feat(android): add subtitle event (#3566)

* feat: add onCues method to get access to subtitle content

android/src/main/java/com/brentvatne/common/react/VideoEventEmitter.java

@@ -59,6 +59,8 @@ public class VideoEventEmitter {
     private static final String EVENT_VOLUME_CHANGE = "onVolumeChange";
     private static final String EVENT_AUDIO_TRACKS = "onAudioTracks";
     private static final String EVENT_TEXT_TRACKS = "onTextTracks";
+
+    private static final String EVENT_TEXT_TRACK_DATA_CHANGED = "onTextTrackDataChanged";
     private static final String EVENT_VIDEO_TRACKS = "onVideoTracks";
     private static final String EVENT_ON_RECEIVE_AD_EVENT = "onReceiveAdEvent";
 
@@ -86,6 +88,7 @@ public class VideoEventEmitter {
             EVENT_VOLUME_CHANGE,
             EVENT_AUDIO_TRACKS,
             EVENT_TEXT_TRACKS,
+            EVENT_TEXT_TRACK_DATA_CHANGED,
             EVENT_VIDEO_TRACKS,
             EVENT_BANDWIDTH,
             EVENT_ON_RECEIVE_AD_EVENT
@@ -116,6 +119,7 @@ public class VideoEventEmitter {
             EVENT_VOLUME_CHANGE,
             EVENT_AUDIO_TRACKS,
             EVENT_TEXT_TRACKS,
+            EVENT_TEXT_TRACK_DATA_CHANGED,
             EVENT_VIDEO_TRACKS,
             EVENT_BANDWIDTH,
             EVENT_ON_RECEIVE_AD_EVENT
@@ -144,6 +148,7 @@ public class VideoEventEmitter {
     private static final String EVENT_PROP_VIDEO_TRACKS = "videoTracks";
     private static final String EVENT_PROP_AUDIO_TRACKS = "audioTracks";
     private static final String EVENT_PROP_TEXT_TRACKS = "textTracks";
+    private static final String EVENT_PROP_TEXT_TRACK_DATA = "subtitleTracks";
     private static final String EVENT_PROP_HAS_AUDIO_FOCUS = "hasAudioFocus";
     private static final String EVENT_PROP_IS_BUFFERING = "isBuffering";
     private static final String EVENT_PROP_PLAYBACK_RATE = "playbackRate";
@@ -284,6 +289,12 @@ public class VideoEventEmitter {
         receiveEvent(EVENT_TEXT_TRACKS, arrayToObject(EVENT_PROP_TEXT_TRACKS, textTracksToArray(textTracks)));
     }
 
+    public void textTrackDataChanged(String textTrackData){
+        WritableMap event = Arguments.createMap();
+        event.putString(EVENT_PROP_TEXT_TRACK_DATA, textTrackData);
+        receiveEvent(EVENT_TEXT_TRACK_DATA_CHANGED, event);
+    }
+
     public void videoTracks(ArrayList<VideoTrack> videoTracks){
         receiveEvent(EVENT_VIDEO_TRACKS, arrayToObject(EVENT_PROP_VIDEO_TRACKS, videoTracksToArray(videoTracks)));
     }

android/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java

@@ -41,6 +41,7 @@ import androidx.media3.common.Timeline;
 import androidx.media3.common.TrackGroup;
 import androidx.media3.common.TrackSelectionOverride;
 import androidx.media3.common.Tracks;
+import androidx.media3.common.text.CueGroup;
 import androidx.media3.common.util.Util;
 import androidx.media3.datasource.DataSource;
 import androidx.media3.datasource.DataSpec;
@@ -1521,6 +1522,13 @@ public class ReactExoplayerView extends FrameLayout implements
         eventEmitter.timedMetadata(metadataArray);
     }
 
+    public void onCues(CueGroup cueGroup) {
+        if (!cueGroup.cues.isEmpty() && cueGroup.cues.get(0).text != null) {
+            String subtitleText = cueGroup.cues.get(0).text.toString();
+            eventEmitter.textTrackDataChanged(subtitleText);
+        }
+    }
+
     // ReactExoplayerViewManager public api
 
     public void setSrc(final Uri uri, final long startPositionMs, final long cropStartMs, final long cropEndMs, final String extension, Map<String, String> headers) {

docs/pages/component/events.mdx

@@ -516,7 +516,7 @@ Example:
 
 ### `onTextTrackDataChanged`
 
-<PlatformsList types={['iOS']} />
+<PlatformsList types={['Android', 'iOS']} />
 
 Callback function that is called when new subtitle data is available. It provides the actual subtitle content for the current selected text track, if available (mainly WebVTT).
 

examples/basic/src/VideoPlayer.tsx

@@ -120,15 +120,14 @@ class VideoPlayer extends Component {
       description: 'another bunny (can be saved)',
       uri: 'https://rawgit.com/mediaelement/mediaelement-files/master/big_buck_bunny.mp4',
     },
-  ];
-
-  srcIosList = [
     {
       description: 'sintel with subtitles',
       uri: 'https://bitmovin-a.akamaihd.net/content/sintel/hls/playlist.m3u8',
     },
   ];
 
+  srcIosList = [];
+
   srcAndroidList = [
     {
       description: 'Another live sample',