1 files changed, 112 insertions, 0 deletions
diff --git a/browser/components/firefoxview/firefox-view-notification-manager.sys.mjs b/browser/components/firefoxview/firefox-view-notification-manager.sys.mjs
new file mode 100644
index 0000000000..97bac34360
--- /dev/null
+++ b/browser/components/firefoxview/firefox-view-notification-manager.sys.mjs
@@ -0,0 +1,112 @@
+/* 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/. */
+
+/**
+ * This module exports the FirefoxViewNotificationManager singleton, which manages the notification state
+ * for the Firefox View button
+ */
+
+const RECENT_TABS_SYNC = "services.sync.lastTabFetch";
+const SHOULD_NOTIFY_FOR_TABS = "browser.tabs.firefox-view.notify-for-tabs";
+const lazy = {};
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+XPCOMUtils.defineLazyModuleGetters(lazy, {
+  BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
+  SyncedTabs: "resource://services-sync/SyncedTabs.jsm",
+});
+
+export const FirefoxViewNotificationManager = new (class {
+  #currentlyShowing;
+  constructor() {
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "lastTabFetch",
+      RECENT_TABS_SYNC,
+      0,
+      () => {
+        this.handleTabSync();
+      }
+    );
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "shouldNotifyForTabs",
+      SHOULD_NOTIFY_FOR_TABS,
+      false
+    );
+    // Need to access the pref variable for the observer to start observing
+    // See the defineLazyPreferenceGetter function header
+    this.lastTabFetch;
+
+    Services.obs.addObserver(this, "firefoxview-notification-dot-update");
+
+    this.#currentlyShowing = false;
+  }
+
+  async handleTabSync() {
+    if (!this.shouldNotifyForTabs) {
+      return;
+    }
+    let newSyncedTabs = await lazy.SyncedTabs.getRecentTabs(3);
+    this.#currentlyShowing = this.tabsListChanged(newSyncedTabs);
+    this.showNotificationDot();
+    this.syncedTabs = newSyncedTabs;
+  }
+
+  showNotificationDot() {
+    if (this.#currentlyShowing) {
+      Services.obs.notifyObservers(
+        null,
+        "firefoxview-notification-dot-update",
+        "true"
+      );
+    }
+  }
+
+  observe(sub, topic, data) {
+    if (topic === "firefoxview-notification-dot-update" && data === "false") {
+      this.#currentlyShowing = false;
+    }
+  }
+
+  tabsListChanged(newTabs) {
+    // The first time the tabs list is changed this.tabs is undefined because we haven't synced yet.
+    // We don't want to show the badge here because it's not an actual change,
+    // we are just syncing for the first time.
+    if (!this.syncedTabs) {
+      return false;
+    }
+
+    // We loop through all windows to see if any window has currentURI "about:firefoxview" and
+    // the window is visible because we don't want to show the notification badge in that case
+    for (let window of lazy.BrowserWindowTracker.orderedWindows) {
+      // if the url is "about:firefoxview" and the window visible we don't want to show the notification badge
+      if (
+        window.FirefoxViewHandler.tab?.selected &&
+        !window.isFullyOccluded &&
+        window.windowState !== window.STATE_MINIMIZED
+      ) {
+        return false;
+      }
+    }
+
+    if (newTabs.length > this.syncedTabs.length) {
+      return true;
+    }
+    for (let i = 0; i < newTabs.length; i++) {
+      let newTab = newTabs[i];
+      let oldTab = this.syncedTabs[i];
+
+      if (newTab?.url !== oldTab?.url) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  shouldNotificationDotBeShowing() {
+    return this.#currentlyShowing;
+  }
+})();