Update default subtitle logic to work with custom subtitle function

components/ItemGrid/LoadVideoContentTask.bs

@@ -151,13 +151,16 @@ sub LoadItems_AddVideoContent(video as object, mediaSourceId as dynamic, audio_s
             end if
 
             addSubtitlesToVideo(video, meta)
+        else
+            video.SelectedSubtitle = subtitle_idx
         end if
+    else
+        video.SelectedSubtitle = subtitle_idx
     end if
 
     video.videoId = video.id
     video.mediaSourceId = mediaSourceId
     video.audioIndex = audio_stream_idx
-    video.SelectedSubtitle = subtitle_idx
 
     video.PlaySessionId = m.playbackInfo.PlaySessionId
 

components/video/VideoPlayerView.bs

@@ -323,11 +323,6 @@ sub onVideoContentLoaded()
     m.top.transcodeParams = videoContent[0].transcodeparams
     m.chapters = videoContent[0].chapters
 
-    ' Allow default subtitles
-    m.top.unobserveField("selectedSubtitle")
-    m.top.selectedSubtitle = videoContent[0].selectedSubtitle
-    m.top.observeField("selectedSubtitle", "onSubtitleChange")
-
     m.osd.itemTitleText = m.top.content.title
 
     populateChapterMenu()
@@ -340,6 +335,29 @@ sub onVideoContentLoaded()
         m.top.allowCaptions = true
     end if
 
+    ' Allow default subtitles
+    m.top.unobserveField("selectedSubtitle")
+
+    ' Set subtitleTrack property is subs are natively supported by Roku
+    selectedSubtitle = invalid
+    for each subtitle in m.top.fullSubtitleData
+        if subtitle.Index = videoContent[0].selectedSubtitle
+            selectedSubtitle = subtitle
+            exit for
+        end if
+    end for
+
+    if isValid(selectedSubtitle)
+        availableSubtitleTrackIndex = availSubtitleTrackIdx(selectedSubtitle.Track.TrackName)
+        if availableSubtitleTrackIndex <> -1
+            m.top.subtitleTrack = m.top.availableSubtitleTracks[availableSubtitleTrackIndex].TrackName
+        end if
+    end if
+
+    m.top.selectedSubtitle = videoContent[0].selectedSubtitle
+
+    m.top.observeField("selectedSubtitle", "onSubtitleChange")
+
     if isValid(m.top.audioIndex)
         m.top.audioTrack = (m.top.audioIndex + 1).toStr()
     else
@@ -587,6 +605,25 @@ function stateAllowsOSD() as boolean
     return inArray(validStates, m.top.state)
 end function
 
+
+' availSubtitleTrackIdx: Returns Roku's index for requested subtitle track
+'
+' @param {string} tracknameToFind - TrackName for subtitle we're looking to match
+' @return {integer} indicating Roku's index for requested subtitle track. Returns -1 if not found
+function availSubtitleTrackIdx(tracknameToFind as string) as integer
+    idx = 0
+    for each availTrack in m.top.availableSubtitleTracks
+        ' The TrackName must contain the URL we supplied originally, though
+        ' Roku mangles the name a bit, so we check if the URL is a substring, rather
+        ' than strict equality
+        if Instr(1, availTrack.TrackName, tracknameToFind)
+            return idx
+        end if
+        idx = idx + 1
+    end for
+    return -1
+end function
+
 function onKeyEvent(key as string, press as boolean) as boolean
 
     ' Keypress handler while user is inside the chapter menu