Adding upstream version 110.0.1.upstream/110.0.1upstream

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

6 files changed, 1539 insertions, 0 deletions

diff --git a/browser/components/customizableui/content/.eslintrc.js b/browser/components/customizableui/content/.eslintrc.js
new file mode 100644
index 0000000000..43ab18578d
--- /dev/null
+++ b/browser/components/customizableui/content/.eslintrc.js
@@ -0,0 +1,13 @@
+/* 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";
+
+module.exports = {
+  env: {
+    "mozilla/browser-window": true,
+  },
+
+  plugins: ["mozilla"],
+};
diff --git a/browser/components/customizableui/content/customizeMode.inc.xhtml b/browser/components/customizableui/content/customizeMode.inc.xhtml
new file mode 100644
index 0000000000..c44cc1bc18
--- /dev/null
+++ b/browser/components/customizableui/content/customizeMode.inc.xhtml
@@ -0,0 +1,119 @@
+<!-- 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/. -->
+
+<box id="customization-content-container">
+<box id="customization-palette-container">
+  <label id="customization-header" data-l10n-id="customize-mode-menu-and-toolbars-header"></label>
+  <vbox id="customization-palette" class="customization-palette" hidden="true"/>
+  <html:div id="customization-pong-arena" hidden="true"/>
+  <spacer id="customization-spacer"/>
+</box>
+<vbox id="customization-panel-container">
+  <vbox id="customization-panelWrapper">
+    <box class="panel-arrowbox">
+      <image class="panel-arrow" side="top"/>
+    </box>
+    <box class="panel-arrowcontent" side="top" flex="1">
+      <vbox id="customization-panelHolder">
+        <description id="customization-panelHeader" data-l10n-id="customize-mode-overflow-list-title"></description>
+        <description id="customization-panelDescription" data-l10n-id="customize-mode-overflow-list-description"></description>
+      </vbox>
+      <box class="panel-inner-arrowcontentfooter" hidden="true"/>
+    </box>
+  </vbox>
+</vbox>
+</box>
+<hbox id="customization-footer">
+<checkbox id="customization-titlebar-visibility-checkbox" class="customizationmode-checkbox"
+# NB: because oncommand fires after click, by the time we've fired, the checkbox binding
+#    will already have switched the button's state, so this is correct:
+          oncommand="gCustomizeMode.toggleTitlebar(this.checked)" data-l10n-id="customize-mode-titlebar"/>
+<button id="customization-toolbar-visibility-button" class="customizationmode-button" type="menu" data-l10n-id="customize-mode-toolbars">
+  <menupopup id="customization-toolbar-menu" onpopupshowing="onViewToolbarsPopupShowing(event)"/>
+</button>
+<button id="customization-uidensity-button"
+        data-l10n-id="customize-mode-uidensity"
+        class="customizationmode-button"
+        type="menu"
+        hidden="true">
+  <panel type="arrow" id="customization-uidensity-menu"
+         orient="vertical"
+         onpopupshowing="gCustomizeMode.onUIDensityMenuShowing();"
+         position="topleft bottomleft"
+         flip="none"
+         role="menu">
+    <menuitem id="customization-uidensity-menuitem-compact"
+              class="menuitem-iconic customization-uidensity-menuitem"
+              role="menuitemradio"
+              data-l10n-id="customize-mode-uidensity-menu-compact-unsupported"
+              tabindex="0"
+              onfocus="gCustomizeMode.updateUIDensity(this.mode);"
+              onmouseover="gCustomizeMode.updateUIDensity(this.mode);"
+              onblur="gCustomizeMode.resetUIDensity();"
+              onmouseout="gCustomizeMode.resetUIDensity();"
+              oncommand="gCustomizeMode.setUIDensity(this.mode);"/>
+    <menuitem id="customization-uidensity-menuitem-normal"
+              class="menuitem-iconic customization-uidensity-menuitem"
+              role="menuitemradio"
+              data-l10n-id="customize-mode-uidensity-menu-normal"
+              tabindex="0"
+              onfocus="gCustomizeMode.updateUIDensity(this.mode);"
+              onmouseover="gCustomizeMode.updateUIDensity(this.mode);"
+              onblur="gCustomizeMode.resetUIDensity();"
+              onmouseout="gCustomizeMode.resetUIDensity();"
+              oncommand="gCustomizeMode.setUIDensity(this.mode);"/>
+#ifndef XP_MACOSX
+    <menuitem id="customization-uidensity-menuitem-touch"
+              class="menuitem-iconic customization-uidensity-menuitem"
+              role="menuitemradio"
+              data-l10n-id="customize-mode-uidensity-menu-touch"
+              tabindex="0"
+              onfocus="gCustomizeMode.updateUIDensity(this.mode);"
+              onmouseover="gCustomizeMode.updateUIDensity(this.mode);"
+              onblur="gCustomizeMode.resetUIDensity();"
+              onmouseout="gCustomizeMode.resetUIDensity();"
+              oncommand="gCustomizeMode.setUIDensity(this.mode);">
+    </menuitem>
+    <spacer hidden="true" id="customization-uidensity-touch-spacer"/>
+    <checkbox id="customization-uidensity-autotouchmode-checkbox"
+              hidden="true"
+              data-l10n-id="customize-mode-uidensity-auto-touch-mode-checkbox"
+              oncommand="gCustomizeMode.updateAutoTouchMode(this.checked)"/>
+#endif
+  </panel>
+</button>
+<label is="text-link"
+       id="customization-lwtheme-link"
+       data-l10n-id="customize-mode-lwthemes-link"
+       onclick="gCustomizeMode.openAddonsManagerThemes();" />
+
+<button id="whimsy-button"
+        type="checkbox"
+        class="customizationmode-button"
+        oncommand="gCustomizeMode.togglePong(this.checked);"
+        hidden="true"/>
+
+<spacer id="customization-footer-spacer"/>
+#ifdef XP_MACOSX
+    <button id="customization-touchbar-button"
+        class="customizationmode-button"
+        hidden="true"
+        oncommand="gCustomizeMode.customizeTouchBar();"
+        data-l10n-id="customize-mode-touchbar-cmd"/>
+    <spacer hidden="true" id="customization-touchbar-spacer"/>
+#endif
+<button id="customization-undo-reset-button"
+        class="customizationmode-button"
+        hidden="true"
+        oncommand="gCustomizeMode.undoReset();"
+        data-l10n-id="customize-mode-undo-cmd"/>
+<button id="customization-reset-button"
+        oncommand="gCustomizeMode.reset();"
+        data-l10n-id="customize-mode-restore-defaults"
+        class="customizationmode-button"/>
+<button id="customization-done-button"
+        oncommand="gCustomizeMode.exit();"
+        data-l10n-id="customize-mode-done"
+        class="customizationmode-button"/>
+</hbox>
diff --git a/browser/components/customizableui/content/jar.mn b/browser/components/customizableui/content/jar.mn
new file mode 100644
index 0000000000..08642a640c
--- /dev/null
+++ b/browser/components/customizableui/content/jar.mn
@@ -0,0 +1,6 @@
+# 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/.
