Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/remote/shared/listeners/LoadListener.sys.mjs b/remote/shared/listeners/LoadListener.sys.mjs
new file mode 100644
index 0000000000..cccfca7a90
--- /dev/null
+++ b/remote/shared/listeners/LoadListener.sys.mjs
@@ -0,0 +1,103 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  EventEmitter: "resource://gre/modules/EventEmitter.sys.mjs",
+});
+
+/**
+ * The LoadListener can be used to listen for load events.
+ *
+ * Example:
+ * ```
+ * const listener = new LoadListener();
+ * listener.on("DOMContentLoaded", onDOMContentLoaded);
+ * listener.startListening();
+ *
+ * const onDOMContentLoaded = (eventName, data = {}) => {
+ *   const { target } = data;
+ *   ...
+ * };
+ * ```
+ *
+ * @fires message
+ *    The LoadListener emits "DOMContentLoaded" and "load" events,
+ *    with the following object as payload:
+ *      - {Document} target
+ *            The target document.
+ */
+export class LoadListener {
+  #abortController;
+  #window;
+
+  /**
+   * Create a new LoadListener instance.
+   */
+  constructor(win) {
+    lazy.EventEmitter.decorate(this);
+
+    // Use an abort controller instead of removeEventListener because destroy
+    // might be called close to the window global destruction.
+    this.#abortController = null;
+
+    this.#window = win;
+  }
+
+  destroy() {
+    this.stopListening();
+  }
+
+  startListening() {
+    if (this.#abortController) {
+      return;
+    }
+
+    this.#abortController = new AbortController();
+
+    // Events are attached to the windowRoot instead of the regular window to
+    // avoid issues with document.open (Bug 1822772).
+    this.#window.windowRoot.addEventListener(
+      "DOMContentLoaded",
+      this.#onDOMContentLoaded,
+      {
+        capture: true,
+        mozSystemGroup: true,
+        signal: this.#abortController.signal,
+      }
+    );
+
+    this.#window.windowRoot.addEventListener("load", this.#onLoad, {
+      capture: true,
+      mozSystemGroup: true,
+      signal: this.#abortController.signal,
+    });
+  }
+
+  stopListening() {
+    if (!this.#abortController) {
+      return;
+    }
+
+    this.#abortController.abort();
+    this.#abortController = null;
+  }
+
+  #onDOMContentLoaded = event => {
+    // Check that this event was emitted for the relevant window, because events
+    // from inner frames can bubble to the windowRoot.
+    if (event.target.defaultView === this.#window) {
+      this.emit("DOMContentLoaded", { target: event.target });
+    }
+  };
+
+  #onLoad = event => {
+    // Check that this event was emitted for the relevant window, because events
+    // from inner frames can bubble to the windowRoot.
+    if (event.target.defaultView === this.#window) {
+      this.emit("load", { target: event.target });
+    }
+  };
+}