LibWeb: Begin SVG element support

This commit starts adding a basic SVG element. Currently, svg elements have support for the width and height properties, as well as the stroke, stroke-width, and fill properties. The only child element supported is the path element, as most other graphical elements are just shorthand for paths.
2025-05-18 23:25:07 +00:00 · 2020-07-19 23:01:53 -07:00 · 2020-07-19 23:01:53 -07:00 · 22f0953fe2
commit 22f0953fe2
parent bbcdab2baa
11 changed files with 1013 additions and 2 deletions
--- a/Libraries/LibWeb/DOM/HTMLPathElement.h
+++ b/Libraries/LibWeb/DOM/HTMLPathElement.h
@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2020, Matthew Olsson <matthewcolsson@gmail.com>
+ * 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 <LibGfx/Bitmap.h>
+#include <LibWeb/DOM/HTMLElement.h>
+#include <LibWeb/DOM/SvgContext.h>
+
+namespace Web {
+
+enum class PathInstructionType {
+    Move,
+    ClosePath,
+    Line,
+    HorizontalLine,
+    VerticalLine,
+    Curve,
+    SmoothCurve,
+    QuadraticBezierCurve,
+    SmoothQuadraticBezierCurve,
+    EllipticalArc,
+    Invalid,
+};
+
+struct PathInstruction {
+    PathInstructionType type;
+    bool absolute;
+    Vector<float> data;
+};
+
+class PathDataParser final {
+public:
+    PathDataParser(const String& source);
+    ~PathDataParser() = default;
+
+    Vector<PathInstruction> parse();
+
+private:
+    void parse_drawto();
+
+    void parse_moveto();
+    void parse_closepath();
+    void parse_lineto();
+    void parse_horizontal_lineto();
+    void parse_vertical_lineto();
+    void parse_curveto();
+    void parse_smooth_curveto();
+    void parse_quadratic_bezier_curveto();
+    void parse_smooth_quadratic_bezier_curveto();
+    void parse_elliptical_arc();
+
+    float parse_coordinate();
+    Vector<float> parse_coordinate_pair();
+    Vector<float> parse_coordinate_sequence();
+    Vector<Vector<float>> parse_coordinate_pair_sequence();
+    Vector<float> parse_coordinate_pair_double();
+    Vector<float> parse_coordinate_pair_triplet();
+    Vector<float> parse_elliptical_arg_argument();
+    void parse_whitespace(bool must_match_once = false);
+    void parse_comma_whitespace();
+    float parse_fractional_constant();
+    float parse_number();
+    float parse_flag();
+
+    bool match_whitespace() const;
+    bool match_comma_whitespace() const;
+    bool match_number() const;
+    bool match(char c) const { return !done() && ch() == c; }
+
+    bool done() const { return m_cursor >= m_source.length(); }
+    char ch() const { return m_source[m_cursor]; }
+    char consume() { return m_source[m_cursor++]; }
+
+    String m_source;
+    size_t m_cursor { 0 };
+    Vector<PathInstruction> m_instructions;
+};
+
+class HTMLPathElement final
+    : public HTMLElement
+    , public SvgGraphicElement {
+public:
+    HTMLPathElement(Document&, const FlyString& tag_name);
+    virtual ~HTMLPathElement() override = default;
+
+    virtual void parse_attribute(const FlyString& name, const String& value) override;
+    virtual void paint(const SvgPaintingContext&, Gfx::Painter& painter) override;
+
+private:
+    Vector<PathInstruction> m_instructions;
+};
+
+template<>
+inline bool is<HTMLPathElement>(const Node& node)
+{
+    return is<Element>(node) && to<Element>(node).tag_name() == HTML::TagNames::path;
+}
+
+}