+
+browser.jar:
+  content/browser/customizableui/panelUI.js
diff --git a/browser/components/customizableui/content/moz.build b/browser/components/customizableui/content/moz.build
new file mode 100644
index 0000000000..d988c0ff9b
--- /dev/null
+++ b/browser/components/customizableui/content/moz.build
@@ -0,0 +1,7 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+JAR_MANIFESTS += ["jar.mn"]
diff --git a/browser/components/customizableui/content/panelUI.inc.xhtml b/browser/components/customizableui/content/panelUI.inc.xhtml
new file mode 100644
index 0000000000..8459d64d7b
--- /dev/null
+++ b/browser/components/customizableui/content/panelUI.inc.xhtml
@@ -0,0 +1,325 @@
+<!-- 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/. -->
+
+<panel id="widget-overflow"
+       class="panel-no-padding"
+       role="group"
+       type="arrow"
+       noautofocus="true"
+       position="bottomright topright"
+       hidden="true">
+  <panelmultiview mainViewId="widget-overflow-mainView">
+    <panelview id="widget-overflow-mainView"
+               context="toolbar-context-menu">
+      <vbox class="panel-subview-body">
+        <vbox id="widget-overflow-list" class="widget-overflow-list"
+              overflowfortoolbar="nav-bar"/>
+        <toolbarseparator id="widget-overflow-fixed-separator" hidden="true"/>
+        <vbox id="widget-overflow-fixed-list" class="widget-overflow-list" hidden="true" />
+      </vbox>
+      <toolbarseparator />
+      <toolbarbutton command="cmd_CustomizeToolbars"
+                      id="overflowMenu-customize-button"
+                      class="subviewbutton panel-subview-footer-button"
+                      data-l10n-id="toolbar-overflow-customize-button"/>
+    </panelview>
+  </panelmultiview>
+  <!-- This menu is here because not having it in the menu in which it's used flickers
+       when hover styles overlap. See https://bugzilla.mozilla.org/show_bug.cgi?id=1378427 .
+       -->
+  <menupopup id="customizationPanelItemContextMenu"
+             onpopupshowing="gCustomizeMode.onPanelContextMenuShowing(event); ToolbarContextMenu.updateExtension(this)">
+    <menuitem oncommand="ToolbarContextMenu.openAboutAddonsForContextAction(this.parentElement)"
+              data-lazy-l10n-id="toolbar-context-menu-manage-extension"
+              contexttype="toolbaritem"
+              class="customize-context-manageExtension"/>
+    <menuitem oncommand="ToolbarContextMenu.removeExtensionForContextAction(this.parentElement)"
+              data-lazy-l10n-id="toolbar-context-menu-remove-extension"
+              contexttype="toolbaritem"
+              class="customize-context-removeExtension"/>
+    <menuitem oncommand="ToolbarContextMenu.reportExtensionForContextAction(this.parentElement, 'toolbar_context_menu')"
+              data-lazy-l10n-id="toolbar-context-menu-report-extension"
+              contexttype="toolbaritem"
+              class="customize-context-reportExtension"/>
+    <menuseparator/>
+    <menuitem oncommand="gCustomizeMode.addToPanel(this.parentNode.triggerNode, 'panelitem-context')"
+              id="customizationPanelItemContextMenuPin"
+              data-lazy-l10n-id="toolbar-context-menu-pin-to-overflow-menu"
+              closemenu="single"
+              class="customize-context-moveToPanel"/>
+    <menuitem oncommand="gCustomizeMode.addToToolbar(this.parentNode.triggerNode, 'panelitem-context')"
+              id="customizationPanelItemContextMenuUnpin"
+              closemenu="single"
+              class="customize-context-moveToToolbar"
+              data-l10n-id="customize-menu-unpin-from-overflowmenu"/>
+    <menuitem oncommand="gCustomizeMode.removeFromArea(this.parentNode.triggerNode, 'panelitem-context')"
+              closemenu="single"
+              class="customize-context-removeFromPanel"
+              data-lazy-l10n-id="toolbar-context-menu-remove-from-toolbar"/>
+    <menuseparator/>
+    <menuitem command="cmd_CustomizeToolbars"
+              class="viewCustomizeToolbar"
+              data-lazy-l10n-id="toolbar-context-menu-view-customize-toolbar"/>
+  </menupopup>
+</panel>
+
+<html:template id="unified-extensions-panel-template">
+  <panel id="unified-extensions-panel"
+         class="panel-no-padding"
+         role="group"
+         type="arrow"
+         noautofocus="true"
+         position="bottomright topright"
+         hidden="true">
+    <panelmultiview mainViewId="unified-extensions-view">
+      <panelview id="unified-extensions-view"
+                 class="cui-widget-panelview"
+                 showheader="true">
+        <vbox class="panel-header">
+          <html:h1>
+            <html:span data-l10n-id="unified-extensions-header-title"/>
+          </html:h1>
+        </vbox>
+
+        <toolbarseparator />
+
+        <vbox class="panel-subview-body" context="unified-extensions-context-menu">
+          <vbox id="overflowed-extensions-list">
+            <!-- overflowed extension buttons from the nav-bar will go here -->
+          </vbox>
+
+          <vbox id="unified-extensions-area">
+            <!-- default area for extension browser action buttons -->
+          </vbox>
+
+          <vbox class="unified-extensions-list">
+            <!-- active visible extensions go here -->
+          </vbox>
+        </vbox>
+
+        <toolbarseparator />
+
+        <toolbarbutton id="unified-extensions-manage-extensions"
+                       class="subviewbutton panel-subview-footer-button unified-extensions-manage-extensions"
+                       data-l10n-id="unified-extensions-manage-extensions"
+                       oncommand="BrowserOpenAddonsMgr('addons://list/extension');" />
+      </panelview>
+    </panelmultiview>
+  </panel>
+</html:template>
+
+<html:template id="panicButtonNotificationTemplate">
+  <panel id="panic-button-success-notification"
+         type="arrow"
+         position="bottomright topright"
+         hidden="true"
+         role="alert"
+         orient="vertical">
+    <hbox id="panic-button-success-header">
+      <image id="panic-button-success-icon" alt=""/>
+      <vbox>
+        <description data-l10n-id="panic-button-thankyou-msg1"></description>
+        <description data-l10n-id="panic-button-thankyou-msg2"></description>
+      </vbox>
+    </hbox>
+    <button id="panic-button-success-closebutton"
+            data-l10n-id="panic-button-thankyou-button"
+            oncommand="PanicButtonNotifier.close()"/>
+  </panel>
+</html:template>
+
+<html:template id="appMenuNotificationTemplate">
+  <panel id="appMenu-notification-popup"
+         class="popup-notification-panel panel-no-padding"
+         type="arrow"
+         position="after_start"
+         flip="slide"
+         orient="vertical"
+         noautofocus="true"
+         noautohide="true"
+         nopreventnavboxhide="true"
+         role="alert">
+    <popupnotification id="appMenu-update-available-notification"
+                       popupid="update-available"
+                       data-lazy-l10n-id="appmenu-update-available2"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hasicon="true"
+                       hidden="true">
+      <popupnotificationcontent id="update-available-notification-content" orient="vertical">
+        <description id="update-available-description" data-lazy-l10n-id="appmenu-update-available-message2"></description>
+      </popupnotificationcontent>
+    </popupnotification>
+
+    <popupnotification id="appMenu-update-manual-notification"
+                       popupid="update-manual"
+                       data-lazy-l10n-id="appmenu-update-manual2"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hasicon="true"
+                       hidden="true">
