1 files changed, 111 insertions, 0 deletions
diff --git a/dom/l10n/L10nOverlays.h b/dom/l10n/L10nOverlays.h
new file mode 100644
index 0000000000..95b1714761
--- /dev/null
+++ b/dom/l10n/L10nOverlays.h
@@ -0,0 +1,111 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef mozilla_dom_l10n_L10nOverlays_h
+#define mozilla_dom_l10n_L10nOverlays_h
+
+#include "mozilla/dom/L10nOverlaysBinding.h"
+#include "mozilla/dom/LocalizationBinding.h"
+
+class nsINode;
+
+namespace mozilla::dom {
+
+class DocumentFragment;
+class Element;
+
+class L10nOverlays {
+ public:
+  /**
+   * Translate an element.
+   *
+   * Translate the element's text content and attributes. Some HTML markup is
+   * allowed in the translation. The element's children with the data-l10n-name
+   * attribute will be treated as arguments to the translation. If the
+   * translation defines the same children, their attributes and text contents
+   * will be used for translating the matching source child.
+   */
+  static void TranslateElement(const GlobalObject& aGlobal, Element& aElement,
+                               const L10nMessage& aTranslation,
+                               Nullable<nsTArray<L10nOverlaysError>>& aErrors);
+  static void TranslateElement(Element& aElement,
+                               const L10nMessage& aTranslation,
+                               nsTArray<L10nOverlaysError>& aErrors,
+                               ErrorResult& aRv);
+
+ private:
+  /**
+   * Create a text node from text content of an Element.
+   */
+  static already_AddRefed<nsINode> CreateTextNodeFromTextContent(
+      Element* aElement, ErrorResult& aRv);
+
+  /**
+   * Transplant localizable attributes of an element to another element.
+   *
+   * Any localizable attributes already set on the target element will be
+   * cleared.
+   */
+  static void OverlayAttributes(
+      const Nullable<Sequence<AttributeNameValue>>& aTranslation,
+      Element* aToElement, ErrorResult& aRv);
+  static void OverlayAttributes(Element* aFromElement, Element* aToElement,
+                                ErrorResult& aRv);
+
+  /**
+   * Helper to set textContent and localizable attributes on an element.
+   */
+  static void ShallowPopulateUsing(Element* aFromElement, Element* aToElement,
+                                   ErrorResult& aRv);
+
+  /**
+   * Sanitize a child element created by the translation.
+   *
+   * Try to find a corresponding child in sourceElement and use it as the base
+   * for the sanitization. This will preserve functional attributes defined on
+   * the child element in the source HTML.
+   */
+  static already_AddRefed<nsINode> GetNodeForNamedElement(
+      Element* aSourceElement, Element* aTranslatedChild,
+      nsTArray<L10nOverlaysError>& aErrors, ErrorResult& aRv);
+
+  /**
+   * Check if element is allowed in the translation.
+   *
+   * This method is used by the sanitizer when the translation markup contains
+   * an element which is not present in the source code.
+   */
+  static bool IsElementAllowed(Element* aElement);
+
+  /**
+   * Sanitize an allowed element.
+   *
+   * Text-level elements allowed in translations may only use safe attributes
+   * and will have any nested markup stripped to text content.
+   */
+  static already_AddRefed<Element> CreateSanitizedElement(Element* aElement,
+                                                          ErrorResult& aRv);
+
+  /**
+   * Replace child nodes of an element with child nodes of another element.
+   *
+   * The contents of the target element will be cleared and fully replaced with
+   * sanitized contents of the source element.
+   */
+  static void OverlayChildNodes(DocumentFragment* aFromFragment,
+                                Element* aToElement,
+                                nsTArray<L10nOverlaysError>& aErrors,
+                                ErrorResult& aRv);
+
+  /**
+   * A helper used to test if the string contains HTML markup.
+   */
+  static bool ContainsMarkup(const nsACString& aStr);
+};
+
+}  // namespace mozilla::dom
+
+#endif