ladybird/Userland/Libraries/LibWeb/TreeNode.h

441 lines
13 KiB
C++

/*
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Assertions.h>
#include <AK/TypeCasts.h>
#include <LibJS/Heap/Cell.h>
#include <LibJS/Heap/GCPtr.h>
#include <LibWeb/Forward.h>
namespace Web {
template<typename T>
class TreeNode {
public:
T* parent() { return m_parent; }
T const* parent() const { return m_parent; }
bool has_children() const { return m_first_child; }
T* next_sibling() { return m_next_sibling; }
T* previous_sibling() { return m_previous_sibling; }
T* first_child() { return m_first_child; }
T* last_child() { return m_last_child; }
T const* next_sibling() const { return m_next_sibling; }
T const* previous_sibling() const { return m_previous_sibling; }
T const* first_child() const { return m_first_child; }
T const* last_child() const { return m_last_child; }
// https://dom.spec.whatwg.org/#concept-tree-index
size_t index() const
{
// The index of an object is its number of preceding siblings, or 0 if it has none.
size_t index = 0;
for (auto* node = previous_sibling(); node; node = node->previous_sibling())
++index;
return index;
}
template<typename ChildType>
Optional<size_t> index_of_child(T const& search_child)
{
VERIFY(search_child.parent() == this);
size_t index = 0;
auto* child = first_child();
VERIFY(child);
do {
if (!is<ChildType>(child))
continue;
if (child == &search_child)
return index;
index++;
} while (child && (child = child->next_sibling()));
return {};
}
bool is_ancestor_of(TreeNode const&) const;
bool is_inclusive_ancestor_of(TreeNode const&) const;
void append_child(JS::NonnullGCPtr<T> node);
void prepend_child(JS::NonnullGCPtr<T> node);
void insert_before(JS::NonnullGCPtr<T> node, JS::GCPtr<T> child);
void remove_child(JS::NonnullGCPtr<T> node);
T* next_in_pre_order()
{
if (first_child())
return first_child();
T* node;
if (!(node = next_sibling())) {
node = parent();
while (node && !node->next_sibling())
node = node->parent();
if (node)
node = node->next_sibling();
}
return node;
}
T* next_in_pre_order(T const* stay_within)
{
if (first_child())
return first_child();
T* node = static_cast<T*>(this);
T* next = nullptr;
while (!(next = node->next_sibling())) {
node = node->parent();
if (!node || node == stay_within)
return nullptr;
}
return next;
}
T const* next_in_pre_order() const
{
return const_cast<TreeNode*>(this)->next_in_pre_order();
}
T const* next_in_pre_order(T const* stay_within) const
{
return const_cast<TreeNode*>(this)->next_in_pre_order(stay_within);
}
T* previous_in_pre_order()
{
if (auto* node = previous_sibling()) {
while (node->last_child())
node = node->last_child();
return node;
}
return parent();
}
T const* previous_in_pre_order() const
{
return const_cast<TreeNode*>(this)->previous_in_pre_order();
}
template<typename Callback>
IterationDecision for_each_in_inclusive_subtree(Callback callback) const
{
if (callback(static_cast<T const&>(*this)) == IterationDecision::Break)
return IterationDecision::Break;
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->for_each_in_inclusive_subtree(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename Callback>
IterationDecision for_each_in_inclusive_subtree(Callback callback)
{
if (callback(static_cast<T&>(*this)) == IterationDecision::Break)
return IterationDecision::Break;
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->for_each_in_inclusive_subtree(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename U, typename Callback>
IterationDecision for_each_in_inclusive_subtree_of_type(Callback callback)
{
if (is<U>(static_cast<T const&>(*this))) {
if (callback(static_cast<U&>(*this)) == IterationDecision::Break)
return IterationDecision::Break;
}
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->template for_each_in_inclusive_subtree_of_type<U>(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename U, typename Callback>
IterationDecision for_each_in_inclusive_subtree_of_type(Callback callback) const
{
if (is<U>(static_cast<T const&>(*this))) {
if (callback(static_cast<U const&>(*this)) == IterationDecision::Break)
return IterationDecision::Break;
}
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->template for_each_in_inclusive_subtree_of_type<U>(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename Callback>
IterationDecision for_each_in_subtree(Callback callback) const
{
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->for_each_in_inclusive_subtree(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename Callback>
IterationDecision for_each_in_subtree(Callback callback)
{
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->for_each_in_inclusive_subtree(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename U, typename Callback>
IterationDecision for_each_in_subtree_of_type(Callback callback)
{
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->template for_each_in_inclusive_subtree_of_type<U>(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename U, typename Callback>
IterationDecision for_each_in_subtree_of_type(Callback callback) const
{
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (child->template for_each_in_inclusive_subtree_of_type<U>(callback) == IterationDecision::Break)