+      <popupnotificationcontent id="update-manual-notification-content" orient="vertical">
+        <description id="update-manual-description" data-lazy-l10n-id="appmenu-update-manual-message2"></description>
+      </popupnotificationcontent>
+    </popupnotification>
+
+    <popupnotification id="appMenu-update-unsupported-notification"
+                       popupid="update-unsupported"
+                       data-lazy-l10n-id="appmenu-update-unsupported2"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hasicon="true"
+                       hidden="true">
+      <popupnotificationcontent id="update-unsupported-notification-content" orient="vertical">
+        <description id="update-unsupported-description" data-lazy-l10n-id="appmenu-update-unsupported-message2"></description>
+      </popupnotificationcontent>
+    </popupnotification>
+
+    <popupnotification id="appMenu-update-restart-notification"
+                       popupid="update-restart"
+                       data-lazy-l10n-id="appmenu-update-restart2"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hasicon="true"
+                       hidden="true">
+      <popupnotificationcontent id="update-restart-notification-content" orient="vertical">
+        <description id="update-restart-description" data-lazy-l10n-id="appmenu-update-restart-message2"></description>
+      </popupnotificationcontent>
+    </popupnotification>
+
+    <popupnotification id="appMenu-update-other-instance-notification"
+                       popupid="update-other-instance"
+                       data-lazy-l10n-id="appmenu-update-other-instance"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hasicon="true"
+                       hidden="true">
+      <popupnotificationcontent id="update-other-instance-notification-content" orient="vertical">
+        <description id="update-other-instance-description" data-lazy-l10n-id="appmenu-update-other-instance-message"></description>
+      </popupnotificationcontent>
+    </popupnotification>
+
+    <popupnotification id="appMenu-addon-installed-notification"
+                       popupid="addon-installed"
+                       closebuttonhidden="true"
+                       secondarybuttonhidden="true"
+                       data-lazy-l10n-id="appmenu-addon-private-browsing-installed2"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true"
+                       buttonhighlight="true"
+                       hidden="true">
+      <popupnotificationcontent class="addon-installed-notification-content" orient="vertical">
+        <description id="addon-install-description" data-lazy-l10n-id="appmenu-addon-post-install-message3"/>
+        <checkbox id="addon-incognito-checkbox"
+                  data-lazy-l10n-id="appmenu-addon-post-install-incognito-checkbox"/>
+      </popupnotificationcontent>
+    </popupnotification>
+  </panel>
+</html:template>
+
+<html:template id="customModeWrapper">
+  <menupopup id="customizationPaletteItemContextMenu"
+             onpopupshowing="gCustomizeMode.onPaletteContextMenuShowing(event)">
+    <menuitem oncommand="gCustomizeMode.addToToolbar(this.parentNode.triggerNode, 'palette-context')"
+              class="customize-context-addToToolbar"
+              data-l10n-id="customize-menu-add-to-toolbar"/>
+    <menuitem oncommand="gCustomizeMode.addToPanel(this.parentNode.triggerNode, 'palette-context')"
+              class="customize-context-addToPanel"
+              data-l10n-id="customize-menu-add-to-overflowmenu"/>
+  </menupopup>
+
+  <panel id="downloads-button-autohide-panel"
+         role="group"
+         type="arrow"
+         onpopupshown="gCustomizeMode._downloadPanelAutoHideTimeout = setTimeout(() => event.target.hidePopup(), 4000);"
+         onmouseover="clearTimeout(gCustomizeMode._downloadPanelAutoHideTimeout);"
+         onmouseout="gCustomizeMode._downloadPanelAutoHideTimeout = setTimeout(() => event.target.hidePopup(), 2000);"
+         onpopuphidden="clearTimeout(gCustomizeMode._downloadPanelAutoHideTimeout);"
+         >
+    <checkbox id="downloads-button-autohide-checkbox"
+              data-l10n-id="customize-mode-downloads-button-autohide" checked="true"
+              oncommand="gCustomizeMode.onDownloadsAutoHideChange(event)"/>
+  </panel>
+</html:template>
+
+<panel id="appMenu-popup"
+       class="cui-widget-panel panel-no-padding"
+       role="group"
+       type="arrow"
+       hidden="true"
+       flip="slide"
+       position="bottomright topright"
+       noautofocus="true">
+  <panelmultiview id="appMenu-multiView" mainViewId="appMenu-protonMainView"
+                  viewCacheId="appMenu-viewCache">
+  </panelmultiview>
+</panel>
+
+<html:template id="extensionNotificationTemplate">
+  <panel id="extension-notification-panel"
+         class="popup-notification-panel panel-no-padding"
+         role="group"
+         type="arrow"
+         flip="slide"
+         position="bottomright topright"
+         tabspecific="true">
+    <popupnotification id="extension-new-tab-notification"
+                       class="extension-controlled-notification"
+                       popupid="extension-new-tab"
+                       hidden="true"
+                       data-lazy-l10n-id="appmenu-new-tab-controlled-changes"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       buttonhighlight="true"
+                       checkboxhidden="true">
+      <popupnotificationcontent orient="vertical">
+        <description id="extension-new-tab-notification-description"/>
+      </popupnotificationcontent>
+    </popupnotification>
+    <popupnotification id="extension-homepage-notification"
+                       class="extension-controlled-notification"
+                       popupid="extension-homepage"
+                       hidden="true"
+                       data-lazy-l10n-id="appmenu-homepage-controlled-changes"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       buttonhighlight="true"
+                       checkboxhidden="true">
+      <popupnotificationcontent orient="vertical">
+        <description id="extension-homepage-notification-description"/>
+      </popupnotificationcontent>
+    </popupnotification>
+    <popupnotification id="extension-tab-hide-notification"
+                       class="extension-controlled-notification"
+                       popupid="extension-tab-hide"
+                       hidden="true"
+                       data-lazy-l10n-id="appmenu-tab-hide-controlled"
+                       data-l10n-attrs="buttonlabel, buttonaccesskey, secondarybuttonlabel, secondarybuttonaccesskey"
+                       closebuttonhidden="true"
+                       dropmarkerhidden="true"
+                       checkboxhidden="true">
+      <popupnotificationcontent orient="vertical">
+        <description id="extension-tab-hide-notification-description"/>
+      </popupnotificationcontent>
+    </popupnotification>
+  </panel>
+</html:template>
diff --git a/browser/components/customizableui/content/panelUI.js b/browser/components/customizableui/content/panelUI.js
new file mode 100644
index 0000000000..cf6461f9fb
--- /dev/null
+++ b/browser/components/customizableui/content/panelUI.js
@@ -0,0 +1,1069 @@
+/* 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/. */
+
+ChromeUtils.defineESModuleGetters(this, {
+  AppMenuNotifications: "resource://gre/modules/AppMenuNotifications.sys.mjs",
+  NewTabUtils: "resource://gre/modules/NewTabUtils.sys.mjs",
+});
+ChromeUtils.defineModuleGetter(
+  this,
+  "PanelMultiView",
+  "resource:///modules/PanelMultiView.jsm"
+);
+ChromeUtils.defineModuleGetter(
+  this,
+  "ToolbarPanelHub",
+  "resource://activity-stream/lib/ToolbarPanelHub.jsm"
+);
+
+/**
+ * Maintains the state and dispatches events for the main menu panel.
