Merge pull request video-dev#1379 from Waidd/subtitleTracks-api

Rewrite setSubtitleTrackInternal method.

doc/API.md

@@ -95,6 +95,10 @@
 - [Audio Tracks Control API](#audio-tracks-control-api)
   - [`hls.audioTracks`](#hlsaudiotracks)
   - [`hls.audioTrack`](#hlsaudiotrack)
+- [Subtitle Tracks Control API](#subtitle-tracks-control-api)
+  - [`hls.subtitleTracks`](#hlssubtitletracks)
+  - [`hls.subtitleTrack`](#hlssubtitletrack)
+  - [`hls.subtitleDisplay`](#hlssubtitledisplay)
 - [Live stream API](#live-stream-api)
   - [`hls.liveSyncPosition`](#hlslivesyncposition)
 - [Runtime Events](#runtime-events)
@@ -1075,6 +1079,22 @@ get : array of audio tracks exposed in manifest
 
 get/set : audio track id (returned by)
 
+## Subtitle Tracks Control API
+
+### `hls.subtitleTracks`
+
+get : array of subtitle tracks exposed in manifest
+
+### `hls.subtitleTrack`
+
+get/set : subtitle track id (returned by)
+
+### `hls.subtitleDisplay`
+
+(default: `false`)
+
+get/set : boolean to enable/disable subtitle display by hls.js
+
 ## Live stream API
 
 ### `hls.liveSyncPosition`

src/controller/subtitle-track-controller.js

@@ -28,6 +28,7 @@ class SubtitleTrackController extends EventHandler {
     this.tracks = [];
     this.trackId = -1;
     this.media = undefined;
+    this.subtitleDisplay = false;
   }
 
   _onTextTracksChanged() {
@@ -164,23 +165,42 @@ class SubtitleTrackController extends EventHandler {
 
  setSubtitleTrackInternal(newId) {
     // check if level idx is valid
-    if (newId >= 0 && newId < this.tracks.length) {
-      // stopping live reloading timer if any
-      if (this.timer) {
-       clearInterval(this.timer);
-       this.timer = null;
-      }
-      this.trackId = newId;
-      logger.log(`switching to subtitle track ${newId}`);
-      let subtitleTrack = this.tracks[newId];
-      this.hls.trigger(Event.SUBTITLE_TRACK_SWITCH, {id: newId});
-       // check if we need to load playlist for this subtitle Track
-      let details = subtitleTrack.details;
-      if (details === undefined || details.live === true) {
-        // track not retrieved yet, or live playlist we need to (re)load it
-        logger.log(`(re)loading playlist for subtitle track ${newId}`);
-        this.hls.trigger(Event.SUBTITLE_TRACK_LOADING, {url: subtitleTrack.url, id: newId});
-      }
+    if (newId < -1 || newId >= this.tracks.length) {
+      return;
+    }
+
+    // stopping live reloading timer if any
+    if (this.timer) {
+      clearInterval(this.timer);
+      this.timer = null;
+    }
+
+    let textTracks = filterSubtitleTracks(this.media.textTracks);
+
+    // hide currently enabled subtitle track
+    if (this.trackId !== -1 && this.subtitleDisplay) {
+      textTracks[this.trackId].mode = 'hidden';
+    }
+
+    this.trackId = newId;
+    logger.log(`switching to subtitle track ${newId}`);
+    this.hls.trigger(Event.SUBTITLE_TRACK_SWITCH, {id: newId});
+
+    if (newId === -1) {
+      return;
+    }
+
+    let subtitleTrack = this.tracks[newId];
+    if (this.subtitleDisplay) {
+      textTracks[newId].mode = 'showing';
+    }
+
+    // check if we need to load playlist for this subtitle Track
+    let details = subtitleTrack.details;
+    if (details === undefined || details.live === true) {
+      // track not retrieved yet, or live playlist we need to (re)load it
+      logger.log(`(re)loading playlist for subtitle track ${newId}`);
+      this.hls.trigger(Event.SUBTITLE_TRACK_LOADING, {url: subtitleTrack.url, id: newId});
     }
   }
 }

src/hls.js

@@ -386,4 +386,16 @@ export default class Hls {
       subtitleTrackController.subtitleTrack = subtitleTrackId;
     }
   }
+
+  get subtitleDisplay() {
+    const subtitleTrackController = this.subtitleTrackController;
+    return subtitleTrackController ? subtitleTrackController.subtitleDisplay : false;
+  }
+
+  set subtitleDisplay(value) {
+    const subtitleTrackController = this.subtitleTrackController;
+    if (subtitleTrackController) {
+      subtitleTrackController.subtitleDisplay = value;
+    }
+  }
 }