dom/base/AncestorIterator.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /**
   8  * Implementation of some generic iterators over ancestor nodes.
   9  *
  10  * Note that these keep raw pointers to the nodes they iterate from, and as
  11  * such the DOM should not be mutated while they're in use. There are debug
  12  * assertions (via nsMutationGuard) that check this in debug builds.
  13  */
  14
  15 #ifndef mozilla_dom_AncestorIterator_h
  16 #define mozilla_dom_AncestorIterator_h
  17
  18 #include "nsINode.h"
  19 #include "nsIContentInlines.h"
  20 #include "FilteredNodeIterator.h"
  21
  22 namespace mozilla::dom {
  23
  24 #ifdef DEBUG
  25 #  define MUTATION_GUARD(class_name_) \
  26     nsMutationGuard mMutationGuard;   \
  27     ~class_name_() { MOZ_ASSERT(!mMutationGuard.Mutated(0)); }
  28 #else
  29 #  define MUTATION_GUARD(class_name_)
  30 #endif
  31
  32 #define DEFINE_ANCESTOR_ITERATOR(name_, method_)                         \
  33   class Inclusive##name_ {                                               \
  34     using Self = Inclusive##name_;                                       \
  35                                                                          \
  36    public:                                                               \
  37     explicit Inclusive##name_(const nsINode& aNode)                      \
  38         : mCurrent(const_cast<nsINode*>(&aNode)) {}                      \
  39     Self& begin() { return *this; }                                      \
  40     std::nullptr_t end() const { return nullptr; }                       \
  41     bool operator!=(std::nullptr_t) const { return !!mCurrent; }         \
  42     void operator++() { mCurrent = mCurrent->method_(); }                \
  43     nsINode* operator*() { return mCurrent; }                            \
  44                                                                          \
  45     MUTATION_GUARD(Inclusive##name_)                                     \
  46                                                                          \
  47    protected:                                                            \
  48     explicit Inclusive##name_(nsINode* aCurrent) : mCurrent(aCurrent) {} \
  49     nsINode* mCurrent;                                                   \
  50   };                                                                     \
  51   class name_ : public Inclusive##name_ {                                \
  52    public:                                                               \
  53     using Super = Inclusive##name_;                                      \
  54     explicit name_(const nsINode& aNode)                                 \
  55         : Inclusive##name_(aNode.method_()) {}                           \
  56   };                                                                     \
  57   template <typename T>                                                  \
  58   class name_##OfTypeIterator : public FilteredNodeIterator<T, name_> {  \
  59    public:                                                               \
  60     explicit name_##OfTypeIterator(const nsINode& aNode)                 \
  61         : FilteredNodeIterator<T, name_>(aNode) {}                       \
  62   };                                                                     \
  63   template <typename T>                                                  \
  64   class Inclusive##name_##OfTypeIterator                                 \
  65       : public FilteredNodeIterator<T, Inclusive##name_> {               \
  66    public:                                                               \
  67     explicit Inclusive##name_##OfTypeIterator(const nsINode& aNode)      \
  68         : FilteredNodeIterator<T, Inclusive##name_>(aNode) {}            \
  69   };
  70
  71 DEFINE_ANCESTOR_ITERATOR(Ancestors, GetParentNode)
  72 DEFINE_ANCESTOR_ITERATOR(FlatTreeAncestors, GetFlattenedTreeParentNode)
  73
  74 #undef MUTATION_GUARD
  75
  76 }  // namespace mozilla::dom
  77
  78 template <typename T>
  79 inline mozilla::dom::AncestorsOfTypeIterator<T> nsINode::AncestorsOfType()
  80     const {
  81   return mozilla::dom::AncestorsOfTypeIterator<T>(*this);
  82 }
  83
  84 template <typename T>
  85 inline mozilla::dom::InclusiveAncestorsOfTypeIterator<T>
  86 nsINode::InclusiveAncestorsOfType() const {
  87   return mozilla::dom::InclusiveAncestorsOfTypeIterator<T>(*this);
  88 }
  89
  90 template <typename T>
  91 inline mozilla::dom::FlatTreeAncestorsOfTypeIterator<T>
  92 nsINode::FlatTreeAncestorsOfType() const {
  93   return mozilla::dom::FlatTreeAncestorsOfTypeIterator<T>(*this);
  94 }
  95
  96 template <typename T>
  97 inline mozilla::dom::InclusiveFlatTreeAncestorsOfTypeIterator<T>
  98 nsINode::InclusiveFlatTreeAncestorsOfType() const {
  99   return mozilla::dom::InclusiveFlatTreeAncestorsOfTypeIterator<T>(*this);
 100 }
 101
 102 template <typename T>
 103 inline T* nsINode::FirstAncestorOfType() const {
 104   return *(AncestorsOfType<T>());
 105 }
 106
 107 #endif  // mozilla_dom_AncestorIterator.h