Smooth scrolling, dark reader, mark-read-on-scroll, feed names, per-feed reader-mode opt-out

- ReaderScreen: AndroidView's update() was reloading the WebView's HTML on
  every recomposition (e.g. isSaving flipping mid-read), resetting scroll
  position -- this is what made scrolling feel unsmooth. Now only reloads
  when the content string actually changes.
- ReaderScreen: reader content now uses a hardcoded dark palette instead of
  browser-default white, matching the app's always-dark theme.
- ArticleListScreen: mark-as-read-on-scroll -- once an article has scrolled
  fully above the viewport it's marked read, the standard feed-reader
  behavior, via a new batched ArticleDao.markReadBatch(). Verified against
  the on-device DB (scrolled-past articles flipped to isRead=1, the
  still-visible one stayed unread).
- ArticleListItem/queries: LEFT JOIN feeds for a feedTitle column, shown per
  row in the Unread/Saved aggregated views and as a reader subtitle; the
  per-feed article list's top bar now shows the real feed title instead of
  a generic "Articles".
- FeedEntity.readerModeDisabled (schema v3, migration 2->3): per-feed
  opt-out of the Readability fallback/toggle, toggled from a new icon in
  FeedListScreen. Added for kottke.org specifically -- confirmed its thin
  linkblog posts were making Readability extract the page footer instead
  of the actual post; disabling reader mode for that feed now shows its
  own (short but correct) content instead.

All verified live on the emulator against the real 107-feed dataset.

1 files changed, 50 insertions, 8 deletions

diff --git a/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt b/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
index cef17c5..2177d72 100644
--- a/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
@@ -5,6 +5,7 @@ import android.net.Uri
 import android.webkit.WebView
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.pager.HorizontalPager
@@ -20,6 +21,7 @@ import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
@@ -35,11 +37,13 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.viewinterop.AndroidView
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import org.terst.feedreader.data.AppDatabase
 import org.terst.feedreader.data.ArticleEntity
+import org.terst.feedreader.data.FeedEntity
 import org.terst.feedreader.data.Net
 import org.terst.feedreader.data.Settings
 import org.terst.feedreader.readability.ReaderExtractor
@@ -100,6 +104,7 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
     val snackbarHostState = remember { SnackbarHostState() }
 
     var article by remember(articleId) { mutableStateOf<ArticleEntity?>(null) }
+    var feed by remember(articleId) { mutableStateOf<FeedEntity?>(null) }
     var feedContent by remember(articleId) { mutableStateOf<String?>(null) }
     var readerContent by remember(articleId) { mutableStateOf<String?>(null) }
     var isReaderMode by remember(articleId) { mutableStateOf(false) }
@@ -110,12 +115,14 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
         val loaded = db.articleDao().getById(articleId) ?: return@LaunchedEffect
         article = loaded
         db.articleDao().setRead(articleId, true)
+        val loadedFeed = loaded.feedId?.let { db.feedDao().getById(it) }
+        feed = loadedFeed
 
         feedContent = loaded.feedContentHtml
         readerContent = loaded.extractedContent
         val plainLength = feedContent?.replace(Regex("<[^>]*>"), "")?.trim()?.length ?: 0
 
-        if (readerContent == null && plainLength < THIN_CONTENT_THRESHOLD) {
+        if (loadedFeed?.readerModeDisabled != true && readerContent == null && plainLength < THIN_CONTENT_THRESHOLD) {
             // Feed content is too thin to be the real article -- auto-extract, since in this
             // case reader mode isn't really an alternative view, it's the only real content.
             isExtracting = true
@@ -131,6 +138,7 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
 
