Fix a race condition when initializing the EPUB navigator (#622)

Author: mickael-menu

CHANGELOG.md

@@ -4,12 +4,22 @@ All notable changes to this project will be documented in this file. Take a look
 
 **Warning:** Features marked as *experimental* may change or be removed in a future release without notice. Use with caution.
 
-<!-- ## [Unreleased] -->
+## [Unreleased]
+
+### Fixed
+
+#### Navigator
+
+* Fixed a race condition causing EPUB decorations to be applied twice when opening a publication.
+
+
 
 ## [3.0.3]
 
 ### Fixed
 
+#### LCP
+
 * Fixed `IllegalArgumentException` when trying to decrypt the end of a `CbcLcpResource`.
 
 

readium/navigator/src/main/java/org/readium/r2/navigator/epub/EpubNavigatorFragment.kt

@@ -672,11 +672,13 @@ public class EpubNavigatorFragment internal constructor(
             RunScriptCommand.Scope.LoadedResources -> {
                 r2PagerAdapter?.mFragments?.forEach { _, fragment ->
                     (fragment as? R2EpubPageFragment)
+                        ?.takeIf { it.isLoaded.value }
                         ?.runJavaScript(command.script)
                 }
             }
-            is RunScriptCommand.Scope.Resource -> {
+            is RunScriptCommand.Scope.LoadedResource -> {
                 loadedFragmentForHref(command.scope.href)
+                    ?.takeIf { it.isLoaded.value }
                     ?.runJavaScript(command.script)
             }
             is RunScriptCommand.Scope.WebView -> {

readium/navigator/src/main/java/org/readium/r2/navigator/epub/EpubNavigatorViewModel.kt

@@ -62,7 +62,7 @@ internal class EpubNavigatorViewModel(
         sealed class Scope {
             object CurrentResource : Scope()
             object LoadedResources : Scope()
-            data class Resource(val href: Url) : Scope()
+            data class LoadedResource(val href: Url) : Scope()
             data class WebView(val webView: R2BasicWebView) : Scope()
         }
     }
@@ -145,22 +145,39 @@ internal class EpubNavigatorViewModel(
             .launchIn(viewModelScope)
     }
 
-    fun onResourceLoaded(webView: R2BasicWebView, link: Link): RunScriptCommand {
-        val templates = decorationTemplates.toJSON().toString()
-            .replace("\\n", " ")
-        var script = "readium.registerDecorationTemplates($templates);\n"
+    fun onResourceLoaded(webView: R2BasicWebView, link: Link): List<RunScriptCommand> =
+        buildList {
+            val scope = RunScriptCommand.Scope.WebView(webView)
 
-        for ((group, decorations) in decorations) {
-            val changes = decorations
-                .filter { it.locator.href == link.url() }
-                .map { DecorationChange.Added(it) }
+            // Applies the Readium CSS properties in case they changed since they were injected
+            // in the HTML document.
+            val properties = css.value.run {
+                rsProperties.toCssProperties() + userProperties.toCssProperties()
+            }
 
-            val groupScript = changes.javascriptForGroup(group, decorationTemplates) ?: continue
-            script += "$groupScript\n"
-        }
+            add(
+                RunScriptCommand(
+                    script = "readium.setCSSProperties(${JSONObject(properties.toMap())});",
+                    scope = scope
+                )
+            )
 
-        return RunScriptCommand(script, scope = RunScriptCommand.Scope.WebView(webView))
-    }
+            // Applies the decorations.
+            val templates = decorationTemplates.toJSON().toString()
+                .replace("\\n", " ")
+            var script = "readium.registerDecorationTemplates($templates);\n"
+
+            for ((group, decorations) in decorations) {
+                val changes = decorations
+                    .filter { it.locator.href == link.url() }
+                    .map { DecorationChange.Added(it) }
+
+                val groupScript = changes.javascriptForGroup(group, decorationTemplates) ?: continue
+                script += "$groupScript\n"
+            }
+
+            add(RunScriptCommand(script, scope = scope))
+        }
 
     // Serving resources
 
@@ -296,7 +313,9 @@ internal class EpubNavigatorViewModel(
         } else {
             for ((href, changes) in source.changesByHref(target)) {
                 val script = changes.javascriptForGroup(group, decorationTemplates) ?: continue
-                cmds.add(RunScriptCommand(script, scope = RunScriptCommand.Scope.Resource(href)))
+                cmds.add(
+                    RunScriptCommand(script, scope = RunScriptCommand.Scope.LoadedResource(href))
+                )
             }
         }