Bug 1766388 - Add Video-Adapter for supporting Hotstar Subtitles. r=kpatenio

Differential Revision: https://phabricator.services.mozilla.com/D144786

browser/extensions/pictureinpicture/data/picture_in_picture_overrides.js

@@ -51,6 +51,12 @@ let AVAILABLE_PIP_OVERRIDES;
       },
     },
 
+    hotstar: {
+      "https://*.hotstar.com/*": {
+        videoWrapperScriptPath: "video-wrappers/hotstar.js",
+      },
+    },
+
     instagram: {
       "https://www.instagram.com/*": { policy: TOGGLE_POLICIES.ONE_QUARTER },
     },

browser/extensions/pictureinpicture/moz.build

@@ -30,6 +30,7 @@ FINAL_TARGET_FILES.features["pictureinpicture@mozilla.org"]["lib"] += [
 FINAL_TARGET_FILES.features["pictureinpicture@mozilla.org"]["video-wrappers"] += [
     "video-wrappers/airmozilla.js",
     "video-wrappers/funimation.js",
+    "video-wrappers/hotstar.js",
     "video-wrappers/mock-wrapper.js",
     "video-wrappers/netflix.js",
     "video-wrappers/piped.js",

browser/extensions/pictureinpicture/video-wrappers/hotstar.js

@@ -0,0 +1,41 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+class PictureInPictureVideoWrapper {
+  setCaptionContainerObserver(video, updateCaptionsFunction) {
+    let container = document.querySelector(".subtitle-container");
+
+    if (container) {
+      updateCaptionsFunction("");
+      const callback = function(mutationsList, observer) {
+        let textNodeList = container
+          .querySelector(".shaka-text-container")
+          ?.querySelectorAll("span");
+        if (!textNodeList) {
+          updateCaptionsFunction("");
+          return;
+        }
+
+        updateCaptionsFunction(
+          Array.from(textNodeList, x => x.textContent).join("\n")
+        );
+      };
+
+      // immediately invoke the callback function to add subtitles to the PiP window
+      callback([1], null);
+
+      let captionsObserver = new MutationObserver(callback);
+
+      captionsObserver.observe(container, {
+        attributes: false,
+        childList: true,
+        subtree: true,
+      });
+    }
+  }
+}
+
+this.PictureInPictureVideoWrapper = PictureInPictureVideoWrapper;

toolkit/actors/PictureInPictureChild.jsm

@@ -1366,6 +1366,8 @@ class PictureInPictureChild extends JSWindowActorChild {
     this.setActiveTextTrack(originatingVideo.textTracks);
 
     if (!this._currentWebVTTTrack) {
+      // If WebVTT track is invalid, try using a video wrapper
+      this.setUpCaptionChangeListener(originatingVideo);
       return;
     }
 
@@ -1787,7 +1789,7 @@ class PictureInPictureChild extends JSWindowActorChild {
     for (let i = 0; i < textTrackList.length; i++) {
       let track = textTrackList[i];
       let isCCText = track.kind === "subtitles" || track.kind === "captions";
-      if (isCCText && track.mode === "showing") {
+      if (isCCText && track.mode === "showing" && track.cues) {
         this._currentWebVTTTrack = track;
         break;
       }