1 files changed, 34 insertions, 0 deletions
diff --git a/toolkit/modules/AboutPagesUtils.sys.mjs b/toolkit/modules/AboutPagesUtils.sys.mjs
new file mode 100644
index 0000000000..5b8ba5e13c
--- /dev/null
+++ b/toolkit/modules/AboutPagesUtils.sys.mjs
@@ -0,0 +1,34 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * vim: sw=2 ts=2 sts=2 expandtab
+ * 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 { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+export const AboutPagesUtils = {};
+
+XPCOMUtils.defineLazyGetter(AboutPagesUtils, "visibleAboutUrls", () => {
+  const urls = [];
+  const rx = /@mozilla.org\/network\/protocol\/about;1\?what\=(.*)$/;
+  for (const cid in Cc) {
+    const result = cid.match(rx);
+    if (!result) {
+      continue;
+    }
+    const [, aboutType] = result;
+    try {
+      const am = Cc[cid].getService(Ci.nsIAboutModule);
+      const uri = Services.io.newURI(`about:${aboutType}`);
+      const flags = am.getURIFlags(uri);
+      if (!(flags & Ci.nsIAboutModule.HIDE_FROM_ABOUTABOUT)) {
+        urls.push(`about:${aboutType}`);
+      }
+    } catch (e) {
+      // getService() might have thrown if the component doesn't actually
+      // implement nsIAboutModule
+    }
+  }
+  urls.sort();
+  return urls;
+});