+ */
+
+const PanelUI = {
+  /** Panel events that we listen for. **/
+  get kEvents() {
+    return ["popupshowing", "popupshown", "popuphiding", "popuphidden"];
+  },
+  /**
+   * Used for lazily getting and memoizing elements from the document. Lazy
+   * getters are set in init, and memoizing happens after the first retrieval.
+   */
+  get kElements() {
+    return {
+      multiView: "appMenu-multiView",
+      menuButton: "PanelUI-menu-button",
+      panel: "appMenu-popup",
+      overflowFixedList: "widget-overflow-fixed-list",
+      overflowPanel: "widget-overflow",
+      navbar: "nav-bar",
+    };
+  },
+
+  _initialized: false,
+  _notifications: null,
+  _notificationPanel: null,
+
+  init(shouldSuppress) {
+    this._shouldSuppress = shouldSuppress;
+    this._initElements();
+
+    this.menuButton.addEventListener("mousedown", this);
+    this.menuButton.addEventListener("keypress", this);
+
+    Services.obs.addObserver(this, "fullscreen-nav-toolbox");
+    Services.obs.addObserver(this, "appMenu-notifications");
+    Services.obs.addObserver(this, "show-update-progress");
+
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "autoHideToolbarInFullScreen",
+      "browser.fullscreen.autohide",
+      false,
+      (pref, previousValue, newValue) => {
+        // On OSX, or with autohide preffed off, MozDOMFullscreen is the only
+        // event we care about, since fullscreen should behave just like non
+        // fullscreen. Otherwise, we don't want to listen to these because
+        // we'd just be spamming ourselves with both of them whenever a user
+        // opened a video.
+        if (newValue) {
+          window.removeEventListener("MozDOMFullscreen:Entered", this);
+          window.removeEventListener("MozDOMFullscreen:Exited", this);
+          window.addEventListener("fullscreen", this);
+        } else {
+          window.addEventListener("MozDOMFullscreen:Entered", this);
+          window.addEventListener("MozDOMFullscreen:Exited", this);
+          window.removeEventListener("fullscreen", this);
+        }
+
+        this.updateNotifications(false);
+      },
+      autoHidePref => autoHidePref && Services.appinfo.OS !== "Darwin"
+    );
+
+    if (this.autoHideToolbarInFullScreen) {
+      window.addEventListener("fullscreen", this);
+    } else {
+      window.addEventListener("MozDOMFullscreen:Entered", this);
+      window.addEventListener("MozDOMFullscreen:Exited", this);
+    }
+
+    window.addEventListener("activate", this);
+    CustomizableUI.addListener(this);
+
+    // We do this sync on init because in order to have the overflow button show up
+    // we need to know whether anything is in the permanent panel area.
+    this.overflowFixedList.hidden = false;
+    // Also unhide the separator. We use CSS to hide/show it based on the panel's content.
+    this.overflowFixedList.previousElementSibling.hidden = false;
+    CustomizableUI.registerPanelNode(
+      this.overflowFixedList,
+      CustomizableUI.AREA_FIXED_OVERFLOW_PANEL
+    );
+    this.updateOverflowStatus();
+
+    Services.obs.notifyObservers(
+      null,
+      "appMenu-notifications-request",
+      "refresh"
+    );
+
+    this._initialized = true;
+  },
+
+  _initElements() {
+    for (let [k, v] of Object.entries(this.kElements)) {
+      // Need to do fresh let-bindings per iteration
+      let getKey = k;
+      let id = v;
+      this.__defineGetter__(getKey, function() {
+        delete this[getKey];
+        return (this[getKey] = document.getElementById(id));
+      });
+    }
+  },
+
+  _eventListenersAdded: false,
+  _ensureEventListenersAdded() {
+    if (this._eventListenersAdded) {
+      return;
+    }
+    this._addEventListeners();
+  },
+
+  _addEventListeners() {
+    for (let event of this.kEvents) {
+      this.panel.addEventListener(event, this);
+    }
+
+    PanelMultiView.getViewNode(document, "PanelUI-helpView").addEventListener(
+      "ViewShowing",
+      this._onHelpViewShow
+    );
+    this._eventListenersAdded = true;
+  },
+
+  _removeEventListeners() {
+    for (let event of this.kEvents) {
+      this.panel.removeEventListener(event, this);
+    }
+    PanelMultiView.getViewNode(
+      document,
+      "PanelUI-helpView"
+    ).removeEventListener("ViewShowing", this._onHelpViewShow);
+    this._eventListenersAdded = false;
+  },
+
+  uninit() {
+    this._removeEventListeners();
+
+    if (this._notificationPanel) {
+      for (let event of this.kEvents) {
+        this.notificationPanel.removeEventListener(event, this);
+      }
+    }
+
+    Services.obs.removeObserver(this, "fullscreen-nav-toolbox");
+    Services.obs.removeObserver(this, "appMenu-notifications");
+    Services.obs.removeObserver(this, "show-update-progress");
+
+    window.removeEventListener("MozDOMFullscreen:Entered", this);
+    window.removeEventListener("MozDOMFullscreen:Exited", this);
+    window.removeEventListener("fullscreen", this);
+    window.removeEventListener("activate", this);
+    this.menuButton.removeEventListener("mousedown", this);
+    this.menuButton.removeEventListener("keypress", this);
+    CustomizableUI.removeListener(this);
+    if (this.whatsNewPanel) {
+      this.whatsNewPanel.removeEventListener("ViewShowing", this);
+    }
+  },
+
+  /**
+   * Opens the menu panel if it's closed, or closes it if it's
+   * open.
+   *
+   * @param aEvent the event that triggers the toggle.
+   */
+  toggle(aEvent) {
+    // Don't show the panel if the window is in customization mode,
+    // since this button doubles as an exit path for the user in this case.
