1 files changed, 107 insertions, 0 deletions
diff --git a/dom/base/AncestorIterator.h b/dom/base/AncestorIterator.h
new file mode 100644
index 0000000000..d8a56267fd
--- /dev/null
+++ b/dom/base/AncestorIterator.h
@@ -0,0 +1,107 @@
+/* -*- 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/. */
+
+/**
+ * Implementation of some generic iterators over ancestor nodes.
+ *
+ * Note that these keep raw pointers to the nodes they iterate from, and as
+ * such the DOM should not be mutated while they're in use. There are debug
+ * assertions (via nsMutationGuard) that check this in debug builds.
+ */
+
+#ifndef mozilla_dom_AncestorIterator_h
+#define mozilla_dom_AncestorIterator_h
+
+#include "nsINode.h"
+#include "nsIContentInlines.h"
+#include "FilteredNodeIterator.h"
+
+namespace mozilla::dom {
+
+#ifdef DEBUG
+#  define MUTATION_GUARD(class_name_) \
+    nsMutationGuard mMutationGuard;   \
+    ~class_name_() { MOZ_ASSERT(!mMutationGuard.Mutated(0)); }
+#else
+#  define MUTATION_GUARD(class_name_)
+#endif
+
+#define DEFINE_ANCESTOR_ITERATOR(name_, method_)                         \
+  class Inclusive##name_ {                                               \
+    using Self = Inclusive##name_;                                       \
+                                                                         \
+   public:                                                               \
+    explicit Inclusive##name_(const nsINode& aNode)                      \
+        : mCurrent(const_cast<nsINode*>(&aNode)) {}                      \
+    Self& begin() { return *this; }                                      \
+    std::nullptr_t end() const { return nullptr; }                       \
+    bool operator!=(std::nullptr_t) const { return !!mCurrent; }         \
+    void operator++() { mCurrent = mCurrent->method_(); }                \
+    nsINode* operator*() { return mCurrent; }                            \
+                                                                         \
+    MUTATION_GUARD(Inclusive##name_)                                     \
+                                                                         \
+   protected:                                                            \
+    explicit Inclusive##name_(nsINode* aCurrent) : mCurrent(aCurrent) {} \
+    nsINode* mCurrent;                                                   \
+  };                                                                     \
+  class name_ : public Inclusive##name_ {                                \
+   public:                                                               \
+    using Super = Inclusive##name_;                                      \
+    explicit name_(const nsINode& aNode)                                 \
+        : Inclusive##name_(aNode.method_()) {}                           \
+  };                                                                     \
+  template <typename T>                                                  \
+  class name_##OfTypeIterator : public FilteredNodeIterator<T, name_> {  \
+   public:                                                               \
+    explicit name_##OfTypeIterator(const nsINode& aNode)                 \
+        : FilteredNodeIterator<T, name_>(aNode) {}                       \
+  };                                                                     \
+  template <typename T>                                                  \
+  class Inclusive##name_##OfTypeIterator                                 \
+      : public FilteredNodeIterator<T, Inclusive##name_> {               \
+   public:                                                               \
+    explicit Inclusive##name_##OfTypeIterator(const nsINode& aNode)      \
+        : FilteredNodeIterator<T, Inclusive##name_>(aNode) {}            \
+  };
+
+DEFINE_ANCESTOR_ITERATOR(Ancestors, GetParentNode)
+DEFINE_ANCESTOR_ITERATOR(FlatTreeAncestors, GetFlattenedTreeParentNode)
+
+#undef MUTATION_GUARD
+
+}  // namespace mozilla::dom
+
+template <typename T>
+inline mozilla::dom::AncestorsOfTypeIterator<T> nsINode::AncestorsOfType()
+    const {
+  return mozilla::dom::AncestorsOfTypeIterator<T>(*this);
+}
+
+template <typename T>
+inline mozilla::dom::InclusiveAncestorsOfTypeIterator<T>
+nsINode::InclusiveAncestorsOfType() const {
+  return mozilla::dom::InclusiveAncestorsOfTypeIterator<T>(*this);
+}
+
+template <typename T>
+inline mozilla::dom::FlatTreeAncestorsOfTypeIterator<T>
+nsINode::FlatTreeAncestorsOfType() const {
+  return mozilla::dom::FlatTreeAncestorsOfTypeIterator<T>(*this);
+}
+
+template <typename T>
+inline mozilla::dom::InclusiveFlatTreeAncestorsOfTypeIterator<T>
+nsINode::InclusiveFlatTreeAncestorsOfType() const {
+  return mozilla::dom::InclusiveFlatTreeAncestorsOfTypeIterator<T>(*this);
+}
+
+template <typename T>
+inline T* nsINode::FirstAncestorOfType() const {
+  return *(AncestorsOfType<T>());
+}
+
+#endif  // mozilla_dom_AncestorIterator.h