return IterationDecision::Break;
}
return IterationDecision::Continue;
}
template<typename Callback>
void for_each_child(Callback callback) const
{
return const_cast<TreeNode*>(this)->template for_each_child(move(callback));
}
template<typename Callback>
void for_each_child(Callback callback)
{
for (auto* node = first_child(); node; node = node->next_sibling())
callback(*node);
}
template<typename U, typename Callback>
void for_each_child_of_type(Callback callback)
{
for (auto* node = first_child(); node; node = node->next_sibling()) {
if (is<U>(node))
callback(verify_cast<U>(*node));
}
}
template<typename U, typename Callback>
void for_each_child_of_type(Callback callback) const
{
return const_cast<TreeNode*>(this)->template for_each_child_of_type<U>(move(callback));
}
template<typename U>
U const* next_sibling_of_type() const
{
return const_cast<TreeNode*>(this)->template next_sibling_of_type<U>();
}
template<typename U>
inline U* next_sibling_of_type()
{
for (auto* sibling = next_sibling(); sibling; sibling = sibling->next_sibling()) {
if (is<U>(*sibling))
return &verify_cast<U>(*sibling);
}
return nullptr;
}
template<typename U>
U const* previous_sibling_of_type() const
{
return const_cast<TreeNode*>(this)->template previous_sibling_of_type<U>();
}
template<typename U>
U* previous_sibling_of_type()
{
for (auto* sibling = previous_sibling(); sibling; sibling = sibling->previous_sibling()) {
if (is<U>(*sibling))
return &verify_cast<U>(*sibling);
}
return nullptr;
}
template<typename U>
U const* first_child_of_type() const
{
return const_cast<TreeNode*>(this)->template first_child_of_type<U>();
}
template<typename U>
U const* last_child_of_type() const
{
return const_cast<TreeNode*>(this)->template last_child_of_type<U>();
}
template<typename U>
U* first_child_of_type()
{
for (auto* child = first_child(); child; child = child->next_sibling()) {
if (is<U>(*child))
return &verify_cast<U>(*child);
}
return nullptr;
}
template<typename U>
U* last_child_of_type()
{
for (auto* child = last_child(); child; child = child->previous_sibling()) {
if (is<U>(*child))
return &verify_cast<U>(*child);
}
return nullptr;
}
template<typename U>
U const* first_ancestor_of_type() const
{
return const_cast<TreeNode*>(this)->template first_ancestor_of_type<U>();
}
template<typename U>
U* first_ancestor_of_type()
{
for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
if (is<U>(*ancestor))
return &verify_cast<U>(*ancestor);
}
return nullptr;
}
~TreeNode() = default;
protected:
TreeNode() = default;
void visit_edges(JS::Cell::Visitor& visitor)
{
visitor.visit(m_parent);
visitor.visit(m_first_child);
visitor.visit(m_last_child);
visitor.visit(m_next_sibling);
visitor.visit(m_previous_sibling);
}
private:
T* m_parent { nullptr };
T* m_first_child { nullptr };
T* m_last_child { nullptr };
T* m_next_sibling { nullptr };
T* m_previous_sibling { nullptr };
};
template<typename T>
inline void TreeNode<T>::remove_child(JS::NonnullGCPtr<T> node)
{
VERIFY(node->m_parent == this);
if (m_first_child == node)
m_first_child = node->m_next_sibling;
if (m_last_child == node)
m_last_child = node->m_previous_sibling;
if (node->m_next_sibling)
node->m_next_sibling->m_previous_sibling = node->m_previous_sibling;
if (node->m_previous_sibling)
node->m_previous_sibling->m_next_sibling = node->m_next_sibling;
node->m_next_sibling = nullptr;
node->m_previous_sibling = nullptr;
node->m_parent = nullptr;
}
template<typename T>
inline void TreeNode<T>::append_child(JS::NonnullGCPtr<T> node)
{
VERIFY(!node->m_parent);
if (m_last_child)
m_last_child->m_next_sibling = node.ptr();
node->m_previous_sibling = m_last_child;
node->m_parent = static_cast<T*>(this);
m_last_child = node.ptr();
if (!m_first_child)
m_first_child = m_last_child;
}
template<typename T>
inline void TreeNode<T>::insert_before(JS::NonnullGCPtr<T> node, JS::GCPtr<T> child)
{
if (!child)
return append_child(move(node));
VERIFY(!node->m_parent);
VERIFY(child->parent() == this);
node->m_previous_sibling = child->m_previous_sibling;
node->m_next_sibling = child;
if (child->m_previous_sibling)
child->m_previous_sibling->m_next_sibling = node;
if (m_first_child == child)
m_first_child = node;
child->m_previous_sibling = node;
node->m_parent = static_cast<T*>(this);
}
template<typename T>
inline void TreeNode<T>::prepend_child(JS::NonnullGCPtr<T> node)
{
VERIFY(!node->m_parent);
if (m_first_child)
m_first_child->m_previous_sibling = node.ptr();
node->m_next_sibling = m_first_child;
node->m_parent = static_cast<T*>(this);
m_first_child = node.ptr();
if (!m_last_child)
m_last_child = m_first_child;
node->inserted_into(static_cast<T&>(*this));
static_cast<T*>(this)->children_changed();
}
template<typename T>
inline bool TreeNode<T>::is_ancestor_of(TreeNode<T> const& other) const
{
for (auto* ancestor = other.parent(); ancestor; ancestor = ancestor->parent()) {
if (ancestor == this)
return true;
}
return false;
}
template<typename T>
inline bool TreeNode<T>::is_inclusive_ancestor_of(TreeNode<T> const& other) const
{
return &other == this || is_ancestor_of(other);
}
}