LibWeb: Rename directory LibHTML => LibWeb

Let's rename this to LibWeb since it aims to provide more parts of the
web platform than just HTML. :^)

Libraries/LibWeb/DOM/Node.h

@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/RefPtr.h>
+#include <AK/String.h>
+#include <AK/Vector.h>
+#include <LibWeb/TreeNode.h>
+
+namespace Web {
+
+enum class NodeType : unsigned {
+    INVALID = 0,
+    ELEMENT_NODE = 1,
+    TEXT_NODE = 3,
+    COMMENT_NODE = 8,
+    DOCUMENT_NODE = 9,
+    DOCUMENT_TYPE_NODE = 10,
+    DOCUMENT_FRAGMENT_NODE = 11,
+};
+
+class Document;
+class Element;
+class HTMLElement;
+class HTMLAnchorElement;
+class ParentNode;
+class LayoutNode;
+class StyleResolver;
+class StyleProperties;
+
+class Node : public TreeNode<Node> {
+public:
+    virtual ~Node();
+
+    NodeType type() const { return m_type; }
+    bool is_element() const { return type() == NodeType::ELEMENT_NODE; }
+    bool is_text() const { return type() == NodeType::TEXT_NODE; }
+    bool is_document() const { return type() == NodeType::DOCUMENT_NODE; }
+    bool is_document_type() const { return type() == NodeType::DOCUMENT_TYPE_NODE; }
+    bool is_comment() const { return type() == NodeType::COMMENT_NODE; }
+    bool is_character_data() const { return type() == NodeType::TEXT_NODE || type() == NodeType::COMMENT_NODE; }
+    bool is_document_fragment() const { return type() == NodeType::DOCUMENT_FRAGMENT_NODE; }
+    bool is_parent_node() const { return is_element() || is_document(); }
+
+    virtual RefPtr<LayoutNode> create_layout_node(const StyleProperties* parent_style) const;
+
+    virtual String tag_name() const = 0;
+
+    virtual String text_content() const;
+
+    Document& document() { return m_document; }
+    const Document& document() const { return m_document; }
+
+    const HTMLAnchorElement* enclosing_link_element() const;
+    const HTMLElement* enclosing_html_element() const;
+
+    virtual bool is_html_element() const { return false; }
+
+    template<typename T>
+    const T* first_child_of_type() const;
+
+    template<typename T>
+    const T* first_ancestor_of_type() const;
+
+    virtual void inserted_into(Node&) {}
+    virtual void removed_from(Node&) {}
+
+    const LayoutNode* layout_node() const { return m_layout_node; }
+    LayoutNode* layout_node() { return m_layout_node; }
+
+    void set_layout_node(Badge<LayoutNode>, LayoutNode* layout_node) const { m_layout_node = layout_node; }
+
+    const Element* previous_element_sibling() const;
+    const Element* next_element_sibling() const;
+
+    virtual bool is_child_allowed(const Node&) const { return true; }
+
+    bool needs_style_update() const { return m_needs_style_update; }
+    void set_needs_style_update(bool value) { m_needs_style_update = value; }
+
+    void invalidate_style();
+
+    bool is_link() const;
+
+protected:
+    Node(Document&, NodeType);
+
+    Document& m_document;
+    mutable LayoutNode* m_layout_node { nullptr };
+    NodeType m_type { NodeType::INVALID };
+    bool m_needs_style_update { false };
+};
+
+template<typename T>
+inline bool is(const Node&)
+{
+    return false;
+}
+
+template<typename T>
+inline bool is(const Node* node)
+{
+    return !node || is<T>(*node);
+}
+
+template<>
+inline bool is<Node>(const Node&)
+{
+    return true;
+}
+
+template<>
+inline bool is<ParentNode>(const Node& node)
+{
+    return node.is_parent_node();
+}
+
+template<typename T>
+inline const T& to(const Node& node)
+{
+    ASSERT(is<T>(node));
+    return static_cast<const T&>(node);
+}
+
+template<typename T>
+inline T* to(Node* node)
+{
+    ASSERT(is<T>(node));
+    return static_cast<T*>(node);
+}
+
+template<typename T>
+inline const T* to(const Node* node)
+{
+    ASSERT(is<T>(node));
+    return static_cast<const T*>(node);
+}
+
+template<typename T>
+inline T& to(Node& node)
+{
+    ASSERT(is<T>(node));
+    return static_cast<T&>(node);
+}
+
+template<typename T>
+inline const T* Node::first_child_of_type() const
+{
+    for (auto* child = first_child(); child; child = child->next_sibling()) {
+        if (is<T>(*child))
+            return to<T>(child);
+    }
+    return nullptr;
+}
+
+template<typename T>
+inline const T* Node::first_ancestor_of_type() const
+{
+    for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
+        if (is<T>(*ancestor))
+            return to<T>(ancestor);
+    }
+    return nullptr;
+}
+
+}