// Copyright 2017 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. // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com #ifndef XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_ #define XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_ template <class NodeType, class TraverseStrategy> class CXFA_NodeIteratorTemplate { public: explicit CXFA_NodeIteratorTemplate(NodeType* pRoot) : m_pRoot(pRoot), m_pCurrent(pRoot) {} NodeType* GetRoot() const { return m_pRoot; } NodeType* GetCurrent() const { return m_pCurrent; } void Reset() { m_pCurrent = m_pRoot; } bool SetCurrent(NodeType* pNode) { if (!RootReachableFromNode(pNode)) { m_pCurrent = nullptr; return false; } m_pCurrent = pNode; return true; } NodeType* MoveToPrev() { if (!m_pRoot) return nullptr; if (!m_pCurrent) { m_pCurrent = LastDescendant(m_pRoot); return m_pCurrent; } NodeType* pSibling = PreviousSiblingWithinSubtree(m_pCurrent); if (pSibling) { m_pCurrent = LastDescendant(pSibling); return m_pCurrent; } NodeType* pParent = ParentWithinSubtree(m_pCurrent); if (pParent) { m_pCurrent = pParent; return m_pCurrent; } return nullptr; } NodeType* MoveToNext() { if (!m_pRoot || !m_pCurrent) return nullptr; NodeType* pChild = TraverseStrategy::GetFirstChild(m_pCurrent); if (pChild) { m_pCurrent = pChild; return m_pCurrent; } return SkipChildrenAndMoveToNext(); } NodeType* SkipChildrenAndMoveToNext() { if (!m_pRoot) return nullptr; NodeType* pNode = m_pCurrent; while (pNode) { NodeType* pSibling = NextSiblingWithinSubtree(pNode); if (pSibling) { m_pCurrent = pSibling; return m_pCurrent; } pNode = ParentWithinSubtree(pNode); } m_pCurrent = nullptr; return m_pCurrent; } private: bool RootReachableFromNode(NodeType* pNode) { if (!pNode) return false; if (pNode == m_pRoot) return true; return RootReachableFromNode(TraverseStrategy::GetParent(pNode)); } NodeType* ParentWithinSubtree(NodeType* pNode) { if (!pNode || pNode == m_pRoot) return nullptr; return TraverseStrategy::GetParent(pNode); } NodeType* NextSiblingWithinSubtree(NodeType* pNode) { if (pNode == m_pRoot) return nullptr; return TraverseStrategy::GetNextSibling(pNode); } NodeType* PreviousSiblingWithinSubtree(NodeType* pNode) { NodeType* pParent = ParentWithinSubtree(pNode); if (!pParent) return nullptr; NodeType* pCurrent = TraverseStrategy::GetFirstChild(pParent); NodeType* pPrevious = nullptr; while (pCurrent != pNode) { pPrevious = pCurrent; pCurrent = TraverseStrategy::GetNextSibling(pCurrent); } return pPrevious; } NodeType* LastChild(NodeType* pNode) { NodeType* pPrevious = nullptr; NodeType* pChild = TraverseStrategy::GetFirstChild(pNode); while (pChild) { pPrevious = pChild; pChild = NextSiblingWithinSubtree(pChild); } return pPrevious; } NodeType* LastDescendant(NodeType* pNode) { NodeType* pChild = LastChild(pNode); return pChild ? LastDescendant(pChild) : pNode; } NodeType* m_pRoot; NodeType* m_pCurrent; }; #endif // XFA_FXFA_PARSER_CXFA_NODEITERATORTEMPLATE_H_