1 files changed, 134 insertions, 0 deletions
diff --git a/comm/mail/components/unifiedtoolbar/modules/CustomizableItems.sys.mjs b/comm/mail/components/unifiedtoolbar/modules/CustomizableItems.sys.mjs
new file mode 100644
index 0000000000..eb9ccee46f
--- /dev/null
+++ b/comm/mail/components/unifiedtoolbar/modules/CustomizableItems.sys.mjs
@@ -0,0 +1,134 @@
+/* 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 CUSTOMIZABLE_ITEMS from "resource:///modules/CustomizableItemsDetails.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+ChromeUtils.defineESModuleGetters(lazy, {
+  AddonManager: "resource://gre/modules/AddonManager.sys.mjs",
+});
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "glodaEnabled",
+  "mailnews.database.global.indexer.enabled",
+  true,
+  () => Services.obs.notifyObservers(null, "unified-toolbar-state-change")
+);
+
+const DEFAULT_ITEMS = ["spacer", "search-bar", "spacer"];
+const DEFAULT_ITEMS_WITHOUT_SEARCH = ["spacer"];
+
+/**
+ * @type {{id: string, spaces: string[], installDate: Date}[]}
+ */
+const EXTENSIONS = [];
+
+export const EXTENSION_PREFIX = "ext-";
+
+/**
+ * Add an extension button that is available in the given spaces. Defaults to
+ * making the button only available in the mail space. To provide it in all
+ * spaces, pass an empty array for the spaces.
+ *
+ * @param {string} id - Extension ID to add the button for.
+ * @param {string[]} [spaces=["mail"]] - Array of spaces the button can be used
+ *   in.
+ */
+export async function registerExtension(id, spaces = ["mail"]) {
+  if (EXTENSIONS.some(extension => extension.id === id)) {
+    return;
+  }
+  const addon = await lazy.AddonManager.getAddonByID(id);
+  EXTENSIONS.push({
+    id,
+    spaces,
+    installDate: addon?.installDate ?? new Date(),
+  });
+  EXTENSIONS.sort(
+    (extA, extB) => extA.installDate.valueOf() - extB.installDate.valueOf()
+  );
+}
+
+/**
+ * Remove the extension from the palette of available items.
+ *
+ * @param {string} id - Extension ID to remove.
+ */
+export function unregisterExtension(id) {
+  const index = EXTENSIONS.findIndex(extension => extension.id === id);
+  EXTENSIONS.splice(index, 1);
+}
+
+/**
+ * Get the IDs for the extension buttons available in a given space.
+ *
+ * @param {string} [space] - Space name, "default" or falsy value to specify the
+ *   space the extension items should be returned for. For default, extensions
+ *   explicitly available in the default space are returned. With a falsy value,
+ *   extensions available in all spaces are returned.
+ * @param {boolean} [includeSpaceAgnostic=false] - When set, extensions that are
+ *   available for all spaces and the provided space are returned. Only has an
+ *   effect if space is not falsy.
+ * @returns {string[]} Array of item IDs for extensions in the given space.
+ */
+function getExtensionsForSpace(space, includeSpaceAgnostic = false) {
+  return EXTENSIONS.filter(
+    extension =>
+      (space && extension.spaces?.includes(space)) ||
+      ((!space || includeSpaceAgnostic) && !extension.spaces?.length)
+  ).map(extension => `${EXTENSION_PREFIX}${extension.id}`);
+}
+
+/**
+ * Get the items available for the unified toolbar in a given space.
+ *
+ * @param {string} [space] - ID of the space to get the available exclusive
+ *   items of. When omitted only items allowed in all spaces are returned.
+ * @param {boolean} [includeSpaceAgnostic=false] - When set, extensions that are
+ *   available for all spaces and the provided space are returned. Only has an
+ *   effect if space is not falsy.
+ * @returns {string[]} Array of item IDs available in the space.
+ */
+export function getAvailableItemIdsForSpace(
+  space,
+  includeSpaceAgnostic = false
+) {
+  return CUSTOMIZABLE_ITEMS.filter(
+    item =>
+      ((space && item.spaces?.includes(space)) ||
+        ((!space || includeSpaceAgnostic) &&
+          (!item.spaces || item.spaces.length === 0))) &&
+      (item.id !== "search-bar" || lazy.glodaEnabled)
+  )
+    .map(item => item.id)
+    .concat(getExtensionsForSpace(space, includeSpaceAgnostic));
+}
+
+/**
+ * Retrieve the set of items that are in the default configuration of the
+ * toolbar for a given space.
+ *
+ * @param {string} space - ID of the space to get the default items for.
+ *   "default" is passed to indicate a default state without any active space.
+ * @returns {string[]} Array of item IDs to show by default in the space.
+ */
+export function getDefaultItemIdsForSpace(space) {
+  return (
+    lazy.glodaEnabled ? DEFAULT_ITEMS : DEFAULT_ITEMS_WITHOUT_SEARCH
+  ).concat(getExtensionsForSpace(space, true));
+}
+
+/**
+ * Set of item IDs that can occur more than once in the targets of a space.
+ *
+ * @type {Set<string>}
+ */
+export const MULTIPLE_ALLOWED_ITEM_IDS = new Set(
+  CUSTOMIZABLE_ITEMS.filter(item => item.allowMultiple).map(item => item.id)
+);
+
+export const SKIP_FOCUS_ITEM_IDS = new Set(
+  CUSTOMIZABLE_ITEMS.filter(item => item.skipFocus).map(item => item.id)
+);