| // Copyright 2019 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef CORE_FXCRT_RETAINED_TREE_NODE_H_ |
| #define CORE_FXCRT_RETAINED_TREE_NODE_H_ |
| |
| #include "core/fxcrt/retain_ptr.h" |
| #include "core/fxcrt/tree_node.h" |
| #include "third_party/base/check.h" |
| |
| namespace fxcrt { |
| |
| // For DOM/XML-ish trees, where references outside the tree are RetainPtr<T>, |
| // and the parent node also "retains" its children but doesn't always have |
| // a direct pointer to them. |
| template <typename T> |
| class RetainedTreeNode : public TreeNode<T> { |
| public: |
| template <typename U, typename... Args> |
| friend RetainPtr<U> pdfium::MakeRetain(Args&&... args); |
| |
| void AppendFirstChild(const RetainPtr<T>& child) { |
| TreeNode<T>::AppendFirstChild(child.Get()); |
| } |
| |
| void AppendLastChild(const RetainPtr<T>& child) { |
| TreeNode<T>::AppendLastChild(child.Get()); |
| } |
| |
| void InsertBefore(const RetainPtr<T>& child, T* other) { |
| TreeNode<T>::InsertBefore(child.Get(), other); |
| } |
| |
| void InsertAfter(const RetainPtr<T>& child, T* other) { |
| TreeNode<T>::InsertAfter(child.Get(), other); |
| } |
| |
| void RemoveChild(const RetainPtr<T>& child) { |
| TreeNode<T>::RemoveChild(child.Get()); |
| } |
| |
| void RemoveSelfIfParented() { |
| if (T* parent = TreeNode<T>::GetParent()) { |
| parent->TreeNode<T>::RemoveChild( |
| pdfium::WrapRetain(static_cast<T*>(this)).Get()); |
| } |
| } |
| |
| protected: |
| RetainedTreeNode() = default; |
| ~RetainedTreeNode() override { |
| while (auto* pChild = TreeNode<T>::GetFirstChild()) |
| RemoveChild(pdfium::WrapRetain(pChild)); |
| } |
| |
| private: |
| template <typename U> |
| friend struct ReleaseDeleter; |
| |
| template <typename U> |
| friend class RetainPtr; |
| |
| RetainedTreeNode(const RetainedTreeNode& that) = delete; |
| RetainedTreeNode& operator=(const RetainedTreeNode& that) = delete; |
| |
| void Retain() { ++m_nRefCount; } |
| void Release() { |
| DCHECK(m_nRefCount > 0); |
| if (--m_nRefCount == 0 && !TreeNode<T>::GetParent()) |
| delete this; |
| } |
| |
| intptr_t m_nRefCount = 0; |
| }; |
| |
| } // namespace fxcrt |
| |
| using fxcrt::RetainedTreeNode; |
| |
| #endif // CORE_FXCRT_RETAINED_TREE_NODE_H_ |