fix(app): keep populated markdown in sync with native layout

Fabric can collapse streaming blocks before asynchronous rendering replaces the old text, producing a blank frame. Commit populated-view updates synchronously while retaining worker preparation for first mounts to avoid moving large history parsing onto the UI thread.
2026-10-24 10:12:44 +00:00 · 2026-10-16 15:17:41 +02:00
parent e42771970f
commit e53d6673b0
1 changed files with 106 additions and 3 deletions
@@ -40,10 +40,9 @@ index 0a1c6c2..5935112 100644
 
   struct OnLinkLongPress {
 diff --git a/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdown.kt b/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdown.kt
-index c12937c..5f288b3 100644
 --- a/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdown.kt
 +++ b/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdown.kt
-@@ -95,7 +95,7 @@ class EnrichedMarkdown(
+@@ -95,7 +95,7 @@
   private var accessibilityLabels = AccessibilityLabels()
   private var textBreakStrategy: String = BreakStrategyUtils.DEFAULT_STRATEGY
 
@@ -52,7 +51,7 @@ index c12937c..5f288b3 100644
   private var onLinkLongPressCallback: ((String) -> Unit)? = null
   private var onTaskListItemPressCallback: ((Int, Boolean, String) -> Unit)? = null
   private var onLatexErrorCallback: LatexErrorReporter? = null
-@@ -296,7 +296,7 @@ class EnrichedMarkdown(
+@@ -296,7 +296,7 @@
     }
   }
 
@@ -61,6 +60,45 @@ index c12937c..5f288b3 100644
     onLinkPressCallback = callback
   }
 
+@@ -405,7 +405,7 @@
+     val codeLinkRegex = inlineCodeLinkRegex
+     val renderId = ++currentRenderId
+ 
+-    executor.execute {
+    dispatchMarkdownRender(segmentViews.isNotEmpty(), executor) {
+       try {
+         val filtered =
+           if (isStreaming) {
+@@ -418,13 +418,13 @@
+ 
+         if (renderableMarkdown.isEmpty()) {
+           postToMain(renderId) { applyRenderedSegments(emptyList(), false) }
+-          return@execute
+          return@dispatchMarkdownRender
+         }
+ 
+         val ast =
+           parser.parseMarkdown(renderableMarkdown, md4cFlags, isGFM, textLinkRegex, codeLinkRegex) ?: run {
+             postToMain(renderId) { applyRenderedSegments(emptyList(), false) }
+-            return@execute
+            return@dispatchMarkdownRender
+           }
+ 
+         val segments = splitASTIntoSegments(ast)
+@@ -646,8 +646,12 @@
+     renderId: Long,
+     action: () -> Unit,
+   ) {
+-    mainHandler.post {
+    if (Looper.myLooper() == Looper.getMainLooper()) {
+       if (renderId == currentRenderId) action()
+    } else {
+      mainHandler.post {
+        if (renderId == currentRenderId) action()
+      }
+     }
+   }
+ 
 diff --git a/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdownManager.kt b/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdownManager.kt
 index 5dd5828..757d2bd 100644
 --- a/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/EnrichedMarkdownManager.kt
@@ -2825,3 +2863,68 @@ index 0000000..b3394c4
 +    assertNull(cache.get(key("other")))
 +  }
 +}
+diff --git a/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/MarkdownRenderDispatch.kt b/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/MarkdownRenderDispatch.kt
+new file mode 100644
+--- /dev/null
+++ b/node_modules/react-native-enriched-markdown/android/src/main/java/com/swmansion/enriched/markdown/MarkdownRenderDispatch.kt
+@@ -0,0 +1,9 @@
+package com.swmansion.enriched.markdown
+
+import java.util.concurrent.Executor
+
+// Keep populated views in step with Fabric geometry when streaming blocks move or collapse.
+// First mounts retain worker preparation so large history rows do not parse on the UI thread.
+internal fun dispatchMarkdownRender(hasContent: Boolean, executor: Executor, render: () -> Unit) {
+  if (hasContent) render() else executor.execute(render)
+}
+diff --git a/node_modules/react-native-enriched-markdown/android/src/test/java/com/swmansion/enriched/markdown/MarkdownRenderDispatchTest.kt b/node_modules/react-native-enriched-markdown/android/src/test/java/com/swmansion/enriched/markdown/MarkdownRenderDispatchTest.kt
+new file mode 100644
+--- /dev/null
+++ b/node_modules/react-native-enriched-markdown/android/src/test/java/com/swmansion/enriched/markdown/MarkdownRenderDispatchTest.kt
+@@ -0,0 +1,46 @@
+package com.swmansion.enriched.markdown
+
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
+import org.junit.Assert.*
+import org.junit.Test
+
+class MarkdownRenderDispatchTest {
+  @Test fun populatedViewUpdatesBeforeReturningEvenWithBusyWorker() {
+    val executor = Executors.newSingleThreadExecutor()
+    val release = CountDownLatch(1)
+    val started = CountDownLatch(1)
+    try {
+      executor.execute { started.countDown(); release.await() }
+      assertTrue(started.await(5, TimeUnit.SECONDS))
+      val caller = Thread.currentThread()
+      var rendered = false
+      dispatchMarkdownRender(true, executor) {
+        assertSame(caller, Thread.currentThread())
+        rendered = true
+      }
+      assertTrue(rendered)
+    } finally {
+      release.countDown()
+      executor.shutdownNow()
+    }
+  }
+
+  @Test fun firstMountPreparesOnWorker() {
+    val executor = Executors.newSingleThreadExecutor()
+    val finished = CountDownLatch(1)
+    val caller = Thread.currentThread()
+    var worker: Thread? = null
+    try {
+      dispatchMarkdownRender(false, executor) {
+        worker = Thread.currentThread()
+        finished.countDown()
+      }
+      assertTrue(finished.await(5, TimeUnit.SECONDS))
+      assertNotSame(caller, worker)
+    } finally {
+      executor.shutdownNow()
+    }
+  }
+}