[Android] Fix audio player wrong elapsed time when shuffling

[Nicolas Pomepuy]

vlc-android | branch: master | Nicolas Pomepuy <nicolas at videolabs.io> | Thu Jul 23 08:01:19 2020 +0200| [76855c9cd701410120de0015e0f1f72e7f14e8d1] | committer: Nicolas Pomepuy

Fix audio player wrong elapsed time when shuffling

Fixes #1423

> https://code.videolan.org/videolan/vlc-android/commit/76855c9cd701410120de0015e0f1f72e7f14e8d1
---

 .../vlc-android/src/org/videolan/vlc/PlaybackService.kt      |  4 ++++
 .../src/org/videolan/vlc/gui/audio/AudioPlayer.kt            |  5 +----
 .../src/org/videolan/vlc/media/PlaylistManager.kt            | 12 ++++++++++++
 .../src/org/videolan/vlc/viewmodels/PlaylistModel.kt         |  3 +++
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/application/vlc-android/src/org/videolan/vlc/PlaybackService.kt b/application/vlc-android/src/org/videolan/vlc/PlaybackService.kt
index 8ae326c9d..be3127ede 100644
--- a/application/vlc-android/src/org/videolan/vlc/PlaybackService.kt
+++ b/application/vlc-android/src/org/videolan/vlc/PlaybackService.kt
@@ -346,6 +346,10 @@ class PlaybackService : MediaBrowserServiceCompat(), LifecycleOwner {
         @MainThread
         get() = playlistManager.getMediaList()
 
+    val previousTotalTime
+        @MainThread
+        get() = playlistManager.previousTotalTime()
+
     val mediaLocations: List<String>
         @MainThread
         get() {
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/audio/AudioPlayer.kt b/application/vlc-android/src/org/videolan/vlc/gui/audio/AudioPlayer.kt
index 70d21eaee..53d689341 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/audio/AudioPlayer.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/audio/AudioPlayer.kt
@@ -310,10 +310,7 @@ class AudioPlayer : Fragment(), PlaylistAdapter.IPlayer, TextWatcher, IAudioPlay
             val text = withContext(Dispatchers.Default) {
                 val medias = playlistModel.medias ?: return at withContext ""
                 if (playlistModel.currentMediaPosition == -1) return at withContext ""
-                val elapsedTracksTime = medias.asSequence()
-                        .take(playlistModel.currentMediaPosition)
-                        .map { it.length }
-                        .sum()
+                val elapsedTracksTime = playlistModel.previousTotalTime ?: return at withContext ""
                 val totalTime = elapsedTracksTime + progress.time
                 val currentProgressText = if (totalTime == 0L) "0s" else Tools.millisToString(totalTime, true, false, false)
 
diff --git a/application/vlc-android/src/org/videolan/vlc/media/PlaylistManager.kt b/application/vlc-android/src/org/videolan/vlc/media/PlaylistManager.kt
index d4b13f12a..190d8e055 100644
--- a/application/vlc-android/src/org/videolan/vlc/media/PlaylistManager.kt
+++ b/application/vlc-android/src/org/videolan/vlc/media/PlaylistManager.kt
@@ -578,6 +578,18 @@ class PlaylistManager(val service: PlaybackService) : MediaWrapperList.EventList
         }
     }
 
+    fun previousTotalTime() = if (shuffling) {
+        mediaList.copy.asSequence()
+                .filterIndexed { index, _ -> previous.contains(index) }
+                .map { it.length }
+                .sum()
+    } else {
+        mediaList.copy.asSequence()
+                .take(currentIndex)
+                .map { it.length }
+                .sum()
+    }
+
     /**
      * Expand the current media.
      * @return the index of the media was expanded, and -1 if no media was expanded
diff --git a/application/vlc-android/src/org/videolan/vlc/viewmodels/PlaylistModel.kt b/application/vlc-android/src/org/videolan/vlc/viewmodels/PlaylistModel.kt
index b496fdfb3..14523f0b6 100644
--- a/application/vlc-android/src/org/videolan/vlc/viewmodels/PlaylistModel.kt
+++ b/application/vlc-android/src/org/videolan/vlc/viewmodels/PlaylistModel.kt
@@ -183,6 +183,9 @@ class PlaylistModel : ViewModel(), PlaybackService.Callback by EmptyPBSCallback
     val medias
         get() = service?.media
 
+    val previousTotalTime
+        get() = service?.previousTotalTime
+
     fun shuffle() = service?.shuffle()
 
     fun load(medialist: List<MediaWrapper>, position: Int) = service?.load(medialist, position)