1 files changed, 92 insertions, 0 deletions
diff --git a/layout/forms/ListMutationObserver.cpp b/layout/forms/ListMutationObserver.cpp
new file mode 100644
index 0000000000..13f9e367a0
--- /dev/null
+++ b/layout/forms/ListMutationObserver.cpp
@@ -0,0 +1,92 @@
+/* -*- 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/. */
+#include "ListMutationObserver.h"
+
+#include "mozilla/dom/HTMLInputElement.h"
+#include "nsIFrame.h"
+
+namespace mozilla {
+NS_IMPL_ISUPPORTS(ListMutationObserver, nsIMutationObserver)
+
+ListMutationObserver::~ListMutationObserver() = default;
+
+void ListMutationObserver::Attach(bool aRepaint) {
+  nsAutoString id;
+  if (InputElement().GetAttr(nsGkAtoms::list_, id)) {
+    Unlink();
+    RefPtr<nsAtom> idAtom = NS_AtomizeMainThread(id);
+    ResetWithID(InputElement(), idAtom);
+    AddObserverIfNeeded();
+  }
+  if (aRepaint) {
+    mOwningElementFrame->InvalidateFrame();
+  }
+}
+
+void ListMutationObserver::AddObserverIfNeeded() {
+  if (auto* list = get()) {
+    if (list->IsHTMLElement(nsGkAtoms::datalist)) {
+      list->AddMutationObserver(this);
+    }
+  }
+}
+
+void ListMutationObserver::RemoveObserverIfNeeded(dom::Element* aList) {
+  if (aList && aList->IsHTMLElement(nsGkAtoms::datalist)) {
+    aList->RemoveMutationObserver(this);
+  }
+}
+
+void ListMutationObserver::Detach() {
+  RemoveObserverIfNeeded();
+  Unlink();
+}
+
+dom::HTMLInputElement& ListMutationObserver::InputElement() const {
+  MOZ_ASSERT(mOwningElementFrame->GetContent()->IsHTMLElement(nsGkAtoms::input),
+             "bad cast");
+  return *static_cast<dom::HTMLInputElement*>(
+      mOwningElementFrame->GetContent());
+}
+
+void ListMutationObserver::AttributeChanged(dom::Element* aElement,
+                                            int32_t aNameSpaceID,
+                                            nsAtom* aAttribute,
+                                            int32_t aModType,
+                                            const nsAttrValue* aOldValue) {
+  if (aAttribute == nsGkAtoms::value && aNameSpaceID == kNameSpaceID_None &&
+      aElement->IsHTMLElement(nsGkAtoms::option)) {
+    mOwningElementFrame->InvalidateFrame();
+  }
+}
+
+void ListMutationObserver::CharacterDataChanged(
+    nsIContent* aContent, const CharacterDataChangeInfo& aInfo) {
+  mOwningElementFrame->InvalidateFrame();
+}
+
+void ListMutationObserver::ContentAppended(nsIContent* aFirstNewContent) {
+  mOwningElementFrame->InvalidateFrame();
+}
+
+void ListMutationObserver::ContentInserted(nsIContent* aChild) {
+  mOwningElementFrame->InvalidateFrame();
+}
+
+void ListMutationObserver::ContentRemoved(nsIContent* aChild,
+                                          nsIContent* aPreviousSibling) {
+  mOwningElementFrame->InvalidateFrame();
+}
+
+void ListMutationObserver::ElementChanged(dom::Element* aFrom,
+                                          dom::Element* aTo) {
+  IDTracker::ElementChanged(aFrom, aTo);
+  RemoveObserverIfNeeded(aFrom);
+  AddObserverIfNeeded();
+  mOwningElementFrame->InvalidateFrame();
+}
+
+}  // namespace mozilla