1 files changed, 59 insertions, 0 deletions
diff --git a/mobile/android/actors/MediaControlDelegateChild.sys.mjs b/mobile/android/actors/MediaControlDelegateChild.sys.mjs
new file mode 100644
index 0000000000..1db32b33f0
--- /dev/null
+++ b/mobile/android/actors/MediaControlDelegateChild.sys.mjs
@@ -0,0 +1,59 @@
+/* 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/. */
+
+import { GeckoViewActorChild } from "resource://gre/modules/GeckoViewActorChild.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  MediaUtils: "resource://gre/modules/MediaUtils.sys.mjs",
+  setTimeout: "resource://gre/modules/Timer.sys.mjs",
+});
+
+export class MediaControlDelegateChild extends GeckoViewActorChild {
+  handleEvent(aEvent) {
+    debug`handleEvent: ${aEvent.type}`;
+
+    switch (aEvent.type) {
+      case "MozDOMFullscreen:Entered":
+      case "MozDOMFullscreen:Exited":
+        this.handleFullscreenChanged(true);
+        break;
+    }
+  }
+
+  async handleFullscreenChanged(retry) {
+    debug`handleFullscreenChanged`;
+
+    const element = this.document.fullscreenElement;
+    const mediaElement = lazy.MediaUtils.findMediaElement(element);
+
+    if (element && !mediaElement) {
+      // Non-media element fullscreen.
+      debug`No fullscreen media element found.`;
+    }
+
+    const activated = await this.eventDispatcher.sendRequestForResult({
+      type: "GeckoView:MediaSession:Fullscreen",
+      metadata: lazy.MediaUtils.getMetadata(mediaElement) ?? {},
+      enabled: !!element,
+    });
+    if (activated) {
+      return;
+    }
+    if (retry && element) {
+      // When media session is going to active, we have a race condition of
+      // full screen event because media session will be activated by full
+      // screen event.
+      // So we retry to call media session delegate for this situation.
+      lazy.setTimeout(() => {
+        this.handleFullscreenChanged(false);
+      }, 100);
+    }
+  }
+}
+
+const { debug } = MediaControlDelegateChild.initLogging(
+  "MediaControlDelegateChild"
+);