+    if (document.documentElement.hasAttribute("customizing")) {
+      return;
+    }
+    this._ensureEventListenersAdded();
+    if (this.panel.state == "open") {
+      this.hide();
+    } else if (this.panel.state == "closed") {
+      this.show(aEvent);
+    }
+  },
+
+  /**
+   * Opens the menu panel. If the event target has a child with the
+   * toolbarbutton-icon attribute, the panel will be anchored on that child.
+   * Otherwise, the panel is anchored on the event target itself.
+   *
+   * @param aEvent the event (if any) that triggers showing the menu.
+   */
+  show(aEvent) {
+    this._ensureShortcutsShown();
+    (async () => {
+      await this.ensureReady();
+
+      if (
+        this.panel.state == "open" ||
+        document.documentElement.hasAttribute("customizing")
+      ) {
+        return;
+      }
+
+      let domEvent = null;
+      if (aEvent && aEvent.type != "command") {
+        domEvent = aEvent;
+      }
+
+      let anchor = this._getPanelAnchor(this.menuButton);
+      await PanelMultiView.openPopup(this.panel, anchor, {
+        triggerEvent: domEvent,
+      });
+    })().catch(Cu.reportError);
+  },
+
+  /**
+   * If the menu panel is being shown, hide it.
+   */
+  hide() {
+    if (document.documentElement.hasAttribute("customizing")) {
+      return;
+    }
+
+    PanelMultiView.hidePopup(this.panel);
+  },
+
+  observe(subject, topic, status) {
+    switch (topic) {
+      case "fullscreen-nav-toolbox":
+        if (this._notifications) {
+          this.updateNotifications(false);
+        }
+        break;
+      case "appMenu-notifications":
+        // Don't initialize twice.
+        if (status == "init" && this._notifications) {
+          break;
+        }
+        this._notifications = AppMenuNotifications.notifications;
+        this.updateNotifications(true);
+        break;
+      case "show-update-progress":
+        openAboutDialog();
+        break;
+    }
+  },
+
+  handleEvent(aEvent) {
+    // Ignore context menus and menu button menus showing and hiding:
+    if (aEvent.type.startsWith("popup") && aEvent.target != this.panel) {
+      return;
+    }
+    switch (aEvent.type) {
+      case "popupshowing":
+        updateEditUIVisibility();
+      // Fall through
+      case "popupshown":
+        if (aEvent.type == "popupshown") {
+          CustomizableUI.addPanelCloseListeners(this.panel);
+        }
+      // Fall through
+      case "popuphiding":
+        if (aEvent.type == "popuphiding") {
+          updateEditUIVisibility();
+        }
+      // Fall through
+      case "popuphidden":
+        this.updateNotifications();
+        this._updatePanelButton(aEvent.target);
+        if (aEvent.type == "popuphidden") {
+          CustomizableUI.removePanelCloseListeners(this.panel);
+        }
+        break;
+      case "mousedown":
+        // On Mac, ctrl-click will send a context menu event from the widget, so
+        // we don't want to bring up the panel when ctrl key is pressed.
+        if (
+          aEvent.button == 0 &&
+          (AppConstants.platform != "macosx" || !aEvent.ctrlKey)
+        ) {
+          this.toggle(aEvent);
+        }
+        break;
+      case "keypress":
+        if (aEvent.key == " " || aEvent.key == "Enter") {
+          this.toggle(aEvent);
+          aEvent.stopPropagation();
+        }
+        break;
+      case "MozDOMFullscreen:Entered":
+      case "MozDOMFullscreen:Exited":
+      case "fullscreen":
+      case "activate":
+        this.updateNotifications();
+        break;
+      case "ViewShowing":
+        if (aEvent.target == this.whatsNewPanel) {
+          this.onWhatsNewPanelShowing();
+        }
+        break;
+    }
+  },
+
+  get isReady() {
+    return !!this._isReady;
+  },
+
+  get isNotificationPanelOpen() {
+    let panelState = this.notificationPanel.state;
+
+    return panelState == "showing" || panelState == "open";
+  },
+
+  /**
+   * Registering the menu panel is done lazily for performance reasons. This
+   * method is exposed so that CustomizationMode can force panel-readyness in the
+   * event that customization mode is started before the panel has been opened
+   * by the user.
+   *
+   * @param aCustomizing (optional) set to true if this was called while entering
+   *        customization mode. If that's the case, we trust that customization
+   *        mode will handle calling beginBatchUpdate and endBatchUpdate.
+   *
+   * @return a Promise that resolves once the panel is ready to roll.
+   */
+  async ensureReady() {
+    if (this._isReady) {
+      return;
+    }
+
+    await window.delayedStartupPromise;
+    this._ensureEventListenersAdded();
+    this.panel.hidden = false;
+    this._isReady = true;
+  },
+
+  /**
+   * Switch the panel to the help view if it's not already
+   * in that view.
+   */
+  showHelpView(aAnchor) {
+    this._ensureEventListenersAdded();
+    this.multiView.showSubView("PanelUI-helpView", aAnchor);
+  },
+
+  /**
+   * Switch the panel to the "More Tools" view.
+   *
+   * @param moreTools The panel showing the "More Tools" view.
+   */
+  showMoreToolsPanel(moreTools) {
+    this.showSubView("appmenu-moreTools", moreTools);
+
+    // Notify DevTools the panel view is showing and need it to populate the
+    // "Browser Tools" section of the panel. We notify the observer setup by
+    // DevTools because we want to ensure the same menuitem list is shared
+    // between both the AppMenu and toolbar button views.
+    let view = document.getElementById("appmenu-developer-tools-view");
+    Services.obs.notifyObservers(view, "web-developer-tools-view-showing");
+  },
+
+  /**
+   * Shows a subview in the panel with a given ID.
+   *
+   * @param aViewId the ID of the subview to show.
+   * @param aAnchor the element that spawned the subview.
+   * @param aEvent the event triggering the view showing.
+   */
+  async showSubView(aViewId, aAnchor, aEvent) {
+    if (aEvent) {
+      // On Mac, ctrl-click will send a context menu event from the widget, so
+      // we don't want to bring up the panel when ctrl key is pressed.
