1 files changed, 48 insertions, 0 deletions
diff --git a/toolkit/content/TopLevelVideoDocument.js b/toolkit/content/TopLevelVideoDocument.js
new file mode 100644
index 000000000..5a2b8a857
--- /dev/null
+++ b/toolkit/content/TopLevelVideoDocument.js
@@ -0,0 +1,48 @@
+/* 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";
+
+// <video> is used for top-level audio documents as well
+let videoElement = document.getElementsByTagName("video")[0];
+
+// 1. Handle fullscreen mode;
+// 2. Send keystrokes to the video element if the body element is focused,
+//    to be received by the event listener in videocontrols.xml.
+document.addEventListener("keypress", ev => {
+  if (ev.synthetic) // prevent recursion
+    return;
+
+  // Maximize the standalone video when pressing F11,
+  // but ignore audio elements
+  if (ev.key == "F11" && videoElement.videoWidth != 0 && videoElement.videoHeight != 0) {
+    // If we're in browser fullscreen mode, it means the user pressed F11
+    // while browser chrome or another tab had focus.
+    // Don't break leaving that mode, so do nothing here.
+    if (window.fullScreen) {
+      return;
+    }
+
+    // If we're not in broser fullscreen mode, prevent entering into that,
+    // so we don't end up there after pressing Esc.
+    ev.preventDefault();
+    ev.stopPropagation();
+
+    if (!document.mozFullScreenElement) {
+      videoElement.mozRequestFullScreen();
+    } else {
+      document.mozCancelFullScreen();
+    }
+    return;
+  }
+
+  // Check if the video element is focused, so it already receives
+  // keystrokes, and don't send it another one from here.
+  if (document.activeElement == videoElement)
+    return;
+
+  let newEvent = new KeyboardEvent("keypress", ev);
+  newEvent.synthetic = true;
+  videoElement.dispatchEvent(newEvent);
+});