     fun toggleReaderMode() {
         val a = article ?: return
+        if (feed?.readerModeDisabled == true) return
         if (isReaderMode) {
             isReaderMode = false
             return
@@ -157,7 +165,20 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
     Scaffold(
         topBar = {
             TopAppBar(
-                title = { Text(article?.title.orEmpty(), maxLines = 1) },
+                title = {
+                    Column {
+                        Text(article?.title.orEmpty(), maxLines = 1, overflow = TextOverflow.Ellipsis)
+                        feed?.title?.let {
+                            Text(
+                                it,
+                                maxLines = 1,
+                                overflow = TextOverflow.Ellipsis,
+                                style = MaterialTheme.typography.labelSmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant
+                            )
+                        }
+                    }
+                },
                 navigationIcon = {
                     IconButton(onClick = onBack) {
                         Icon(Icons.Default.ArrowBack, contentDescription = "Back")
@@ -166,9 +187,9 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
                 actions = {
                     val currentArticle = article
                     // Only offer the toggle when there's an actual feed-provided alternative to
-                    // switch back to -- if we already had to auto-extract (thin feed content),
-                    // reader mode IS the only content, so there's nothing to toggle between.
-                    if (feedContent != null) {
+                    // switch back to (if we already had to auto-extract for thin feed content,
+                    // reader mode IS the only content) and the feed hasn't opted out of it.
+                    if (feedContent != null && feed?.readerModeDisabled != true) {
                         IconButton(enabled = !isExtracting, onClick = { toggleReaderMode() }) {
                             Icon(
                                 if (isReaderMode) Icons.Filled.Article else Icons.Outlined.Article,
@@ -223,15 +244,28 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
             val content = if (isReaderMode) readerContent else (feedContent ?: readerContent)
             val baseUrl = article?.link
             if (content != null) {
+                // AndroidView's update lambda reruns on every recomposition of this
+                // composable -- including ones unrelated to content, like isSaving
+                // flipping while a Stash save is in flight. Reloading the WebView's HTML
+                // on those unrelated recompositions was resetting scroll position mid-swipe,
+                // which is what made scrolling feel unsmooth/janky. Track what's actually
+                // loaded and only reload when the content string itself changes.
+                val loadedContent = remember(articleId) { mutableStateOf<String?>(null) }
                 AndroidView(
                     modifier = Modifier.fillMaxSize(),
                     factory = { ctx ->
                         WebView(ctx).apply {
                             settings.javaScriptEnabled = false
                             loadDataWithBaseURL(baseUrl, wrapHtml(content), "text/html", "UTF-8", null)
+                            loadedContent.value = content
+                        }
+                    },
+                    update = { webView ->
+                        if (loadedContent.value != content) {
+                            webView.loadDataWithBaseURL(baseUrl, wrapHtml(content), "text/html", "UTF-8", null)
+                            loadedContent.value = content
                         }
                     },
-                    update = { webView -> webView.loadDataWithBaseURL(baseUrl, wrapHtml(content), "text/html", "UTF-8", null) },
                     // AndroidView does not destroy() the underlying WebView on its own --
                     // without this, swiping through many articles (each page holding its own
                     // WebView) leaks a WebView's native resources per page and eventually
@@ -245,9 +279,17 @@ private fun ReaderContent(articleId: String, onBack: () -> Unit) {
     }
 }
 
+// Hardcoded dark palette, not @media (prefers-color-scheme) -- the app itself always
+// forces dark colorScheme() regardless of system setting (see MainActivity), so the
+// reader content should match rather than following a system light/dark that the rest
+// of the app ignores.
 private fun wrapHtml(bodyContent: String): String = """
     <html><head><meta name="viewport" content="width=device-width, initial-scale=1">
-    <style>body { font-family: sans-serif; font-size: 18px; line-height: 1.5; padding: 16px; }
-    img { max-width: 100%; height: auto; }</style></head>
+    <style>
+    body { font-family: sans-serif; font-size: 18px; line-height: 1.5; padding: 16px;
+           background-color: #121212; color: #e1e1e1; }
+    a { color: #8ab4f8; }
+    img { max-width: 100%; height: auto; }
+    </style></head>
     <body>$bodyContent</body></html>
 """.trimIndent()