+      if (
+        aEvent.type == "mousedown" &&
+        (aEvent.button != 0 ||
+          (AppConstants.platform == "macosx" && aEvent.ctrlKey))
+      ) {
+        return;
+      }
+      if (
+        aEvent.type == "keypress" &&
+        aEvent.key != " " &&
+        aEvent.key != "Enter"
+      ) {
+        return;
+      }
+    }
+
+    this._ensureEventListenersAdded();
+
+    let viewNode = PanelMultiView.getViewNode(document, aViewId);
+    if (!viewNode) {
+      Cu.reportError("Could not show panel subview with id: " + aViewId);
+      return;
+    }
+
+    if (!aAnchor) {
+      Cu.reportError(
+        "Expected an anchor when opening subview with id: " + aViewId
+      );
+      return;
+    }
+
+    this.ensureWhatsNewInitialized(viewNode);
+    this.ensurePanicViewInitialized(viewNode);
+
+    let container = aAnchor.closest("panelmultiview");
+    if (container && !viewNode.hasAttribute("disallowSubView")) {
+      container.showSubView(aViewId, aAnchor);
+    } else if (!aAnchor.open) {
+      aAnchor.open = true;
+
+      let tempPanel = document.createXULElement("panel");
+      tempPanel.setAttribute("type", "arrow");
+      tempPanel.setAttribute("id", "customizationui-widget-panel");
+      if (viewNode.hasAttribute("neverhidden")) {
+        tempPanel.setAttribute("neverhidden", "true");
+      }
+
+      tempPanel.setAttribute("class", "cui-widget-panel panel-no-padding");
+      tempPanel.setAttribute("viewId", aViewId);
+      if (aAnchor.getAttribute("tabspecific")) {
+        tempPanel.setAttribute("tabspecific", true);
+      }
+      if (aAnchor.getAttribute("locationspecific")) {
+        tempPanel.setAttribute("locationspecific", true);
+      }
+      if (this._disableAnimations) {
+        tempPanel.setAttribute("animate", "false");
+      }
+      tempPanel.setAttribute("context", "");
+      document
+        .getElementById(CustomizableUI.AREA_NAVBAR)
+        .appendChild(tempPanel);
+
+      let multiView = document.createXULElement("panelmultiview");
+      multiView.setAttribute("id", "customizationui-widget-multiview");
+      multiView.setAttribute("viewCacheId", "appMenu-viewCache");
+      multiView.setAttribute("mainViewId", viewNode.id);
+      multiView.appendChild(viewNode);
+      tempPanel.appendChild(multiView);
+      viewNode.classList.add("cui-widget-panelview", "PanelUI-subView");
+
+      let viewShown = false;
+      let panelRemover = () => {
+        viewNode.classList.remove("cui-widget-panelview");
+        if (viewShown) {
+          CustomizableUI.removePanelCloseListeners(tempPanel);
+          tempPanel.removeEventListener("popuphidden", panelRemover);
+        }
+        aAnchor.open = false;
+
+        PanelMultiView.removePopup(tempPanel);
+      };
+
+      if (aAnchor.parentNode.id == "PersonalToolbar") {
+        tempPanel.classList.add("bookmarks-toolbar");
+      }
+
+      let anchor = this._getPanelAnchor(aAnchor);
+
+      if (aAnchor != anchor && aAnchor.id) {
+        anchor.setAttribute("consumeanchor", aAnchor.id);
+      }
+
+      try {
+        viewShown = await PanelMultiView.openPopup(tempPanel, anchor, {
+          position: "bottomright topright",
+          triggerEvent: aEvent,
+        });
+      } catch (ex) {
+        Cu.reportError(ex);
+      }
+
+      if (viewShown) {
+        CustomizableUI.addPanelCloseListeners(tempPanel);
+        tempPanel.addEventListener("popuphidden", panelRemover);
+      } else {
+        panelRemover();
+      }
+    }
+  },
+
+  /**
+   * Sets up the event listener for when the What's New panel is shown.
+   *
+   * @param {panelview} panelView The What's New panelview.
+   */
+  ensureWhatsNewInitialized(panelView) {
+    if (panelView.id != "PanelUI-whatsNew" || panelView._initialized) {
+      return;
+    }
+
+    if (!this.whatsNewPanel) {
+      this.whatsNewPanel = panelView;
+    }
+
+    panelView._initialized = true;
+    panelView.addEventListener("ViewShowing", this);
+  },
+
+  /**
+   * Adds FTL before appending the panic view markup to the main DOM.
+   *
+   * @param {panelview} panelView The Panic View panelview.
+   */
+  ensurePanicViewInitialized(panelView) {
+    if (panelView.id != "PanelUI-panicView" || panelView._initialized) {
+      return;
+    }
+
+    if (!this.panic) {
+      this.panic = panelView;
+    }
+
+    MozXULElement.insertFTLIfNeeded("browser/panicButton.ftl");
+    panelView._initialized = true;
+  },
+
+  /**
+   * When the What's New panel is showing, we fetch the messages to show.
+   */
+  onWhatsNewPanelShowing() {
+    ToolbarPanelHub.renderMessages(
+      window,
+      document,
+      "PanelUI-whatsNew-message-container"
+    );
+  },
+
+  /**
+   * NB: The enable- and disableSingleSubviewPanelAnimations methods only
+   * affect the hiding/showing animations of single-subview panels (tempPanel
+   * in the showSubView method).
+   */
+  disableSingleSubviewPanelAnimations() {
+    this._disableAnimations = true;
+  },
+
+  enableSingleSubviewPanelAnimations() {
+    this._disableAnimations = false;
+  },
+
+  updateOverflowStatus() {
+    let hasKids = this.overflowFixedList.hasChildNodes();
+    if (hasKids && !this.navbar.hasAttribute("nonemptyoverflow")) {
+      this.navbar.setAttribute("nonemptyoverflow", "true");
+      this.overflowPanel.setAttribute("hasfixeditems", "true");
+    } else if (!hasKids && this.navbar.hasAttribute("nonemptyoverflow")) {
+      PanelMultiView.hidePopup(this.overflowPanel);
+      this.overflowPanel.removeAttribute("hasfixeditems");
+      this.navbar.removeAttribute("nonemptyoverflow");
+    }
+  },
+
+  onWidgetAfterDOMChange(aNode, aNextNode, aContainer, aWasRemoval) {
+    if (aContainer == this.overflowFixedList) {
+      this.updateOverflowStatus();
+    }
+  },
+
+  onAreaReset(aArea, aContainer) {
+    if (aContainer == this.overflowFixedList) {
+      this.updateOverflowStatus();
+    }
+  },
+
+  /**
+   * Sets the anchor node into the open or closed state, depending
+   * on the state of the panel.
+   */
+  _updatePanelButton() {
+    let { state } = this.panel;
+    if (state == "open" || state == "showing") {
+      this.menuButton.open = true;
+      document.l10n.setAttributes(
+        this.menuButton,
+        "appmenu-menu-button-opened2"
+      );
+    } else {
+      this.menuButton.open = false;
+      document.l10n.setAttributes(
+        this.menuButton,
+        "appmenu-menu-button-closed2"
+      );
+    }
+  },
+
+  _onHelpViewShow(aEvent) {
+    // Call global menu setup function
+    buildHelpMenu();
+
+    let helpMenu = document.getElementById("menu_HelpPopup");
+    let items = this.getElementsByTagName("vbox")[0];
+    let attrs = [
+      "command",
+      "oncommand",
+      "onclick",
+      "key",
+      "disabled",
+      "accesskey",
+      "label",
+    ];
+
+    // Remove all buttons from the view
+    while (items.firstChild) {
+      items.firstChild.remove();
+    }
+
+    // Add the current set of menuitems of the Help menu to this view
+    let menuItems = Array.prototype.slice.call(
+      helpMenu.getElementsByTagName("menuitem")
+    );
+    let fragment = document.createDocumentFragment();
+    for (let node of menuItems) {
+      if (node.hidden) {
+        continue;
+      }
+      let button = document.createXULElement("toolbarbutton");
+      // Copy specific attributes from a menuitem of the Help menu
+      for (let attrName of attrs) {
+        if (!node.hasAttribute(attrName)) {
+          continue;
+        }
+        button.setAttribute(attrName, node.getAttribute(attrName));
+      }
+
+      // We have AppMenu-specific strings for the Help menu. By convention,
+      // their localization IDs are set on "appmenu-data-l10n-id" attributes.
