#ifndef ComposedTreeWalker_h
#define ComposedTreeWalker_h
#include "core/dom/NodeRenderingTraversal.h"
#include "core/dom/shadow/InsertionPoint.h"
#include "core/dom/shadow/ShadowRoot.h"
namespace WebCore {
class Node;
class ShadowRoot;
class ComposedTreeWalker {
public:
typedef NodeRenderingTraversal::ParentDetails ParentTraversalDetails;
enum StartPolicy {
CanStartFromShadowBoundary,
CannotStartFromShadowBoundary
};
ComposedTreeWalker(const Node*, StartPolicy = CannotStartFromShadowBoundary);
Node* get() const { return const_cast<Node*>(m_node); }
void firstChild();
void lastChild();
void nextSibling();
void previousSibling();
void parent();
void next();
void previous();
Node* traverseParent(const Node*, ParentTraversalDetails* = 0) const;
private:
ComposedTreeWalker(const Node*, ParentTraversalDetails*);
enum TraversalDirection {
TraversalDirectionForward,
TraversalDirectionBackward
};
void assertPrecondition() const
{
#ifndef NDEBUG
ASSERT(m_node);
ASSERT(!m_node->isShadowRoot());
ASSERT(!isActiveInsertionPoint(*m_node));
#endif
}
void assertPostcondition() const
{
#ifndef NDEBUG
if (m_node)
assertPrecondition();
#endif
}
static Node* traverseNode(const Node*, TraversalDirection);
static Node* traverseLightChildren(const Node*, TraversalDirection);
Node* traverseFirstChild(const Node*) const;
Node* traverseLastChild(const Node*) const;
Node* traverseChild(const Node*, TraversalDirection) const;
static Node* traverseNextSibling(const Node*);
static Node* traversePreviousSibling(const Node*);
static Node* traverseSiblingOrBackToInsertionPoint(const Node*, TraversalDirection);
static Node* traverseSiblingInCurrentTree(const Node*, TraversalDirection);
static Node* traverseSiblings(const Node*, TraversalDirection);
static Node* traverseDistributedNodes(const Node*, const InsertionPoint*, TraversalDirection);
static Node* traverseBackToYoungerShadowRoot(const Node*, TraversalDirection);
Node* traverseParentOrHost(const Node*) const;
const Node* m_node;
};
inline ComposedTreeWalker::ComposedTreeWalker(const Node* node, StartPolicy startPolicy)
: m_node(node)
{
#ifndef NDEBUG
if (m_node && startPolicy == CannotStartFromShadowBoundary)
assertPrecondition();
#endif
}
inline void ComposedTreeWalker::parent()
{
assertPrecondition();
m_node = traverseParent(m_node);
assertPostcondition();
}
inline void ComposedTreeWalker::nextSibling()
{
assertPrecondition();
m_node = traverseSiblingOrBackToInsertionPoint(m_node, TraversalDirectionForward);
assertPostcondition();
}
inline void ComposedTreeWalker::previousSibling()
{
assertPrecondition();
m_node = traverseSiblingOrBackToInsertionPoint(m_node, TraversalDirectionBackward);
assertPostcondition();
}
inline void ComposedTreeWalker::next()
{
assertPrecondition();
if (Node* next = traverseFirstChild(m_node)) {
m_node = next;
} else {
while (m_node) {
if (Node* sibling = traverseNextSibling(m_node)) {
m_node = sibling;
break;
}
m_node = traverseParent(m_node);
}
}
assertPostcondition();
}
inline void ComposedTreeWalker::previous()
{
assertPrecondition();
if (Node* previous = traversePreviousSibling(m_node)) {
while (Node* child = traverseLastChild(previous))
previous = child;
m_node = previous;
} else {
parent();
}
assertPostcondition();
}
inline void ComposedTreeWalker::firstChild()
{
assertPrecondition();
m_node = traverseChild(m_node, TraversalDirectionForward);
assertPostcondition();
}
inline void ComposedTreeWalker::lastChild()
{
assertPrecondition();
m_node = traverseLastChild(m_node);
assertPostcondition();
}
inline Node* ComposedTreeWalker::traverseNextSibling(const Node* node)
{
ASSERT(node);
return traverseSiblingOrBackToInsertionPoint(node, TraversalDirectionForward);
}
inline Node* ComposedTreeWalker::traversePreviousSibling(const Node* node)
{
ASSERT(node);
return traverseSiblingOrBackToInsertionPoint(node, TraversalDirectionBackward);
}
inline Node* ComposedTreeWalker::traverseFirstChild(const Node* node) const
{
ASSERT(node);
return traverseChild(node, TraversalDirectionForward);
}
inline Node* ComposedTreeWalker::traverseLastChild(const Node* node) const
{
ASSERT(node);
return traverseChild(node, TraversalDirectionBackward);
}
}
#endif