1 files changed, 61 insertions, 0 deletions
diff --git a/accessible/base/EventTree.h b/accessible/base/EventTree.h
new file mode 100644
index 0000000000..bd9976b4fb
--- /dev/null
+++ b/accessible/base/EventTree.h
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_a11y_EventTree_h_
+#define mozilla_a11y_EventTree_h_
+
+#include "AccEvent.h"
+#include "LocalAccessible.h"
+
+#include "mozilla/a11y/DocAccessible.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+namespace a11y {
+
+class NotificationController;
+
+/**
+ * This class makes sure required tasks are done before and after tree
+ * mutations. Currently this only includes group info invalidation. You must
+ * have an object of this class on the stack when calling methods that mutate
+ * the accessible tree.
+ */
+class TreeMutation final {
+ public:
+  static const bool kNoEvents = true;
+  static const bool kNoShutdown = true;
+
+  explicit TreeMutation(LocalAccessible* aParent, bool aNoEvents = false);
+  ~TreeMutation();
+
+  void AfterInsertion(LocalAccessible* aChild);
+  void BeforeRemoval(LocalAccessible* aChild, bool aNoShutdown = false);
+  void Done();
+
+ private:
+  NotificationController* Controller() const {
+    return mParent->Document()->Controller();
+  }
+
+  LocalAccessible* mParent;
+  uint32_t mStartIdx;
+  uint32_t mStateFlagsCopy;
+
+  /*
+   * True if mutation events should be queued.
+   */
+  bool mQueueEvents;
+
+#ifdef DEBUG
+  bool mIsDone;
+#endif
+};
+
+}  // namespace a11y
+}  // namespace mozilla
+
+#endif  // mozilla_a11y_EventQueue_h_