+      let l10nId = node.getAttribute("appmenu-data-l10n-id");
+      if (l10nId) {
+        button.setAttribute("data-l10n-id", l10nId);
+      }
+
+      if (node.id) {
+        button.id = "appMenu_" + node.id;
+      }
+
+      button.classList.add("subviewbutton");
+      fragment.appendChild(button);
+    }
+
+    // The Enterprise Support menu item has a different location than its
+    // placement in the menubar, so we need to specify it here.
+    let helpPolicySupport = fragment.querySelector(
+      "#appMenu_helpPolicySupport"
+    );
+    if (helpPolicySupport) {
+      fragment.insertBefore(
+        helpPolicySupport,
+        fragment.querySelector("#appMenu_menu_HelpPopup_reportPhishingtoolmenu")
+          .nextSibling
+      );
+    }
+
+    items.appendChild(fragment);
+  },
+
+  _hidePopup() {
+    if (!this._notificationPanel) {
+      return;
+    }
+
+    if (this.isNotificationPanelOpen) {
+      this.notificationPanel.hidePopup();
+    }
+  },
+
+  /**
+   * Selects and marks an item by id from the main view. The ids are an array,
+   * the first in the main view and the later ids in subsequent subviews that
+   * become marked when the user opens the subview. The subview marking is
+   * cancelled if a different subview is opened.
+   */
+  async selectAndMarkItem(itemIds) {
+    // This shouldn't really occur, but return early just in case.
+    if (document.documentElement.hasAttribute("customizing")) {
+      return;
+    }
+
+    // This function was triggered from a button while the menu was
+    // already open, so the panel should be in the process of hiding.
+    // Wait for the panel to hide first, then reopen it.
+    if (this.panel.state == "hiding") {
+      await new Promise(resolve => {
+        this.panel.addEventListener("popuphidden", resolve, { once: true });
+      });
+    }
+
+    if (this.panel.state != "open") {
+      await new Promise(resolve => {
+        this.panel.addEventListener("ViewShown", resolve, { once: true });
+        this.show();
+      });
+    }
+
+    let currentView;
+
+    let viewShownCB = event => {
+      viewHidingCB();
+
+      if (itemIds.length) {
+        let subItem = window.document.getElementById(itemIds[0]);
+        if (event.target.id == subItem?.closest("panelview")?.id) {
+          Services.tm.dispatchToMainThread(() => {
+            markItem(event.target);
+          });
+        } else {
+          itemIds = [];
+        }
+      }
+    };
+
+    let viewHidingCB = () => {
+      if (currentView) {
+        currentView.ignoreMouseMove = false;
+      }
+      currentView = null;
+    };
+
+    let popupHiddenCB = () => {
+      viewHidingCB();
+      this.panel.removeEventListener("ViewShown", viewShownCB);
+    };
+
+    let markItem = viewNode => {
+      let id = itemIds.shift();
+      let item = window.document.getElementById(id);
+      item.setAttribute("tabindex", "-1");
+
+      currentView = PanelView.forNode(viewNode);
+      currentView.selectedElement = item;
+      currentView.focusSelectedElement(true);
+
+      // Prevent the mouse from changing the highlight temporarily.
+      // This flag gets removed when the view is hidden or a key
+      // is pressed.
+      currentView.ignoreMouseMove = true;
+
+      if (itemIds.length) {
+        this.panel.addEventListener("ViewShown", viewShownCB, { once: true });
+      }
+      this.panel.addEventListener("ViewHiding", viewHidingCB, { once: true });
+    };
+
+    this.panel.addEventListener("popuphidden", popupHiddenCB, { once: true });
+    markItem(this.mainView);
+  },
+
+  updateNotifications(notificationsChanged) {
+    let notifications = this._notifications;
+    if (!notifications || !notifications.length) {
+      if (notificationsChanged) {
+        this._clearAllNotifications();
+        this._hidePopup();
+      }
+      return;
+    }
+
+    if (
+      (window.fullScreen && FullScreen.navToolboxHidden) ||
+      document.fullscreenElement ||
+      this._shouldSuppress()
+    ) {
+      this._hidePopup();
+      return;
+    }
+
+    let doorhangers = notifications.filter(
+      n => !n.dismissed && !n.options.badgeOnly
+    );
+
+    if (this.panel.state == "showing" || this.panel.state == "open") {
+      // If the menu is already showing, then we need to dismiss all
+      // notifications since we don't want their doorhangers competing for
+      // attention. Don't hide the badge though; it isn't really in competition
+      // with anything.
+      doorhangers.forEach(n => {
+        n.dismissed = true;
+        if (n.options.onDismissed) {
+          n.options.onDismissed(window);
+        }
+      });
+      this._hidePopup();
+      if (!notifications[0].options.badgeOnly) {
+        this._showBannerItem(notifications[0]);
+      }
+    } else if (doorhangers.length) {
+      // Only show the doorhanger if the window is focused and not fullscreen
+      if (
+        (window.fullScreen && this.autoHideToolbarInFullScreen) ||
+        Services.focus.activeWindow !== window
+      ) {
+        this._hidePopup();
+        this._showBadge(doorhangers[0]);
+        this._showBannerItem(doorhangers[0]);
+      } else {
+        this._clearBadge();
+        this._showNotificationPanel(doorhangers[0]);
+      }
+    } else {
+      this._hidePopup();
+      this._showBadge(notifications[0]);
+      this._showBannerItem(notifications[0]);
+    }
+  },
+
+  _showNotificationPanel(notification) {
+    this._refreshNotificationPanel(notification);
+
+    if (this.isNotificationPanelOpen) {
+      return;
+    }
+
+    if (notification.options.beforeShowDoorhanger) {
+      notification.options.beforeShowDoorhanger(document);
+    }
+
+    let anchor = this._getPanelAnchor(this.menuButton);
+
+    // Insert Fluent files when needed before notification is opened
+    MozXULElement.insertFTLIfNeeded("branding/brand.ftl");
+    MozXULElement.insertFTLIfNeeded("browser/appMenuNotifications.ftl");
+
+    // After Fluent files are loaded into document replace data-lazy-l10n-ids with actual ones
+    document
+      .getElementById("appMenu-notification-popup")
+      .querySelectorAll("[data-lazy-l10n-id]")
+      .forEach(el => {
+        el.setAttribute("data-l10n-id", el.getAttribute("data-lazy-l10n-id"));
+        el.removeAttribute("data-lazy-l10n-id");
+      });
+
+    this.notificationPanel.openPopup(anchor, "bottomright topright");
+  },
+
+  _clearNotificationPanel() {
+    for (let popupnotification of this.notificationPanel.children) {
+      popupnotification.hidden = true;
+      popupnotification.notification = null;
+    }
+  },
+
+  _clearAllNotifications() {
+    this._clearNotificationPanel();
+    this._clearBadge();
+    this._clearBannerItem();
+  },
+
+  get notificationPanel() {
+    // Lazy load the panic-button-success-notification panel the first time we need to display it.
