From aedd651cd01ed9458a6f2380c03f07c1da3ccad7 Mon Sep 17 00:00:00 2001
From: "tramline-github[bot]"
 <98346001+tramline-github[bot]@users.noreply.github.com>
Date: Mon, 3 Jun 2024 11:04:52 +0530
Subject: [PATCH] Run reader view parsing in the background thread (#595)

Co-authored-by: Sasikanth Miriyampalli <hello@sasikanth.dev>
---
 .../dev/sasikanth/rss/reader/app/App.kt       |  8 +++-
 .../rss/reader/reader/ui/ReaderHTML.kt        |  5 +--
 .../rss/reader/reader/ui/ReaderScreen.kt      | 43 ++++++++++++-------
 3 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/app/App.kt b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/app/App.kt
index ad2483415..4e59cd126 100644
--- a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/app/App.kt
+++ b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/app/App.kt
@@ -49,6 +49,7 @@ import dev.sasikanth.rss.reader.search.ui.SearchScreen
 import dev.sasikanth.rss.reader.settings.ui.SettingsScreen
 import dev.sasikanth.rss.reader.share.LocalShareHandler
 import dev.sasikanth.rss.reader.share.ShareHandler
+import dev.sasikanth.rss.reader.util.DispatchersProvider
 import dev.sasikanth.rss.reader.utils.LocalWindowSizeClass
 import me.tatarka.inject.annotations.Inject
 
@@ -62,6 +63,7 @@ fun App(
   shareHandler: ShareHandler,
   linkHandler: LinkHandler,
   imageLoader: ImageLoader,
+  dispatchersProvider: DispatchersProvider,
 ) {
   setSingletonImageLoaderFactory { imageLoader }
 
@@ -109,7 +111,11 @@ fun App(
                 AboutScreen(aboutPresenter = screen.presenter, modifier = fillMaxSizeModifier)
               }
               is Screen.Reader -> {
-                ReaderScreen(presenter = screen.presenter, modifier = fillMaxSizeModifier)
+                ReaderScreen(
+                  presenter = screen.presenter,
+                  dispatchersProvider = dispatchersProvider,
+                  modifier = fillMaxSizeModifier
+                )
               }
               is Screen.AddFeed -> {
                 AddFeedScreen(presenter = screen.presenter, modifier = fillMaxSizeModifier)
diff --git a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderHTML.kt b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderHTML.kt
index f8d646a6a..a45494c12 100644
--- a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderHTML.kt
+++ b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderHTML.kt
@@ -16,9 +16,6 @@
 
 package dev.sasikanth.rss.reader.reader.ui
 
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.IO
-import kotlinx.coroutines.withContext
 import twine.shared.generated.resources.Res
 
 object ReaderHTML {
@@ -89,6 +86,6 @@ object ReaderHTML {
   }
 
   private suspend fun readFile(fileName: String): String {
-    return withContext(Dispatchers.IO) { Res.readBytes("files/reader/$fileName").decodeToString() }
+    return Res.readBytes("files/reader/$fileName").decodeToString()
   }
 }
diff --git a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderScreen.kt b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderScreen.kt
index 63e8ee61b..8ca78bf13 100644
--- a/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderScreen.kt
+++ b/shared/src/commonMain/kotlin/dev/sasikanth/rss/reader/reader/ui/ReaderScreen.kt
@@ -68,11 +68,17 @@ import dev.sasikanth.rss.reader.resources.icons.TwineIcons
 import dev.sasikanth.rss.reader.resources.icons.Website
 import dev.sasikanth.rss.reader.share.LocalShareHandler
 import dev.sasikanth.rss.reader.ui.AppTheme
+import dev.sasikanth.rss.reader.util.DispatchersProvider
 import dev.sasikanth.rss.reader.utils.asJSString
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 @Composable
-internal fun ReaderScreen(presenter: ReaderPresenter, modifier: Modifier = Modifier) {
+internal fun ReaderScreen(
+  presenter: ReaderPresenter,
+  dispatchersProvider: DispatchersProvider,
+  modifier: Modifier = Modifier
+) {
   val state by presenter.state.collectAsState()
   val coroutineScope = rememberCoroutineScope()
   val linkHandler = LocalLinkHandler.current
@@ -229,25 +235,30 @@ internal fun ReaderScreen(presenter: ReaderPresenter, modifier: Modifier = Modif
         }
 
         LaunchedEffect(state.content) {
-          val html =
-            ReaderHTML.create(
-              title = state.title!!,
-              feedName = state.feed!!.name,
-              feedHomePageLink = state.feed!!.homepageLink,
-              publishedAt = state.publishedAt!!,
-            )
+          withContext(dispatchersProvider.io) {
+            val htmlTemplate =
+              ReaderHTML.create(
+                title = state.title!!,
+                feedName = state.feed!!.name,
+                feedHomePageLink = state.feed!!.homepageLink,
+                publishedAt = state.publishedAt!!,
+              )
 
-          navigator.loadHtml(html, state.link)
+            navigator.loadHtml(htmlTemplate, state.link)
+          }
         }
 
         LaunchedEffect(webViewState.loadingState) {
-          if (
-            webViewState.loadingState == LoadingState.Finished && !state.content.isNullOrBlank()
-          ) {
-            navigator.evaluateJavaScript(
-              script =
-                "renderReaderView(${state.link.asJSString}, ${state.content.asJSString}, ${colors.asJSString})"
-            )
+          withContext(dispatchersProvider.io) {
+            val hasHtmlTemplateLoaded =
+              webViewState.loadingState == LoadingState.Finished && !state.content.isNullOrBlank()
+
+            if (hasHtmlTemplateLoaded) {
+              navigator.evaluateJavaScript(
+                script =
+                  "renderReaderView(${state.link.asJSString}, ${state.content.asJSString}, ${colors.asJSString})"
+              )
+            }
           }
         }