1 files changed, 57 insertions, 0 deletions
diff --git a/browser/components/migration/MigrationWizardChild.sys.mjs b/browser/components/migration/MigrationWizardChild.sys.mjs
new file mode 100644
index 0000000000..4a7db8f043
--- /dev/null
+++ b/browser/components/migration/MigrationWizardChild.sys.mjs
@@ -0,0 +1,57 @@
+/* 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 { MigrationWizardConstants } from "chrome://browser/content/migration/migration-wizard-constants.mjs";
+
+/**
+ * This class is responsible for updating the state of a <migration-wizard>
+ * component, and for listening for events from that component to perform
+ * various migration functions.
+ */
+export class MigrationWizardChild extends JSWindowActorChild {
+  #wizardEl = null;
+
+  /**
+   * General event handler function for events dispatched from the
+   * <migration-wizard> component.
+   *
+   * @param {Event} event
+   *   The DOM event being handled.
+   * @returns {Promise}
+   */
+  async handleEvent(event) {
+    if (event.type == "MigrationWizard:Init") {
+      this.#wizardEl = event.target;
+      let migrators = await this.sendQuery("GetAvailableMigrators");
+      this.setComponentState({
+        migrators,
+        page: MigrationWizardConstants.PAGES.SELECTION,
+      });
+    }
+  }
+
+  /**
+   * Calls the `setState` method on the <migration-wizard> component. The
+   * state is cloned into the execution scope of this.#wizardEl.
+   *
+   * @param {object} state The state object that a <migration-wizard>
+   *   component expects. See the documentation for the element's setState
+   *   method for more details.
+   */
+  setComponentState(state) {
+    if (!this.#wizardEl) {
+      return;
+    }
+    // We waive XrayWrappers in the event that the element is embedded in
+    // a document without system privileges, like about:welcome.
+    Cu.waiveXrays(this.#wizardEl).setState(
+      Cu.cloneInto(
+        state,
+        // ownerGlobal doesn't exist in content windows.
+        // eslint-disable-next-line mozilla/use-ownerGlobal
+        this.#wizardEl.ownerDocument.defaultView
+      )
+    );
+  }
+}