Fix audiobook locators' total progression (#553)

Author: mickael-menu

CHANGELOG.md

@@ -4,7 +4,14 @@ 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 computing the total progression of audiobook locators.
+
 
 ## [3.0.0-beta.2]
 

readium/navigators/media/audio/src/main/java/org/readium/navigator/media/audio/AudioNavigator.kt

@@ -90,11 +90,12 @@ public class AudioNavigator<S : Configurable.Settings, P : Configurable.Preferen
             val currentItem = readingOrder.items[playback.index]
             val link = requireNotNull(publication.linkWithHref(currentItem.href))
             val item = readingOrder.items[playback.index]
-            val itemStartPosition = readingOrder.items
-                .slice(0 until playback.index)
-                .mapNotNull { it.duration }
-                .takeIf { it.size == readingOrder.items.size }
-                ?.sum()
+            val itemStartPosition =
+                readingOrder.items
+                    .takeIf { readingOrderHasDuration }
+                    ?.slice(0 until playback.index)
+                    ?.mapNotNull { it.duration }
+                    ?.sum()
 
             val coercedOffset =
                 playback.coerceOffset(currentItem.duration)
@@ -114,6 +115,9 @@ public class AudioNavigator<S : Configurable.Settings, P : Configurable.Preferen
             )
         }
 
+    private val readingOrderHasDuration: Boolean =
+        readingOrder.items.all { it.duration != null }
+
     override val playback: StateFlow<Playback> =
         audioEngine.playback.mapStateIn(coroutineScope) { playback ->
             val itemDuration =