1 files changed, 72 insertions, 0 deletions
diff --git a/toolkit/components/satchel/FormHandlerChild.sys.mjs b/toolkit/components/satchel/FormHandlerChild.sys.mjs
new file mode 100644
index 0000000000..6b1af3dbc3
--- /dev/null
+++ b/toolkit/components/satchel/FormHandlerChild.sys.mjs
@@ -0,0 +1,72 @@
+/* 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/. */
+
+/**
+ * The FormHandlerChild is the place to implement logic that is shared
+ * by child actors like FormAutofillChild, LoginManagerChild and FormHistoryChild
+ * or in general components that deal with form data.
+ */
+
+export const FORM_SUBMISSION_REASON = {
+  FORM_SUBMIT_EVENT: "form-submit-event",
+  FORM_REMOVAL_AFTER_FETCH: "form-removal-after-fetch",
+  IFRAME_PAGEHIDE: "iframe-pagehide",
+  PAGE_NAVIGATION: "page-navigation",
+};
+
+export class FormHandlerChild extends JSWindowActorChild {
+  handleEvent(event) {
+    if (!event.isTrusted) {
+      return;
+    }
+    switch (event.type) {
+      case "DOMFormBeforeSubmit":
+        this.processDOMFormBeforeSubmitEvent(event);
+        break;
+      default:
+        throw new Error("Unexpected event type");
+    }
+  }
+
+  /**
+   * Process the DOMFormBeforeSubmitEvent that is dispatched
+   * after a form submit event. Extract event data
+   * that is relevant to the form submission listeners
+   *
+   * @param {Event} event DOMFormBeforeSubmit
+   */
+  processDOMFormBeforeSubmitEvent(event) {
+    const form = event.target;
+    const formSubmissionReason = FORM_SUBMISSION_REASON.FORM_SUBMIT_EVENT;
+
+    this.#dispatchFormSubmissionEvent(form, formSubmissionReason);
+  }
+
+  // handle form-removal-after-fetch
+  processFormRemovalAfterFetch(params) {}
+
+  // handle iframe-pagehide
+  processIframePagehide(params) {}
+
+  // handle page-navigation
+  processPageNavigation(params) {}
+
+  /**
+   * Dispatch the CustomEvent form-submission-detected also transfer
+   * the information:
+   *            detail.form   - the form that is being submitted
+   *            detail.reason - the heuristic that detected the form submission
+   *                            (see FORM_SUBMISSION_REASON)
+   *
+   * @param {HTMLFormElement} form
+   * @param {string} reason
+   */
+  #dispatchFormSubmissionEvent(form, reason) {
+    const formSubmissionEvent = new CustomEvent("form-submission-detected", {
+      detail: { form, reason },
+      bubbles: true,
+    });
+    this.document.dispatchEvent(formSubmissionEvent);
+  }
+}