+    if (!this._notificationPanel) {
+      let template = document.getElementById("appMenuNotificationTemplate");
+      template.replaceWith(template.content);
+      this._notificationPanel = document.getElementById(
+        "appMenu-notification-popup"
+      );
+      for (let event of this.kEvents) {
+        this._notificationPanel.addEventListener(event, this);
+      }
+    }
+    return this._notificationPanel;
+  },
+
+  get mainView() {
+    if (!this._mainView) {
+      this._mainView = PanelMultiView.getViewNode(
+        document,
+        "appMenu-protonMainView"
+      );
+    }
+    return this._mainView;
+  },
+
+  get addonNotificationContainer() {
+    if (!this._addonNotificationContainer) {
+      this._addonNotificationContainer = PanelMultiView.getViewNode(
+        document,
+        "appMenu-proton-addon-banners"
+      );
+    }
+
+    return this._addonNotificationContainer;
+  },
+
+  _formatDescriptionMessage(n) {
+    let text = {};
+    let array = n.options.message.split("<>");
+    text.start = array[0] || "";
+    text.name = n.options.name || "";
+    text.end = array[1] || "";
+    return text;
+  },
+
+  _refreshNotificationPanel(notification) {
+    this._clearNotificationPanel();
+
+    let popupnotificationID = this._getPopupId(notification);
+    let popupnotification = document.getElementById(popupnotificationID);
+
+    popupnotification.setAttribute("id", popupnotificationID);
+    popupnotification.setAttribute(
+      "buttoncommand",
+      "PanelUI._onNotificationButtonEvent(event, 'buttoncommand');"
+    );
+    popupnotification.setAttribute(
+      "secondarybuttoncommand",
+      "PanelUI._onNotificationButtonEvent(event, 'secondarybuttoncommand');"
+    );
+
+    if (notification.options.message) {
+      let desc = this._formatDescriptionMessage(notification);
+      popupnotification.setAttribute("label", desc.start);
+      popupnotification.setAttribute("name", desc.name);
+      popupnotification.setAttribute("endlabel", desc.end);
+    }
+    if (notification.options.onRefresh) {
+      notification.options.onRefresh(window);
+    }
+    if (notification.options.popupIconURL) {
+      popupnotification.setAttribute("icon", notification.options.popupIconURL);
+      popupnotification.setAttribute("hasicon", true);
+    }
+
+    popupnotification.notification = notification;
+    popupnotification.show();
+  },
+
+  _showBadge(notification) {
+    let badgeStatus = this._getBadgeStatus(notification);
+    this.menuButton.setAttribute("badge-status", badgeStatus);
+  },
+
+  // "Banner item" here refers to an item in the hamburger panel menu. They will
+  // typically show up as a colored row in the panel.
+  _showBannerItem(notification) {
+    const supportedIds = [
+      "update-downloading",
+      "update-available",
+      "update-manual",
+      "update-unsupported",
+      "update-restart",
+    ];
+    if (!supportedIds.includes(notification.id)) {
+      return;
+    }
+
+    if (!this._panelBannerItem) {
+      this._panelBannerItem = this.mainView.querySelector(".panel-banner-item");
+    }
+
+    let l10nId = "appmenuitem-banner-" + notification.id;
+    document.l10n.setAttributes(this._panelBannerItem, l10nId);
+
+    this._panelBannerItem.setAttribute("notificationid", notification.id);
+    this._panelBannerItem.hidden = false;
+    this._panelBannerItem.notification = notification;
+  },
+
+  _clearBadge() {
+    this.menuButton.removeAttribute("badge-status");
+  },
+
+  _clearBannerItem() {
+    if (this._panelBannerItem) {
+      this._panelBannerItem.notification = null;
+      this._panelBannerItem.hidden = true;
+    }
+  },
+
+  _onNotificationButtonEvent(event, type) {
+    let notificationEl = getNotificationFromElement(event.originalTarget);
+
+    if (!notificationEl) {
+      throw new Error(
+        "PanelUI._onNotificationButtonEvent: couldn't find notification element"
+      );
+    }
+
+    if (!notificationEl.notification) {
+      throw new Error(
+        "PanelUI._onNotificationButtonEvent: couldn't find notification"
+      );
+    }
+
+    let notification = notificationEl.notification;
+
+    if (type == "secondarybuttoncommand") {
+      AppMenuNotifications.callSecondaryAction(window, notification);
+    } else {
+      AppMenuNotifications.callMainAction(window, notification, true);
+    }
+  },
+
+  _onBannerItemSelected(event) {
+    let target = event.originalTarget;
+    if (!target.notification) {
+      throw new Error(
+        "menucommand target has no associated action/notification"
+      );
+    }
+
+    event.stopPropagation();
+    AppMenuNotifications.callMainAction(window, target.notification, false);
+  },
+
+  _getPopupId(notification) {
+    return "appMenu-" + notification.id + "-notification";
+  },
+
+  _getBadgeStatus(notification) {
+    return notification.id;
+  },
+
+  _getPanelAnchor(candidate) {
+    let iconAnchor = candidate.badgeStack || candidate.icon;
+    return iconAnchor || candidate;
+  },
+
+  _ensureShortcutsShown(view = this.mainView) {
+    if (view.hasAttribute("added-shortcuts")) {
+      return;
+    }
+    view.setAttribute("added-shortcuts", "true");
+    for (let button of view.querySelectorAll("toolbarbutton[key]")) {
+      let keyId = button.getAttribute("key");
+      let key = document.getElementById(keyId);
+      if (!key) {
+        continue;
+      }
+      button.setAttribute("shortcut", ShortcutUtils.prettifyShortcut(key));
+    }
+  },
+};
+
+XPCOMUtils.defineConstant(this, "PanelUI", PanelUI);
+
+/**
+ * Gets the currently selected locale for display.
+ * @return  the selected locale
+ */
+function getLocale() {
+  return Services.locale.appLocaleAsBCP47;
+}
+
+/**
+ * Given a DOM node inside a <popupnotification>, return the parent <popupnotification>.
+ */
+function getNotificationFromElement(aElement) {
+  return aElement.closest("popupnotification");
+}