatedContent(
+        targetState = article,
+        transitionSpec = {
+            val direction = when {
+                initialState.nextArticleId == targetState.articleId -> ArticleDirection.UPWARD
+                initialState.previousArticleId == targetState.articleId -> ArticleDirection.DOWNWARD
+                else -> ArticleDirection.NONE
+            }
+
+            val directionMultiplier = when (direction) {
+                ArticleDirection.UPWARD -> 1
+                ArticleDirection.DOWNWARD -> -1
+                ArticleDirection.NONE -> 0
+            }
+
+            val exitDuration = 100
+            val enterDuration = exitDuration * 2
+
+            (slideInVertically(
+                initialOffsetY = { (it * 0.2f * directionMultiplier).toInt() },
+                animationSpec = spring(
+                    dampingRatio = 0.9f,
+                    stiffness = Spring.StiffnessLow,
+                ),
+            ) + fadeIn(
+                animationSpec = tween(enterDuration, delayMillis = exitDuration / 2),
+                initialAlpha = 0.3f,
+            )) togetherWith (slideOutVertically(
+                targetOffsetY = { -(it * 0.2f * directionMultiplier).toInt() },
+                animationSpec = tween(exitDuration)
+            ) + fadeOut(
+                animationSpec = tween(exitDuration)
+            ))
+        },
+        label = "article_transition"
+    ) { state ->
+        content(state)
+    }
+}
+
+data class ArticleTransitionState(
+    val articleId: String,
+    val previousArticleId: String?,
+    val nextArticleId: String?,
+)