1 files changed, 157 insertions, 0 deletions
diff --git a/toolkit/components/formautofill/shared/FormStateManager.sys.mjs b/toolkit/components/formautofill/shared/FormStateManager.sys.mjs
new file mode 100644
index 0000000000..064b4e5356
--- /dev/null
+++ b/toolkit/components/formautofill/shared/FormStateManager.sys.mjs
@@ -0,0 +1,157 @@
+/* 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/. */
+
+const lazy = {};
+ChromeUtils.defineESModuleGetters(lazy, {
+  FormLikeFactory: "resource://gre/modules/FormLikeFactory.sys.mjs",
+  FormAutofillHandler:
+    "resource://gre/modules/shared/FormAutofillHandler.sys.mjs",
+});
+
+export class FormStateManager {
+  constructor(onSubmit, onAutofillCallback) {
+    /**
+     * @type {WeakMap} mapping FormLike root HTML elements to FormAutofillHandler objects.
+     */
+    this._formsDetails = new WeakMap();
+    /**
+     * @type {object} The object where to store the active items, e.g. element,
+     * handler, section, and field detail.
+     */
+    this._activeItems = {};
+
+    this.onSubmit = onSubmit;
+
+    this.onAutofillCallback = onAutofillCallback;
+  }
+
+  /**
+   * Get the active input's information from cache which is created after page
+   * identified.
+   *
+   * @returns {object | null}
+   *          Return the active input's information that cloned from content cache
+   *          (or return null if the information is not found in the cache).
+   */
+  get activeFieldDetail() {
+    if (!this._activeItems.fieldDetail) {
+      let formDetails = this.activeFormDetails;
+      if (!formDetails) {
+        return null;
+      }
+      for (let detail of formDetails) {
+        let detailElement = detail.element;
+        if (detailElement && this.activeInput == detailElement) {
+          this._activeItems.fieldDetail = detail;
+          break;
+        }
+      }
+    }
+    return this._activeItems.fieldDetail;
+  }
+
+  /**
+   * Get the active form's information from cache which is created after page
+   * identified.
+   *
+   * @returns {Array<object> | null}
+   *          Return target form's information from content cache
+   *          (or return null if the information is not found in the cache).
+   *
+   */
+  get activeFormDetails() {
+    let formHandler = this.activeHandler;
+    return formHandler ? formHandler.fieldDetails : null;
+  }
+
+  get activeInput() {
+    return this._activeItems.elementWeakRef?.deref();
+  }
+
+  get activeHandler() {
+    const activeInput = this.activeInput;
+    if (!activeInput) {
+      return null;
+    }
+
+    // XXX: We are recomputing the activeHandler every time to avoid keeping a
+    // reference on the active element. This might be called quite frequently
+    // so if _getFormHandler/findRootForField become more costly, we should
+    // look into caching this result (eg by adding a weakmap).
+    let handler = this._getFormHandler(activeInput);
+    if (handler) {
+      handler.focusedInput = activeInput;
+    }
+    return handler;
+  }
+
+  get activeSection() {
+    let formHandler = this.activeHandler;
+    return formHandler ? formHandler.activeSection : null;
+  }
+
+  /**
+   * Get the form's handler from cache which is created after page identified.
+   *
+   * @param {HTMLInputElement} element Focused input which triggered profile searching
+   * @returns {Array<object> | null}
+   *          Return target form's handler from content cache
+   *          (or return null if the information is not found in the cache).
+   *
+   */
+  _getFormHandler(element) {
+    if (!element) {
+      return null;
+    }
+    let rootElement = lazy.FormLikeFactory.findRootForField(element);
+    return this._formsDetails.get(rootElement);
+  }
+
+  identifyAutofillFields(element) {
+    let formHandler = this._getFormHandler(element);
+    if (!formHandler) {
+      let formLike = lazy.FormLikeFactory.createFromField(element);
+      formHandler = new lazy.FormAutofillHandler(
+        formLike,
+        this.onSubmit,
+        this.onAutofillCallback
+      );
+    } else if (!formHandler.updateFormIfNeeded(element)) {
+      return formHandler.fieldDetails;
+    }
+    this._formsDetails.set(formHandler.form.rootElement, formHandler);
+    return formHandler.collectFormFields();
+  }
+
+  updateActiveInput(element) {
+    if (!element) {
+      this._activeItems = {};
+      return;
+    }
+    this._activeItems = {
+      elementWeakRef: new WeakRef(element),
+      fieldDetail: null,
+    };
+  }
+
+  getRecords(formElement, handler) {
+    handler = handler || this._formsDetails.get(formElement);
+    const records = handler?.createRecords();
+
+    if (
+      !handler ||
+      !records ||
+      !Object.values(records).some(typeRecords => typeRecords.length)
+    ) {
+      return null;
+    }
+    return records;
+  }
+
+  didDestroy() {
+    this._activeItems = null;
+  }
+}
+
+export default FormStateManager;