Libraries: Move to Userland/Libraries/

Userland/Libraries/LibWeb/Layout/Node.h

@@ -0,0 +1,278 @@
+/*
+ * Copyright (c) 2018-2021, 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/NonnullRefPtr.h>
+#include <AK/TypeCasts.h>
+#include <AK/Vector.h>
+#include <LibGfx/Rect.h>
+#include <LibWeb/CSS/ComputedValues.h>
+#include <LibWeb/CSS/StyleProperties.h>
+#include <LibWeb/Forward.h>
+#include <LibWeb/Layout/BoxModelMetrics.h>
+#include <LibWeb/Layout/LayoutPosition.h>
+#include <LibWeb/Painting/PaintContext.h>
+#include <LibWeb/TreeNode.h>
+
+namespace Web::Layout {
+
+enum class LayoutMode {
+    Default,
+    AllPossibleLineBreaks,
+    OnlyRequiredLineBreaks,
+};
+
+enum class PaintPhase {
+    Background,
+    Border,
+    Foreground,
+    FocusOutline,
+    Overlay,
+};
+
+struct HitTestResult {
+    RefPtr<Node> layout_node;
+    int index_in_node { 0 };
+
+    enum InternalPosition {
+        None,
+        Before,
+        Inside,
+        After,
+    };
+    InternalPosition internal_position { None };
+};
+
+enum class HitTestType {
+    Exact,      // Exact matches only
+    TextCursor, // Clicking past the right/bottom edge of text will still hit the text
+};
+
+class Node : public TreeNode<Node> {
+public:
+    virtual ~Node();
+
+    virtual HitTestResult hit_test(const Gfx::IntPoint&, HitTestType) const;
+
+    bool is_anonymous() const { return !m_dom_node; }
+    const DOM::Node* dom_node() const { return m_dom_node; }
+    DOM::Node* dom_node() { return m_dom_node; }
+
+    DOM::Document& document() { return m_document; }
+    const DOM::Document& document() const { return m_document; }
+
+    const Frame& frame() const;
+    Frame& frame();
+
+    const InitialContainingBlockBox& root() const;
+    InitialContainingBlockBox& root();
+
+    bool is_root_element() const;
+
+    String class_name() const;
+
+    bool has_style() const { return m_has_style; }
+
+    virtual bool can_have_children() const { return true; }
+
+    bool is_inline() const { return m_inline; }
+    void set_inline(bool b) { m_inline = b; }
+
+    bool is_inline_block() const;
+
+    virtual bool wants_mouse_events() const { return false; }
+
+    virtual void handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers);
+    virtual void handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers);
+    virtual void handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers);
+
+    virtual void before_children_paint(PaintContext&, PaintPhase) {};
+    virtual void paint(PaintContext&, PaintPhase);
+    virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const { }
+    virtual void after_children_paint(PaintContext&, PaintPhase) {};
+
+    virtual bool is_box() const { return false; }
+
+    bool is_floating() const;
+    bool is_positioned() const;
+    bool is_absolutely_positioned() const;
+    bool is_fixed_position() const;
+
+    const BlockBox* containing_block() const;
+    BlockBox* containing_block() { return const_cast<BlockBox*>(const_cast<const Node*>(this)->containing_block()); }
+
+    bool can_contain_boxes_with_position_absolute() const;
+
+    const Gfx::Font& font() const;
+    const CSS::ImmutableComputedValues& computed_values() const;
+
+    NodeWithStyle* parent();
+    const NodeWithStyle* parent() const;
+
+    void inserted_into(Node&) { }
+    void removed_from(Node&) { }
+    void children_changed() { }
+
+    virtual void split_into_lines(InlineFormattingContext&, LayoutMode);
+
+    bool is_visible() const { return m_visible; }
+    void set_visible(bool visible) { m_visible = visible; }
+
+    virtual void set_needs_display();
+
+    bool children_are_inline() const { return m_children_are_inline; }
+    void set_children_are_inline(bool value) { m_children_are_inline = value; }
+
+    Gfx::FloatPoint box_type_agnostic_position() const;
+
+    float font_size() const;
+
+    enum class SelectionState {
+        None,        // No selection
+        Start,       // Selection starts in this Node
+        End,         // Selection ends in this Node
+        StartAndEnd, // Selection starts and ends in this Node
+        Full,        // Selection starts before and ends after this Node
+    };
+
+    SelectionState selection_state() const { return m_selection_state; }
+    void set_selection_state(SelectionState state) { m_selection_state = state; }
+
+    template<typename Callback>
+    void for_each_child_in_paint_order(Callback callback) const
+    {
+        for_each_child([&](auto& child) {
+            if (is<Box>(child) && downcast<Box>(child).stacking_context())
+                return;
+            if (!child.is_positioned())
+                callback(child);
+        });
+        for_each_child([&](auto& child) {
+            if (is<Box>(child) && downcast<Box>(child).stacking_context())
+                return;
+            if (child.is_positioned())
+                callback(child);
+        });
+    }
+
+protected:
+    Node(DOM::Document&, DOM::Node*);
+
+private:
+    friend class NodeWithStyle;
+
+    NonnullRefPtr<DOM::Document> m_document;
+    RefPtr<DOM::Node> m_dom_node;
+
+    bool m_inline { false };
+    bool m_has_style { false };
+    bool m_visible { true };
+    bool m_children_are_inline { false };
+    SelectionState m_selection_state { SelectionState::None };
+};
+
+class NodeWithStyle : public Node {
+public:
+    virtual ~NodeWithStyle() override { }
+
+    const CSS::ImmutableComputedValues& computed_values() const { return static_cast<const CSS::ImmutableComputedValues&>(m_computed_values); }
+
+    void apply_style(const CSS::StyleProperties&);
+
+    const Gfx::Font& font() const { return *m_font; }
+    float line_height() const { return m_line_height; }
+    float font_size() const { return m_font_size; }
+    const CSS::ImageStyleValue* background_image() const { return m_background_image; }
+
+    NonnullRefPtr<NodeWithStyle> create_anonymous_wrapper() const;
+
+protected:
+    NodeWithStyle(DOM::Document&, DOM::Node*, NonnullRefPtr<CSS::StyleProperties>);
+    NodeWithStyle(DOM::Document&, DOM::Node*, CSS::ComputedValues);
+
+private:
+    CSS::ComputedValues m_computed_values;
+    RefPtr<Gfx::Font> m_font;
+    float m_line_height { 0 };
+    float m_font_size { 0 };
+    RefPtr<CSS::ImageStyleValue> m_background_image;
+
+    CSS::Position m_position;
+};
+
+class NodeWithStyleAndBoxModelMetrics : public NodeWithStyle {
+public:
+    BoxModelMetrics& box_model() { return m_box_model; }
+    const BoxModelMetrics& box_model() const { return m_box_model; }
+
+protected:
+    NodeWithStyleAndBoxModelMetrics(DOM::Document& document, DOM::Node* node, NonnullRefPtr<CSS::StyleProperties> style)
+        : NodeWithStyle(document, node, move(style))
+    {
+    }
+
+    NodeWithStyleAndBoxModelMetrics(DOM::Document& document, DOM::Node* node, CSS::ComputedValues computed_values)
+        : NodeWithStyle(document, node, move(computed_values))
+    {
+    }
+
+private:
+    BoxModelMetrics m_box_model;
+};
+
+inline const Gfx::Font& Node::font() const
+{
+    if (m_has_style)
+        return static_cast<const NodeWithStyle*>(this)->font();
+    return parent()->font();
+}
+
+inline float Node::font_size() const
+{
+    if (m_has_style)
+        return static_cast<const NodeWithStyle*>(this)->font_size();
+    return parent()->font_size();
+}
+
+inline const CSS::ImmutableComputedValues& Node::computed_values() const
+{
+    if (m_has_style)
+        return static_cast<const NodeWithStyle*>(this)->computed_values();
+    return parent()->computed_values();
+}
+
+inline const NodeWithStyle* Node::parent() const
+{
+    return static_cast<const NodeWithStyle*>(TreeNode<Node>::parent());
+}
+
+inline NodeWithStyle* Node::parent()
+{
+    return static_cast<NodeWithStyle*>(TreeNode<Node>::parent());
+}
+
+}